Panpsychism and the Emergence of Consciousness: A Proposal for a New Solution to the Mind-Body Problem [1st ed.] 9783662622575, 9783662622582

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Fabian Klinge

Panpsychism and the Emergence of Consciousness A Proposal for a New Solution to the Mind-Body Problem

Panpsychism and the Emergence of Consciousness

Fabian Klinge

Panpsychism and the Emergence of Consciousness A Proposal for a New Solution to the Mind-Body Problem

Fabian Klinge Universität Tübingen Tübingen, Germany Dissertation zur Erlangung des akademischen Grades Doktor der Philosophie in der Philosophischen Fakultät der Eberhard Karls Universität Tübingen, angenommen im Sommersemester 2019. Gefördert durch ein Promotionsstipendium der Konrad Adenauer Stiftung, 2015–2018.

ISBN 978-3-662-62257-5 ISBN 978-3-662-62258-2  (eBook) https://doi.org/10.1007/978-3-662-62258-2 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2020 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This J.B. Metzler imprint is published by the registered company Springer-Verlag GmbH, DE part of Springer Nature. The registered company address is: Heidelberger Platz 3, 14197 Berlin, Germany

Table of Contents List of Figures and Tables..........................................................................................................ix Acknowledgments......................................................................................................................xi 1 Introduction...........................................................................................................................xiii 2 Physicalism and Fundamentalism............................................................................................1 2.1 Metaphysical Dependence................................................................................................1 2.1.1 Identity, Multiple Realizability, and Functionalism.................................................2 2.1.2 The Hyperintensionalist Turn and Metaphysical Fundamentalism..........................4 2.1.3 Sider’s Version of Fundamentalism..........................................................................7 2.1.4 The Fine-Dasgupta Account of Metaphysical Grounding......................................10 2.2 What is ‘Physical’?.........................................................................................................13 3 The Case Against Physicalism...............................................................................................19 3.1 Special Epistemic Gaps..................................................................................................20 3.1.1 Three Epistemic Gaps.............................................................................................20 3.1.2 Are the Gaps Special?.............................................................................................23 3.2 Chalmers’ Two-Dimensional Argument.........................................................................29 3.2.1 The Architecture of the Argument..........................................................................29 3.2.2 Various Objections..................................................................................................31 3.2.3 Goff’s Transparency Conceivability Argument......................................................36 3.3 The Phenomenal Concept Strategy................................................................................38 3.4 Two Problems for the Strategy.......................................................................................43 3.4.1 Levine’s Lack-of-Thickness Objection...................................................................43 3.4.2 Chalmers’ Master Argument...................................................................................47 4 Understanding Emergence.....................................................................................................55 4.1 The Notion of Emergence..............................................................................................56 4.2 Kinds of Emergence.......................................................................................................58 4.3 Varieties of Emergent Phenomena..................................................................................60 4.3.1 Epistemologically Emergent Phenomena in Complex Systems.............................60 4.3.2 Realized Phenomena as Metaphysically Weakly Emergent Entities......................62 4.3.3 Reductively Unpredictable Behavior in Cell Biology............................................64 4.3.4 Macrophenomenality as Ontologically Emergent Phenomenon............................65 4.4 Autonomy and Dependence............................................................................................67 4.5 Strong Autonomy...........................................................................................................69 4.6 The Power Inheritance Objection...................................................................................72 4.6.1 Solution I: Causal Emergence................................................................................74 4.6.2 Solution II: Micro-Latent Grounding Bases...........................................................75 4.6.3 Solution III: The New Power Condition.................................................................79 4.6.4 Solution IV: Emergence as Fusion..........................................................................85 4.7 Causal Ontological Emergence......................................................................................88 4.7.1 Micro-Latent Emergence Bases..............................................................................91

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Contents

4.7.2 Strong Dependence as Causal Relation..................................................................91 4.7.3 The Explicability of Ontologically Emergent Phenomena.....................................98 5 Alternatives to Physicalism..................................................................................................101 5.1 Varieties of Antiphysicalism.........................................................................................101 5.2 Dualism........................................................................................................................104 5.3 Russellian Monism.......................................................................................................105 5.3.1 Dispositionalism and Russellian Categoricalism..................................................105 5.3.2 The Circularity Objection to Dispositionalism.....................................................109 5.3.3 The Power-Swapping Problem for Categoricalism...............................................111 5.4 Problems for Dualism...................................................................................................113 5.4.1 The Pairing Problem.............................................................................................115 5.4.2 The Causal Exclusion Problem.............................................................................122 5.4.3 The Fundamental Interaction Problem.................................................................131 5.5 Mental Causation in Russellian Monism......................................................................134 5.6 Panpsychism or Panprotopsychism?............................................................................136 6 Problems for Constitutive Russellian Panpsychism.............................................................139 6.1 Multiple Combination Problems..................................................................................139 6.2 James’ Original Argument............................................................................................139 6.3 The Conceivability Argument Redux...........................................................................140 6.4 Phenomenal Bonding and Consciousness+..................................................................141 6.5 Coleman’s Anti-Subject-Summing Argument..............................................................144 6.6 The Palette Problem.....................................................................................................146 6.7 The Structural Mismatch Problem................................................................................150 6.8 The Revelation Argument.............................................................................................154 6.9 Revelation and Phenomenal Confusion.......................................................................158 6.10 Cosmopsychism..........................................................................................................160 6.10.1 Priority Monism, Cosmopsychism, and Microphenomenality...........................162 6.10.2 Overcoming the Combination Problem Via Grounding by Subsumption?........163 6.11 The Limits of Phenomenal Combination....................................................................167 6.12 Structural Exclusion...................................................................................................167 6.13 Mørch's Phenomenal Powers Panpsychism...............................................................169 6.14 Impure Russellian Powers Panpsychism....................................................................171 6.15 A New Combination Problem.....................................................................................174 7 Emergence in Panpsychism..................................................................................................177 7.1 Non-Constitutive Versions of Panpsychism.................................................................177 7.1.1 Autonomous Panpsychism and Identity Panpsychism.........................................177 7.1.2 Emergent Panpsychism.........................................................................................179 7.2 Two Variants of Emergent Panpsychism......................................................................179 7.2.1 Against Fusionism................................................................................................180 7.2.2 Causal Emergent Panpsychism.............................................................................182 7.2.3 The Architecture of Emergent Macrophenomenality...........................................183 Excursus I: Macrointentions and Free Will........................................................................185 7.3 Solving the Causal Exclusion Problem........................................................................187

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7.4 Pairing and Fundamental Interaction...........................................................................191 7.4.1 Categoricalism’s Intrinsic Dimension...................................................................193 7.4.2 Russellian Monism’s Two-Layered Intrinsic Dimension.....................................195 7.4.3 Phenomenal Emergence Within the Two-Layered Structure................................197 7.4.4 The Model’s Inapplicability to Emergent Dualism...............................................200 7.5 Solving the Problem of Structural Fit...........................................................................201 7.5.1 The Structural Mismatch Problem for Constitutive Russellian Panpsychism......201 7.5.2 The Problem of Structural Fit for Emergent Russellian Panpsychism.................203 7.5.3 An Evolutionary Explanation of Structural Fit.....................................................204 Excursus II: The Emergence Law......................................................................................206 8 Re-Evaluating the Antiphysicalist Options..........................................................................213 8.1 Mental Causation and Phenomenal Emergence...........................................................213 8.1.1 Microphenomenality and the Metaphysics of Dispositions..................................214 8.1.2 The Pairing and the Fundamental Interaction Problems.......................................214 8.1.3 The Causal Exclusion Problem.............................................................................216 8.2 The Prospects of Panpsychist Idealism........................................................................217 Bibliography............................................................................................................................223

List of Figures and Tables Table 4.1: Taxonomy of Emergence

58

Table 4.2: Kinds of Entities According to Their Ontological Status (after Barnes 2012)

72

Table 4.3: Similarities and Differences Between Ordinary Causation and EmergenceCausation

96

Table 5.1: Accounts of the Production of Macrophenomenality

103

Figure 7.1: Mental-to-Physical Downward Causation

189

Figure 7.2: Mental-to-Mental Downward Causation

189

Figure 7.3: Extrinsic and Intrinsic Dimensions in Constitutive Russellian Panpsychism 197 Figure 7.4: Extrinsic and Intrinsic Dimensions in Emergent Russellian Panpsychism

198

Acknowledgments First and foremost, I should like to thank my primary supervisor, Thomas Sattig, who’s advice was always both on the point and very precise, and simultaneously very constructive and encouraging. I have greatly benefited from his guidance, and from his constant reminders that crazy views on consciousness must take particular care to remain compatible with widely accepted theories in other parts of philosophy. Moreover, having a supervisor who also specializes in metaphysics has proved to be very fruitful; Thomas has helped me to uncover links between topics in both the philosophy of mind and metaphysics which I would never have been aware of without his counsel. I would also like to thank my co-supervisor, Hong Yu Wong, who provided very helpful comments on my thesis, especially in the initial stage of my project. Furthermore, I have greatly benefited from the excellent articles on emergence and dualism which he published a decade ago. Very special thanks to Tobias Wilsch for extensive and thoughtful comments on various drafts of two papers, the material of which also forms part of my dissertation, and for many discussions from which I benefited greatly. I also owe thanks to my fellow PhD students, Claudius Berger and Bahadır Eker, for valuable comments and discussions on various material of this thesis. During my PhD, I had the opportunity to participate in two masterclasses, led by David Chalmers and Jonathan Schaffer respectively, presenting therein parts of my thesis. The masterclass featuring David Chalmers was at the very beginning of my PhD It was tremendously helpful to receive comments from one of the leading experts on panpsychism at such an early stage: his positive feedback on my initial ideas greatly encouraged me to place trust in them and to develop them further. At the masterclass with Jonathan Schaffer, I presented my critique of cosmopsychism, and greatly benefited from the comments of today’s leading proponent of priority monism. I am also grateful to many others for valuable comments on the materials of my thesis. These include: Zach Blaesi, Philip Goff, Matteo Grasso, Blaine Kenneally, Micha Kieser, Greg Miller, Garret Mindt, Hedda Hassel Mørch, Dan Pallies, Peter Rauschenberger, Hannah Tomczyk, and the audiences at several talks which I gave in Budapest, Osnabrück, and Tübingen respectively. This work was made possible by the Konrad Adenauer Stiftung, from which I received a 3-year doctoral scholarship. I also greatly benefited from the seminar program on political, economic, and cultural topics which is part of the scholarship.

1

Introduction

Seeing a certain shade of violet, having a pleasant memory about one’s last holiday, and experiencing sharp pain are all mental episodes accompanied by specific qualitative dimensions of subjective experience, the often hard to describe what-it-feels-like-character of such mental events. This character of subjective experience coinciding with mental states of which we are aware while entertaining them is what philosophers call phenomenal consciousness. Someone new to the debate might be surprised to hear that phenomenal consciousness has proved to be one of the biggest mysteries in contemporary philosophy: the degree to which it is intimately familiar to us is matched only by the degree to which it appears to resist our efforts to integrate it into our theories of the natural world. At the heart of this conundrum lies the mindbody problem, the question as to how a physical system such as the human brain can give rise to phenomenal consciousness. In the last couple of decades, there has been major progress in the philosophical debate on the mind-body problem. But this progress to a lesser extend consisted of developing new ways of explaining consciousness in terms of phenomena that we already know how to integrate in our scientific theories such as certain sorts of neural activity in the brain; the view that consciousness is thus explicable, physicalism, began to dominate the philosophical debate in the 1950’s, and has remained influential ever since. Rather, the real progress since the 1980’s has arguably consisted of taking consciousness seriously in its own right, and understanding that it might very well be a fundamental, irreducible ingredient of the natural world—or so, at least, has argued a growing number of participants within the current debate on consciousness. According to this narrative, which I myself endorse, important contributions by the likes of Nagel (1974), Jackson (1982), Levine (1983), and Chalmers (1996) made us realize that there is no straightforward way to explain consciousness in physical terms. Some theorists such as Loar (1997), Hill (1997), Papineau (2002), and Balog (2012a) reacted by conceding this point, but developed sophisticated ways of explaining as to why, although consciousness resists straightforward reductive explanation in physical terms, it is nonetheless a physically grounded phenomenon.1 Yet others, led by Jackson (1982) and Chalmers (1996), took those antiphysicalist doubts at face value, and wondered how consciousness might fit into the natural world if it is a truly fundamental phenomenon possessing comparable metaphysical status to fundamental physical properties such as mass, charge, and spin. This led to a revival of the previously widely rejected doctrine of dualism, according to which there are both fundamental physical properties and fundamental phenomenal properties without either being reducible to the other. Some dared to go even further: what, they asked, if it is the other way round to what we originally thought? What if only consciousness is truly fundamental, while everything else is 1

Of course, many just outright demised these antiphysicalist reasonings. But from the perspective of the narrative I am outlining here, these appear to be reactionary outsiders who were unable to revise their outdated beliefs in the light of better arguments.

© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2020 F. Klinge, Panpsychism and the Emergence of Consciousness, https://doi.org/10.1007/978-3-662-62258-2_1

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Introduction

reducible to it? We have evidence that consciousness is irreducible, but what makes us think that matter is, besides the conviction that it must be, given the undeniable success of physics? These philosophers, beginning with Strawson (2006), unearthed an old argument, provided inter alia by Russell (1927) and Eddington (1928), leading to the conclusion that to take consciousness to be uniquely fundamental does not necessarily precipitate the undermining of physics: if consciousness underlies the quantum-level processes studied by physicists in a manner similar to the foundational role which it plays for human behavior, then consciousness can be taken to be uniquely fundamental without dethroning physics. The properties invoked by fundamental physics such as charge, mass, and spin are, indeed, the fundamental building blocks of the universe, in terms of which everything else can be explained. Yet they have a double nature: in addition to their behavioral inclinations as uncovered by physicists, they also have a deep, intrinsic nature according to which they are subjective experiences. By means of both of their facets, we can explain all phenomena in the world: their material side allows us to account for everything in external reality, while their phenomenal side elucidates the existence and characteristics of our inner mental lives. This doctrine, according to which microphysical properties are ultimately grounded in subjective experience, bears the name of panpsychism. While panpsychism is, indeed, an ancient theory (in some form or other probably a standard conviction in almost all traditional cultures that has also periodically been defended over the history of Western philosophy [Skrbina 2005]),this position witnessed a particularly fruitful heyday during the first decades of the 20th century, culminating in the work of James (1904), the aforementioned Russell (1927), and Whitehead (1978/1929). While panpsychism has not played any important role in the philosophy of mind during the second half of the 20th century, the last decade has witnessed the formation of a new research program exploring the viability of versions of panpsychism in the Russellian tradition sketched above. The case against physicalism and the renewed philosophical interest in panpsychism also influenced empirical research: the currently most promising neuroscientific theory of consciousness, the Integrated Information Theory (IIT), originally proposed by Tononi (2004), explicitly takes consciousness to be a fundamental, physically irreducible phenomenon, and even entails a form of panpsychism. There is a promising exchange between neuroscientists working on this theory and philosophers, and important future breakthroughs in the study of consciousness are to be expected from bringing together our best philosophical accounts and IIT. However, before engaging in interdisciplinary adventures, philosophers must do their homework. Even among proponents of panpsychism, there are considerable differences of opinion. The focus of attention has thereby been the question as to how to account for the relationship between quantum-level microconsciousness and the macroconsciousness of humans and other higher organisms. The prima facie appealing idea of reductively explaining macro- in terms of microconsciousness has been severely challenged: what is termed the combination problem comprises a whole host of arguments against the possibility of such phenomenal constitution. At the heart of my thesis lies a defense of the case against phenomenal constitution, and the development of what I consider to be a viable alternative, namely phenomenal emergence:

Introduction

xv

the idea that while macroconsciousness is brought about by microconsciousness, this production relation is not constitution, but rather ontological emergence. That is, macroconsciousness cannot be reductively explained in terms of microconsciousness, but rather the former is as fundamental as the latter. Nonetheless, macroconsciousness depends on microconsciousness: as I shall argue, it comes into existence by being causally produced by the latter. The bulk of this work is then devoted to defending this idea against various objections advanced by opponents, proposing solutions to a number of inherent problems of this position, and thereby working out the details of my view. In the first two chapters after the Introduction, I aim to fully flesh out and defend the narrative I presented above: I begin by discussing physicalism about consciousness, the topic of Chapter 2. In Chapter 3, this is followed by discussion of the objections to this position that have been provided by the likes of the aforementioned Jackson (1982), and Chalmers (1996). In Chapter 4, I introduce and analyze the concept of emergence. This will provide the groundwork for a theory of emergence in panpsychism which I develop in Chapter 7. However, the ambition of this chapter goes beyond addressing solely what is needed to explain emergence in panpsychism. My aim is to provide a substantial contribution to the metaphysics of emergence: I believe that while there are a number of compelling theories about various kinds of emergent phenomena, what is currently missing is a systematic and comprehensive treatment of the concept. Here, I propose such a systematic theory of emergence. Chapter 5 discusses the two most promising antiphysicalist options, dualism and panpsychism. I analyze various problems of mental causation that have been raised against dualism, and explain how the constitutive version of Russellian panpsychism can avoid those problems. In Chapter 6, I discuss the combination problems for constitutive Russellian panpsychism. I argue that several of the arguments based on these problems are sound, and cannot be rejected by this position. Hence, constitutive Russellian panpsychism is false. Chapter 7 is devoted to the most promising alternative to constitutive Russellian panpsychism, namely emergent Russellian panpsychism. Since this view allows for irreducible macromental causation, it faces the same mental causation problems as dualism. However, I shall argue that, in contrast to dualism, emergent Russellian panpsychism can solve these problems, rendering it the preferable option for the antiphysicalist. In Chapter 8, I summarize my argument for phenomenal emergence. Moreover, I address the question whether panpsychism can indeed allow for a fully monistic worldview that grounds all concrete phenomena in consciousness. While microphysical dispositions indeed appear to allow for a Russellian analysis as sketched above, it is currently not clear whether spatiotemporal properties do. However, fundamental physics invokes both dispositions and spatiotemporal properties. It is therefore a crucial desideratum for future panpsychist research to evaluate whether spatiotemporal properties possess a conscious deep nature. The Sections 6.12, 6.13, 6.14, and 7.3 are based on material from the article “The Role of Mental Powers in Panpsychism”, Topoi (2019).

2

Physicalism and Fundamentalism

Physicalism is the most parsimonious and elegant view about consciousness. Providing forceful objections to the position is a crucial part of any argument for rival views. Yet in order to criticize it, one has to thoroughly understand the core commitments of this metaphysical doctrine. This is the subject of the chapter at hand. Since physicalism is the by far most developed theory of consciousness and comes in many different versions, it is necessary to provide at least a rough overview of several variants of the doctrine as well as their historical evolution. Moreover, in answer to various objections, theorists have employed some of the more technical devices in contemporary metaphysics in order to improve physicalism. A discussion of the evolution of physicalism therefore provides a good opportunity for introducing theories that are not only needed for a proper understanding of physicalism, but also for the discussion of dualism and Russellian monism in later chapters. In particular, the nature of fundamentality and the metaphysical dependence relation of nothing-over-and-aboveness are therefore given a more thorough analysis in this chapter than what would have been required for merely understanding the standard debate about antiphysicalist arguments and physicalist replies. So, what does physicalism claim? The straightforward answer is as follows: physicalism is the view that everything is physical. This simple definition faces a double challenge: it must first be explained as to what ‘everything’ here means, and, secondly also what ‘being physical’ here means. The former is the subject of Section 2.1, and the latter is discussed in Section 2.2. The first task has attracted considerably more attention in the literature than the second. Nevertheless, a tenable account of the nature of being physical is of no less importance for the evaluation of physicalism. Moreover, subtle details about the nature of the physical will play a crucial role in the discussion of mental causation problems for the antiphysicalist views discussed in Chapters 5 and 7. 2.1 Metaphysical Dependence For the purpose of discussing what ‘everything is physical’ actually amounts to, it is helpful to work with a preliminary characterization of ‘physical’. For the time being, ‘being physical’ can be understood as belonging to the properties or objects which are treated by fundamental physics. On this understanding, paradigmatic physical properties are having mass, being charged, having spin, and the like, and physical objects are various types of elementary particles. We will see in Section 2.2 that this characterization is too simplistic. Nevertheless, it provides a useful first approximation. Given this understanding of ‘physical’, it is obvious that there are many nonphysical phenomena in the world. Even if we restrict the relevant class of entities to scientifically studied entities, the special sciences provide a wide range of examples of phenomena that are prima facie not physical. Organisms are alive, some currencies are overvalued, and natural substances such as water can be liquid. Yet neither organisms, currencies, or water, nor being

© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2020 F. Klinge, Panpsychism and the Emergence of Consciousness, https://doi.org/10.1007/978-3-662-62258-2_2

2

Physicalism and Fundamentalism

alive, being overvalued, or being liquid are entities one encounters in physics textbooks. Restricting our focus on properties for the moment, this nevertheless does not necessarily entail that the named properties are not, in fact, physical properties. Although they are studied by special sciences under different descriptions, all these properties might very well be identical to (combinations of) physical properties. If this is the case, then, while special sciences such as biology, economics, and chemistry study phenomena by utilizing high-level descriptions denoting high-level properties, those properties are fully reducible to combinations of physical properties such that the former are identical to the latter. This view is called type-type identity theory, or type physicalism. According to it, all types of special science properties are identical to types of combinations of physical properties. 2.1.1

Identity, Multiple Realizability, and Functionalism

The type-type identity theory provided the basis for the most influential contributions in both philosophy of science and philosophy of mind during the 1950’s and 1960’s. In philosophy of science, influential theorists such as Oppenheim & Putnam (1958) and Nagel (1961) argued that the various scientific disciplines can be understood as standing in a hierarchical order such that disciplines studying macrophenomena are reducible to disciplines studying microphenomena. On this conception of inter-theoretic reduction, each scientific theory is reducible to the theory studying phenomena on the adjacent lower ontological level: economics is assumed to be reducible to psychology, psychology to neurobiology, neurobiology to chemistry, and chemistry to microphysics. In contrast to philosophers of science, theorists working in the philosophy of mind are not concerned with the relationship between scientific theories, but rather with the nature of mental phenomena. Here, the type-type identity approach entails that mental properties such as propositional attitudes, qualia, and emotions are identical to the neural states they correlate with. If pain correlates with a certain neural pattern such as C-fiber stimulation, then the mental kind ‘pain’ is identical to the neural kind ‘C-fiber stimulation’. C-fiber stimulation, in turn, is a pattern of complex brain activity which is reducible to the causal interactions between myriads of elementary particles bearing various microphysical properties. Hence, the mental kind ‘pain’, by being identical to C-fiber stimulation, is identical to a very complex type of combination of interacting microphysical properties. However, both inter-theoretic reduction in the philosophy of science and type physicalism about mental states are today widely rejected. The reason is that many higher-level phenomena appear to be realizable by many different types of combinations of physical properties. This gives rise to the so-called multiple realizability argument, originating from Putnam (1967). Putnam argues that a great variety of animals appear capable of experiencing sensations such as pain. But crucial distinctions in neuroanatomy between such different species as birds, reptiles, mammals, and amphibians render the assumption implausible that there is precisely one identifiable neural kind, correlating with pain, which all these creatures have in common. Yet if there is no such common neural kind, then the type-identity theory cannot get off the ground: there is not just one physical type to which the mental type ‘pain’ can be taken to be identical.

Metaphysical Dependence

3

This problem is amplified by the fact that it seems plausible that it is not only a great variety of known creatures that can experience pain. Indeed, future artificial systems such as robots or silicon-made androids appear to be potential realizers of pain—and even extraterrestrials with completely unfamiliar neural make-up. Furthermore, as Fodor (1974) argues, the same is true for a great variety of other special science properties. Many biological, psychological, and economic properties appear to be multiply realizable. For instance, enzymes working as catalysts for cellular metabolism must not necessarily be realized by the macromolecules we study in microbiology. Their role in cell-systems could, in principle, also be fulfilled by some other kind—perhaps silicon-based—which has specific causal powers making it appropriate for the task. However, the multiple realizability argument against type physicalism allows for an obvious physicalist solution, functionalism. The dominant version of the view, role functionalism, claims that mental kinds—as well as many other special science kinds—are causal role properties. On this view, the fact that a certain multiply realizable state qualifies as pain does not primarily concern its internal constitution. Rather, pain’s identity is also essentially due to the causal role it plays in a certain system of which it is a part. To give a toy example, pain might be the state which is caused by tissue injuries and brings about certain beliefs about the body’s being in danger, the desire to avoid pain, and the inclination to moan. Any system capable of possessing an internal state of this type—regardless of specificities about the state’s internal constitution—is a potential bearer of pain. The rise of functionalism can be understood as establishing an ‘a priori turn’ in physicalism. Type-identity theorists provided topic neutral descriptions of mental states, arguing that empirical findings allow us to identify types of mental states with types of neural patterns. On role functionalism, in contrast, conceptual analysis allows us to a priori discover the nature of mental states, since the nature of a mental state consists in its being a certain role property. Empirical investigation within neuroscience can, in turn, find out which neural states realize these functional roles in the human brain. However, we would hardly expect to find the functional properties identified with higherlevel properties studied by the special sciences such as pain within physics textbooks. How can functionalism then qualify as a version of physicalism and do justice to the creed that everything is physical? The basic idea is that although there is no type-identity between mental and neural properties, realized properties are nonetheless nothing-over-and-above their realizers. Nothing-over-and-aboveness describes a relation of strong ontological dependence between entities. The dependence relation, in turn, is accounted for in modal terms: realized properties are taken to metaphysically supervene on their realizers. That is, in all possible worlds inhabited by one of its potential realizers, the realized property also exists. Supervenience physicalism is then the view that all high-level truths metaphysically supervene on microphysical truths and that, furthermore, the fact that realized entities are nothing-over-andabove their realizers can be accounted for in purely modal notions. Supervenience physicalism is the modal variant of nonreductive physicalism, whereas nonreductive physicalism is the umbrella term for physicalist views abolishing the critical role of type identity in favor of some relation of nothing-over-and-aboveness.

4

Physicalism and Fundamentalism

One consequence is that according to the supervenience view, physicalism is true iff any possible world which is physically identical to the actual world exhibits all phenomena which the actual world exhibits. In other words, when God plans to create a world identical to ours, She merely has to fix the microphysical facts, that is, the distribution of microphysical entities and the fundamental laws of physics; everything else directly results from these facts. Note that this does not preclude worlds physically identical to ours from having ‘surplus’ ontology. For physicalism being true about the actual world is compatible with the possibility of worlds identical to our world in every physical detail which, in addition, also exhibit other phenomena such as disembodied Cartesian souls: God might very well decide to add a little something special to Her novel world, sharing all of our world’s microphysical truths. If so, physicalism about the actual world is true, but not about the other possible world. Now, nonreductive physicalists assume that functionalism thusly understood can still count as fulfilling physicalism’s core creed. The idea is that since fixing the microphysical facts suffices to fix all facts, realized macrophenomena can be fully explained in physical terms. In turn, such global reductive explainability of the macrorealm suffices in fulfilling physicalism’s criteria.2 Since the 1970’s, the nonreductive supervenience view has been the standard account for formulating physicalism. Yet by the early 2000’s, there have been provided strong arguments which suggest that nothing-over-and-aboveness cannot be fully characterized in modal notions. Critics have pointed out that there are cases of metaphysical supervenience which do not entail that the supervenient entity is nothing-over-and-above its supervenience base. Rejecting the supervenience approach to nothing-over-and-aboveness, they provide an alternative metaphysical framework which is based on a primitive notion of fundamentality. Metaphysical fundamentalism involves a metaphysical structure according to which realizers are metaphysically prior to what they realize. The former are fundamental and exist ontologically independently, while the latter are ontologically dependent and exist only derivatively. However, taking primitive fundamentality as a common ground, proponents differ on how to cash out the nature of the relation of nothing-over-and-aboveness. In the next section, I will discuss various versions of the fundamentalist framework, and I will argue that it appears very promising for characterizing nothing-over-and-aboveness, although the details remain contentious. 2.1.2

The Hyperintensionalist Turn and Metaphysical Fundamentalism

Fundamentalist theories assume that there is a sharp distinction between fundamental and nonfundamental, derivative entities, rather than degrees of fundamentality. That is, being fundamental is an all-or-nothing property: an entity is either fundamental or derivative. 3 Moreover, the fundamentalist framework takes fundamentality to be a primitive notion not analyzable in more basic terms. A major reason why primitivism about fundamentality is very attractive to many is that it allows for the reframing of traditional metaphysical questions (Schaffer 2 3

Note that ‘reductive’ is here understood in a broader sense than in ‘nonreductive physicalism’ such that it does not require identity. Henceforth, I use the notion ‘reductive explanation’ in this sense. I discuss reductive explainability of realized phenomena more thoroughly in the following chapter. There is also a notion of relative fundamentality, being-more-fundamental-than-x-but-less-fundamentalthan-y, which admits of degree. But this notion is itself derivative on the basic distinction between funda mentality and derivativeness which, as explained, are all-or-nothing notions.

Metaphysical Dependence

5

2009a). On a traditional conception originating from Quine (1948), metaphysics is concerned with the question as to what exists. Metaphysical fundamentalism, in contrast, takes metaphysics to be primarily concerned with what is fundamental. Entities which are not fundamental nevertheless exist, but only derivatively, being ontologically dependent on fundamental entities. Fundamentals are thus metaphysically prior to derivatives. It is the task of metaphysics to tell us what those fundamental entities are, as well as how they relate to derivative phenomena. One particular version of metaphysical fundamentalism has attracted considerable attention in the last few years. Following Fine (2001), there has been a new research program in metaphysics that links the idea that fundamentality does not admit of degree with two other conceptions. The first is the assumption that the world has a hierarchical order in such a way that in addition to fundamental entities, all sorts of derivatives ‘built’ from fundamentals exist. The second idea is that derivative entities are not only built from the former, but are, in a certain sense, also explicable by them. The combination of these assumptions takes the form of postulating a primitive metaphysical relation, metaphysical grounding, that not only links derivative to fundamental entities, functioning as their dependence base, but also renders the former explicable in terms of the latter. Now, proponents of ground argue that in contrast to supervenience, grounding is able to capture the asymmetry of dependence that we naturally assume derivative entities to instantiate towards the entities upon which they depend. To take a well-known case from Fine (2001), assume that the singleton {Socrates} is ontologically dependent on Socrates. This entails that {Socrates} metaphysically supervenes on Socrates. In every possible world in which Socrates exists his singleton also exists. Hence, one might think (and many have thought so in analogous cases) that the singleton’s dependence can be cashed out in modal terms. But notice that Socrates also metaphysically supervenes on {Socrates}. Not only does the singleton exist in every possible world in which Socrates exists, but so does Socrates in every world that {Socrates} inhabits. Supervenience does not tell us who depends on whom: Socrates on its singleton, or Socrates’ singleton on Socrates. Yet it seems that an asymmetric and, therefore, hyperintensional dependence relation holds in such cases. Fine’s singleton-case shows that the existence of a relation of metaphysical necessitation is not a sufficient condition for the existence of a relationship of nothing-over-and-aboveness: {Socrates} metaphysically necessitates Socrates, but Socrates is not ontologically dependent on {Socrates}. Hence, it seems that views such as physicalism cannot be characterized in purely modal notions: supervenience physicalism is wanting because the relation of nothing-over-and-aboveness cannot be cashed out in terms of metaphysical supervenience.4 4

Another case which demonstrates the inadequacy of supervenience physicalism is the status of ontologically emergent phenomena given the truth of dispositionalism. I will discuss both ontological emergence and dispositionalism more thoroughly in Chapters 4 and 5. For the issue at hand, it suffices to note that ontological emergence is the view that some macrophenomena are not realized by microphenomena, but rather are connected to them by fundamental laws: ontologically emergent phenomena are ontologically irreducible entities which do not even bear relations of token-identity to microphenomena such that the existence of ontologically emergent entities is incompatible with physicalism. Nevertheless, ontologically emergent entities nomologically supervene on microphenomena due to emergence-engendering laws which govern their generation from those microentities. Dispositionalism is the view that all fundamental properties are essentially primitive dispositions, and that laws of nature are metaphysically necessary, since they are entailed by the

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Physicalism and Fundamentalism

In addition to being able to capture the asymmetry of dependence, ground is also taken to perform explanatory work in the following way.5 One can, in a specifically metaphysical sense of explanation, explain derivative entities in terms of their grounds. That is, one understands why a certain derivative entity exists if one knows that its ground is instantiated. Take the following question: why is there a table in my room? Besides the causal explanation that I put it there when I moved in two years ago, there is another, namely a metaphysical explanation. The table is in my room because there is a huge amount of elementary particles in my room arranged in a certain fashion such that they constitute this table. The table is not only grounded in the particles, but can also be explained by them.6 While this characterization outlines some of the crucial assumptions most proponents of grounding share, controversies loom large when it comes to more specific questions such as whether grounds necessitate derivatives (Leuenberger 2014 and Skiles 2015), whether grounding is irreflexive (Jenkins 2011 and Correia 2014), or whether grounding is transitive (Schaffer 2012 and Tahko 2013). Even its asymmetric nature has been questioned (Bliss 2014 and Barnes 2018). I lack the space to delve into these issues. Instead, I shall concentrate on the version of the grounding-view provided by Dasgupta (2014), who stands in the tradition of Fine (2001, 2012), and on Sider (2011), a prominent alternative fundamentalist view which does not invoke metaphysical grounding. Since Dasgupta develops his view as a solution proposal to a major objection to ground provided by Sider and the specificities of Dasgupta’s account can only be understood against the background of Sider’s objection, I begin by discussing Sider’s view and his criticism of ground. I pick out these two versions of metaphysical fundamentalism not only because they are amongst the most prominent and widely discussed fundamentalist views, but also because both are at play in one of the most intriguing arguments against constitutive Russellian monism, Goff’s (2015, 2017: chapter 8) subject irreducibility argument, which will be at the center of my discussion of objections against this version of panpsychism in Chapter 6: Goff develops two versions of the subject irreducibility argument, one utilizing Dasgupta’s frame-

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dispositional essences of microphysical properties. Now, assume that dispositionalism is true, and that there are ontologically emergent phenomena. If so, emergence-engendering laws are metaphysically necessary such that ontologically emergent entities metaphysically supervene on certain microphenomena. Yet their existence is not compatible with physicalism. However, supervenience physicalism wrongly deems the exis tence of ontologically emergent phenomena as being compatible with physicalism. Amongst proponents of ground, it is controversial whether ground itself is a type of metaphysical explanation, as the likes of Fine (2012) and Dasgupta (2014) claim, or merely backs metaphysical explanations, as, for instance, Schaffer (2012) maintains. According to most fundamentalist views, this is not exactly true. The relata of the grounding are usually taken to be either facts, or propositions, or sentences. On the fact view, the fact that there is a table is in my room is grounded in the fact that there is a huge number of elementary particles arranged table-wise. Schaffer (2009a) is an important exception. He allows for all different sorts of grounding relata including objects. Notice also that contrary to what I claimed above, not all proponents take grounding to be a relation. The alternative is to think of it as a sentence operator (see Fine 2012 and Dasgupta 2014). This has several advan tages, inter alia, that one is not committed to realism about facts. On the other hand, as Raven (2015) emphasizes, if grounding is taken to explain how derivative are produced by fundamental phenomena, then it is hard to see how grounding could play this role without being a relation, relating derivative and fundamental facts.

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work (Goff 2017: chapter 8) and the other utilizing Sider’s framework (Goff 2015); an adequate understanding of Goff’s reasoning presupposes familiarity with those accounts. 2.1.3

Sider’s Version of Fundamentalism

Sider (2011) cashes out metaphysical fundamentalism in the following way: for a sentence to describe the world as it really is, it does not suffice that it is true; rather, the sentence must use the right concepts and linguistic items. Here, Sider expands on Lewis’ (1983) idea that there is a privileged class of predicates, those describing natural properties: there is a crucial difference between ordinary predicates of everyday speech, such as ‘is red’, and the predicates used by our best theory about the world. Suppose that not only contemporary, but also ‘ideal’ fundamental physics invokes negative charge. If so, negative charge is a natural property, an irreducible feature of certain fundamental particles, ‘carving reality at the joints’, as Sider puts it. In contrast, the property of being red is not natural: it can be explained in terms of certain microphysical properties, accounting for an object’s redness—it is those microphysical properties, and not red, which carve at the joints. Sider takes Lewisean naturalness a step further, extending ‘predicate-elitism’ to other grammatical categories: in addition to the class of privileged predicates, there are classes of privileged linguistic expressions of various sorts. Together, these natural expressions form a fundamental metalanguage that can be used to describe the world as it really is. For every feature or entity of fundamental reality, this language has a matching linguistic expression. If there are fundamental facts as to what exists, then the language contains an existential quantifier. But this existential quantifier is not that used in ordinary English. While the latter goes together with linguistic notions and concepts of ordinary English, the former is restricted to other natural notions. There might also be fundamental negation and other fundamental sentential connectives such as ‘and’. If so, those expressions can be used to form true sentences which are not only true, but also literally mirror the world as it structurally is. To be clear, Sider does not assume that if the fundamental language features ‘and’, then there is an object in the world, an ‘extralinguistic conjunction’, to which the fundamental ‘and’ refers. Rather, Sider takes it that metaphysics is not restricted to ontology, the study of what there is: in addition to a theory’s ontology, a theory comes with an ideology, the conceptual resources it employs. Ideology concerns the way how a theory describes the things its ontology postulates. With regard to the fundamental language, its ontological dimension concerns what entities exist in fundamental reality, and its ideological dimension is mirrored by how those entities are. Of course, no one currently speaks the fundamental metalanguage and we might never be able to learn it. Yet if we succeed in completing fundamental physics in the distant future, then this science would employ this language. And it is only once we possess the fully correct theory about the world that we can know which ontological and ideological dimensions the fundamental language’s expressions mirror. In other words, Sider accounts for fundamental reality in terms of a fundamental structure of reality. This fundamental structure not only concerns which entities exist, but also how they are. What entities exist is captured by the ontology, and the way how those things really are is mirrored by the ideology of the fundamental language. Note that Sider’s conception of fundamental reality crucially differs from how fundamentality is accounted for in grounding views.

8

Physicalism and Fundamentalism

For the majority of grounding theorists takes grounding to be a relation between facts: fundamental reality consists of fundamental facts which ground derivative facts. The grounding view thus conceived is a propositional approach to fundamentality, where fundamentality consists of primitive facts such as the facts ‘c is an electron’ and ‘there are electrons’. In contrast, Sider defends a subpropositional view of fundamental reality: expressions such as the fundamental quantifier ‘there are’, the predicate ‘electron’, and other subsentential expressions carve at the joints.7 8 As proponents of metaphysical grounding, Sider thinks that “[e]very nonfundamental truth holds in virtue of some fundamental truth” (2011: 115), where a fundamental truth is a truth which involves only fundamental notions. But in difference to the former, he does not take this to mean that there is a primitive grounding relation at work between fundamental and derivative facts. Rather, Sider analyzes the in-virtue-of-relation holding between nonfundamental and fundamental truths in terms of a metaphysical semantics which provides us with metaphysical truth conditions for nonfundamental sentences: for every sentence of a certain nonfundamental language, there is a corresponding sentence in the fundamental language which has to be true in order for the former to be true.9 While believing in absolute fundamentality, Sider holds (in a certain sense which has to be cashed out very carefully) that there are not any extralinguistic derivative entities. Suppose again that tables are derivative. If so, Sider does not take the sentence “The table in my room is made from wood” to be false. This sentence is literally true. But its definite description does not really refer to an extralinguistic derivative entity, the table in my room. There is no real direct connection between any of the linguistic expressions of this nonfundamental sentence and the extralinguistic world. That is, contrary to appearance, the sentence does not describe the world as it really is. Nevertheless, the sentence has a truth-value. Yet its truth-value is the result of its having a metaphysical truth condition which is expressed by another sentence. This latter sentence is a sentence of the fundamental language, and only this sentence describes the extralinguistic structure of the world as it really is. Not only everyday English, but also special sciences such as economics or psychology are cast in nonfundamental languages, whereat those languages partly differ from each other by using special vocabulary. Regardless of these differences, each of the sentences of a nonfun7

8

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In contrast to the majority view that grounding is a relation between facts, Fine (2012) takes grounding to be a sentential operator which conjoins sentences stating an explanandum with sentences stating the appropriate metaphysical explanans. However, both approaches provide propositional accounts of fundamentality, and thus differ from Sider’s subpropositional account. Sider argues that his subpropositional approach is preferable to the propositional approach of proponents of ground, because it allows us to explain pattern in the fundamental facts: the facts ‘ c is an electron’ and ‘d is an electron’ are both fundamental, because ‘c’, ‘d’, and ‘electron’ carve at the joints. On the grounding approach, in contrast, such patterns remain unexplained, both facts are fundamental without there being an ex planation of their subpropositional commonalities. For a reply on behalf of the propositional approach, see Fine (2013). More precisely, every expression of a nonfundamental language has a metaphysical semantics in terms of expressions of the fundamental language. Sider takes it to be a plausible assumption that in the case of nonfundamental sentences, their metaphysical semantics might be given in terms of metaphysical truth conditions, but he is not strongly committed to the claim that the metaphysical semantics of nonfundamental sentences must take on this particular form. And even if this is the case for most sentences, there might be exceptions: given that moral expressivism is true, the metaphysical semantics of normative sentences might take on the form of a fundamental sentence specifying the speaker’s attitudes.

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damental language has a truth-condition stated in terms of the fundamental language describing what the world must be like in fundamental, joint-carving notions such that the nonfundamental sentence comes out true in the nonfundamental language. Only mediated through the fundamental language, so to speak, can sentences from nonfundamental languages describe the world. Derivative entities such as the table in this room exist in the sense that sentences stating their existence are true. However, those sentences employ nonfundamental existential quantifiers which only go together with terms for derivative objects like tables. In contrast, derivative entities are by definition not among the things to which the fundamental language has expressions to refer. And since only fundamental notions carve at the joints of reality, there are no derivative entities in the extralinguistic world as it really is. In other words, Sider gives “a linguistic account of connecting facts”, whereat connecting facts are “facts connecting nonfundamental to fundamental” (Sider 2011: 124). For every sentence of a nonfundamental language, its connecting fact is the fact that is has a certain metaphysical truth-condition: for every nonfundamental sentence, there is a sentence of the fundamental language that must be true in order for the former to be true. Compare this to ground. The grounding-view posits nonlinguistic connecting facts. Here, the nonfundamental is not the domain of nonfundamental languages, but the extralinguistic realm of derivative facts. These derivative facts are worldly entities rather than linguistic ones, and the connection between fundamental and derivative entities is assumed to be a relationship between extralinguistic facts. Both the fundamental and the nonfundamental realm are located in the extralinguistic world, while the latter is in a certain sense a purely linguistic phenomenon in Sider. The grounding view is often described in terms of the difference between what exists and what really, or fundamentally exists. This distinction can be also made sense of in Sider. But it is only on the grounding approach that it describes states of being a worldly entity can have, being either fundamental or derivative. In Sider, on the other hand, it concerns the difference between what exists according to true existence claims of some nonfundamental language, and the entities that really exist in the world and that are described by the fundamental language. To use Barnes’ (2012) terminology, the grounding-view can aptly be described as an inflationary approach, and Sider (2011) as a deflationary approach, within the fundamentalist framework. The deflationary approach comes with a representational, linguistic account of connecting facts and derivative phenomena, while the inflationary view gives a worldly account of connecting facts and derivatives.10 10 Another version of the deflationary approach to metaphysical fundamentalism is Cameron’s (2008, 2016) truthmaker theory of fundamentality. Central to truthmaker theories is the idea that in order for a propositions p to be true, there has to be something which makes it true, that entity being the truthmaker of p. Moreover, it is the sole existence of this entity that is responsible for the truth of p. Accordingly, the ontology of the truthmaker theorist is quite sparse. It only contains singular existential facts which serve as truthmakers for all true sentences. Cameron (2016) analyses truthmaking in terms of grounding. Yet his grounding relation does not hold between worldly entities, but rather only between worldly entities and linguistic expres sion and between different linguistic expression. Hence, his view is a version of the representational account of fundamentality: similar to Sider, he assumes that there is a special fundamental metalanguage; in contrast to Sider, however, his fundamental language only consists of pure existence claims, sentences of the form “x exists”—it has no rich ideology. Such parsimony of fundamental ideology might be considered an advantage. However, Sider (2011: 157–161) argues that truthmaker fundamentalism cannot abide by its restrictive take on fundamentality, and must allow for further fundamental facts and richer ideology in order to be

10

Physicalism and Fundamentalism

Which approach is preferable? Sider’s central argument for the superiority of his approach and the untenability of the grounding-view is that the grounding approach takes connecting facts to be fundamental, whereas his approach does not. Suppose the following (toy) grounding fact is true, whereby ‘n’ is a very large number: ‘The fact that there are n particles arranged table-wise in location l grounds the fact that there is a table in my room.’ On a natural understanding of the grounding view, this grounding fact is fundamental. After all, grounding was introduced to explain derivative facts in terms of fundamental ones which, in turn, was understood in terms of a primitive determination-relation between fundamental and derivative facts. And since this determination-relation is a primitive and thereby fundamental relation, grounding facts have to be fundamental as well. But the problem is that the above grounding fact incorporates a derivative fact, namely a fact about tables. Hence, it cannot be a fundamental fact, as fundamental facts cannot be about derivative entities such as tables. Sider’s own account, in contrast, does not assume that connective facts are fundamental. The fact that a sentence about tables has a metaphysical truth-condition is not a fundamental fact. For a fundamental fact can only be described by a sentence of the fundamental language. And since the sentence that describes this fact is not part of the fundamental language (it uses the nonfundamental notion ‘table’), it follows that it is not a fundamental fact. Rather, only the sentence that states metaphysical truth-condition for the sentence about tables is fundamental, and so is the fact that this sentence describes. 2.1.4

The Fine-Dasgupta Account of Metaphysical Grounding

Sider’s objection has resulted in the widespread conviction amongst proponents of ground that grounding claims themselves must have grounds. One can distinguish between what Raven (2015) calls a reductionist strategy and a connectivist strategy respectively in dealing with this problem. Reductionists such as Bennett (2011) and deRosset (2013) hold that the same fundamental fact that grounds the derivative fact also grounds the grounding fact. That is, not only is the fact that there is a table in my room grounded in the fact that there are n elementary particles arranged table-wise in location l—the grounding fact that the former is grounded in the latter is grounded in the latter as well. A problem for this account is that there seems to be no explanatory connection between the grounding fact and the ground (see Dasgupta 2014: 571-2 and Raven 2015: 328-9). Why is it that the fact that there is a table in my room is grounded in the fact that there are n particles arranged table-wise in l? Answer: because there are n particles arranged table-wise in l. This does not seem a satisfactory explanation. Yet grounding was introduced as both a dependence and an explanatory relation—or at least as a dependence relation backing a certain kind of metaphysical explanation. It seems to be an illegitimate break with this central idea if the grounding of grounding facts is non-explanatory. Connectivists, in contrast, hold that grounding facts are grounded in general connections between derivative entities and their grounds. The connectivist strategy originates from Fine (2012). Dasgupta (2014), developing Fine’s ideas, provides an especially interesting version of connectivism in direct answer to Sider’s criticism of ground. Dasgupta’s account is based on Fine’s (e.g. 1994) view on essence, according to which essence is a primitive, hyperintenworkable.

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sional notion.11 On this view, the essence of an object is its real definition. Real definitions are worldly analogues of linguistic definitions of words, the context independent description of what something is. Dasgupta’s (2014) core theoretical innovation is his distinction between substantive and autonomous facts. Substantive facts can either be derivative or fundamental facts. What sets them apart from autonomous facts is that they are “apt for being grounded” (575), although only the former are, in fact, grounded. Fundamental substantive facts have the right form for being grounded, but qua being fundamental, they are not grounded. Also, autonomous facts are not grounded—but for the principled reason that they are not apt for being grounded in the first place. One might allow for several distinct categories of autonomous facts, depending on what metaphysical views one holds. For example, facts about God or arithmetic facts might be considered autonomous. On Dasgupta’s account of grounding, the crucial category of autonomous facts are essentialist facts. These are facts about the essence of an entity, where the essence of an entity are truths which figure in his real definition. Dasgupta explains the crucial difference between the two types of ungrounded facts, fundamental and autonomous facts, as follows: [F]undamental facts are, in a sense, arbitrary. Suppose it is a fundamental fact that a given particle is located where it is. Its position is arbitrary in the sense that there is no rhyme or reason why it is there; it is just there, and that is all there is to say about the matter. In contrast, autonomous facts are not in the same sense arbitrary. The case of essentialist facts arguably demonstrates this: even if essentialist facts are groundless, they are not arbitrary in the way that brute facts are. There is nothing arbitrary about the fact that {Socrates} is by definition the unique singleton containing Socrates: this is, after all, just what {Socrates} is! (Dasgupta 2014: 580) While causal explanations of fundamental fact can be given (that is, we can trace the causal origin of the location of Dasgupta’s particle) metaphysical explanations of such facts cannot be provided. Essentialist facts, in contrast, while also resisting metaphysical explanation, are not metaphysically arbitrary. Being part of a real definition makes them have a ‘metaphysical function’ without being explicable by something else. Now, Dasgupta’s version of connectivism claims that the essence of a grounded entity specifies a general connection between what that grounded entity is and its ground. That is, if an entity is grounded in underlying phenomena, then the essence of the former reveals how and why it is grounded in the latter. From this, it follows that the grounding relation between two entities itself is grounded in essentialist truths about the grounded entity. Consider the following example from Goff (2017: section 2.2.2). Part of the essence of parties is the fact that

11 Fine (1994) raises severe objections to modal accounts of essential properties. Roughly, these views take an object’s essential properties to be the properties that the object necessarily has. Fine argues that this is mistaken, since there are cases where an object necessarily has certain properties that we would not consider to be essential to the respective object. For instance, Socrates has the necessary property of belonging to its singleton. However, it does not seem right to say that it is essential to Socrates to belong to {Socrates}. Fine concludes from this and similar considerations that essence is neither analyzable in terms of modal, nor any other notions, but is rather a primitive, hyperintensional concept.

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a party occurs iff an event occurs involving various people reveling. Hence, the fact that various people revel grounds the fact that there is a party. Moreover, the fact that the essence of the grounded entity is responsible for the grounding relation is the reason why grounding can aptly be described as an explanatory relation. Knowledge of the essence of the grounded entity entails knowledge of the metaphysical reason why the entity exists. There is a party going on in the neighbors’ apartment because the neighbor and several friends of his are reveling. The party that occurs at 4 am and keeps me awake is nothing over and above the fact that the neighbor and his friends are reveling. If I know what a party in general is, I know that it is grounded in an event which involves people reveling. If I know the essence of this particular party that is occurring at 4 am in the above apartment, I know that Kilian, Caro, Stevie, and Anja are reveling. This particular grounding fact is grounded in an essentialist truth concerning parties. The distinctive explanatory status of grounding claims results from the fact that the essence of the grounded entity states that it is nothing-over-and-above the grounding entities. This gives the connectivist strategy an advantage over the reductionist approach which, as we saw, cannot provide significant metaphysical explanations of grounding facts. As a result, we get brute essentialism, the view that the grounding facts are grounded in essentialist facts wherein the latter are groundless, since they are autonomous fact, not apt for being grounded.12 Dasgupta argues that since first-order grounding claims are themselves grounded in essentialist facts, this view can avoid Sider’s concern that the fundamental grounding facts involve derivative facts. However, the aforementioned essentialist fact about parties that provides the ground of the first-order grounding fact still mentions derivative entities, namely parties. How, then, can Dasgupta’s account avoid Sider’s objection? The answer is that brute essentialism holds that essentialist facts are autonomous, and qua being autonomous they are nonfundamental facts. Recall that only substantive facts are candidates for being fundamental facts. It follows that derivative entities can figure in autonomous fact without thereby poisoning fundamental reality. Since autonomous facts are themselves not part of fundamental reality, there is no reason to assume that the entities they involve have to be fundamental. Where does this discussion of metaphysical fundamentalism leave us? In conclusion, I take it that we have compelling reasons for accepting some version of metaphysical fundamentalism, since the alternative modal account of nothing-over-and-aboveness has been shown to be false. But it is currently not clear which of the various versions of metaphysical fundamentalism is correct because all varieties face serious problems. For instance, it has been criticized that Sider’s concept of metaphysical truth-conditions is an unintelligible notion for which he does not provide any illuminating account. Moreover, Dasgupta’s conception of

12 Note that although Dasgupta cashes out his view in terms of Finean essence, he points out that the basic idea of his account is also compatible with alternative theories of essence. Assume that the modal account of essence is correct: essentialist facts are reducible to conceptual facts. If so, Dasgupta takes those conceptual facts to be autonomous. Consequently, it would be conceptual facts about grounded entities that would provide the ground for first-order grounding relations. Brute connectivism is Dasgupta’s umbrella term, encompassing all versions of his account that result from invoking different theories of essence. Brute essentialism is the version which utilizes Finean primitive essence.

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autonomous facts which are not apt for being grounded might also seem difficult to make sense of. Henceforth, I shall use ‘grounding’ as an umbrella term for different ways to cash out nothing-over-and-aboveness within the framework of metaphysical fundamentalism, be it various versions of metaphysical grounding, or Sider’s linguistic account of connecting facts in terms of a metaphysical semantics. Grounding physicalism is then the view that fundamental reality is purely microphysical, while all concrete macrophenomena are grounded in fundamental phenomena. As supervenience physicalism, grounding physicalism is a variety of nonreductive physicalism, abolishing the critical role of type identities. The difference between both approaches is that grounding physicalism rejects a purely modal account of nothing-over-and-aboveness in favor of primitive fundamentality and grounding. Having thus a clear conception of the notion of nothing-over-and-aboveness at play in physicalism, this leaves us with the task of understanding what ‘physical’ means. 2.2 What is ‘Physical’? The proposals within the literature can roughly be divided into theory- and object-based conceptions of the physical (Stoljar 2017). Theory-based accounts assume that being physical amounts to belonging to the entities which explicitly figure in physics’ equations and models. On this view, a prototypical physical property is having mass or being negatively charged. Object-based approaches, in contrast, allow for a broader understanding of ‘physical’: a property is physical iff it is a property of a physical object, where physical objects are the objects studied by physics. If we restrict what counts as physics in the relevant sense to fundamental physics, then physical objects are electrons, quarks, atoms, and the like. One might think that the properties of elementary particles are just the properties which figure in physical theory. If so, both conceptions identify the same set of properties as being physical. However, note that the object-based conception allows for all non-trivial properties of elementary particles to count as physical, and not only those examinable by physics. This gives rise to the so-called panpsychism problem for the object-based conception. If panpsychism is true, then elementary particles have microphenomenal properties. Yet if all non-trivial properties of physical objects are physical, then, given the truth of panpsychism, microphenomenal properties count as physical properties, and panpsychism turns out to be a version of physicalism. While one might bite the bullet and defend such an account of ‘physical’, a view of the physical which entails that panpsychism is a version of physicalism is not acceptable for the purposes at hand for obvious reasons. Hence, if panpsychism is to be understood as an antiphysicalist doctrine (and I am strongly in favor of doing so), then it is mandatory to subscribe to a theory-based conception. However, a somewhat analogous problem exists for the theory-based conception as well. In what is termed Hempel’s dilemma, originating from Hempel (1969), it is pointed out that there are two possible versions of the theory-based view, both of which have unacceptable implications. Either ‘physical theory’ is taken to refer to contemporary (fundamental) physics, or it is taken to refer to a more developed, future version of the science. If the first route is taken, then physicalism is false: contemporary physics is obviously incomplete, because physicists

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have not yet managed to develop a unified theory. If the second route is taken, yet another panpsychism problem arises : we cannot predict what properties will be postulated by future physics: it might very well be the case that the final successor of contemporary physics involves the ascription of primitive phenomenal states to elementary particles. If so, then microphenomenal properties turn out to be physical—a consequence which, for the above reasons, hardly seems acceptable. Wilson (2006) provides an interesting solution to this dilemma. Her approach aspires to take a middle way between the two routes open to the theory-based conception by defining ‘physical’ via reference to future versions of physics, but explicitly ruling out fundamental mentality. According to this view, [a]n entity existing at a world w is physical if and only if (i’) it is treated, approximately accurately, by current or future (in the limit of inquiry, ideal) versions of fundamental physics at w, and (ii) it is not fundamentally mental (that is, does not individually either possess or bestow mentality) (Wilson 2006: 72) Wilson’ account manages to avoid the first horn of Hempel’s dilemma by assumption (i’) which restricts ‘being physical’ to those properties figuring in fundamental physical theory (both contemporary and future versions thereof) that give a correct account of their referents. By explicitly allowing for properties which figure in contemporary physics, provided that they give an approximately correct account of their referents, Wilson can also preserve an important epistemological motivation for the acceptance of physicalism: namely that the success of contemporary physics (and not that of some unknown future successor thereof) provides the major reason for theorists to adopt physicalism.13 The second horn is avoided by (ii), the No Fundamental Mentality constraint. Wilson identifies fundamental mentality (that is, phenomenality and/or intentionality) as the only ingredient which might feature in ideal physics that is in tension with the physicalist doctrines held by contemporary theorists. This is a crucial point: arguably, no other potential ingredient of future physics besides fundamental mentality could be considered problematic. Theorists who identify themselves as physicalists are clearly committed to rejecting the existence of fundamental mentality, even if it follows from ideal physics. In such a case, ideal physics will just have proved physicalism to be false. But it seems there is no other red line the physicalist is committed to not crossing even if ideal physics suggests otherwise. Note that Wilson’s characterization of ‘physical’ is not meant to provide an explanation from first principles why ‘physical’ has to be understood in a certain way, nor is it meant to deliver a conceptual analysis of the concept. Rather, her characterization aims to capture what contemporary physicalists willingly (both explicitly and implicitly) subscribe to when they commit themselves to the thesis that concrete reality can be fully accounted for in terms of physics. This has some sociological components to it. For ‘physical’ is to be understood in a way such that we can make sense of a certain research program in contemporary metaphysics 13 Assumption (i’) differs from assumption (i) which figured in preliminary versions of Wilson’s account by explicitly allowing for reference to contemporary physics whenever this theory provides an approximately correct description of some part of reality.

What is ‘Physical’?

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and the philosophy of mind, namely physicalism. It is therefore no shortcoming of Wilson’s characterization that it might turn out that future physics postulates fundamental properties which are not physical according to Wilson’s criteria. In contrast, if the aim of our characterization is to understand ‘physical’ in a way such that we can make sense of the theories of physicists whatever they might come up with, then such an implication would obviously be unacceptable. However, for the purposes of the work at hand, it is of interest to gain a clear understanding of what contemporary physicalism is committed to. Hence, a characterization along the lines of Wilson’s serves our interest here. However, I believe that even given this explanatory aim, Wilson’s account is incomplete. For it entails that another prima facie antiphysicalist view, Russellian panprotopsychism, turns out to be a variant of physicalism. Russellian panprotopsychism is a specific version of categoricalism. Categoricalism is the view that microphysical dispositions are realized by categorical properties, or quiddities. There is a widespread agreement that (most or even all) physical properties are dispositions. For instance, having a certain mass is nothing more than exhibiting the disposition of attracting other entities with mass according to the laws of gravitation. Yet it is also widely believed that dispositions have an intrinsic dimension. Together, both convictions entail categoricalism, the view that microphysical dispositions are grounded in categorical properties.14 Now, panprotopsychism is the view that macrophenomenality is grounded in combinations of nonmental microquiddities as such. In turn, according to Wilson’s characterization, panprotopsychism thus qualifies as a version of physicalism. This is so because (ii) does not rule out that quiddities qua their categorical nature ground macrophenomenality. By merely ruling out fundamental mental properties, the account implicitly accepts protophenomenal properties given that they figure in future physics. Those properties do not ground macrophenomenality by playing various microphysical roles, but by way of the combination of their quidditistic natures. Yet since the latter are not fundamentally mental themselves, (ii) does not exclude them from being physical. However, physicalists are usually assumed to be committed to the thesis that consciousness is fully grounded in microphysical causal structure. This might be called the panprotopsychism problem. In order to see how this problem might be solved, it is helpful to combine Wilson’s characterization of the physical with Chalmers’ (2013) distinction between narrowly and broadly physical properties: Narrowly physical properties are microphysical role properties, such as the dispositional property associated with having a certain mass, or the second-order property of having a property that plays the mass role. […] We can say that broadly physical properties are physical role properties along with any properties that realize the relevant roles: categorical bases for the mass dispositions, first-order prop14 Categoricalism is not uncontroversial. Dispositionalists deny the existence of quidditistic underpinnings of the dispositions studied by microphysics. Yet, as will be discussed in Chapter 5, plausible versions of panpsychism require the existence of categorical bases. Moreover, subtle details concerning the difference between structural and quidditistic aspects will play an important role in arguments I develop in later chap ters. I will therefore return to the debate between categoricalism and dispositionalism within these later chapters, and there provide a more thorough discussion of both views. For the purposes at hand, the rough characterization presented above suffices.

16

Physicalism and Fundamentalism erties that play the mass role. In effect, narrowly physical properties include structural properties of microphysical entities but exclude quiddities, while broadly physical properties include both structural properties and quiddities. Here a structural property is one that can be fully characterized using structural concepts alone, which I take to include logical, mathematical, and nomic concepts, perhaps along with spatiotemporal concepts. (Chalmers 2013: 11)

In this passage, Chalmers provides a fourfold distinction between different ways of categorizing properties. The distinction between categorical bases and structural properties concerns the difference between the quidditistic nature and the dispositional (or otherwise scientifically examinable) profile of properties.15 The distinction between narrowly and broadly physical properties concerns the question whether what counts as ‘physical’ only concerns the structural aspects of properties, or also their quidditistic nature. The properties at play in Wilson’s characterization are clearly broadly physical properties because otherwise assumption (ii) would not be needed: it does not make sense to assume that microphysical role properties as such can be fundamentally mental, since the fact that a property is fundamentally mental entails that its mental aspect is not grounded in structural aspects. 16 More precisely, the very existence of the panpsychism and the panprotopsychism problem for the theory-based conception demonstrates that physicalism is a theory which not only involves claims about structural properties, but also about their categorical bases—provided that such exist. Hence, in order to avoid the panprotopsychism problem, Wilson’s account has to be modified such that it also rules out that broadly physical quiddities are protophenomenal. This can be done by specifying that Wilson’s account concerns broadly physical properties, and adding a third clause to it: [a]n entity existing at a world w is physical if and only if (i) it is treated, approximately accurately, by current or future (in the limit of inquiry, ideal) versions of fundamental physics at w, (ii) it is not fundamentally mental (that is, does not individually either possess or bestow mentality) (iii): it is only involved in the generation of w’s causal and metaphysical structure qua the structural role it plays but not qua its quidditistic essence (provided that it has a categorical nature). Assumption (iii) specifies that in order to count as physical, quiddities must not engage in metaphysical or causal work qua their very categorical nature. Note that this is more than what would be needed to merely rule out panprotopsychism. For, doing so, it would suffice to 15 It is controversial whether all properties figuring in fundamental physics are dispositions. For instance, microphysics invokes spatial relations; it is, however, not obvious that spatial relations are dispositions (but see Bird 2007a: chapter 7 for an argument that they are). Nevertheless, one might think that spatial relations have a categorical nature even if they are not dispositions (one might of course doubt that they have quiddi tistic underpinnings in this case, but it is not obvious why they should not have such grounds). The terms ‘structural property’ as used by Chalmers functions as an umbrella concept for all property-profiles which as such can be studied by physics. ‘Structural property’ might thus refer to both dispositions and also other kinds of profiles. Note that ‘structural property’ in this sense means something different to that meant as used by Armstrong (1997) and others. In this latter usage, the term refers to complex properties which are grounded in more fundamental properties and relations. In this work, I use ‘structural properties’ in Chalmers’ sense. 16 I discuss this point more thoroughly in the next chapter.

What is ‘Physical’?

17

postulate that quiddities as such do not engage in any metaphysical work, in particular in grounding processes. Yet the further restriction—call it no-causation-by-quiddities-qua-quiddities constraint—naturally follows from the intended characterization of physicalism. On what I take to be a plausible interpretation, contemporary physicalism involves the claim that the complete causal and metaphysical story of the world can be accounted for in terms of narrowly microphysical properties. Yet this requires that the categorical bases of microphysical properties are not involved in further causal work besides their playing the causal roles described by physics. If they participate in causal interactions qua categorical nature, then ex hypothesis these causal interactions cannot be accounted for in narrowly microphysical terms. The reason is that microphysics can only study their structural causal powers. Hence, the existence of non-structural causal powers of quiddities is not compatible with physicalism. In other words, I argue that in contrast to what was suggested above, there is indeed another red line contemporary physicalists are committed to not crossing, even if ideal physics would suggest so. This is the conviction that microphysics can fully describe the fundamental causal structure of the world. Hence, physicalism turns out to be false, if future scientists identify the existence of certain fundamental causal structure which is not directly examinable by ideal physics, and further conclude that the quidditistic nature of elementary particles must be responsible for the phenomena in question. One might wonder whether it is even conceivable that quiddities have nonstructural causal powers. That this is indeed a coherent possibility will only become intelligible in the context of the discussion in Chapter 7. Therein, I shall address subtle details of physicalist versions of categoricalism, arguing that the no-causation-by-quiddities-qua-quiddities constraint plays a crucial role in evaluating the prospects of dualism vs. emergent panpsychism. Note that I do not intend to commit myself in any strong sense to this account of ‘physical’. This extended version of Wilson’s (2006) characterization might ultimately be deficient, even given its intended explanatory goals. I will stay neutral on this question. But, at least, it provides a workable account for my purposes. Moreover, any better alternative will also have to make sure to avoid both the panpsychism and panprotopsychism problems, presumably in a way roughly similar to that suggested here. In the remainder of this work, I shall understand the property of being physical in terms of this characterization.

3

The Case Against Physicalism

In the last chapter, we saw that grounding physicalism is a plausible and elegant theory about the world: all fundamental entities are microphysical beings, and all nonfundamental phenomena are grounded in fundamental reality. Yet there are two potential problems facing this doctrine. First, there might be strongly autonomous causal structure within complex systems: for instance, biological systems such as cells might feature types of behavior which cannot be reductively explained in terms of the combined dispositions of microphysical phenomena. That is, certain macromolecules might exhibit behavioral dispositions which are not explicable in terms of what we know about the dispositions of their microphysical constituents and how they behave in isolation or as parts of simpler systems. If there is, in fact, such behavior, then it is due to non-microphysical, strongly emergent causal powers of the molecules in question, thus violating grounding physicalism. Second, there are strong reasons for thinking that phenomenal consciousness is not microphysically grounded. Before addressing this problem, some terminological clarifications are in order. Note that the term ‘consciousness’ is used in two quite different senses: on the one hand, it is used to describe psychological functions such as voluntary control of behavior, discrimination of perceptual stimuli, or introspection and reportability of information about the contents of one’s mental states; on the other hand, it is used to describe the phenomenal aspects that some of our mental states possess. These states involve subjective experience: there is something it feels like to be in them. Seeing a certain shade of color, having a specific memory, or experiencing dull pain comes with certain qualitative dimensions of subjective experience, the often hard to describe what-it-feels-like-character of those mental events. In order to avoid confusion, I will follow Chalmers (1996) in labeling consciousness in the first sense psychological consciousness, and consciousness in the second sense phenomenal consciousness. Henceforth, I use the term ‘consciousness’ as an abbreviation for ‘phenomenal consciousness’ unless indicated otherwise. The prime reason why one might think that phenomenal consciousness is not microphysically grounded is that in contrast to other mental states, phenomenal properties, also called qualia, appear to resist a priori functional analyses. The discussion in Section 2.1.1 revealed that there is a broad consensus that mental states such as propositional attitudes, or the mechanisms of psychological consciousness described above, allow for such functionalization. From this, and the multiple realizability argument, it can be concluded that they are causal role properties which—at least in humans and other higher animals of the actual world—are realized by microphysical phenomena. By means of contrast, the phenomenal character of qualia appears to be quite different from anything that could be considered structural or functional. Take the subjective experience of being in dull pain: this feeling as such seems to be neither the property of playing a specific causal role—such that it could straightforwardly considered to be a certain function in the brain—, nor a specific spatiotemporal structure. At least, it appears so. This gives us a prima facie reason to be suspicious of its reductive explicability in terms of microphysical

© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2020 F. Klinge, Panpsychism and the Emergence of Consciousness, https://doi.org/10.1007/978-3-662-62258-2_3

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The Case Against Physicalism

properties. Nonetheless, (types of) phenomenal properties correlate at least nomologically with (types of) neural/functional states. For instance, neuroscientists found in the case of humans that a certain type of dull pain correlates with C-fiber stimulation. What Chalmers (1995) coined the hard problem of consciousness is the task of explaining why such psychophysical correlations hold. In particular, are they rooted in grounding relations, or are they due to processes of ontological emergence? If physicalists aspire to show that these correlations hold in virtue of underlying grounding relations, they have to explain how this can be the case although the relata appear to resist the common functionalization strategies of reductive explanation. In this chapter, I focus on the question whether the hard problem allows for a physicalist solution. The other potential problem of physicalism—the existence of strongly emergent causal structure in complex systems—will be addressed in Chapters 4 and 5. 3.1 Special Epistemic Gaps 3.1.1

Three Epistemic Gaps

The hard problem gives rise to a number of more specific epistemic problems for the reductive explicability of phenomenal consciousness in microphysical terms. Let P be the conjunction of all microphysical truths about the actual world, and Q an ordinary phenomenal truth such as that right now I have the subjective experience of seeing green leaves on the tree in front of my window. There appear to be several epistemic gaps between truths such as P and Q. For one thing, Jackson (1982) argues that there is a knowledge gap between physical and phenomenal truths. Consider the case of future neuroscientist Mary who possesses the complete physical information about all neural processes involved in the visual perception of a certain shade of green. That is, Mary has the complete information about the subset of P which encompasses all plausible microphysical candidates for grounding truths like Q. However, Mary lives in a black-and-white room, and has never experienced any sensations of seeing colors. It is a plausible assumption that Mary learns something new when she, after having left her room and entered the outside world, sees green leaves for the first time. What it feels like to see this specific shade of green appears to be new information to her, although she already had all physical information about visual perception. Hence, there is an epistemic gap between her old knowledge of the relevant subset of P and her newly acquired knowledge of what it feels like to see green leaves. Furthermore, there appears to be a conceivability gap in the mind-body domain. It seems conceivable that someone with the same physical/functional make-up as Mary when she sees this particular shade of green might have a different experience, say, seeing a shade of red. Such cases of inverted spectra might not be possible given the actual laws of nature. Yet one can conceive of a possible world with slightly different laws allowing for a physically/functionally identical twin of Mary to experience the perception of the color red in this situation. These epistemic gaps give rise to an explanatory gap (Levine 1983): if knowledge of Q is not derivable from knowledge of P, and it is further conceivable that both truths can come apart, then it is hard to see how Q could be explained in terms of P. Again, the underlying rea-

Special Epistemic Gaps

21

son for the existence of such epistemic gaps is that qualia do not allow for straightforward functional analyses. In contrast to other types of mental states, their nature appears to resist reductive explanation in terms of behavioral dispositions. It seems to follow that if qualia are nonetheless grounded in physical phenomena, our epistemic access to these grounding facts is very different from our access to grounding facts in other domains, involving facts such as ‘water is H2O’. In order to evaluate the prospect of a physicalist explanation of consciousness, it is therefore mandatory to contrast the alleged psycho-physical/functional identities with ordinary macroscopic identities. Following Kripke (1980), it is widely believed that the latter types of identities are a posteriori necessities. The reason is that terms designating natural substances appear to have considerable similarities with proper names such that the reference theory Kripke develops for the latter is also applicable to the former. Kripke (1980) famously argued that proper names are not synonymous with certain definite descriptions, as had previously been the standard view since Frege. Rather, as Kripke points out, names are rigid designators. That is, names denote the same entities in all possible worlds—or they denote their counterparts if there are no transworld identities. Now, Kripke points out that terms designating natural substances (for instance, ‘water’), natural kinds (‘tiger’), or natural phenomena (‘heat’) are rigid designators, too. These terms, therefore, pick out the same kind of entity in all possible worlds. As in the case of proper names, we might use definite descriptions such as ‘the drinkable, transparent fluid in our lakes and oceans’ to fix their reference. Moreover, analogously to the case of proper names, these descriptions must not be understood as providing the meaning of these terms. We pick out these kinds of entities via certain contingent appearance properties figuring in the descriptions we utilize. However, those properties are not essential properties of their referents. Yet there are definite descriptions which do describe their essential properties. An example is the description ‘H2O’, the abbreviation of ‘the substance consisting of molecules that contain one oxygen atom and two hydrogen atoms connected by covalent bonds’. Since ‘water’ is a rigid designator and ‘H2O’ describes the essence of the natural substance ‘water’ denotes—such that ‘H2O’ is rigid, too—, the identity claim ‘water is H 2O’ is a metaphysically necessary truth. It is true in all possible worlds. Nonetheless, it is an empirical finding that water has this particular chemical nature. Water’s essence was, in fact, discovered long after the term ‘water’ was introduced. It is not a priori that water is H2O. Knowing the concept ‘water’ by itself does not put one in the position of being capable to derive the fact that water is H 2O through a priori reasoning. Hence, the identity is an a posteriori necessity. Nonetheless, there are circumstances in which the water-H 2O-identity is a priori knowable. Once I possess the concept ‘water’ and also know about the chemical substance H 2O, I can derive a priori that water is H2O. This seems to be fundamentally different in the case of phenomenal consciousness: assume that pain is identical to a certain functional property which is realized in the human brain by C-fiber stimulation. If so, pain’s phenomenal character—what it feels like to be in pain—seems not to be derivable from any empirical knowledge about neural states and the causal roles they play. In contrast, my combined knowledge of the chemical substance H2O and the concept ‘water’ allows me to derive that H 2O is drinkable. This lack of a priori entailment of the phenomenal character of qualia given possession of the respective phenomenal concepts and empirical knowledge of their neural correlates seems to

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The Case Against Physicalism

constitute a specific explanatory gap which is not present in the case of a posteriori necessities in other domains. Physicalists must explain why the mind-body domain exhibits such special epistemic gaps which do not arise in ordinary cases of grounding, and why, nonetheless, not only the latter, but also the former are genuine cases of grounding. Different versions of physicalism can be distinguished depending on what kind of explanation for the existence of those gaps is provided. Chalmers (2003a) distinguishes the following three broad variants: type-A physicalists outright deny the existence of such epistemic gaps. This view comes in two versions. Analytic functionalism postulates a priori functional analyses of qualia, while eliminativism bluntly denies their existence. Type-B physicalists defend an a posteriori physicalism according to which qualia are explanatorily irreducible but, nonetheless, ontologically derivative. While they admit that because of the epistemic gaps, a reductive explanation of phenomenal consciousness cannot be given, they aspire to give an explanation of the existence of these gaps compatible with physicalism. In contrast to type-B physicalists, type-C physicalists hold that the epistemic gaps cannot just be made intelligible but that they can be closed. However, they claim that bridging these gaps is not (currently) possible for us for one of two reasons: either because it requires a scientific revolution which will eventually materialize and allow us or our descendants to give a physicalist explanation of consciousness, or because our cognitive design renders us in principle incapable of understanding psycho-functional/physical identities. In combination with the systematization discussed in Section 2.1, this gives us two taxonomies of versions of physicalism: the first distinguishes variants according to the account of the nature of nothing-over-and-aboveness they provide, and the second according to their explanation of qualia and our epistemic access to them. All versions of the two taxonomies can be combined, and most combinations have been defended. For instance, there is functionalist type-B physicalism according to which phenomenal states are identical to functional states but this identity is an empirical finding: functional states in human brains are, in turn, grounded in physical states, and here the theorist can choose among different accounts of grounding. Another type-B version, combining functionalism with the psychophysical identity theory, holds that mental states which allow for straightforward functionalizations are causal role properties, while phenomenal states are identical to neural states.17 Type-B seems to be the most attractive approach for providing a physicalist account of consciousness. In contrast to type-A theories, which appear to deny the obvious, type-B views involve full-blown realism about qualia. Furthermore, in contrast to type-C views, they aim to provide an explicit explanation of the epistemic gaps, rather than merely shifting the burden onto a potential future conceptual revolution. Antiphysicalists, in contrast, employ the opposite strategy to type-B physicalists. They argue that the epistemic gaps are not microphysically explicable, since they are rooted in an ontological gap between phenomenal states and their physical correlates. The two most important of these so-called epistemic arguments against physicalism are Jackson’s (1982) knowl17 There are also more complex views such as Shoemaker (1984), who holds that phenomenal states are functional properties but that the specific phenomenal character of a token quale is determined by the nature of its realizer.

Special Epistemic Gaps

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edge, and Chalmers’ (1996, 2003a, 2010) two-dimensional argument. As discussed above, Jackson argues that in cases such as Mary’s, full knowledge of all relevant physical facts does not entail knowledge of all the facts. From this, he concludes that physically irreducible phenomenal facts exist, facts such as Q which are due to the existence of ontologically emergent qualia. Chalmers’ argument is based on considerations about conceivability and metaphysical possibility. It is this argument which is widely considered to be the most severe objection to physicalism. Type A and type C physicalists avoid those objections by questioning the very existence of epistemic gaps in the mind-body domain. Those of type B, by contrast, accept the gaps’ existence; there are two kinds of replies they can give to the epistemic arguments: one strategy is to they argue that the existence of the epistemic gaps in the mind-body domain allow for an explanation compatible with physicalism, the most prominent version of this approach being the so-called phenomenal concept strategy. Alternatively, they demonstrate that the gaps are in no means specific to the mind-body domain, but also arise in cases in which everyone accepts physicalist explanations. Yet if it is accepted that in other domains grounding is compatible with the existence of epistemic gaps, and, furthermore, it can be shown that those domains are sufficiently similar to the mind-body domain in the relevant sense, then there is no reason why this should not also be the case in the mind-body domain. Since Chalmers’ two-dimensional argument is arguably the most important of the epistemic arguments, I concentrate on this objection to physicalism in what follows. The physicalist replies I mainly focus upon are the two versions of the type-B strategy. There is a version of the second reply-strategy which attacks the epistemic arguments at a preliminary state: epistemic gaps arise in all macroscopic domains such that there is no way to exploit a special gap in the mind-body domain in arguing against physicalism because there is none—all ordinary cases of grounding involve analogous gaps. If so, the epistemic arguments cannot get off the ground to begin with. Therefore, it makes sense to begin with this strategy, and to discuss Chalmers’ argument only after I have argued for the failure of this reasoning. In Section 3.1.2, I discuss two versions of it: Block & Stalnaker (1999), the locus classicus for this strategy, and Schaffer (2017) who has recently provided an interesting new version of the reasoning. Section 3.2 is then devoted to Chalmers’ argument, and a number of other objections to it, amongst these a more limited version of the second reply which argues for the existence of epistemic gaps only in a specific case which is taken to be sufficiently similar to the mindbody domain for inferring the harmlessness of the gaps therein. In Section 3.3, I address the first reply route, and discuss various versions of the phenomenal concept strategy. All of them, I argue, fail for reasons discussed in Section 3.4. 3.1.2

Are the Gaps Special?

Block & Stalnaker (1999) argue that ordinary macroscopic truths like ‘Water is H 2O’ cannot be derived from microphysical truths. If this is true, then standard Kripkean a posteriori necessities involve explanatory gaps, too. Yet ordinary macroscopic identities such as the identity between water and H2O are uncontroversial. If so, then physicalists should not be worried by analogous gaps in the mind-body domain.

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The Case Against Physicalism

But why should there be explanatory gaps in ordinary cases of grounding? Is it not obvious that I can a priori derive a satisfying explanation why water is H 2O once I possess the concept ‘water’ and the concept ‘H2O’? Block and Stalnaker do not think so. Their argument is based on the assumption that explanatory gaps arise in every domain in which there is no strict a priori entailment from grounding base to grounded phenomenon: indeed, they argue that such entailment does not hold for grounding relations in ordinary domains. Understanding their subtle reasoning requires a precise definition of a priori entailment. A priori entailment is the holding of a material conditional between two statements S1 and S2—if S1 is true, then S2 is true—which is a priori accessible. That is, if a priori entailment does not hold in a case of grounding, then full knowledge of the grounding base does not put one in a position to a priori deduce the truth of the grounded fact. Moreover, Block and Stalnaker claim that knowledge of P—as before, P stands for the complete microphysical truths about our universe—does not admit one to derive a priori macroscopic truths such as ‘Water is H2O’. The reason, they argue, is that full knowledge of the definition of water is required for an a priori entailment of water-facts from microphysical facts. Yet, as Stalnaker and Block point out, we do not possess explicit conceptual analyses of ordinary concepts such as ‘water’. That is, there is no a priori entailment in the water-case, since we do not dispose of a satisfying definition of ‘water’. Nonetheless, it is uncontroversial that ‘Water is H 2O’ is an example of a successful reductive explanation of a macroscopic phenomenon in terms of chemical properties. Thus, we encounter explanatory gaps in many reductive explanations of macroscopic phenomena for the simple reason that we do not possess full explicit definitions of most of our macroscopic concepts. The mind-body domain is in no way special in this regard, and it is thus premature to postulate any ontological gaps in this domain. In reply to Block and Stalnaker, Chalmers & Jackson (2001) argue that a priori entailment cannot require explicit conceptual analysis because this would have the absurd consequence that the search for conceptual analyses is impossible to begin with. The reason for this is that this search already requires a priori entailment. Consider the example of the epistemological debate on the nature of knowledge: Gettier cases show that the traditional definition of knowledge as justified true belief is wanting (see Gettier 1963). It follows that we do not possess a correct analysis of the concept ‘knowledge’. Yet Gettier’s very argument utilizes a priori entailment from certain cases where someone has justified true beliefs to the conclusion that the person does not possess knowledge in virtue of those beliefs. However, if a priori entailment presupposes possession of true definitions, then we are not capable of telling that Gettier cases do not involve knowledge. This seems absurd. Even without possessing the true definition of knowledge, our concept of knowledge seems to allow us to derive a priori the fact that certain justified true beliefs do not constitute knowledge. It follows that the a priori application of concepts does not require the availability of complete explicit analyses of these concepts. In addition to rejecting Block and Stalnaker’s argument, Chalmers & Jackson (2001) provide a detailed account of how our epistemic situation in the mind-body domain diverges from that in other domains. This is of interest to our discussion, since it provides a deeper understanding of what the explanatory gap really consists. Chalmers and Jackson point out that all macroscopic truths M are a priori derivable from the truth PQTI given that one possesses

Special Epistemic Gaps

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all concepts figuring in M—whereas possession of a concept does only require full competence in applying the concept but not the availability of an explicit analysis of the concept. PQT is the conjunction of all microphysical truths P, all phenomenal truths Q, all truths entailed by P and Q and a that-is-all statement T which asserts that the world only contains P and Q and their implications. I is a position information which tells one at which location and time one is in the universe. I is an important information, since the universe might contain phenomena such as a Twin Earth planet which is an exact duplicate of Earth and is inhabited by qualitatively identical twins of those humans living on our planet. On Twin Earth, everything is qualitatively identical to the situation on Earth, except for the fact that the lakes, rivers, and oceans are not filled with H 2O but with an alternative chemical substance, XYZ, which has identical macroscopic features to H 2O. I then might inform one that one is located on Earth and that one’s concept ‘water’ does thus refer to whatever substance the Earth’s lakes, oceans, and rivers are filled with. This information is thus a crucial precondition for being capable to derive such facts as ‘Water is H2O’ from PQT. Note that if physicalism is true, all macroscopic truths are also derivable from PTI because if so, Q is derivable from P. (In their 2001 article, Chalmers and Jackson stay neutral with regard to the truth of physicalism.) Now, Chalmers and Jackson argue that if one possesses the concept ‘water’ and knows PQTI, then one can a priori entail that water is H 2O. No further empirical information is required, there remains no doubt with regard to this truth. Moreover, it is inconceivable that PQTI holds and water is not H2O. Mere possession of a concept such as ‘water’ and the empirical information provided by PQTI allows a subject to identify a priori the extension of the respective concept. In contrast, physicalism requires that all macroscopic truths are derivable from PTI. But again, the situation with regard to an arbitrary phenomenal fact—such as that I am in pain right now—and its a priori entailment from PTI is considerably different from the water-case. It seems not to be possible to a priori derive the fact that I am in pain now from PTI. It seems conceivable that PTI holds, yet that I do not experience pain but have some other experience —say the perception of a particular shade of blue—or that I even have no experience at all. Possession of the concept ‘pain’ and the information of PTI do not allow me to a priori identify the extension of ‘pain’. Hence, the mind-body domain features a specific explanatory gap which is not present in other domains. Another version of second reply-route has recently been provided by Schaffer (2017). Schaffer argues for an even more radical ubiquity of explanatory gaps. Not only are there explanatory gaps between ordinary macroscopic and physicochemical truths, but such gaps exist between all kinds of higher-level truths and the microtruths they are grounded in. There is not only a gap between water- and H2O-truths but also between H2O-truths and the truths concerning the combination of two hydrogen atoms and one oxygen atom. The same is the case for truths about the respective atoms and their microconstituents. Schaffer argues that these gaps result from the fact that it is neither a priori knowable whether complex phenomena exist at all, nor, insofar as they exist, what kinds of entities they are: It is conceivable, logically possible, and not a priori knowable otherwise that there are no derivative entities (flatworldism), and conceivable, logically possible, and

26

The Case Against Physicalism not a priori knowable otherwise that there are derivative entities but they are all epiphenomenal (ghostworldism). [...] explanatory gaps are everywhere in nature, lurking in every concrete transition from more to less fundamental […]. (Schaffer 2017: 14)

In this paragraph, Schaffer discusses two views as examples for the thesis that we cannot a priori derive any macroscopic truth from the existence of certain microphysical truths. The first is a variant of mereological nihilism. Nihilism is the view that mereological composition never occurs. Flatworldism is the extension of nihilism to all relations of grounding such that only fundamental entities exist but no derivative phenomena whatsoever. Ghostworldism is the view that there exist certain kinds of complex derivative phenomena, but all of them are epiphenomenal. That is, ghost-water is grounded in elementary particles which bear certain microphysical relationships to each other that prompt chemists to classify them as samples of H2O. (Call particles bearing such relations particles being arranged water-wise.) But ghostwater does not inherit any of those particles’ causal powers. While regular water, if existent, has the power to quench my thirst, ghost-water cannot do so. If we live in a ghost-waterworld, then my thirst is quenched by combinations of particles being arranged water-wise, but not by the ghost-water they compose—and also not by water because water does not exist. As we have seen, Jackson and Chalmers think that from the information that there are certain elementary particles adequately related to each other in a certain location we can derive the information that there is water in this location. Schaffer argues that we cannot a priori rule out the truth of such doctrines as flatworldism and ghostworldism. Moreover, since we cannot a priori know that these views are false, it cannot be ruled out that there is either no water at all or only ghost-water in this particular location. Yet if we cannot a priori rule out these possibilities, then we cannot a priori entail the existence of water in the location. Thus, explanatory gaps between micro- and macro-facts not only arise in the mind-body domain, but in all domains. But then, in turn, we cannot derive antiphysicalist arguments from the existence of special epistemic gaps in the mind-body domain. For the gaps in this domain are in no way special. On the basis of this argument for the radical ubiquity of epistemic gaps and the resulting failure of epistemic antiphysicalist arguments, Schaffer provides a positive argument for physicalism. Recall that the gaps Schaffer postulates concern the existence and the nature of derivative entities generated in a potential case of grounding. He argues that since we cannot a priori rule out metaphysical views such as flat- or ghostworldism, we cannot a priori know the grounding principles which govern the generation of derivative entities. Therefore, we cannot rule out that no grounding principles exist at all, or that the grounding principles might have rather strange contents such as involving rules prohibiting the inheritance of causal powers. Yet if so, Schaffer reasons, then there might also be different grounding principles and metaphysical laws at play in different domains—note that he takes grounding principles to be governed by metaphysical laws. In particular, there might be rather complicated grounding principles at play in the case of consciousness. If we have no chance to a priori know which grounding principles in fact hold, then only considerations of parsimony and elegance can guide us in the selection of such principles. But then, the elegance of physicalism provides a

Special Epistemic Gaps

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strong argument for accepting the view that there are idiosyncratic grounding principles at work in the mind-body domain that govern the realization of phenomenal states by physical/ functional states. While grounding principles in other domains might have a purely additive character such that combinations of microentities and the relations they bear to each other straightforwardly result in complex phenomena which have these microentities as parts, there is nothing wrong with assuming that the grounding principles in the mind-body domain are non-additive. They might as well govern the production of something which has a completely different nature than its ground. Yet because of the fact that we have no a priori way to rule out that grounding principles can be non-additive, physicalists are free to hold that the resulting type of ontological dependence still qualifies as a case of nothing-over-and-aboveness. However, I consider the whole reasoning to be based on a misconception. Chalmers’ and Jackson’s epistemic arguments are not based on the assumption that there is a specific lack of a priori entailment of grounding facts in the mind-body domain. Rather, these arguments are based on the assumption that there is a special lack of a priori entailment of concept application; that is, a priori entailments of the form ‘Water is H 2O’ must not be understood as ontological claims as to the existence of the macroscopic substance water (which is then asserted to be identical to H2O). Rather, as I argue in the following, such claims have to be understood as claims about the extension of certain macroscopic concepts or theory-induced modifications thereof. Schaffer is right that if flat- or ghostworldism is true, our concept ‘water’ does not refer to the chemical substance H2O—there is none. Nevertheless, this has no dramatic consequences for concept application. For even in this case, it is beyond question that some kind of physical stuff—such as particles arranged water-wise—falls under the extension of ‘water’ or some theory-induced modification thereof. Assume that flatworldism is true. Now, depending on which metaphysical framework one accepts, either our concept ‘water’ itself refers to particles being arranged water-wise, or our theory leads us to replace ‘water’ by the concept ‘waterwise arranged particles’ (or something similar) which then, of course, refers to such particles. For instance, Sider’s representational version of metaphysical fundamentalism (see Section 2.1.3) assumes that ‘water’ has a metaphysical semantics stated in terms of a fundamental language. If flat- or ghostworldism is true, its metaphysical semantics makes ‘water’ refer to particles arranged water-wise. In contrast, views such as Quine (1948) take ‘water’ to be an empty term if flat- or ghostworldism is true. But such theories instruct us to replace ‘water’ with an alternative concept such as ‘particles arranged water-wise’ playing the same theoretical role as ‘water’ does in Sider’s framework. Hence, in the case of ordinary domains, our concepts allow for replacement with empirically adequate alternatives, should the ontological facts and our metaphysical framework require this. Now, the special explanatory gap in the mind-body domain consists in the fact that in contrast to other macroscopic domains, given full knowledge of PTI, there is no a priori entailment of which physical entities fall under a given phenomenal concept, nor are there any theory-induced modifications of this phenomenal concept for which entailment holds. Again, this has no implications whatsoever for the truth or falsity of general metaphysical doctrines such as flat- or ghostworldism.

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In other words, crucial for the special explanatory gap postulated by Chalmers and Jackson is the fact that it is a priori deducible from PTI that amongst the phenomena falling under concepts outside of the mind-body domain are phenomena which either figure in fundamental physics or are grounded in phenomena figuring in fundamental physics (again, the choice between both options depends on the ontological facts and our metaphysical framework). ‘Water’ (or the concept our metaphysical framework tells us to replace it with) applies either to microphysical stuff being arranged water-wise, or to H 2O (if the chemical substance in fact exists). More generally, PTI a priori implies that ordinary concepts or their theory-induced replacements—at least those which do not involve phenomenal aspects—are applicable to phenomena allowing for microphysical explicability. Ghostworldism might very well be true. If so, all grounded entities are epiphenomenal macroscopic beings. Then, however, our concepts (or their replacements) do not apply to them, but only to their microphysical grounds. Whatever falls under the concept ‘water’ (or its replacement) can quench my thirst, and ghost-water cannot. Hence, regardless which metaphysical doctrine is true, there is a special explanatory gap in the mind-body case which does not arise in other domains. This gap results from the fact that—in contrast to concepts not involving phenomenal aspects—phenomenal concepts are not a priori applicable to microphysical phenomena or microphysically grounded phenomena, even if full knowledge of PTI is given, and there are also no theory-induced replacements for phenomenal concept applicable to microphysical phenomena. To avoid confusion with the gaps Schaffer postulates, henceforth, I call the epistemic gaps of the mind-body domain identified by Chalmers and Jackson special gaps. In conclusion, Schaffer's argument that we have no reason to assume that there are ontological gaps in the mind-body domain since the domain’s epistemic gaps which give rise to antiphysicalist objections are mirrored by analogous gaps in all cases of grounding is not sound: there are no analogous gaps in other domains; the existence and nature gaps Schaffer postulates are different gaps than the ones that figure in antiphysicalist arguments. Of course, Schaffer can still argue that one has to allow for special grounding principles in order to bridge his existence and nature gaps; but then, all plausible candidates for such principles take on some form of purely additive function. Complex entities such as samples of H2O straightforwardly result from the combination of their microconstituents as well as the relations they bear to each other. This is even true if ghostworldism is correct. If so, the function is only partly additive. The metaphysical laws at play in this view involve addition of at least some aspects of the microphysical grounds, while precluding any inheritance of causal powers. But then, it is ad hoc to argue that metaphysical laws can nonetheless take on the form of any other function. For this assumption is only needed to bridge the special epistemic gaps of the mind-body domain. Note that no other version of physicalism makes such ad hoc assumptions; all other versions take constitution to have a merely additive nature in all domains. The fact that it relies on such unintelligible ad hoc assumptions renders Schaffer's grounding physicalism a less than attractive view. Even if we cannot a priori know the content of metaphysical laws, we should not accept an inelegant and ad hoc view according to which all domains adhere to the same grounding principle but only one domain exhibits radically different principles.

Chalmers’ Two-Dimensional Argument

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3.2 Chalmers’ Two-Dimensional Argument In the last section, two prominent arguments for doubting the existence of special epistemic gaps in the mind-body domain were rejected. In this section, I discuss Chalmers’ influential argument to the conclusion that the special gaps are symptoms of an underlying ontological gap. Besides Jackson’s (1982) knowledge argument, Chalmers’ (1996, 2003a, 2010) two-dimensional argument is probably the most widely discussed objection to physicalism. While Jackson’s argument concerns the knowledge gap, the two-dimensional argument concerns the conceivability gap. Recall that this gap involves the conceivability of worlds which feature duplicates physically-functionally identical to us but which lack phenomenal consciousness. This argument aims to show that the conceivability of these so-called ‘philosophical zombies’ entails their metaphysical possibility. Moreover, if zombies are metaphysically possible, then physicalism is false. As Chalmers (2010) explains, the mode of conceivability at work in the argument is idealized negative conceivability: a scenario is negatively idealized conceivable iff a hyper-rational being with unlimited cognitive capacities cannot a priori rule out its coherence. 3.2.1

The Architecture of the Argument

The two-dimensional argument is based on modal rationalism, namely the thesis that there is a legitimate method for deriving metaphysical possibilities from conceivable scenarios. One might presume that modal rationalism is incompatible with Kripkean a posteriori necessities. I can conceive that water is not H2O—recall the Twin Earth scenario—yet this is not a metaphysical possibility. The existence of such obvious breakdowns of our modal intuitions is a considerable challenge for any view which aims to derive metaphysical possibility from conceivability. This notwithstanding, Chalmers defends a version of modal rationalism which he claims to be compatible with Kripke-cases: he derives his modal rationalism from epistemic two-dimensionalism, a semantically conservative extension of the Kripke-model of a posteriori necessities. At the heart of Chalmers’ version of two-dimensionalism is the distinction between two ways of conceiving of possible worlds: conception as counterfactual, and conception as actual. Kripke only discusses the counterfactuality-mode. On this form of conception, the Kripkean water-case works as follows. Given that the drinkable, transparent fluid in the actual world’s lakes and oceans is H2O, there is no world in which water is not H2O but, say, XYZ.18 For if ‘water’ refers to H 2O in the actual world, it designates H 2O in all possible worlds. Moreover, since the finding that water is H 2O is an empirical discovery, water being H 2O is an a posteriori necessity. When one employs conception in the actuality-mode, one conceives of a possible world as actual. That is, one imagines that the actual world turns out to have a different metaphysical set-up as it really has: it could have turned out that in the actual world water is not H2O 18 Recall the Twin Earth thought-experiment, according to which there is a possible world featuring a planet identical in detail to Earth with the exception that the chemical nature of the transparent, drinkable liquid the inhabitants call ‘water’ is not H 2O but XYZ. Is there water on Twin Earth? Since ‘water’ is a rigid designator, and in this respect comparable to names like ‘Plato’ and ‘Alexander’, there are no worlds in which water is not H2O. Accordingly, there is no water on Twin Earth.

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but XYZ. Tomorrow, scientists might discover that they were wrong about the nature of water, and that water is in fact XYZ. This corresponds to a highly unlikely yet real epistemic possibility. In Chalmers’ terminology, there is a possible world which verifies ‘Water is XYZ’—the actual world turning out to be a XYZ-world. Generally speaking, if a sentence S is true in a possible world w considered as actual, w verifies S. In contrast, if S is true in w considered as counterfactual, w satisfies S. Hence, there are worlds which verify ‘Water is XYZ’, but there is no world which satisfies this sentence. In this sense, Chalmers distinguishes two intensions of a sentence S, where intensions are functions from worlds to truths values: the primary intension of S which is a function from verification at w to truth of S at w; and the secondary intension of S which is a function from satisfaction at w to truth of S at w. Hence, ‘Water is XYZ’ is 1-possible. There are possible worlds considered as actual, where the sentence is true given the primary intension of ‘water’. But there is no world in which the sentence is true given the term’s secondary intension. This makes ‘Water is H2O’ an a posteriori necessity; in Chalmers’ terminology: ‘Water is H2O’ is 2-necessary. Primary conceivability—conceivability without the relevant empirical knowledge about the nature of the referent—entails primary possibility. Secondary conceivability— conceivability with the relevant empirical knowledge about the nature of the referent—entails secondary possibility. From this, Chalmers (2010) derives the conceivability-possibility principle CP, a general thesis as to the relationship between conceivability and metaphysical possibility: if S is (negatively idealized) primary conceivable, then S is 1-possible. Hence, the version of modal rationalism based on this two-dimensional framework and CP appears to be tenable in the light of Kripkean cases. Note that Chalmers’ modal rationalism is officially based on epistemic two-dimensionalism which takes primary and secondary intension merely to correspond to the epistemic conditions language user are in when possessing certain concepts. Crucially, this does not involve any claims about the meaning of the linguistic expressions corresponding to those concepts. While there are versions of two-dimensionalism which do take primary and secondary intensions to correspond to dimensions of linguistic meaning, epistemic two-dimensionalism refrains from such a linguistic interpretation. The reason why Chalmers subscribes to an epistemic version of the framework will only be of relevance for evaluating certain objections to the two-dimensional argument, and will therefore be discussed in the next section. Now, on the basis of his version of modal rationalism, Chalmers develops the two-dimensional argument against physicalism. (As above, P stands for the complete microphysical truths about our universe, and Q is some arbitrary phenomenal truth such as that I right now experience a certain shade of green.) (1) P&~Q is conceivable. (2) If P&~Q is conceivable, then P&~Q is 1-possible. (3) If P&~Q is 1-possible, then P&~Q is 2-possible or Russellian monism is true. (4) If P&~Q is 2-possible, materialism is false. ______________ (5) Materialism is false or Russellian monism is true. (Chalmers 2010: 152)

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Premise (1) asserts that zombies are conceivable. (2) states that this entails that they are 1possible. Above, we saw how Chalmers argues for the conceivability of zombies and for the derivability of 1-possibility from conceivability. Premise (3) claims that if they are 1-possible, then they are 2-possible or Russellian monism is true. (This premise is in need of explanation. I will thoroughly discuss it below, but for the moment accept it in order to see how the argument works.) Now, if we can infer from the conceivability of zombies that they are 1-possible, and from the 1-possibility of zombies that they are 2-possible (unless Russellian monism is true), then we can infer from the conceivability of zombies that physicalism is false (or Rus sellian monism is true). For, as (4) states, if zombies are 2-possible, then physicalism is false. Premises (1) to (3) are the core premises of the argument. I will thoroughly analyze them in the course of discussing some of the replies physicalists have provided to the argument. While physicalists can (and indeed have) attacked all of those premises, they cannot attack premise (4), claiming that the metaphysical possibility of zombies is incompatible with physicalism. As discussed in Section 2.1, it is uncontroversial that physicalism—while probably not being characterizable in purely modal notions—has modal implications. Hence, there is no way for physicalists to deny (4). The upshot is that the conceivability of zombies entails either physicalism being false or Russellian monism being true.19 In the following, I will briefly discuss some of the most prominent strategies open to the physicalist for rejecting the two-dimensional argument. This is just an outline of what I consider to be the most serious objections; Chalmers (2010) provides a very detailed discussion of various other physicalist replies. 3.2.2

Various Objections

As we have seen, type-A and type-C physicalists reject premise (1). Type-B theorists, by acknowledging the epistemic gaps of the mind-body domain, are committed to this premise. Note that (1) does not necessarily require the conceivability of full-blown zombies or even full-blown inverts. It suffices for the premise to go through that Q is something as unspectacular as my seeing a green cup in front of me right now, and that my twin in the P&~Q-world sees a slightly lighter green surface than I do. Thus, even if one holds that zombies are not ideally conceivable, such small phenomenal divergence from the actual world in the presence of full physical duplication seems obviously conceivable—of course, unless one has strong type-A inclinations. (2) is the premise which has been the subject of the majority of the objections to Chalmers’ argument. Before discussing those objections, let me explain why according to premise (3), there is an entailment of 2-possibility from 1-possibility in the case of P&~Q, unless Russellian monism is true. First, consider P. The identification of primary and secondary intension in the case of P follows naturally from the characterization of ‘physical’ discussed in Section 2.2. As therein discussed, the truth of physicalism requires that every macrophenomenon is grounded in narrowly microphysical properties. If, in contrast, it is the case that a certain macrophenomenon is grounded in broadly microphysical properties, then this is compatible with the possibility that categorical properties which realize microphysical properties 19 Recall from Section 2.2 that Russellian monism cannot be considered a version of physicalism. The truth of Russellian monism would thus imply that physicalism is false.

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are grounds for consciousness merely qua being quiddities but not qua playing such and such causal roles. However, this is compatible with Russellian monism such that physicalism is false. In other words, if the broadly microphysical is invoked, P does not necessarily have coinciding primary and secondary intensions. In particular, primary and secondary intension of P diverge if microquiddities as such, by being proto- or microphenomenal, are instrumental in grounding consciousness. If so, in conceiving of zombie-cases, we would only conceive P’s primary intension, the structural properties of microphysics, but not their quidditistic nature. For the latter determines the instantiation of consciousness and it would thus be inconceivable that a world features P according to its secondary intension without featuring consciousness. Yet if the quiddities of microphysical dispositions ground consciousness, Russellian monism is true and physicalism is false. This is reflected in (3) by the addition of the qualification that in the mind-body domain, 1-possibility of P entails 2-possibility, unless Russellian monism is true. The relevant dimension of ‘physical’ at play in physicalism is the narrowly microphysical. Moreover, the narrowly microphysical is what fundamental physics reveals us about it (i.e. charge, mass, spin etc.), while ‘fundamental physics’ here includes the idealized in the limit of inquiry science as discussed in Section 2.2. Hence, in the case of the narrowly microphysical, the primary intension which corresponds to the information provided by fundamental physics coincides with the secondary intension. In contrast, Chalmers’ argument for the thesis that primary and secondary intensions of phenomenal terms coincide might seem as if it comes down to a somewhat brute stipulation. This is essentially an argument already made by Kripke (1980). Kripke notes that we do not seem to pick out qualia via a contingent mode of presentation, as we do in cases such as heat and water; we seem to have direct access to the essence of phenomenal states. In contrast to water, where the natural substance is not necessarily the thing which plays the water-role, it seems intuitive that pain is essentially what-it-feels-like to be in pain. This phenomenal character of pain—call it the ‘pain-role’—seems not to be something which in other worlds could be played by some arbitrary natural phenomenon which is not pain. Yet while this line of reasoning might provide some prima facie plausibility, I do not think that it suffices in this form to justify the identification of primary and secondary intensions of qualia. Indeed, Chalmers (2010) does not provide any more substantial justification than Kripke. Denying that they coincide might thus seem to constitute a promising option for the physicalist.20 21 However, I think the Kripke-Chalmers reasoning can be backed up by the following illustration: by way of considering a Kripke-case which is exactly analogous to the P&~Q-world, it becomes obvious how extremely counterintuitive the rejection of the identification of pri20 In fact, Carruthers & Veillet (2007) defend something close to this strategy. 21 Chalmers (2010) argues that the two-dimensional argument also works if Q does not have the same primary and secondary intension. In this case, physicalism could explain phenomenal properties as such. Yet qualia would have physically inexplicable appearance properties resulting from the primary intension of Q, such that physicalism turns out false because of the existence of these latter properties. However, Chalmers (2014)—for subtle reasons concerning the rigidity of primary intensions I cannot enter into here—withdraws this assessment and acknowledges that the two-dimensional argument can only go through if Q’s primary and secondary intension coincide. A compelling argument for their identification is therefore indispensable.

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mary and secondary intensions of qualia really is. Recall that in Kripkean a posteriori necessities, one conceives of a world as actual in which the primary intension is present, but the secondary intension is missing. On Twin Earth, the natural substance in the lakes and seas is XYZ, yet this alien chemical substance plays the water-role. However, in the P&~Q-case— given that physicalism is true—the secondary intension of consciousness is present, but the primary intension is not instantiated. Thus, an analogous case outside the mind-body domain has to feature secondary without primary intension. Such a scenario can easily be constructed in the case of heat: assume that heat’s secondary intension is molecular motion, while its primary intension is heat sensation; now, consider a world exactly similar to ours, except for the fact that molecular motion does not give rise to heat sensations. When we conceive of this world as actual, we can say that in this world, there is heat but heat does not play the heat-role, namely generating heat sensation in higher animals. When we conceive of this world as actual, it verifies ‘heat is not molecular motion’, but it does not satisfy this sentence. On the assumption that physicalism is true, when we conceive of the P&~Q-world as actual, then the P&~Q-world verifies ‘consciousness is not physical/functional’. After all, all physical and functional properties of the actual world are instantiated in this world, but nothing plays the role of consciousness. Yet now it becomes obvious why the heat-case and the qualia-case appear to be so different. It is by no means strange to assume that there can be heat in a world without heat sensation. Nothing appears unreasonable in considering a scenario involving heat that does not give rise to heat sensations, so this seems to be indeed 1-possible. However, it is highly counterintuitive to say that there is consciousness in the P&~Q-world yet no one in this world has any subjective experiences whatsoever—my zombie-twin is in pain qua possessing a certain neural pattern, yet he does not feel anything. It appears hardly deniable that if nothing plays the role of consciousness, then there is no consciousness. In contrast, it seems perfectly fine to allow for the conceivability of heat which does not play the heat-role. I take it therefore that we should accept that a world which verifies ~Q also satisfies it. It follows then that if we can conceive of zombies and this conceivability entails their being 1-possible, then zombies are 2-possible. Premise (2) is based on CP, which directly follows from Chalmers’ two-dimensionalism. Hence, once it is acknowledged that two-dimensionalism is a conservative elaboration of the Kripke-model of the relationship between conceivability and possibility, (2) should be uncontroversial, unless one is willing to reject the Kripke-model. Recall that one physicalist strategy is to demonstrate that CP breaks down in cases outside the mind-body domain, and to argue that those cases are sufficiently similar to the phenomenal case such we do not have reasons for assuming that CP holds in mind-body domain. Those cases outside the mind-body domain would then be cases of what Chalmers calls strong necessities: psycho-functional/physical identities are not 1-possible and 2-necessary, as ordinary a posteriori necessities are, but both 1- and 2-necessary.22 Another important sort of argument against (2) acknowledges Chalmers’ modal rationalism in ordinary cases but claims that it breaks down in the case of consciousness because of 22 In the last section, we already encountered extreme versions of this reasoning which claimed that all ordinary macroscopic facts (Block & Stalnaker 1999), or even all grounded facts whatsoever (Schaffer 2017) involve strong necessities.

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the special nature of our phenomenal concepts which are cognitively isolated from all other kinds of concepts we endorse. This approach claims that the mind-body case is exceptional in involving strong necessities. Hence, with regard to premise (2), the type-B physicalist can take two routes of argumentation. First, they can provide reasons for the modal exceptionality of the mind-body domain according to which we encounter strong necessities only here. Second, they can argue that the general CP thesis is (at least partly) wrong by providing clear examples of strong necessities from outside the mind-body domain. The first route is taken by proponents of the phenomenal concept strategy which I discuss in the next section. In the remainder of this section, I address a few examples of the second route. Goff (2017: chapter 4, see also Goff & Papineau 2014: section 2) takes a version of the second route by questioning the very concept of primary intensions Chalmers endorses. He argues that Chalmers’ two-dimensionalism is a highly controversial global semantic theory which assumes without justification that every term has a primary intension as part of its linguistic meaning. If so, the physicalist might just deny two-dimensionalism and adopt an alternative semantic theory, thereby getting rid of primary intensions. After all, while it is widely agreed upon that some linguistic expressions such as indexicals have two sorts of meaning, it is by no means universally accepted that this is the case for all terms. In particular, if phenomenal concepts do not have primary intensions, then Chalmers’ two-dimensional argument cannot get off the ground. It is easy to see that Goff’s critique is based on a misconception of Chalmers’ version of two-dimensionalism. For Chalmers is merely committed to epistemic two-dimensionalism, which does not make any contentious claims about the meaning of linguistic expressions whatsoever. It is solely a theory about the epistemic conditions language users are in when possessing certain concepts. It is natural to associate these epistemic conditions with certain semantic dimensions of their vocabulary, but this does not entail controversial theses about the meaning of those expressions as such. In particular, the semantic dimensions two-dimensionalism postulates are not directly linked to the actual reference of the expressions. Chalmers (2006b) points out that primary intensions might be taken to explain Fregean sense. Yet this is just one possible application of the two-dimensional framework for a global semantic theory. The crucial point is that while such a project might be successful, epistemic two-dimensionalism does not stand or fall based on its tenability.23 What about the prospect of finding cases of strong necessities outside the mind-body domain? It has been argued that there is an obvious example of a strong necessity in Kripke’s 23 While epistemic two-dimensionalism is an independent theory about the epistemic conditions of language users, and has no further implications with respect to the linguistic meaning of expressions and utterances, nonetheless, as Chalmers (2006b) explains, the framework most naturally combines with semantic pluralism. According to semantic pluralism, linguistic expressions can have an unrestricted number of semantic values which are associated with different potential applications. On this view, there is no such thing as the content of an expression. However, according to rival theories which restrict the semantic value of an ex pression to such and such content, the primary intension of the expression just turns out to be ‘quasi-seman tic content’ which informs us about epistemic conditions of speakers, but is not part of the official meaning of the expression. Nothing depends on this when it comes to the role of primary intensions, especially in the two-dimensional argument: this argument merely relies on implications with regard to the epistemic conditions we must be in according to physicalism when possessing phenomenal concepts.

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work, namely proper names. Recall that according to Kripke (1980), names are not synonymous with definite descriptions, but rather are rigid designators. Also, in contrast to terms such as ‘water’, the definite descriptions which might have been used to fix their reference do not apply to their bearers anymore. After all, grown-up Alice is not ‘the baby in the baptismal font’ anymore. Many theorists therefore believe that given Kripke’s reference theory, names do not have an a priori accessible primary intension. Once their reference is fixed, names directly denote their bearers. They do not have any cognitive significance which can be identified with a dimension of meaning that, in turn, could serve as their primary intension. Insofar as we want to ascribe a primary intension to names, this primary intension therefore seems to be identical to the secondary intension, namely the referent. If so, names provide a case of strong necessities. For the purpose of illustration, consider the case of a posteriori necessities involving coextensive names such as ‘Augustus is Octavian’. Prima facie, this appears to be a strong necessity, at least if the direct reference account of names is true. Since names are rigid designators, there is no possible world in which Augustus is not Octavian. Therefore, the identity statement is 2-necessary. Furthermore, since names have no additional semantic content, their primary intension—given that they have one—coincides with their secondary intension. It follows that the statement is also 1-necessary. Thus, when it comes to proper names, the two-dimensionalist appears to have the choice between accepting that there are terms which do not have a primary intension at all, or that there are terms which involve strong necessities. Either way, the type-B physicalist is free to claim that phenomenal concepts are in this respect similar to expressions such as names and that the CP principle is wrong for a number of expressions including phenomenal concepts. Once again, however, epistemic two-dimensionalism provides an escape route. Chalmers is not committed to the thesis that every linguistic expression has a special dimension of meaning to which we have a priori access. Rather, he holds that for every expression, there is a special epistemic condition language users are in if possessing the respective concepts. Indeed, as Chalmers points out, this appears also to be the case when it comes to names; in contrast to what was claimed above, there is an epistemic scenario which corresponds to the possibility that Augustus is not Octavian. Augustus’ birth name is Octavian. Octavian was honored by the Roman Senate with the name ‘Augustus’ after achieving a number of political successes, of which the most important was his victory at the Battle of Actium. There is a possible world in which it was not Octavian who won this battle, but rather his rival Mark Antony such that he and not Octavian received the honorific title ‘Augustus’. Now, as Kripke (1980) points out, the reference of names is transmitted through a causal-historical chain of communication. I can conceive of a possible world, similar to the one describe above, in which the chains of the respective names pick out different individuals. Consider that I have a functionally/physically identical twin in this world. Yet, unbeknown to the twin, the twin’s concepts of the names ‘Octavian’ and ‘Augustus’ diverges from mine because the chains of the respective names do not establish reference to same individual. If I consider this world as actual—now I am in an identical epistemic situation to my twin—, then I can imagine that one day historians discover that due to some unreliable sources our historical account of the first century BC is seriously flawed. Not Octavian

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but Mark Antony was the first emperor of the Roman Empire. If so, I would reject the claim that Octavian is Augustus. Hence, even on the direct reference view, names appear to have primary intensions. The primary intensions of names correspond to the pathways of their associated causal-historical chains. There are possible worlds in which the primary and secondary intensions of a given name might come apart. Hence, names do not give rise to strong necessities. Thus, the physicalist cannot utilize the case of names in order to reject CP and premise (2). Finally, let me comment on an alternative antiphysicalist conceivability argument delivered by Goff (2017: chapter 5). Goff claims that his argument is preferable to the two-dimensional argument because it involves less contentious commitments. Yet I shall argue that the opposite is the case: the premises of Goff’s argument are based on much more controversial assumptions than those of the two-dimensional argument. 3.2.3

Goff’s Transparency Conceivability Argument

Above, we saw that Goff rejects the two-dimensional framework. In his alternative conceivability argument, Goff (2017: section 4.3.3) aims at replacing Chalmers’ CP-principle with another conceivability-possibility principle that does not rely on the distinction between primary and secondary intensions. This is a narrower principle which is only applicable to what Goff calls transparent concepts. While opaque concepts are terms which do not reveal anything about the nature of their referents, possessing a transparent concept provides one with full knowledge of the essential properties of its referents. Paradigmatic examples of opaque terms are proper names: ‘Aristotle’ by itself does not provide me with any substantial information about its referent whatsoever. By contrast, for example, mathematical concepts are transparent. Possession of ‘circle’ allows one to derive a priori that a circle consists of points equidistant from a given center. Transparency plays an analogous role in Goff’s framework as coincidence of primary and secondary intension in Chalmers’. Both criteria are only fulfilled by concepts which reveal the full nature of their referents. Now, Goff (2017: chapter 5) argues that only transparent concepts allow for a priori entailment of metaphysical possibilities from conceivable scenarios. The idea is that iff the nature of a concept’s referents is revealed to me, then I can a priori entail that conceivable scenarios concerning the referent are indeed metaphysical possibilities. A transparent sentence is a sentence which only involves transparent concepts. Goff thus postulates the following Transparency Conceivability Principle (TCP): If a transparent sentence is conceivably true, then it’s possibly true. (Goff 2017: 100) From TCP in combination with Direct Phenomenal Transparency, the thesis that phenomenal concepts are transparent, Goff can derive what he calls the transparency conceivability argument against physicalism: Premise 1 – “P and nothing has Q” is conceivably true. Premise 2 – (TCP) If a transparent sentence is conceivably true, then it’s possibly true.

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Premise 3 – “P and nothing has Q” is transparent. Conclusion – “P and nothing has Q” is possibly true, and so pure physicalism is false. (Goff 2017: 123) The crucial premise is (3). It asserts that P&~Q is a transparent sentence. Recall from the discussion of Chalmers’ argument that it is plausible that P is transparent. Yet why should the physicalist accept Direct Phenomenal Transparency and believe that Q is transparent? Above, I argued that considerations about the metaphysical possibility of the separation of primary and secondary intensions of qualia give us compelling reasons for accepting the thesis that they coincide. Yet since Goff rejects the two-dimensionalist framework on which these considerations are based, he cannot utilize this reasoning. However, Goff provides an alternative argument for the transparency of phenomenal concepts; this argument is based on Super-Justification, the thesis that judgments about the contents of our subjective experiences we make by way of introspection allow for the same high degree of confidence as mathematical judgments permit. That is, I am entitled to place as much confidence in my introspective judgment that I am in pain right now as in the belief that all points of a circle are equidistant from its center. Goff does not claim that we can be absolutely certain about our phenomenal beliefs; but, neither can we be about mathematical beliefs. Yet what distinguishes both from empirical beliefs is that well-known skeptical doubts— such as the possibility of hallucination or the non-existence of the external world—do not apply to them. Goff provides a detailed analysis of a variety of potential physicalist accounts of SuperJustification, and argues that there is no physicalist approach able to explain the thesis. In contrast, Super-Justification can be easily explained by means of Direct Phenomenal Transparency. If introspection provides us with direct access to the nature of our phenomenal states, then we are entitled to place an extraordinary high degree of confidence in the content of our phenomenal beliefs. Goff thus defends Direct Phenomenal Transparency with an inference to the best explanation: we should accept Direct Phenomenal Transparency because it is the only plausible explanation of Super-Justification. The truth of Direct Phenomenal Transparency, in turn, secures the truth of premise (3). There is a problem this reasoning encounters: even if Goff is correct that there is no alternative physicalist explanation for Super-Justification, why should physicalists accept the thesis in the first place? Denying it seems a rather easy means of avoiding Goff’s argument. Surprisingly, Goff does not offer an argument for the thesis but takes it to be a primitive truth devoid of any further explanation: There will of course be philosophers who will deny Super-Justification, insisting that what I have described are merely psychological facts about human beings, or perhaps human beings infected by a Cartesian philosophical heritage. It could be claimed that, although mathematical truths are known with much greater certainty than empirical truths, empirical and introspective truths are in the same epistemic boat. Or it could even be denied that mathematical truths are known with greater certainty than empirical beliefs. […] At this point we have reached bedrock. The thesis that introspective truths are super-justified [...] seems to me as evident as any

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The Case Against Physicalism philosophical starting point. Super-Justification is the rock upon which I shall build my argument. (Goff 2017: 112)

I see no reason why the physicalist should feel compelled to accept Goff’s ‘bedrock commitment’ to Super-Justification.24 She might rightfully consider sacrificing this Cartesian intuition a price worth paying for avoiding antiphysicalism. In contrast, the modal considerations implicit in Chalmers’ two-dimensional argument provide compelling reasons for the thesis that primary and secondary intentions of qualia coincide. As we have seen, comparing zombie-cases with analogous modal settings involving ordinary a posteriori necessities reveals how and why the mind-body case is radically different. Moreover, since general objections to two-dimensionalism are based on false assumptions about Chalmers’ semantic commitments, the underlying framework of the two dimensional argument seems tenable. Chalmers’ antiphysicalist argument is clearly preferable to Goff’s. 3.3 The Phenomenal Concept Strategy Many consider the so-called phenomenal concept strategy to be the most promising route for rejecting CP and, in extension, premise (2) of Chalmers’ two-dimensional argument. The strategy can be understood as making as many concessions to antiphysicalist intuitions as possible, without endangering the resulting approach’s compatibility with physicalism. In contrast to other versions of type-B physicalism, the phenomenal concept strategy does not only concede that there are unbridgeable epistemic gaps in the mind-body domain but also that these gaps are unique to this domain. Yet those special gaps are not due to the fact that phenomenal states have a special nature which renders them reductively inexplicable in microphysical terms as antiphysicalists would have it. Rather, the special gaps are rooted in the fact that phenomenal concepts have a special nature, distinguishing them from other concepts. Phenomenal concepts are the concepts we employ in thinking introspectively about our own subjective experiences. For instance, when I think about the way a current instance of headache feels, I employ a phenomenal concept of this very experience. One can also think about phenomenal states in a non-introspective way. I might have a heated argument with someone and wonder what feelings my words must have caused in her, making her act that angrily. In this case, I am thinking about a phenomenal state (of my interlocutor) in a non-introspective way not involving any phenomenal concepts. Now, phenomenal concept strategists claim that phenomenal states as such are identical to functional/physical properties. Yet the way they are picked out by the concepts with which we refer to them introspectively is such that we are not capable to infer a priori this identity, even when provided with full knowledge of the relevant physical information. This allows proponents to concede that in ordinary cases, the existence of the types of gaps we encounter in the mind-body domain would indeed entail a breakdown of reductive explicability. However, because of the uniqueness of the concepts we employ in the mind-body domain, this is no ordi24 As we will see in the next section, there is in fact a version of type-B physicalism, namely the constitutional version of the phenomenal concept strategy, which can allow for the infallibility of phenomenal judgments. However, Goff (2017: section 5.3) complains that the version of infallibility at play in this view does not amount to Super-Justification because it lacks a normative dimension. Yet, once more, physicalists might just abandon Super-Justification and go with infallibility.

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nary domain. In this and only this domain, explanatory gaps are not necessarily due to ontological gaps, conceivability is not a reliable guide to metaphysical possibility, and a posteriori truths are not only 2- but also 1-necessary.25 But what is it that makes phenomenal concepts special? Proponents claim that the reference of phenomenal concepts is mediated by specific psychological mechanisms, by way of which we pick out phenomenal states. Due to these unique mechanisms, the specific mode of presentation of phenomenal states provided by phenomenal concepts is completely different from the mode of presentation of ordinary concepts. The former is so unique that it cognitively isolates phenomenal concepts from scientific concepts. The information provided by phenomenal concepts is thus not commensurable with the information provided by scientific concepts: even if physicalism is true, the combined possession of a phenomenal concept and the relevant physical information does not put one in a position to infer a priori that the state picked out by the phenomenal concept is identical to a state picked out by scientific concepts. It is, therefore, to be excepted that epistemic gaps arise in the mind-body domain. Again, there is no a priori entailment between the physical description of neural/functional states and our knowledge of phenomenal states acquired via phenomenal concepts even if both states are identical. While this lack of a priori entailment does appear to be due to a dualism of properties, it is, in fact, due to a dualism of concepts. Note that the phenomenal concept strategy does not attempt to provide a reductive explanation of consciousness in microphysical terms. Rather, it attempts to provide an explanation of the existence of special epistemic gaps. The findings of the phenomenal concept strategy do not provide by themselves an argument for physicalism. The tactic is to argue that the existence of the special gaps can be explained by the existence of a special psychological mechanism. Moreover, proponents usually assume that the mechanism itself can be given both a physicalist and an antiphysicalist explanation. The mechanism’s compatibility with physicalism, in turn, provides the basis for an inference to the best explanation: since physicalism, all things being equal, clearly has more theoretical virtues than antiphysicalist views, a physicalist explanation is preferable. Numerous variants of cashing out this main idea have been put forwards. It originates from Loar (1997). Loar argues that phenomenal concepts are a specific type of recognitional concepts; on his view, recognitional concepts are type demonstratives which pick out their referents under the description of ‘one of those’. Employing such concepts, we recognize a referent as belonging to a certain kind. For example, we might recognize a plant in the desert as being a cactus. Typically, recognitional concepts pick out their referents under contingent modes of presentation: a cactus might be recognized by its property of causing such and such visual experience, a metaphysically contingent property of the referent. In contrast to regular cases, phenomenal concepts pick out their referents under non-contingent modes of presentation. That is, the very same entity that is the referent also serves as the reference-fixer. While a 25 Not all proponents of the phenomenal concept strategy do, in fact, maintain that conceivability is a reliable guide to metaphysical possibility outside the mind-body domain. For instance, Papineau denies the existence of any systematic relationship between conceivability and modality (see e.g. Goff & Papineau 2014: section 3). However, while he has independent reasons for questioning such a relationship, his version of the phe nomenal concept strategy would allow him to accept modal rationalism for ordinary domains, while still rejecting Chalmers’ antiphysicalist conclusions.

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cactus is recognized via its metaphysically contingent property of causing such and such experience, a phenomenal state is picked out as the property of being such and such experience, an essential property of that state. Since phenomenal concepts employ the reference-mechanism of type demonstratives, their primary and secondary intension coincide, but in such a way that an explanatory gap remains. For, while our phenomenal concepts directly denote the essential properties of phenomenal states, they only provide us with very meager information as to the nature of these states. This information merely allows us to recognize various token states we experience as belonging to this rather than that type of phenomenal state. For instance, information provided by a phenomenal concept might allow me to identify its referent as being an instance of headache rather than, say, the visual experience of light green. Yet the concept does not provide me with such substantive information about its referent that—given the relevant physical information about the brain—I can a priori infer its identity with a particular type of functional/physical state. Accordingly, Loar distinguishes two different ways of how a concept can directly denote the essence of its referent: [A] phenomenal concept rigidly designates the property it picks out. But then it rigidly designates the same property that some theoretical physical concept rigidly designates. This could seem problematic, for if a concept rigidly designates a property not via a contingent mode of presentation must that concept not capture the essence of the designated property? And if two concepts capture the essence of the same property, must we not be able to know this a priori? These are equivocating uses of 'capture the essence of'. On one use, it expresses a referential notion that comes to no more than 'directly rigidly designate.' On the other, it means something like 'be conceptually interderivable with some theoretical predicate that reveals the internal structure of' the designated property. But the first does not imply the second. What is correct in the observation about rigid designation has no tendency to imply that the two concepts must be a priori interderivable. (Loar 1997: 603) While our physical/neuroscientific concepts provide us with descriptions of phenomenal states which reveal their physical/functional nature, our phenomenal concepts do not reveal this nature. The latter capture this physical/functional essence merely demonstratively. Hence, Loar’s account can reject CP and premise (2) of Chalmers’ two-dimensional argument: zombies are ideally conceivable, but their conceivability does not entail the metaphysical possibility of zombies. The reason is that phenomenal concepts and certain physical/functional concepts rigidly designate the same states. When we conceive of a P&~Q-world as actual, they pick out the same states in this world. Hence, there is no world which verifies P&~Q. It follows that phenomenal-functional/physical identities are strong necessities. However, Balog (2009) has compellingly argued that there is a tension in Loar’s account between two core ideas: the idea that phenomenal concepts are directly referring type demonstratives, and the idea that they involve a non-contingent mode of presentation of their referents which, in a certain way, captures their essence. Yet if a phenomenal concept merely provides one with a description of its referent as ‘one of those experiences’—how does this mode

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of presentation involve the phenomenal state as such? It seems that the mode of presentation of type demonstratives involves a certain distance between concept and referent which is not compatible with the idea of coincidence of primary and secondary intensions. As Balog explains, subsequent versions of the phenomenal concept strategy can be understood as elaborating upon either the one idea or the other. Accounts employing the direct-reference idea are, amongst others, Perry (2001), Tye (2003), and Levin (2007). They usually take phenomenal concepts to stand in a causal relation to their referents, either providing only a demonstrative presentation of their referents, or not involving any mode of presentation at all. One problem for these accounts is that because phenomenal concepts and phenomenal states are taken to be distinct entities only related by causation, a phenomenal concept can, in principle, occur without an instantiation of the phenomenal states it is usually associated with. Due to an irregular breakdown of the causal link, a token of the phenomenal concept ‘pain’ could be instantiated without the simultaneous occurrence of pain. Yet this seems wrong: when someone thinks she experiences pain because of introspective evidence, it appears that she really has to be in pain. Direct-reference accounts seem unable to preserve the intuitive idea of the infallibility of our phenomenal concepts. In contrast, accounts which develop the idea that the mode of presentation of phenomenal concepts involve their referents can arguably preserve our infallibility intuition. On the dominant version of this view as developed by Papineau (2002) and Balog (2012a), phenomenal concepts are partially constituted by phenomenal states. This is taken to work roughly analogous to quotation, where a word is referred to by embedding it between quotation marks. A quotational concept refers to a word by having this very word built into the concept. Now, Balog and Papineau take it that similar to quotational concepts, phenomenal concepts are compound terms. They are composed of an experience operator ‘the experience:_’ and the referent this operator encompasses. They refer by featuring in the operator the phenomenal state they denote. Moreover, because a token phenomenal concept is partly constituted by its referent, the former cannot occur without the latter. Hence, the constitutional account can allow for the infallibility of our phenomenal concepts. Balog (2012a) emphasizes that the existence of a constitution relationship between phenomenal concepts and phenomenal states does not require that phenomenal concepts reveal the nature of their referents. The non-contingent mode of presentation at work in the constitutional account merely involves the presence of the referent itself in the concept. This contrasts with the mode of presentation of scientific concepts which provides an analysis of the nature of the referent. Thus, the constitutional account’s crucial idea of how to square non-contingency of mode of presentation with non-revelation of the referent’s nature appears to be the following. I cannot successfully employ a linguistic expression if I do not know its meaning. In contrast, the linguistic operation of quotation does not require knowledge of the meaning of the quoted expressions. One might successfully use the assertion ‘I do not understand what Chalmers means by “phenomenal concepts and phenomenal beliefs do not supervene conceptually on physical properties”.’ without knowing what ‘supervene’ means. Nonetheless, the word ‘supervene’ is fully present in the utterances. If phenomenal concepts refer via a quotational mechanism, then, analogously to the linguistic case, quotation can take place without full knowledge of the quoted entities. Yet the difference between the linguistic and the con-

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The Case Against Physicalism

ceptual operation is that in the conceptual case, lack of knowledge does not concern the meaning of the quoted entity—it is not a linguistic expression—but the entity’s metaphysical nature. And, the difference in mode of presentation between phenomenal and scientific concepts is taken to explain why we encounter special gaps in the mind-body domain, although the mode of presentation of phenomenal concepts features phenomenal states as such. Hill (1997) and Hill & McLaughlin (1999) provide yet another version of the phenomenal concept strategy; they assume that phenomenal and neural concepts involve distinct mental faculties. This has the consequence that the two kinds of concepts are governed by differing cognitive processes. The involvement of distinct cognitive processes, in turn, renders them conceptually isolated such that we are incapable to know that they refer to the same properties. Building on an idea of Nagel (1974), Hill and McLaughlin argue that when we conceive of zombie-worlds, we simultaneously employ two distinct types of imagination: we perceptually conceive of the existence of certain neural patterns in beings functionally/physically identical to us, while sympathetically conceiving that those beings do not possess any associated experiences. Perceptive imagination works by putting oneself into a mental state resembling the state one is in when perceiving a certain phenomenon. Sympathetic, introspective imagination works by putting oneself into a mental state resembling the imagined phenomenon itself: in sympathetic imagination, one imagines phenomenal states such as pain by imagining being in this very state. Hill and McLaughlin argue that because there are such distinct cognitive processes at work in the conception of zombie-cases, zombie-cases are not a reliable guide to modal truths. However, Chalmers (1999) points out that the involvement of distinct mental faculties and cognitive processes as such can hardly provide an insightful explanation for the unreliability of a modal intuition: distinct cognitive processes are at work in all kinds of conceptions outside the mind-body domain, without modal illusions arising thereby. For instance, the conception of red squares involves distinct mental faculties and associated cognitive processes, namely color and space conception. The same is the case in conceptions of five-horned animals which feature mathematical and perceptive imagination. Yet it would be absurd to infer from this that red squares and five-horned animals are metaphysically impossible. That is, we can conceive of red squares, and this conception involves distinct cognitive processes—color and space conception—yet the conceivability of red squares seems a perfectly fine guide to the metaphysical possibility of such entities. Hence, the involvement of distinct cognitive processes as such cannot be the reason why the conceivability of zombie-cases is unreliable. Yet it appears to me that a close reading of Hill & McLaughlin (1999) reveals that what (implicitly) drives their argument is not the involvement of distinct cognitive processes per se, but rather the fact that in sympathetic imagination, the mode of presentation of phenomenal concepts involves their referents: Hill and McLaughlin explicitly subscribe to the thesis that phenomenal concepts have coinciding primary and secondary intensions (see Hill & McLaughlin 1999: 452). Therefore, Balog (2009) is right in classifying Hill and McLaughlin’s approach as a version of the constitutional account of the phenomenal concept strategy. But, in contrast to Papineau and Balog, Hill and McLaughlin fail to provide a detailed account of how the referring mechanism of direct phenomenal concepts works. I assume therefore that the quotational view is preferable to Hill and McLaughlin’s approach.

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Now, is the phenomenal concept strategy’s explanation of the special gaps and the existence of strong necessities in the mind-body domain successful? I do not think so. Levine (2001) and Chalmers (2007) have provided severe objections to which all variants of the approach are subject. I argue in the next section that there is no version of the strategy which can satisfactorily solve those problems. 3.4 Two Problems for the Strategy In the last section, we saw that the phenomenal concept strategy explains the special gaps by claiming that phenomenal concepts merely provide us with quite meager information about our phenomenal states. Proponents provide various accounts of the mechanism by which phenomenal concepts pick out their referents, and what kind of information they provide about them. However, regardless of whether they provide demonstrative or indexical descriptions— as direct-reference accounts have it—, or the information of the presence of their referents— as quotational accounts claim—, all approaches agree that the knowledge generated about the nature of our qualia is rather thin. The reason is obvious: thinness of information plays a key role in the strategy’s explanation of the special gaps. Since phenomenal concepts do not provide us with substantive information about their referents, we cannot a priori entail their identity with particular types of functional/physical states, even if full knowledge of the latter is available. 3.4.1

Levine’s Lack-of-Thickness Objection

However, the assumption that we merely possess non-substantive introspective knowledge of our subjective experiences is rather unintuitive. As Levine (2001) points out, […] with phenomenal concepts, such as our concept of a reddish quale, there is a “thick,” substantive mode of presentation. We are not just labeling some “we know not what” with the term “reddish,” but rather we have a fairly determinate conception of what it is for an experience to be reddish. This is […] a reflection of the subjectivity of conscious experience, the fact that my qualia are “for me” in a cognitively substantive and determinate way. When we compare this substantive and determinate conception with what is represented in a physical description of the neural processes underlying color vision, there is genuine cognitive significance to our wondering how these two conceptions could be conceptions of the same thing. Qualia present a problem for reductive explanation precisely because there is a real content to our idea of a quale, and not [...] because it is merely ostensive. (Levine 2001: 84) It is an undeniable introspective datum that phenomenal concepts of color experiences provide us with rich information about what-it-feels-like to see, e.g., a certain shade of red— an information which obviously cannot be captured by the likes of plain demonstratives or indexical descriptions. One might call this the lack-of-thickness objection to the phenomenal concept strategy. Chalmers (2003b) makes a similar point; in employing a phenomenal concept, he says,

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The Case Against Physicalism […] a subject attends to the quality of an experience, and forms a concept wholly based on the attention to the quality, ‘taking up’ the quality into the concept. (Chalmers 2003b: 235)

As Chalmers’ image of ‘taking up’ helpfully illustrates, it seems to be a key feature of phenomenal concepts that their contents mirror the phenomenal character of their referents; yet such mirroring cannot be accomplished by purely demonstrative characterizations. Note, however, that Chalmers (2003b) distinguishes between different kinds of phenomenal concepts, some of which can be accurately captured by demonstrative accounts along the line of the phenomenal concept strategy. Yet the substantiveness criterion clearly applies to the kind of phenomenal concepts at stake in antiphysicalist arguments, namely direct phenomenal concepts. These are formed when a person attends to the subjective quality of the experience she is having at the very moment of introspection. Now, in order to evaluate the lack-of-thickness objection, it is crucial to thoroughly analyze what kind of information the likes of pure demonstratives provide. Levine (2001) discusses an example from outside the mind-body domain: consider a case in which someone blindly points at an object in front of herself and wonders what object she refers to. Here, one acquires no information about the referent of one’s concept besides the fact that one denotes something. But this involves no knowledge whatsoever about the referent’s nontrivial properties. In everyday situations, the content of a demonstrative is accompanied by various sorts of perceptual information. However, this must not deceive us as to the content of pure demonstratives as such. Thus, in order to understand the phenomenal concept strategy’s take on phenomenal content by way of an analogy with the non-phenomenal case, it is crucial to isolate the demonstrative’s contribution. This is achieved by means of the assumption that the pointing takes place blindly. If the phenomenal concept strategy is correct, then our phenomenal concepts must have a comparably shallow content; and, for the reasons discussed above, the constitutional approach cannot allow for more substantive phenomenal information, either.26 The inadequacy of the suggestion that phenomenal concepts have such thin contents may be even more apparent in non-visual perception. Consider pain. My phenomenal concept of pain seems to deliver much more than the mere information of the occurrence of a certain type of event which I might then label ‘pain’. The concept provides considerable information about what-it-feels-like to be in pain—it is this information rather than any recognitional knowledge that makes pain so disagreeable. Now, in order to avoid the lack-of-thickness objection, proponents of the phenomenal concept strategy must either deny the intuition that our phenomenal concepts have substantive content, or they must improve the phenomenal concept approach such that it can meet the challenge of providing phenomenal concepts with more substantial content. Since the first option appears to come close to denying the obvious, the second option seems favorable. Yet recall that it is crucial for the phenomenal concept strategy’s explanation of the special gaps that phenomenal concepts do not reveal the nature of their referents. Hence, a revised version of the strategy has to fulfill two seemingly conflicting desiderata: phenomenal concepts have to 26 See Levine (2007) for a similar case, as well as an extensive critical discussion of Perry’s (2001) suggestion that indexicals provide more substantial information.

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characterize their referents in a substantive way, while not revealing their nature. Physicalists have tried to develop such solutions: for example, Levin (2002) and Schroer (2010) propound theories aiming to master this delicate balancing act. Levin (2002) takes phenomenal concepts to be hybrids of type-demonstratives and causalfunctional concepts. On this view, the substantial content of phenomenal concepts is rooted in their functional dimension which determines certain dispositions to judgments of similarities to and differences from other experiences. For instance, the phenomenal concept orange comes with a functional dimension which involves the disposition to judge that orange is similar to red but different to, say, green. In this regard, Levin’s approach bears strong similarities to analytic functionalism. Differing from the latter position, however, Levin holds that a specific causal-functional profile is merely necessary, but not sufficient for being a certain phenomenal concept. In addition, phenomenal concepts also have a purely demonstrative nature. Only the combination of functional and demonstrative elements fully characterizes a certain phenomenal concept. Therefore, although Levin’s account shares similarities with analytic functionalism, it is nonetheless a version of type-B physicalism. The reason why there is a special explanatory gap is that phenomenal concepts refer to phenomenal states exclusively via their partly being demonstratives. Their functional profile, in contrast, only describes their referents’ relations to other phenomenal states. It does not reveal anything about the intrinsic nature of phenomenal states.27 Yet the functional element explains why phenomenal concepts have substantive content: they inform us about resemblance relations between phenomenal states. Schroer (2010) develops his account, starting from a problem he identifies with Levin’s proposal. On Levin’s view, phenomenal concepts only characterize their referents in terms of their relations to other phenomenal states. However, they do not provide any substantial information about their non-relational, intrinsic properties. Since Levin assumes that intrinsic properties are captured by the demonstrative element of phenomenal concepts, the only characterization of them is given in the form of a meager ‘that property (again)’. Yet the lack-of-thickness objection demands that phenomenal concepts provide us with substantial information as to the intrinsic nature of phenomenal states. Levine’s point is that our phenomenal concepts obviously provide us with a substantial characterization of what-it-feels-like to entertain a specific phenomenal state. This cannot be encompassed in terms of the functional relationships the state bears to other phenomenal states. Levin’s view only partly qualifies as a solution to the lack-of-thickness objection. It explains how phenomenal concepts inform us about resemblance relations between different types of phenomenal states. Yet with regard to the intrinsic nature of phenomenal states, the approach adopts a standard type-demonstrative analysis in the tradition of Loar, and is thereby subject to the same concerns. Schroer attempts to sidestep this problem by improving Levin’s analysis in two stages. First, he provides a novel analysis of phenomenal states, according to which the everyday phenomenal properties we experience are not simple, but structurally complex entities, consisting of combinations of simple phenomenal elements. Schroer illustrates this analysis by 27 Levin (2007) develops a revision of her earlier view. On this account, phenomenal concepts as such are pure type-demonstratives and functional characterizations merely play a role in the acquisition of novel phenomenal concepts.

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using the example of phenomenal colors. He argues that phenomenal colors consist of three phenomenal elements: lightness, saturation, and hue. The last element itself comes in a simple or a complex configuration. There are the unique hues red, green, blue, and yellow. Furthermore, there are binary hues which are combinations of unique hues, an example being orange, a blend of red and yellow. The combination of levels of intensity of each element allows for locating a given color within color space. Having a certain location in color space, a certain color more or less resembles other colors, depending on the elements and the respective intensity the color shares with other colors. Although Schroer discusses only phenomenal colors, he claims that phenomenal states of all modalities have comparable quality spaces. The account he develops specifically for phenomenal concepts of colors is, in principle (albeit probably with some modifications), applicable to all other phenomenal concepts as well, thus providing a comprehensive solution to the lack-of-thickness objection. Second, Schroer argues that our phenomenal concepts mirror the structural complexity of their referents. They provide us with both a characterization of the respective phenomenal elements of which a given qualia consists, and informations about the intensity of each element present in the state. With regard to the phenomenal elements, Schroer adopts a standard recognitional account according to which the characterization of these elements is given in terms of type-demonstratives. Yet in addition to providing such demonstrative information about the various types of elements figuring in a phenomenal state, phenomenal concepts also offer a description of how much of the respective elements are present in the state. It is this latter information which lets us see resemblance relations between different types of phenomenal states. For instance, specific shades of phenomenal red and phenomenal orange resemble each other because they share the hue red. Moreover, they differ because only phenomenal orange features yellow. In addition, they might also have divergent levels of intensity of lightness and saturation, resulting in various other complex dimensions of resemblances and dissimilarities. Now, by arguing that our ordinary phenomenal states as well as our phenomenal concepts are structurally complex, Schroer paves the way for a version of the phenomenal concept strategy which, he claims, can satisfyingly fulfill both desiderata: it can retain the key insight of the traditional phenomenal concept strategy that phenomenal concepts only provide us with meager insight into the nature of their referents, while nonetheless allowing that they come with a rich characterization of their phenomenal character. The trick is that the meager demonstrative characterization merely concerns the primitive phenomenal elements.28 Phenomenal concepts do not give us any substantial information about the nature of saturation as such, for instance. But they do tell us how much intensity of this unspecified element is present in a given phenomenal color. This latter information, in combination with analogous informations as to other phenomenal elements, provides us with a rich characterization—not of the ultimate elements, but of our ordinary phenomenal states constituted by these elements. Crucially, this rich characterization concerns the intrinsic nature of our ordinary phenomenal states: it informs us about their internal structure. Moreover, knowledge of this structure makes us see relations of resemblance between different types of ordinary phenomenal states. 28 With regard to phenomenal elements, Schroer explicitly adopts the direct-reference version of the phenomenal concept strategy. Yet his general idea is also compatible with a quotational account with regard to phenomenal elements.

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Hence, our knowledge of these resemblance relations is rooted in knowledge of the intrinsic nature of the phenomenal states we enjoy. Schroer therefore claims that his account provides a fully satisfactory solution to the lack-of-thickness problem. Phenomenal concepts have substantive content which gives us both insight into the nature of our phenomenal states, and the resemblance relations between them. Nonetheless, it is to be expected that there are special epistemic gaps in the mind-body domain: the nature of our phenomenal states is only revealed at the level of combination of primitive phenomenal elements; but this revelation does not involve informations about the essential properties of the elements as such—these elements might very well be identical to functional/physical properties. As he points out, we have no reason to demand such information. The lack-of-thickness objection demands that phenomenal concepts provide a substantive characterization of ordinary phenomenal states. It is silent as to the potential phenomenal constituents of these states. However, while Schroer appears to provide a prima facie plausible account of phenomenal concepts of colors, I believe that his approach is not applicable to all kinds of phenomenal concepts. In particular, phenomenal concepts of bodily sensations seem to resist analogous treatment. Consider, for instance, the characteristic unpleasantness that is a key feature of the subjective experience of pain. It is plausible that our phenomenal concept of pain ‘takes up’ this quality of unpleasantness into its content. Yet it is hard to imagine that knowledge of this feeling of unpleasantness could be accounted for in terms of resemblance relations between primitive demonstratives. How can pain’s unpleasantness be explained by the fact that it consists of numerous phenomenal elements, some of which it shares with other types of bodily sensations such as tickles, tingles, or orgasms? It might seem plausible that pain shares some of its phenomenal characteristics with the orgasm. Nonetheless, how can it be that the former feels unpleasant, and yet the latter pleasant, just because different proportions of the same phenomenal elements constitute both types of feelings, respectively? Again, Schroer assumes that our concepts of phenomenal elements are pure demonstratives. That is, some measure of certain types of demonstratives figures in our pain-concept, while a different amount of partly overlapping and partly distinctive types of demonstratives constitutes our orgasm-concept. Furthermore, these different demonstratives merely characterize a certain type of phenomenal states as belonging to this but not that kind of entity. How can their respective combination of different types of demonstratives account for the characteristic unpleasantness of pain and the specific pleasantness of orgasms? It is hard to see how these differences in internal structure should permit the explaining of the subjective experience of pleasantness or unpleasantness. I am therefore skeptical as to the full-scale tenability of Schroer's solution to the lack-of-thickness objection. Levine’s lack-of-thickness argument is not the only notable objection to the phenomenal concept strategy. Chalmers (2007) presents with what he calls his master argument against the strategy, an arguably even more grave problem for this approach. 3.4.2

Chalmers’ Master Argument

Chalmers’ objection concerns an underlying inconsistency in the phenomenal concept strategy’s key idea. Recall that all variants of the strategy explain the special gaps of the mindbody domain in terms of a special psychological mechanism which governs the reference of

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The Case Against Physicalism

phenomenal concepts, and which distinguishes them from other concepts. As we have seen, this mechanism can be cashed out in different ways, whereat the direct-reference view and the quotational account are the most prominent variants. What all versions of the strategy have in common is that the mechanism as such is taken to be microphysically explicable. Of course, this is crucial to the strategy because the mechanism’s microphysical explicability secures the strategy’s compatibility with physicalism. Yet if the mechanism as such is itself physical or at least grounded in physical facts, then any physical duplicate of a conscious human being also features this mechanism and the phenomenal concepts it gives rise to. But then zombies must possess phenomenal concepts. Consider my otherworldly zombie twin who shares the complete physical make-up I have at this very moment. If my phenomenal concepts are part of this make-up or at least grounded in it, then the twin also shares the phenomenal concepts I have right now. At this moment, I entertain the phenomenal concept of the experience of seeing green leaves and so does my twin. However, being a zombie, the twin does not share what Chalmers calls my “epistemic situation with regard to consciousness” (Chalmers 2007: 172): I am conscious, yet my zombie twin is not. As discussed, the phenomenal concept strategy accounts for my being conscious in terms of my possession of physically explicable phenomenal concepts. Now, if this explanation succeeds, then my twin is as conscious as I am. Yet this is an unacceptable implication: zombies ex hypothesis are not conscious. Hence, if phenomenal concepts can explain my being conscious, my twin cannot have phenomenal concepts. But then, since my twin has the same physical make-up as I have, phenomenal concepts cannot be physical or physically grounded. However, the assumption of physically inexplicable phenomenal concepts makes the phenomenal concept strategy incompatible with physicalism: while phenomenal concepts explain the original special gaps between qualia and physical facts, there arises a novel explanatory gap between phenomenal concepts and physical facts. In other words, while explaining the original gaps between the nature of phenomenal states and our introspective knowledge about them, phenomenal concepts are themselves not physically explicable, and therefore subject to analogous gaps as the ones they were invoked to explain. The upshot is that the phenomenal concept theorist faces the following dilemma (E stands for the epistemic situation with regard to consciousness of an arbitrary human being at a given time in our world, and C represents the psychological mechanism which, according to the theorist, gives rise to phenomenal concepts. As usual, P stand for the complete microphysical truths about our world): (1) P&~E is conceivable. (2) If P&~E is conceivable, then P&~C is conceivable or C&~ E is conceivable. (3) If P&~C is conceivable, P cannot explain C. (4) If C&~E is conceivable, C cannot explain E. ______________ (5) P cannot explain C or C cannot explain E. (Chalmers 2007: 179) Premise (1) asserts that zombies who do not share our epistemic situation with regard to consciousness are conceivable. (2) asserts that if such zombies are conceivable, then either

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they do not have phenomenal concepts such that it is conceivable that the complete microphysical facts about our world are instantiated but no phenomenal concepts are, or they do have phenomenal concepts, but these concepts do not give rise to the characteristic epistemic situations we enjoy. As (3) points out, if the former is true, then phenomenal concepts are not physically explicable. Premise (4) asserts that if the latter is true, then phenomenal concepts cannot explain our characteristic epistemic situation. (5) concludes that either phenomenal concepts are not physically explicable, or phenomenal concepts cannot explain our relationship to our phenomenal states. Whatever option the proponent chooses, the phenomenal concept strategy is not capable of providing an explanation of the special gaps compatible with physicalism. At first glance, the objection might seem harmless. Recall that on type-B physicalism, zombie-scenarios are conceivable, but not metaphysically possible. One might therefore wonder why the physicalist should be bothered by an argument claiming that inconsistencies arise in our conception of such scenarios on the phenomenal concept strategy. After all, the phenomenal concept strategy takes these scenarios as being merely epistemic settings which do not correspond to genuine metaphysical possibilities. Thus, as long as the approach does not become embroiled in difficulties with its assumption regarding possible worlds, why care whether it implies inconsistencies with regard to merely conceivable scenarios? Chalmers has surprisingly little to say regarding this response. He merely points out that type-B physicalists grant that zombies are conceivable, and that their conceivability is threatened by his argument. However, if it is not essential to the phenomenal concept strategy to provide a fully consistent account of zombie-invoking epistemic scenarios, then Chalmers’ argument is hardly viable. Yet it can be easily shown that it is essential to the strategy to provide a fully satisfying account of zombie-scenarios. Recall that the phenomenal concept strategy’s central move consists in an ingenious change of subject: proponents point out that instead of providing a physicalist explanation of consciousness, it suffices to provide a physicalist explanation of the special gaps in order to establish physicalism. That is, the strategy’s self-defined goal is to explain why these gaps arise in the mind-body domain and only in this domain. Then, however, it is crucial to the strategy to submit a fully consistent explanation as to why we can conceive of P&~E-scenarios. If it turns out that the strategy’s assumptions entail that we cannot consistently conceive of P&~E-scenarios, then the proposed explanation—at least of the conceivability gap—breaks down. But an explanation cannot rest on assumptions which imply the non-existence of the explanandum, namely our ability to consistently conceive of P&~E-scenarios—at least when it is proposed as a non-eliminative explanation. Proponents of the phenomenal concept strategy have developed a number of replies to this argument. Carruthers & Veillet (2007) claim that in crucial respects, zombies are, indeed, in analogous epistemic situations to us: while we have phenomenal states, zombies have schmenomenal states:29 Well, on our view zombies are still zombies in that they are not phenomenally conscious. Their perceptual states don’t have phenomenal feels. In this respect it is all 29 Papineau (2007) provides a similar response.

50

The Case Against Physicalism dark inside. Yet they have something playing a certain role in their psychology — a role analogous to the role that phenomenal consciousness plays in ours. They have something epistemically just as good as consciousness, but they don’t have anything that is phenomenally as good. It seems that this is what matters here. The schmenomenal states they undergo do not feel like anything. Even though their schmenomenal beliefs are true when our corresponding phenomenal beliefs are, their beliefs are, sadly enough, not about the same good stuff as our corresponding beliefs — they are not about the feel of experiences. Zombies are still, it seems, in quite a dreadful situation. So our intuitions about zombies are preserved. (Carruthers & Veillet 2007: 224–5)

If it makes sense to assume that zombies have states that—although not phenomenal—are epistemically comparable to our phenomenal states, then C can be physical and yet this does not give rise to novel epistemic gaps. Humans and zombies have C, and C explains both the epistemic situation of zombies and ours. The situation is then comparable to standard a posteriori necessities. Consider Oscar and his duplicate on Twin Earth. Both Oscar and Twin Oscar have a concept named ‘water’. In Oscar’s case, it refers to H2O. In Twin Oscar’s case, it refers to XYZ. Analogously, I and my zombie twin have physically explicable phenomenal concepts. Yet in my case, they refer to phenomenal states, while in my zombie twin’s case, they refer to schmenomenal states. However, this analogy between zombie and Twin Earth cases should make us suspicious: if both cases are epistemically analogous, then epistemic gaps cannot arise in one case which do not also exist in the other case. But if there are no special epistemic gaps in the mind-body domain, then there is no need for the phenomenal concept strategy to begin with. If we can conceive of genuine zombies, there is a special conceivability gap—which, in turn, gives rise to a special explanatory gap as discussed above. Thus, it appears that for their argument to go through, Carruthers and Veillet must assume that we cannot conceive of zombies. For if it is the case that when we conceive of physically identical creatures, we cannot help but conceive of beings which share our epistemic situation—and this does seem to be what they claim—, then zombies are inconceivable. As Chalmers (2007) explains, when we ordinarily conceive of zombies, we are not conceiving of beings with something analogous to consciousness that is epistemically just as good. Rather, we are conceiving of beings with nothing epistemically analogous to consciousness at all. (Chalmers 2007: 328) Moreover, if Carruthers and Veillet do not allow that we can conceive of such beings, then their argument entails a version of type-A rather than type-B physicalism. Hence, this reply fails in rescuing the phenomenal concept strategy: the strategy is a version of type-B physicalism. However, Carruthers and Veillet also present a back-up strategy in case of their main argument failing to succeed. Note that an important implication of the differences between my epistemic situation and the one of my zombie-twin is that my phenomenal beliefs are true, while the twin’s phenomenal beliefs are false. Bearing the same cognitive processes due to his psychological identicalness with me, my twin forms the belief that he is in pain in analogous

Two Problems for the Strategy

51

situations to those wherein I believe myself to be in pain. But, while we feature the identical physical/functional make-up in these situations, my phenomenal belief is true while his is false. After all, only I suffer the subjective experience of being in pain—the twin’s phenomenal concepts, however, fail to refer.30 Now, Carruthers and Veillet argue that if this is true, then the phenomenal concept strategy can explain the zombie’s epistemic situation: What, then, explains the zombie’s reasoning and behaviour? Clearly, the presence of phenomenal feels can’t explain that reasoning. Just as in the case in which we assume that the zombie’s phenomenal concepts refer to physical states, so in the case in which his concepts are empty, his reasoning can’t be explained by an appeal to phenomenal states. The only thing that can truly explain the relevant bits of reasoning is the fact that [the zombie] has a concept (in the original case, referring to a physical property, now being allowed to be empty) which is conceptually isolated from all physical, functional and intentional concepts. (Carruthers & Veillet 2007: 233) For instance, when Chalmers’ zombie-twin conceives of a zombie scenario, he might imagine his own zombie-twin, let us call him Zombie-Zombie-Chalmers. The conceivability gap which Zombie-Chalmers encounters in such conceptions can be fully accounted for by means of the phenomenal concept strategy. But then, they continue to argue, the same explanatory method should also work for Chalmers’ epistemic situation: Since it is the conceptual isolation of Zombie Chalmers’ (empty) phenomenal concepts that explains the conceivability to him of Zombie-Zombie Chalmers and so forth, parity of reasoning suggests that in Chalmers’ case, too, it is the conceptual isolation of his phenomenal concepts and not the presence of phenomenal consciousness itself which explains the various problematic thought experiments. (Carruthers & Veillet 2007: 233–234) However, as Chalmers (2007) points out, the phenomenal concept strategy can only explain why creatures with false direct phenomenal beliefs cannot a priori deduce their phenomenal beliefs from their physical knowledge. But this does not allow for any implications with regard to the explanatory force the strategy has with regard to our true phenomenal beliefs. That is, in order to explain our epistemic situation, the physicalist must explain why we cannot a priori derive our direct phenomenal knowledge from our physical knowledge. Type-B physicalists are realists about consciousness, and allow for our direct phenomenal beliefs to be true. That is, when I come to the belief to be in pain by way of making use of a direct phenomenal concept, then it is really the case that I am in pain. The phenomenal concept strategy might be capable of demonstrating that the false phenomenal beliefs of zombies are compatible with physicalism. But, as Chalmers remarks, “this is something that we knew already” (Chalmers 2007: 325): there was never a doubt that zombie-worlds are purely physical.

30 A consequence is that Chalmers’ zombie-twin who is a realist about consciousness is wrong, while Dennett’s twin, endorsing eliminativism, is right—even if, in the actual world, antiphysicalism is true such that Chalmers is right and Dennett is wrong.

52

The Case Against Physicalism

In contrast to Carruthers and Veillet, Balog (2012b) concedes that zombies are not in an analogous epistemic situation to us. Hence, C cannot be explained by P such that new epistemic gaps arise between P and C. However, she does not take this to be a worrisome result. Balog argues that the physicalist is not committed to the assumption that special gaps give rise to ontological gaps because she rejects CP in the mind-body domain. Hence, there is no harm in conceding the physical inexplicableness of C: This merely entails novel special gaps, and the phenomenal concept strategy already showed that such gaps are no threat to physicalism. However, as Chalmers (2007) points out, this is a circular argument. The phenomenal concept strategy claimed to provide a physically acceptable explanation of the existence of the special gaps. Yet if this explanation itself comes at the cost of creating new higher-order gaps, then these new gaps cannot be declared harmless by way of reference to the successful physical explanation of the first-order gaps. After all, the phenomenal concept strategy was only capable of explaining the old gaps by creating unexplained new gaps. The theory was advertised as providing an account of how physically explicable psychological mechanisms can give rise to special gaps. When it now turns out that these mechanisms themselves are not physically explicable, then this is just not a successful physical explanation of the special gaps. Moreover, the novel gaps inherent in the mechanism cannot be declared harmless by means of referring to the success of the strategy in demonstrating that special gaps do not give rise to ontological gaps: for this was never successfully demonstrated. It seems that none of the physicalist replies to Chalmers’ argument discussed is tenable. I take it that this presents us with strong reasons to conclude that no version of the phenomenal concept strategy can provide a tenable physicalist account of phenomenal consciousness. However, some of the tools developed by the strategy prove helpful in giving an antiphysicalist account of consciousness. Recall that Chalmers (2003b) distinguishes between different kinds of phenomenal concepts, some of which can be accurately captured by demonstrative accounts along the line of the phenomenal concept strategy. The substantiveness criterion at stake in the lack-of-thickness objection only applies to some of them. In particular, it applies to the kind which is at stake in antiphysicalist arguments, namely direct phenomenal concepts. These are the concepts formed when a person attends to the subjective quality of the experience she is having at the time of introspection. In his account of direct phenomenal concepts, Chalmers (2003b) endorses a version of the constitutional view according to which phenomenal concepts are partly constituted by phenomenal states along the lines of the quotational accounts of Balog and Papineau. Yet, in contrast to physicalist versions of the view, Chalmers takes direct phenomenal concepts as not just providing ‘empty quotes’ of phenomenal states but revealing the full nature of the qualia which partly constitute them. In introspection, a psychological mechanism is at play which delivers us direct phenomenal concepts which are partly constituted by the very qualia they refer to, revealing to us the essences of these states. As a result, we bear an intimate relation of what has been termed acquaintance to our phenomenal states: their nature is fully disclosed; it just consists of the subjective experience we enjoy in bearing these states. Employing once

Two Problems for the Strategy

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more Chalmers’ image, this phenomenal character as such is ‘taken up’ into the concept. As Chalmers explains, acquaintance might be a brute epistemic relation:31 If necessary, a dualist can simply take this relation as primitive. The dualist is already committed to positing primitive mental features, and this relation may reasonably be taken to be part of the primitive structure of consciousness. (Chalmers 2007: 192) In conclusion, I take it that we have strong reasons to believe that neither phenomenal consciousness, nor the existence of special epistemic gaps in the mind-body domain are in the end physically explicable. At the very least, existent versions of physicalism appear untenable in light of the two-dimensional argument and the objections to the phenomenal concept strategy discussed. Of course, it is hard to predict with certainty that there might not be ways for developing stronger versions of physicalism which manage to avoid all of the discussed problems. Nevertheless, we have good reason to evaluate the tenability of antiphysicalist alternatives for explaining phenomenal consciousness. This will be the subject of the remainder of this work.

31 Levine (2007) reaches a similar conclusion.

4

Understanding Emergence

The subject of this chapter is the concept of emergence. A thorough discussion of the notion and various accounts of it will provide us with a better understanding of emergentist versions of dualism as discussed in the next chapter and, moreover, provide the groundwork for a theory of emergence in panpsychism which I develop in Chapter 7. In order to develop such a theory, it is mandatory to discuss different kinds of emergence, and various competing accounts of those kinds of emergence: as will become clear in the course of both this chapter and Chapter 7, a proper theory of the emergence in panpsychism can greatly profit from combining ideas from a number of different proposals advanced within the literature. However, the ambition of this chapter goes well beyond addressing solely what is needed to explain emergence in dualism and panpsychism. My aim is to provide a substantial contribution to the metaphysics of emergence. I believe that while there are a number of compelling theories about various kinds of emergent phenomena, what is currently missing is a systematic and comprehensive treatment of the concept. I take it that a systematic approach to emergence must thoroughly explore what possible kinds of emergence there are, and explain what those various kinds have in common (making them instances of the same notion) as well as how they respectively differ from each other (making them distinct types of one and the same overarching concept). Sections 4.1 to 4.3 aim to provide such a systematization. Section 4.1 analyzes the notion of emergence in its most general form. Section 4.2 derives from this notion what I believe to be possible ways phenomena can be emergent. I take these various ways of being emergent to correspond to different types of emergence. All types I discuss fall under one of the two classes, weak and strong emergence, where weakly emergent phenomena allow for a reductive explanation in terms of microscopic entities, while strongly emergent entities do not. While I cannot think of ways a phenomenon can be emergent in a different manner than one of those captured in my taxonomy, I do not claim to provide an exhaustive list of all possible kinds of emergence: there might be potential or even actually existing kinds of emergence I have overlooked. Nonetheless, I believe that my taxonomy at least captures the varieties of emergence which figure prominently in the literature. In Section 4.2, I develop my taxonomy of emergence, without considering which of the types on the list in fact exist in the actual world. Section 4.3 deals with actual cases of emergent phenomena. I discuss various types of phenomena which have been claimed to be emergent and analyze to which types of emergence they belong, given that they are correctly identified as being emergent. As it turns out, for every type of emergence in my list, there are real world phenomena which have been claimed to belong to it. Yet, for most phenomena, it is controversial whether they indeed are emergent in the suggested way. As a result of this discussion, it will become clear which type of emergence macrophenomenality belongs to according to emergentist versions of dualism and panpsychism, namely ontological emergence, which is a variant of strong emergence.

© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2020 F. Klinge, Panpsychism and the Emergence of Consciousness, https://doi.org/10.1007/978-3-662-62258-2_4

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Understanding Emergence

From Section 4.4 onwards, I concentrate on the class of strong emergence and its three different types. Severe objections against the very concept of strong emergence have been put forward, the most important of which are Kim’s (2006) critique that standard theories of emergence do not provide intelligible characterizations of the concept, Kim’s (1999) power inheritance objection, and the causal exclusion problem (e.g. Kim 2005). The latter two arguments both aim to show that strongly emergent phenomena cannot have genuine causal powers of their own, whereby the power inheritance objection focuses on the dependence relation at play in emergence, and the causal exclusion argument on downward causal interaction. Since I address problems of downward causation in the context of higher-level phenomenal properties as they figure in dualism and emergent panpsychism in Chapters 5 and 7, I shall postpone discussion of the causal exclusion problem to those chapters. This also makes sense for systematical reasons. Kim’s concern about the possibility of providing an intelligible characterization of emergence, and his power inheritance objection threaten the intelligibility of the very concept of (powerful) strongly emergent phenomena, while the causal exclusion argument questions the occurrence of such entities in the actual world based on empirical evidence. It seems appropriate to first address worries about their general logical possibility, before asking whether such phenomena might also be nomologically possible and existent in our world. I discuss the prospects of providing intelligible characterizations of various types of emergence in Section 4.5. The power inheritance objection as well as four strategies to avoid it are addressed in Section 4.6. I shall argue that two of those strategies are (partly) successful: Shoemaker (2002) provides a perfectly acceptable account of one sub-type of strong emergence, namely deflationary emergence, while O’Connor & Wong’s (2005) account appears promising for explaining the other two sub-types (which are both variants of ontological emergence) but leaves crucial desiderata. In Section 4.7, on the basis of O’Connor and Wong’s strategy, I develop a theory of ontological emergence which I take to fulfill those desiderata. This theory will then serve as a basis for the discussion of the emergence of macrophenomenality in emergent versions of dualism and panpsychism in later chapters. 4.1 The Notion of Emergence ‘Emergence’ is a technical term which has been used by different authors in various ways to describe a variety of distinct types of phenomena. Nonetheless, I believe that a general characterization can be given which captures the essence of what these phenomena have in common, making all of them fall under the same concept. I hold that emergence, in the broadest sense of the term, means irreducibility or autonomy along one or several of the three dimensions of predictability, causation, and ontology. That is, a higher-level phenomenon is emergent iff it ‘arises’ from a lower-level condition—its ‘emergence base’—but is irreducible to this condition with respect to one or several of those dimensions. Put otherwise, emergence occurs iff a high-level phenomenon arises from lower-level phenomena yet truth concerning the former are irreducible to truths concerning the latter along one or several of these dimensions.

The Notion of Emergence

57

Predictive autonomy means that the occurrence of a high-level phenomenon cannot be predicted given full empirically obtainable knowledge of its emergence base. More precisely, a phenomenon is predictively autonomous iff one cannot predict its occurrence given the full empirical information about its emergence base that the (ideal) science studying the ontological level of the emergence base provides. Causal irreducibility occurs if only if a high-level phenomenon has causal powers which are not derivable from the causal powers of its emergence base. Conversely, causal reducibility is given for a complex object iff all of its causal powers are entailed by the causal powers of its parts and their relations. If a complex object exhibits emergent phenomena which are nonetheless causally reducible, then these emergent phenomena do not add genuine novel causal powers to the system. Ontological emergence means that a high-level phenomenon is not grounded in its emergence base. By means of contrast, ontological reducibility holds iff all truths about all highlevel phenomena are grounded in truths about the parts and their relations. In some cases, one dimension of irreducibility entails another. For instance, ontological irreducibility entails predictive irreducibility: if an emergent is not grounded in its emergence base, then, ex hypothesi, it cannot be predicted solely on the basis of knowledge of the latter. But this is not true vice versa: as we will see, there are cases of predictive irreducibility which do not involve ontological autonomy. There is a broad divide between weak and strong types of emergence. Weak emergence is compatible with what might be termed smallist views, while strong emergence is not. Smallist accounts are views according to which everything is either some sort of micro-stuff, or grounded in this sort of micro-stuff. There are different versions of smallism depending on what the micro-stuff is taken to be. Physicalism is the smallist view which assumes the microstuff to be purely physical. In contrast, constitutive panpsychism is the smallist view which assumes that at least some microphenomena are phenomenal. Note that weak emergence is traditionally understood as the version of emergence which is compatible with physicalism (e.g. Bedau 2003, Chalmers 2006a, Wilson 2015). But in light of alternative smallist views such as constitutive panpsychism or panprotopsychism, we have to allow for a broader understanding: it would be absurd if the truth of constitutive panpsychism entails that there cannot be any weakly emergent phenomena. Although weakly emergent entities are in some respect autonomous form their emergence bases, they are nonetheless grounded in them.32 Strongly emergent phenomena, on the other hand, are autonomous in such a way that they are not grounded in their emergence bases. I shall call this kind of autonomy strong autonomy, and dimensions of autonomy which are compatible with the autonomous entities being grounded in other entities weak autonomy: that is, strongly emergent entities are strongly autonomous, while weakly emergent entities are only weakly autonomous. 32 The criterion of compatibility with smallist views is often cashed out in terms of metaphysical supervenience (e.g. Chalmers 2006a). Yet as discussed in Section 2.1, nothing-over-and-aboveness cannot be analyzed in terms of purely modal notions, but rather requires a hyperintensional interpretation such as given by metaphysical grounding or alternative fundamentalist views such as Sider’s (2011). As a consequence, weak emergence must be understood as involving such a hyperintensional notion. As in Chapter 2, I shall use ‘grounding’ in a broad sense, being committed to the fundamentalist interpretation of nothing-over-andaboveness, but staying neutral with regard to the various ways of how to cash out fundamentalism.

58

Understanding Emergence

To summarize, three dimensions of autonomy can be distinguished that are relevant to all cases of emergence. There is a predictive, a causal, and an ontological dimension of autonomy, and different possible combinations of these dimensions correspond to different types of emergence. In the next section, I develop a taxonomy of various kinds of emergence, based on this general notion of emergence. 4.2 Kinds of Emergence The following table lists various types of emergence deriving from the possible combinations of dimensions of autonomy and reducibility. The types belong to the classes of weak or strong emergence, depending on their compatibility with smallist ontologies. Table 4.1: Taxonomy of Emergence class weak emergence

strong emergence

reductive predictability

causal reducibil- ontological reity ducibility

subclass

type

epistemological

nonlinear

-

✓

✓

metaphysical

multi. realizable

✓

-

✓

nonontological

deflationary

-

-

✓

epiphenomenal

-

✓

-

interactionist

-

-

-

ontological

Weak emergence comes in two flavors. First, a phenomenon is weakly emergent if predictability fails in spite of causal and ontological reducibility. I call this type epistemological weak emergence: the phenomenon is in principle both causally and ontologically reducible, yet, for some reason, this does not translate into reductive predictability. Second, weak emergence occurs if a phenomenon is ontologically reducible and reductively predictable, yet causally irreducible. On first glance, it might seem counterintuitive that something is reductively predictable but causally irreducible. Does not causal irreducibility of a phenomenon entail that it is not fully reductively predictable? Yet, as we will see in Section 4.3.2, Wilson (e.g. 2015, forthcoming: chapter 3) argues that this is indeed possible if a weakly emergent property inherits only some but not all of the causal powers of its emergence base. Wilson holds that functional properties conform to this type of emergence. There are three types of strong emergence.33 First, a system might have macrocausal powers irreducible to the system’s micropowers which are also not reductively explainable in terms of the latter, while all macrophenomena of the system are ontologically reducible to the system’s microconstituents. As this type comes without ontologically irreducible macroentities, I will call it deflationary strong emergence. It might seem incoherent that a system exhibits causally and explanatory irreducible macropowers which nonetheless are ontologically reducible. Does not ontological reducibility entail causal and explanatory reducibility? Yet in Section 4.6.2, I introduce an approach which successfully explains how both can come apart such that deflationary emergence is, indeed, a coherent notion. Deflationary emergence does 33 Stephan (2002) develops a similar distinction.

Kinds of Emergence

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not exhibit ontological autonomy, and, therefore, no ungrounded macrophenomena. Hence, one might think that this type of emergence is compatible with smallism, and thereby a type of weak emergence. In 4.6.2, however, I shall argue that there are good reasons to assume that deflationary emergence is not compatible with smallist ontologies. The two other types of strong emergence are far more straightforward. Epiphenomenal strong emergence occurs iff there are ontologically irreducible macroentities which do not possess genuine causal powers. Interactionist strong emergence occurs iff a system exhibits irreducible macroentities which have genuine causal powers. The latter two types can be ascribed to the subclass of ontological emergence, since they feature ontological autonomy. It is sometimes claimed that if a macroentity is not ontologically reducible, then it does not supervene on microphenomena (e.g. Van Gulick 2001). But this is not true. To consider a concrete case, assume for the sake of argument that property dualism is true. It follows that one does not obtain a certain emergent quale without the neural activation pattern with which it is correlated, and vice versa. The difference between ontologically reducible and irreducible macroentities concerns the kind of supervenience at stake. The former metaphysically supervene on microphenomena: they supervene on them in all possible worlds. The latter, in contrast, nomologically supervene on them: they only supervene on them in worlds with the same laws as those our world has. As discussed in Chapter 2, there are compelling reasons for assuming that reductive explainability cannot be analyzed in modal terms, but rather must be cashed out utilizing hyperintensional notions such as metaphysical grounding. In other words, it is not the case that metaphysical supervenience entails reductive explainability, but rather that reductive explicability entails metaphysical supervenience. Nonetheless, emergent entities contrast with reductively explainable ones in that they only nomologically supervene on their dependence base. Depending on the theory of laws that one assumes, nomological supervenience might, however, entail supervenience in all possible worlds. This is, for instance, the case on the dispositionalist account of laws (see Section 2.1, Footnote 4). What has been said entails that an emergent entity ontologically depends on its emergence base. If a high-level entity needs a low-level condition to get instantiated and to be sustained, then the former is ontologically dependent on the latter: in order to obtain and maintain the former, one needs the latter. It follows that the nomological supervenience relation at play here is a relation of ontological dependence. (Henceforth, I will use ‘ontological dependence’ and ‘dependence’ interchangeably.) Note that an entity is not in a strong sense dependent if other phenomena are only needed to bring it into existence but, after being produced, the entity can exist independently. Strong dependence as it is in play in emergence entails that the dependent cannot exist without being sustained by other entities. In this sense, one is not dependent on one’s parents even if the thesis of essentiality of origin is true (on which it takes exactly identical genetic material to generate a specific person such that one could not have had different parents). For one’s parents might die, while one survives. In contrast, an ordinary object such as a table is strongly dependent on microparticles. The microparticles upon which the object is dependent might change such as when I replace a broken table leg with a new one. Nonetheless, the object needs some particles to exist: without table legs, there is no table.

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Understanding Emergence

As becomes clear in this example, strong dependence is a characteristic shared by grounding and all types of emergence.34 Both grounded entities and emergent phenomena depend on their respective grounding or emergence bases. Explaining how phenomena can be ontologically dependent on their emergence bases while not being grounded in them is, therefore, an important desideratum within any account of strong emergence. I will address this issue in the following. But how should we understand the general notion of strong dependence, at play in both grounding and strong emergence? Barnes (2012) provides the following characterization of strong dependence applicable to grounding and strong emergence: An entity x is dependent iff for all possible worlds w and times t at which a duplicate of x exists, that duplicate is accompanied by other concrete, contingent objects in w at t. (Barnes 2012: 880) That is, if an entity is dependent, then it is metaphysically necessarily co-instantiated with other contingent, concrete entities. These entities constitute its dependence base. When I speak of dependence in the following, I mean strong dependence in Barnes’ sense. 4.3 Varieties of Emergent Phenomena In this section, I discuss various cases of phenomena which have been deemed emergent in the literature, analyzing under which type of emergence they respectively fall. 4.3.1

Epistemologically Emergent Phenomena in Complex Systems

In the sciences, emergent phenomena occur in circumstances of complexity. In complex systems, we often encounter macrophenomena which are not predictable given complete knowledge of the systems’ micro-conditions and the laws by which those conditions are governed. Often, such cases are instantiations of deterministic chaos. Deterministic chaos occurs iff the causal evolution of a complex system is completely determined by deterministic causal processes wherein the system’s microconstituents are involved, yet the system’s macroevolution is not predictable, even given full knowledge of the relevant properties of the microconstituents and the laws by which they are governed. The reason is that these systems exhibit sensitive dependence on initial conditions. That is, even the smallest differences in the initial state of the system’s microconstituents can result in dramatically different causal evolutions over time. Their high sensitivity to small changes in initial conditions renders such systems nonlinear. That is, changes in certain macrophenomena such as the causal evolution of the system as a whole are not proportionally dependent upon changes in initial conditions. Rather, very tiny differences in microsettings can result in extraordinary differences in macrodynamics. Linear system, in contrast, exhibit what Bishop (2008) calls the principle of linear superposition: a system is linear iff any change affecting a variable of the system’s initial conditions by a certain factor results in a proportional change of the system’s output by the same factor. Bishop 34 Of course, it is shared by types of weak emergence for the trivial reason that weakly emergent phenomena are grounded in their emergence bases.

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provides the following example in order to illustrate the difference between linear and nonlinear behavior: [I]f you start with your stereo at low volume and turn the volume control one unit, the volume increases one unit. If you now turn the control two units, the volume increases two units. These are examples of linear responses. In a nonlinear system, [...] linear superposition does not hold and a system need not change proportionally to the change in a variable. If you turn your volume control too far, the volume not only increases more than the number of units of the turn, but whistles and various other distortions occur in the sound. These are examples of nonlinear responses. (Bishop 2008: 523) Edward Lorenz, one of the pioneers of chaos theory, coined such high sensitivity to initial conditions butterfly effect, after a meteorological thought-experiment: the evolution of weather is so fragilely dependent on small changes of meteorological microstates that, in principle, the flapping of the wings of a butterfly in Asia could produce a tornado in the US a few weeks later. Since no scientific method is, or will ever be, so accurate that it can take account of the exact state of a complex system down to the quantum level, the dynamical evolution of deterministically chaotic systems, though completely determined by micro-level causal interactions, will never be predictable over longer periods of time. Hence, these systems qualify as epistemologically weak emergent: although all of their higher-level phenomena are fully grounded in micro-level occurrences, we are not able to derive the evolution of the former from the evolution of the latter because it is impossible to predict their macro-behavior from knowledge of their micro-configurations. Often, epistemological emergence is considered to be “an observer-relative property” (Chalmers 2006a: 251; italics in original), and characterized in terms of unexpectedness or unpredictability of truths concerning higher-level phenomena from knowledge of the underlying low-level dynamics. This seems to suggest that epistemological emergence has a subjective and temporary element to it. Given this characterization, phenomena that are right now weakly emergent for us might cease to be so with progress in science. In contrast, Bedau (1997, 2003) argues for an objectivist interpretation of epistemological emergence. On this account, a macrophenomenon is epistemologically emergent iff it is in principle (even for God) not predictable and derivable from underlying processes except by simulation. Bedau’s characterization is based on a crucial difference between prediction via modeling and prediction via simulation. The study of complex systems involves the construction of mathematical and/or computational models of these systems. Such models provide an idealized account of the targeted systems.35 Much of the complexity of the original systems is eliminated in order to concentrate on the dominant causal interactions, that is, the interactions which, to a great extent, determine the causal evolution of the system as a whole. That is, models in the complexity sciences are necessarily incomplete: they leave out at least some variables that are somewhat causally relevant in order to concentrate on the dominant causally relevant variables. Linear systems can be successfully studied via this method: as long as our models provide us with a rough characterization of its initial conditions and the laws by which 35 In the following, I make use of Wimsatt’s (2007: 100–103) account of idealization in modeling.

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they are governed, we can derive a roughly correct prediction of the future states of a linear system. Our predictions will not be completely correct, since the models on which they are based eliminate some of the complexity of the target system, and this additional complexity generates minor deviations in the evolution of the latter vis-à-vis the evolution predicted by the model. But these differences might be negligible for the practical purposes of prediction. In contrast, in nonlinear systems exhibiting sensitive dependence on initial conditions, the smallest deviations between the initial conditions in our models and the target systems result in large, nonproportional differences in output. It is, therefore, impossible to predict their future states via modeling techniques. We can say that for such systems, the necessary incompleteness of our models results in severe misdescriptions of the causal interactions in the system. The only way to successfully predict the macroevolution of nonlinear systems is to construct completely accurate simulations of them which represent the complete microstructure of their initial conditions down to the smallest molecular (and probably even sub-atomic) details.36 Bedau’s concept of epistemological weak emergence is tailor-made for understanding the dynamics of deterministic chaos and the resulting emergent phenomena in nonlinear systems. I leave it open whether an even weaker, subjective version of epistemological emergence along the line of Chalmers’ (2006) suggestion might also be intelligible. The crucial point is that such a subjective version would be a different type of emergence to Bedau’s, and the former would not be sufficient to characterize emergent phenomena in nonlinear complex systems. While nonlinear phenomena are also epistemologically emergent in the subjective sense, their special status of unpredictability in principle via modeling can only be captured by Bedau’s objective notion of epistemological emergence. 4.3.2

Realized Phenomena as Metaphysically Weakly Emergent Entities

Traditionally, weak emergence has been considered a purely epistemological notion. But Wilson (e.g. 2011, forthcoming: chapters 2 & 3) argues that realized entities such as functional properties are not epistemologically but metaphysically weakly emergent, since they are causally autonomous, yet ontologically and explanatorily reducible.37 Their causal autonomy renders them emergent, while their ontological reducibility secures their compatibility with smallist views such that they qualify as weakly emergent. But, since they are explanatorily reducible, they are not epistemologically weakly emergent. According to Wilson, what makes them causally autonomous is the fact that realized entities satisfy the following two conditions, where S is a property of the realized entity, and P the property of the realization base which grounds S:38 36 For many complex systems, it currently remains an open question whether quantum-level differences are amplified to a sufficient degree to influence macrocausal dynamics, or whether they are leveled out such that only molecular-level differences can constitute differences in initial conditions (see Bishop 2008 for a discussion of the empirical evidence). 37 To be precise, Wilson claims that they are also ontologically irreducible, but she uses the notion of ontological reducibility differently, and in such a way that it is compatible with smallism. Realized properties on Wilson’s account are ontologically reducible given my reading of ontological reducibility. 38 The subset view has independently been defended by Shoemaker (2001, 2007). Yet Shoemaker does not discuss its implications for theories of weak emergence.

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Token Identity Condition: Every token power of an apparently higher-level feature S, on a given occasion, is identical with a token power of a lower-level feature P on which S synchronically depends, on that occasion. […] Proper Subset Condition: Token higher-level feature S has, on a given occasion, a non-empty proper subset of the token powers of the token lower-level feature P on which S synchronically depends, on that occasion. (Wilson forthcoming: chapter 2) The idea can best be illustrated using the example of functional properties. As discussed in Chapter 2, a functional property is the second-order property of playing such and such a causal role in a given system. According to (partly) functionalist accounts of the mind, 39 for instance, a belief with such and such content might be a functional state which is produced by certain other states such as sense-perceptions or other beliefs, and which, in interaction with certain desires, is capable of producing certain kinds of behavior. For a given cognitive system, a certain belief is any state which fulfills a specific causal role characterized along these lines. That is, as long as it fulfills the required function, virtually any type of state can realize a specific functional property. This makes functional properties multiply realizable. There is no restriction on the kinds of entities which can figure as realization bases for functional properties. While in humans, propositional attitudes such as beliefs are realized by patterns of neural activity, there could, in principle, be artificial systems wherein the same types of states are realized by silicon-made bases. In other words, functional properties essentially involve causal role properties which, in turn, are specific sets of causal powers. Now, Wilson argues that for a given token functional property, this property is identical to certain token causal powers of its realizer. This is the token identity condition. Moreover, as the proper subset condition specifies, the set of causal powers with which the functional property is identical is not the complete set of causal powers possessed by the realizer, but merely a proper subset of the realizer’s powers. This seems to follow naturally from the principle of multiple realizability. If different types of states can realize the same type of functional property S, then these different types of realizers have a great variety of different properties over and above the ones allowing them to realize S in certain systems. After all, neurons and silicon consist of quite different materials with very different properties and resulting powers. At least some of these additional properties come with additional powers such that for any token realizer, a token of S only is identical to a subset of the realizers’ powers. Moreover, this power subset is the same for any possible realizer. It is the very fact that a potential realizer has the specific set of powers (as a part of certain systems) that makes it a potential realizer of S. Now, Wilson argues that functional properties are rendered causally autonomous by the fact that any type of functional property comes with a specific set of powers which is identical to a proper subset of the realizer’s token powers on every occasion of realization. While each 39 By a partly functionalist theory of the mind, I mean any account which assumes that at least some mental states are functional properties. Most antiphysicalist views qualify as being partly functionalist, since, while doubting that phenomenal states are realized properties, they allow that other mental kinds such as propositional attitudes are functional properties.

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individual power of a token of S is identical to a token power of its realizer P, its complete power profile is not identical to the realizer’s power profile, since the latter encompasses powers which do not figure in the former. Hence, S’s power profile is irreducible to P’s, but, nonetheless, fully explainable in terms of the latter: any token power figuring in the former is derivable from (qua being identical to) a token power figuring in the latter. Wilson’s account seems appealing for explaining functional properties. Further, she thinks that it is also applicable to other types of realization and constitution such as ordinary objects and artifacts.40 I cannot discuss these further applications of the powers subset theory here, but it is important to note that it is not uncontroversial, even for the case of functional property, where Wilson’s account might seem most directly applicable. For instance, Morris (2011, 2013) argues that functional properties inherit all of their realizers’ powers, and Pereboom (2002) claims that the relation between the power tokens of the realizer and the power tokens of the functional property is constitution rather than identity. I personally find Wilson’s arguments for the thesis that realized entities are metaphysically weakly emergent compelling, but nothing depends on this for the purpose of the foregoing discussion. All that matters for us here is that Wilson shows that the proper subset condition constitutes an interesting novel type of weak emergence. 41 It is a different question whether any real-world phenomena instantiate this kind of emergence. 4.3.3

Reductively Unpredictable Behavior in Cell Biology

Besides deterministic chaos and realized entities, there is another potential type of emergent phenomenon in complex systems, namely reductive, or micro-theoretically, unpredictable macromechanisms. Examples of these can be found in microbiology. We have evidence that biological systems such as cells have irreducible macrocausal powers. Some macromolecules seem to exhibit a qualitatively very different behavior in certain cellular contexts than we would expect from studying them in simpler contexts or in isolation. In these cases, cells do have irreducible macrocausal powers; yet not because they have irreducible biological macroproperties, as vitalists would have it, but rather because the micropowers of some of their molecular constituents change in certain ways iff they are part of a cell. Thus, these appear to be cases of deflationary strong emergence: the macro-system has irreducible, strongly autonomous causal structure, but all macroconstituents are ontologically reducible. That is, the cell consists of nothing other than molecular constituents such that there is no ontological emergence in such cases. But the behavior of some of the cell’s molecules changes, this giving rise to irreducible macrocausal structure.42 40 Wilson (2010) argues that ordinary objects such as stones have fewer powers than their basic constituents realizing them: elementary particles as such are subject to indeterministic quantum laws which allow for a great range of possible behaviors, most of which are canceled out once these particles are part of ordinary objects. As a result of the behavioral limitations of its constituents, ordinary objects are systems which have a much more limited range of behavior at their disposal than quantum systems. These limitations of degrees of freedom makes these systems describable by classical mechanics. Hence, given the proper subset condition, ordinary objects qualify as metaphysically weakly emergent. 41 To be precise, Wilson’s claim is more ambitious than this. She assumes that her account captures all versions of weak emergence. I deem this to be false, since, as seen, epistemological weak emergence is a different but coherent concept in its own right. 42 These cases of emergent behavior in biology will be discussed more thoroughly in Chapter 5 in the context of the exclusion argument. For empirical evidence, see, for instance, Boogerd et al. (2005) and Noble

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One objection to such an interpretation might be that if molecules exhibit different behavior in cells, then this different behavior must be due to novel properties they obtain in cellular environments. But then, the causal autonomy of the cell results from the ontological emergence of these novel properties. It would follow that the biological cases are cases of ontological emergence. However, in Section 4.6.2, I shall discuss an approach by Shoemaker (2002, 2007) which can explain causal autonomy and change in molecular behavior in such cases without invoking the ontological emergence of novel properties. I will argue that this is the most advantageous way to interpret these cases such that they are indeed cases of deflationary emergence. However, independently of the question as to which type of emergence is at play in these cases, we can say that the behavior of the respective molecules is micro-theoretically unpredictable: if studied in vitro, that is, in isolation, or as a part of simpler systems, they display no traces of the behavior we observe them to exhibit in cellular contexts. Chemistry ascribes to these molecules certain behavioral dispositions which allow us to predict how they would behave in any complex setting with various causal influences. Yet, if we study them in situ, that is, in cellular contexts, then they behave very differently from what we would expect given our chemical theory about their behavior in vitro. The cellular behavior is still regular and, thereby, theoretically predictable for microbiologists. But it is not predictable given only the micro-science chemistry (‘micro’ in relation to biology). This makes the cellular behavior micro-theoretically unpredictable. Note that the issue in these cases is not that predictions are not possible because of high sensitivity to initial conditions, as in chaotic systems. Predictions of cell behavior are in fact possible, and various of these micro-theoretically unpredictable cellular mechanisms have been thoroughly studied. The point is, however, that the behavior certain macromolecules exhibit when involved in those mechanisms is not predictable from what would be expected from studying them in simpler systems or in isolation. 43 In other words, mechanisms involved in those kinds of irreducible macrocausal structure have been successfully modeled and predicted. But they cannot be reductively modeled and predicted. 4.3.4

Macrophenomenality as Ontologically Emergent Phenomenon

As has been seen, there is evidence for both weakly and strongly emergent phenomena in complex systems. Compare the cases discussed to emergentist antiphysicalist accounts of consciousness. In contrast to the above cases, what is at stake in the question as to whether consciousness is a strongly emergent phenomenon is not emergent behavior, but rather the emergence of categorical properties or substances. That is, if consciousness is strongly emergent, then it is emergent because the qualitative, intrinsic dimension of phenomenality is irreducible. As discussed in Chapter 3, this insight is at the heart of Chalmers’ (1995) distinction between the hard problem of phenomenal consciousness, and various easy problems concerning cognitive behavior. (2012). Kaiser (2011) is an overview of cases of causal irreducibility in biology. Other works arguing for strong emergence in biology include Bechtel & Richardson (2010), and Powell & Dupré (2009). 43 Accordingly, Richardson & Stephan (2007) develop an account of explanations in cell biology allowing for nonreductive, yet mechanistic explanations of strongly emergent behavior. Similarly, Kaiser (2015) sharply distinguishes reductive explanation from mechanistic explanation in biology.

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In other words, antiphysicalist views are motivated by the conviction that there is a categorical dimension to consciousness which is not reducible to neuronal-physical causal structure. Dualists agree that consciousness exhibits such an emergent categorical dimension, but differ on the question whether this categorical dimension can be explained solely in terms of emergent properties, or whether we have to assume emergent substances as well. The former view is property dualism, while the latter is substance dualism. This provides us with two kinds of emergent phenomena. First, there is emergent behavior which is fully explainable in terms of emergent causal powers of microentities, as the discussed examples from the complexity sciences suggest. Second, there are what might be called emergent categorical entities, that is, strongly emergent categorical properties and substances. These entities are ontologically emergent phenomena. While they might also have autonomous causal powers—in which case they fall under the type interactionist ontological emergence—their autonomy transcends purely behavioral matters. First and foremost, it concerns the autonomy of the categorical nature of the respective phenomena. Truths concerning the categorical nature of these phenomena are not grounded in lower-level truths. It follows that such phenomena exhibit ontological strong autonomy, which is why I term this type of emergence ontological strong emergence. Consciousness appears to be the only phenomenon in the debate about emergence for which, transcending the autonomy of behavior and causal structure, the question arises as to whether it is ontologically emergent. Again, this is crucial to Chalmers’ distinction between the hard problem of phenomenal consciousness and various other easy problems pertaining to the explanation of brain functions: only phenomenal consciousness qualifies as a potential candidate for being ontological emergent. In analogy to Chalmers’ distinction, we can say that there is substantive ontological strong emergence concerning the strong autonomy of the categorical nature of higher-level entities, and nonontological deflationary strong emergence which merely concerns the strong autonomy of higher-level causal processes and functions. On a categoricalist view, it might seem that the latter presupposes categorical underpinning such that the latter case also constitutes a case of ontological emergence. But, as I will argue in 4.6.2, there is a theory developed by Shoemaker (2002, 2007) which can successfully explain such cases in terms of deflationary emergence. Note that since consciousness is the only natural phenomenon which plausibly is ontologically emergent, epiphenomenal and interactionist ontological emergence are rival concepts. If consciousness is ontologically emergent, then it is either epiphenomenal, or has strongly autonomous causal powers. And since consciousness is then the only ontologically emergent phenomenon, there is no other phenomenon which could be epiphenomenally ontologically emergent if consciousness is indeed interactionist, or vice versa. Since emergent panpsychism views macrophenomenality as being an ontologically emergent phenomenon, this type of emergence will be given a prominent place in the following sections of this chapter. Emergence in panpsychism can only be explained if a satisfying account of ontological emergence can be provided. I shall argue that none of the existing approaches fully succeed in explaining ontological emergence. This notwithstanding, several accounts manage to explain certain crucial aspects of the concept such that the view I shall develop can make use of some of their resources.

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There are particularly two major challenges a theory of ontological emergence must meet. Both have been presented by Kim (e.g. 1999, 2006). The first is the challenge of providing positive accounts of autonomy and dependence. It is faced not only by ontological emergence, but indeed by all types. I discuss this challenge in the next section, arguing that the accounts of weak emergence discussed above can easily meet it. The task of providing a positive account of autonomy in types of strong emergence is addressed in Section 4.5. The task of providing a positive account of dependence can only be usefully discussed in the context of the other challenge, the so-called power inheritance objection, since this argument imposes further demands on accounts of dependence. Hence, a theory of dependence is only intelligible if it can fulfill the demands of both challenges. In Section 4.6, I address the power inheritance objections, and, in Section 4.7, I provide an account of ontological emergence which I consider capable of meeting both challenges. This account can then serve as a basis for the discussion of emergence in dualism and panpsychism in later chapters. 4.4 Autonomy and Dependence Kim (2006) explains that in order to count as an intelligible characterization, a theory of emergence must provide positive accounts of autonomy and dependence. This might seem to be an obvious requirement. Yet Kim shows that the way in which autonomy and dependence have been cashed out in traditional accounts of strong emergence merely qualifies as negative characterization. That is, these accounts only tell us what autonomy and dependence are not, but they tell us not what they, in fact, are. Note that the distinction between different types of strong emergence is not taken into account by Kim and most other commentators. I will therefore introduce Kim’s argument without differentiating between the three types, returning to these distinctions only later, when I discuss solution proposals to Kim’s objection. Although Kim (2006) ignores weak emergence, it also is a reasonable demand that these kinds exemplify Kim’s criterion of positive characterization. Hence, before discussing Kim’s challenge for strong emergence, I briefly outline how the two approaches to weak emergence discussed in the last section can meet the characterization challenge. Wilson’s proper subset condition explains autonomy and dependence in metaphysical weak emergence in terms of the set of causal powers of macrophenomena: macrocausal powers are individually identical to causal powers of the realizer of the respective macrophenomenon, but collectively autonomous, since the set of macropowers as such is identical to only a proper subset of the realizer’s set of powers. Thereby, Wilson can be taken to provide positive criteria for autonomy and dependence in metaphysical weak emergence: dependence results from individual identity between token macro- and micropowers, and autonomy from collective non-identity, that is, non-identity between the complete sets of macro- and micropowers. Bedau’s account of epistemological weak emergence in nonlinear systems explains dependence in terms of the full causal and ontological reducibility of the emergent macrophenomena to the microphenomena of a given system. Since causal and ontological reducibility can be accounted for in terms of metaphysical grounding or alternative conceptions of nothingover-and-aboveness, Bedau can be taken to have provided a positive account of dependence

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for this type of emergence. Autonomy, on the other hand, is accounted for in terms of unpredictability of macrophenomena from knowledge of the microphenomena generated by modeling techniques. Supplemented with an account of idealization in modeling along the lines provided above, this can count as a positive criterion of autonomy. With regard to strong emergence, Kim (2006) argues that standard theories lack intelligible characterizations of the autonomy and dependence. The concept of emergence was first discussed by the so-called British Emergentists John Stuart Mill, C. Lloyd Morgan, Samuel Alexander, and C. D. Broad. These 19th and early 20th century founding fathers of emergentism effectively characterized strong emergence in terms of supervenience and irreducibility, employing different vocabulary.44 Characterizations along these lines can still be considered the standard view, versions of it being endorsed by inter alia Van Cleve (1990), O'Connor (1994), and McLaughlin (1997). However, Kim complains that a commitment to the merely negative and prima facie incompatible notions of supervenience and irreducibility does not suffice for a successful characterization: What we have in supervenience and irreducibility [...] are two essentially negative conditions, and they do not amount to a positive account of what emergence really is. They tell us what emergence is not; they do not tell us anything—at least, not much—about what it is. I believe one pressing item on the emergentist agenda is to provide an illuminating positive characterization of emergence. [...] the proposed characterization of emergence must explain why emergents so characterized supervene on their base properties and why, in spite of the supervenience relation, the former are not reducible to the latter [...]. (Kim 2006: 557; italics in original) If strong emergence is solely characterized in terms of supervenience and irreducibility, then the concept is under-specified, since those notions cannot by themselves render it intelligible: they only point out what strong emergence is not, but not what it is. A satisfying characterization must provide a positive account which is, moreover, able to explain how a phenomenon can be both supervenient on other entities and irreducible to them. There is another important aspect to this. In Section 4.2, we saw that ontological dependence occurs in emergence as well as in relations of nothing-over-and-aboveness. Explaining how a phenomenon can be both supervenient on other entities and irreducible to them involves therefore explaining how dependence in emergence diverges from dependence in nothing-over-and-aboveness. We more or less understand how a phenomenon can be supervenient on other entities and reducible to them. At least, the literature provides a variety of approaches to nothing-over-and-aboveness (such as various ways to cash out metaphysical grounding, or Sider’s representational account of fundamentalism) for explaining this kind of dependence relation. The challenge for the emergentist is to explain the possibility of another kind of dependence relation in which supervenience combines with strong irreducibility. Kim’s demand has, in effect, a similar rationale to that for the hyperintensional turn in the discussion on nothing-over-and-aboveness (see Section 2.1.2): as they merely describe a symptom of the underlying phenomenon in need of explanation, purely modal characterizations of dependence 44

See McLaughlin (1992) for an overview article on British Emergentism.

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relations are not only unsatisfying in the case of nothing-over-and-aboveness, but also in the case of strong emergence. Above, I distinguished between different kinds of irreducibility (namely predictive, causal, and ontological autonomy) and argued that different types of strong emergence feature different combinations of those kinds of autonomy. This allows for a more fine-grained discussion, since, with these distinction in hand, it is obvious that different types of strong emergence require different accounts. It must then be shown how accounts of the three types of strong emergence identified can meet Kim’s challenge. I begin by discussing the notion of autonomy in Section 4.5. I argue that there is one notion of strong autonomy, developed by Barnes (2012), which is applicable to all three types of strong emergence and compatible with different takes on dependence. Dependence is the subject of Sections 4.6 and 4.7. As stated above, it is useful to begin the analysis of dependence by discussing the most widely reviewed objection against the concept of strong emergence, Kim’s power inheritance argument (the name was coined by Baysan & Wilson 2017), since almost all accounts in the literature were developed as replies to this objection. Although put forward as replies to the power inheritance objection, these approaches also provide, at least partially, positive accounts of dependence: while the aim of these theories is first and foremost to reject the power inheritance objection, they nonetheless can also be taken to constitute answers to Kim’s characterization challenge with regard to dependence in emergence. It thus makes sense to discuss their take on dependence in the course of discussing the power inheritance objection. This form of presentation has the additional advantage that an overview is immediately granted as to which accounts succeed in fending off Kim’s objection. 4.5 Strong Autonomy As seen, complex systems are usually taken to be reducible to combinations of microparticles. Nonetheless, in principle, they can have causally and/or ontologically irreducible properties, although the empirical evidence for such irreducible properties is contested. Let us call the causal and/or ontological irreducibility at play in strong emergence strong autonomy (see Section 4.2 for the details of this entailment). How might then strong autonomy of macrophenomena, if existent, be explained? It is obvious that absolutely fundamental entities such as elementary particles and their micropowers are strongly autonomous. However, it is unclear how a high-level and thereby less fundamental entity could be so. Does not the fact that an entity is ontologically dependent entail that it is reducible as well? And if not, what is the positive component of strong autonomy that explains the entity’s irreducibility? Barnes (2012) has provided an ingenious answer to those questions: a dependent highlevel entity is strongly autonomous iff it is fundamental. The explanatory power of Barnes’ proposal stems from the fact that her characterization utilizes a primitive notion of fundamentality. Barnes’ idea is to explain the negative criterion ‘irreducibility’ of strong emergence in terms of a primitive concept that is already well established. Primitivism about fundamentality is central to a metametaphysical framework that has lately received a lot of attention: metaphysical fundamentalism has been defended by proponents of metaphysical grounding such as

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Fine (2001, 2012), Schaffer (2009a), and Dasgupta (2014) but also by rival hyperintensionalist theories of nothing-over-and-aboveness such as Sider (2011). I discussed the common core of those different versions of fundamentialism thoroughly in Section 2.1. Here, I concentrate on only those aspects of the framework which are important for Barnes’ account of strong autonomy. Recall that metaphysical fundamentalism assumes a sharp distinction between fundamental and nonfundamental, or ‘derivative’ entities, rather than degrees of fundamentality: an entity is either fundamental or derivative.45 Moreover, the fundamentalist framework takes fundamentality to be a primitive notion that is not analyzable in more basic terms. Usually, debates about emergence are not tied to discussions in metametaphysics and accounts are not explicitly cast in any specific metametaphysical framework. Nevertheless, the common metaphor of ontological levels seduced philosophers into imagining emergent phenomena as being less fundamental than their lower-level emergence bases. This is motivated by the often implicit assumption that the degree of fundamentality of an entity is determined by the ontological level on which it is located, only the lowest level allowing for absolute fundamentality. More precisely, on this traditional view, fundamentality is analyzed in terms of ontological independence. Yet, since independence requires that entities are fully self-sufficient, only entities located at the lowest level can be absolutely fundamental. For instance, in their survey article on emergence, O’Connor and Wong (2015) provide the following characterization of the general notion of emergence: […] emergent entities (properties or substances) ‘arise’ out of more fundamental entities and yet are ‘novel’ or ‘irreducible’ with respect to them. (O’Connor & Wong 2015: 1; italics added) Now, Barnes objects to this widespread take on fundamentality. She takes it to be the core obstacle standing in the way of providing a positive characterization of strong autonomy. Yet by divorcing ‘being fundamental’ from ‘being instantiated at the lowest level’, we can trace the irreducibility of dependent and independent entities back to something they have in common: independent entities and dependent emergents are both fundamental. Note, however, that it is not uncommon for the notion of fundamentality to figure in characterizations of strong emergence. For instance, O’Connor & Wong (2005: 665) characterize a strongly emergent property as a “fundamentally new kind of feature” and Wilson (2002) provides an account of the causal powers of strongly emergent properties in terms of fundamental interactions. But, Barnes points out, the crucial point is that this common strategy to account for strong autonomy in terms of fundamentality is only intelligible if combined with primitivism about fundamentality. Only then can fundamentality put to work in explaining strong autonomy. If, in contrast, emergents are specified as being fundamental, yet fundamentality itself is accounted for in terms of a hierarchy of ontological level such that only base-level phenomena qualify as fundamental (due to their being ontologically independent), then fundamentality is of no help to the emergentist. For if so, it is impossible for a high-level phenome45 The notion of relative fundamentality, being-more-fundamental-than-x-but-less-fundamental-than-y, in turn, is itself derivative on the basic distinction between fundamentality and derivativeness.

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non to be fundamental. But then, autonomy must be accounted for in another way, or taken to be primitive. Yet to my knowledge, alternative reductive accounts of strong autonomy have not so far been developed. Hence, without the help of a primitive notion of fundamentality, and in the absence of an alternative analysis of strong autonomy, the emergentist is forced to do with an unexplained, primitive notion of strong autonomy which she postulates for the mere reason that it might figure in strong emergence. Since the introduction of such a notion of irreducibility is ad hoc—it has no metaphysical role but to enable strong emergence—this is not an advisable option. Let me illustrate the importance of primitivism about fundamentality for the emergentist project with a recent example from the literature. This is Van Gulick’s (2001) discussion of Chalmers’ (1996) view: Though [emergent property dualists] treat mental properties as distinct from physical ones, they do not regard mental properties as fundamental. On the emergent property dualist view, mental properties are something over and above their physical bases, but they are not fundamental in so far as they owe their existence to their emergence from their nonmental physical bases. They are more than their bases, but they are nonetheless in some way dependent upon them. By contrast, fundamental property dualism gives basic mental properties the same bedrock foundational status as our fundamental physical forces (Chalmers, 1996). Just as the nuclear force and the electromagnetic force are equally primitive features of physical reality according to the so-called standard theory, so too are basic mental and physical properties according to the fundamental property dualist. (Van Gulick 2001: 23) Because he implicitly presupposes a non-primitive notion of fundamentality, Van Gulick cannot classify Chalmers’ (1996) view as emergent property dualism. But this view, although not cast in terms of emergence, is obviously a version of epiphenomenal emergent property dualism, on which emergent phenomenal property strongly depend on microphysical emergence bases.46 Yet because Chalmers (1996: e.g. 213) describes consciousness as fundamental, Van Gulick misinterprets this as the thesis that phenomenal properties do not emerge for physical bases, but are instead somehow ontologically independent. The underlying rationale seems to be that Van Gulick takes it for granted that fundamentality is analyzable in terms of independence such that emergent entities cannot be fundamental. According to Barnes’ proposal, then, there are three kinds of ontological status an entity might have: firstly, there are fundamental independents, that is, entities located at the basal ontological level. Secondly, there are fundamental dependents, that is, strongly emergent 46 This is explicitly confirmed by Chalmers in his (2006a) article on emergence: “I think there is exactly one clear case of a strongly emergent phenomenon, and that is the phenomenon of consciousness. We can say that a system is conscious when there is something it is like to be that system; that is, when there is something it feels like from the system’s own perspective. It is a key fact about nature that it contains conscious systems; I am one such. And there is reason to believe that the facts about consciousness are not deducible from any number of physical facts. I have argued this position at length elsewhere (Chalmers 1996; [2003a]) […].” Of course, in chapter 8 of The Conscious Mind, Chalmers considers panpsychism as an alternative to property dualism. But while he deems some forms of panpsychism plausible, he does not definitely endorse any such view. It seems obvious that Van Gulick (2001) means to discuss Chalmers’ view as he presents it in the main chapters of his (1996).

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high-level entities. And thirdly, there are derivative dependents, that is, resultant or grounded high-level entities. Usually, proponents of metaphysical fundamentalism do not consider the possibility of entities of the second kind. It is Barnes’ idea that incorporating them in the fundamentalist framework provides us with a metaphysical niche for strong emergence. She effectively argues that by way of its basic assumptions, an independently motivated metametaphysical framework already has a place for strong emergence. As a result, the emergentist does not have to engage in metametaphysical work on her own, but she can rather subscribe to an already well-established metametaphysical framework, for which a compelling case can be made independently of consideration about emergence, as is discussed in Section 2.1. Table 4.2: Kinds of Entities According to Their Ontological Status (after Barnes 2012) 47 ontologically independent fundamental

ontologically dependent

elementary particles and their propstrongly emergent entities erties

derivative

various complex systems, ordinary objects, and higher-level properties

4.6 The Power Inheritance Objection Kim’s (1999) power inheritance argument is widely regarded as one of the most severe objections to strong emergence. It is a variant of the causal exclusion problem, and concerns downward causation of strongly emergent entities. Both the ordinary causal exclusion argument as developed e.g. by Kim (2005), and the power inheritance objection are thus only directed at deflationary and interactionist emergence, but not at epiphenomenal emergence. In the following, I will use ‘strong emergence’ to refer only to the former two types. In its main part, the ordinary causal exclusion argument, derives from two premises (the first of which is taken to be strongly confirmed by empirical evidence, while the second is assumed to be a plausible a priori hypothesis) that supervenient entities such as emergents cannot have causal powers.48 Rather than invoking empirical evidence, the power inheritance objection claims to disclose a logical incoherence in the very concept of strong emergence. Although the power inheritance argument is widely discussed in the literature on emergence, in my own opinion, it has often been misinterpreted, with the consequence that some of the solutions put forward are wrongheaded.49 I begin my discussion by presenting what I take to be the correct interpretation of the argument. In the following subsections, I will then discuss what I consider to be the four major solution proposals advanced in the literature. Kim’s (1999) power inheritance objection has two stages, the first of which, with a minor modification, also appears in Kim’s (2005) version of the causal exclusion argument: all vari47 Note that Barnes also considers whether entities can be derivative without being dependent on anything. She cites the mathematical trivialism of Rayo (2009), on which mathematical entities appear to be independent derivatives, as an example. If so, numbers would appear in the second row of the middle column of the table. 48 I thoroughly discuss the causal exclusion argument in the version directed against dualism in Section 5.4.2, and as an objection against emergent panpsychism in Section 7.3. 49 For instance, Wong (2010) claims that the power inheritance argument cannot succeed without the aid of the two premises of the original causal exclusion argument, while Baysan & Wilson (2017) take the argument to be directed against causal accounts of emergence.

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ants of macrocausation in strong emergence involve downward causation. This is straightforward in cases where an emergent property causes a microproperty. Yet an emergent macroproperty must also downward-causally impact properties of the lower level on which it supervenes when it causes another macroproperty. Assume that emergent E causes emergent E* of the same ontological level. In order to cause E*, E must bring about E*’s emergence base B*, since E* is ontologically dependent on B*: in order to obtain the former, one must bring about the latter. It follows that same-level causation from E to E* involves downward causation from E to the microconfiguration B*. In the second stage, and in deviation from the causal exclusion argument, it is argued that downward causation by a supervenient entity is incompatible with the very concept of supervenience.50 It is of crucial importance thereby that analogously to E* supervening on B*, E supervenes on its own emergence base B. As Kim explains, [...] we are faced with [B’s] threat to preempt [E’s] status as a cause of [B*] (and hence of [E*]). For if causation is understood as nomological (law-based) sufficiency, [B], as [E’s] emergence base, is nomologically sufficient for it, and [E], as [B*’s] cause, is nomologically sufficient for [B*]. Hence [B] is nomologically sufficient for [B*] and hence qualifies as its cause. The same conclusion follows if causation is understood in terms of counterfactuals—roughly, as a condition without which the effect would not have occurred. Moreover, is not possible to view the situation as involving a causal chain from [B] to [B*] with [E] as an intermediate causal link. The reason is that the emergence relation from [B] to [E] cannot properly be viewed as causal. This appears to make the emergent property [E] otiose and dispensable as a cause of [B*]; it seems that we can explain the occurrence of [B*] simply in terms of [B], without invoking [E] at all. (Kim 1999: 32; italics in original) Kim argues that in order to bring about E*, it suffices to cause B which, in turn, causes B*, and thereby generates E*, thus preempting E from being a cause of B*. But why should E not qualify as cause of B* in this setting? After all, the causal powers of E are required to produce B*—B does not have this power on its own. Kim is not perfectly clear on this point. But I think he has the following in mind: B is an immediate sufficient cause of E* because the causal chain goes from B to B*, while E and E* are not caused in the process. Of course, E and E* are generated in the process, since they supervene on their respective emergence bases B and B*. But they themselves are not part of the causal chain as such, since they do not qualify as additional causal links. It follows that B excludes E from being the immediate sufficient cause of E*. E’s causal powers are inherited by its emergence base B such that B, and not E, is the immediate sufficient cause of any effect E might seem to generate. By depriving E of causal powers, the power inheritance objection claims to identify an inconsistency in the concept of strong emergence. The concept’s commitment to supervenience 50 Therefore, the argument can also be directed against other positions involving supervenience such as nonreductive physicalism. But since these views assume that the supervenient entities are grounded in their supervenience base, further options for answering the objection are open to them. Those options are analogous to the nonreductive physicalist’s options for rejecting the causal exclusion argument discussed in the next chapter.

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is incompatible with its commitment to autonomous macropowers. Hence, this type of emergence is impossible—it rests on contradictory conceptual foundations. 4.6.1

Solution I: Causal Emergence

Close analysis reveals that the power inheritance objection relies on a further crucial but implicit premise, namely the assumption that the nomological supervenience between emergent and emergence base is not rooted in a causal relation. Kim admits this in the following passage from the prior quote: [I]t is not possible to view the situation as involving a causal chain from [B] to [B*] with [E] as an intermediate causal link. The reason is that the emergence relation from [B] to [E] cannot properly be viewed as causal. (Kim 1999: 32; italics in original.) However, Kim just mentions this possibility in passing without providing an argument why the supervenience relation cannot be due to an underlying causal connection. In fact, O’Connor & Wong (2005) argue that strong emergence involves such a causal relation. In this way, they can reject Kim’s objection. They assume that the causal chain from B to E* has E and B* as causal intermediates.51 Hence, B is not an immediate sufficient cause for E*, but E is. I consider the assumption that the emergence relation is a causal process to be an ingenious way for rejecting the power inheritance argument.52 However, a crucial desideratum remains: O’Connor & Wong (2005) do not provide an account of the kind of causal relation at play here. They do specify how causation in strong emergence relates to ordinary causation. Explaining this is a necessary requirement for a positive account of dependence in strong emergence. For the causal process at play in strong emergence is obviously different from ordinary causal relations, since the latter do not generate dependence of the effect on the cause. Recall Barnes’ characterization of ontological dependence: An entity x is dependent iff for all possible worlds w and times t at which a duplicate of x exists, that duplicate is accompanied by other concrete, contingent objects in w at t. (Barnes 2012: 880)

51 O’Connor & Wong’s (2005) causal model is more complicated than this, since they assume that in the next period, for E to be able to cause B*, B must remain instantiated in order to sustain E. This is due in part to the fact that they assume strong emergence to be a diachronic causal relation. 52 Note that O’Connor and Wong do not adopt the causal view in reply to the power inheritance objection (as suggested here), but rather develop their causal approach to emergence on an independent rationale. Part of the reason for this is that they do not endorse my interpretation of the power inheritance argument. Indeed, they confess that they cannot make sense of Kim’s reasoning. In reply to the power inheritance objection, they merely explain that their account takes emergent properties to have genuine causal powers such that Kim’s complaint does not apply to it: “[...]Kim’s argument clearly cannot get off the ground against the dy namical model of emergence set forth above […] the distinctive potentialities of emergent properties do stem indirectly from the total potentialities of the basic physical properties. But they do not determine the emergent effects (or fix the emergent probabilities) independently of the causal activity of those emergents” (670). In line with my proposal in the main text, I take it that O’Connor and Wong’ view can indeed avoid the objection—yet reasons other than those they think.

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Consider, for instance, the downward causal relation between E and B*: if E causes B*, then B* is not dependent E. B* can survive the loss of E. In contrast, the causal emergence process between B and E entails the ontological dependence of E on B: if B ceases to exist, then E vanishes, too. So, E depends on B, while B* does not depend on E. Nonetheless, on the causal account of strong emergence, the relations between both the former and the latter are causal relations. It must be explained how the causal relation at play in strong emergence can be a dependence relation, although ordinary causation does not involve dependence. An approach accounting for the dependence relation of strong emergence in terms of causation must explain how a causal relation can be such that the cause sustains the effect. Nevertheless, I shall argue that the causal view is the best option for accounting for dependence in ontological emergence—as will be discussed in the next section, there is a compelling theory of deflationary emergence which can account for the dependence relation in this type of emergence in terms of grounding. Yet in the following, we will see that rival views of ontological emergence are disadvantaged in comparison with the causal view. Part of the merit of a fully developed version of causal view would be that besides overcoming the power inheritance objection, this view would have a considerable advantage in parsimony over alternative views because it explains the dependence relation of ontological emergence in terms of a causal process. This is advantageous because, on this view, the dependence relation is not a novel sui generis primitive relation we must introduce to account for emergence, but is rather just a variant of a well-established relation, namely causation. In contrast, rival accounts must allow for a sui generis primitive relation. Dependence in ontological emergence cannot be explained in terms of grounding, since then emergents would not be strongly autonomous. But, besides grounding, there is no other established relation of dependence, except for causation. Hence, it seems that if dependence in ontological emergence is not causal, then it must be a novel primitive relation. If dependence is a causal relation, then, whatever theory of ordinary causation is true, this theory does also apply to causal emergence. Yet explaining causal emergence in terms of our best theory of causation presupposes understanding the crucial differences between ordinary causation and causal emergence. I will return to this issue in Section 4.7, providing a proposal for how to account for these differences. But before this, I shall address a variety of other replies to the power inheritance objection. As it will turn out, some of the ideas at play in these other accounts will prove very useful in developing my own account of causal ontological emergence in 4.7. 4.6.2

Solution II: Micro-Latent Grounding Bases

Shoemaker (2002, 2007) proposes another way to overcome the power inheritance objection. In contrast to the strategy of the causal view, his proposal attacks the argument’s first stage, rather than the second. The idea is that if it can be shown that causation by emergents does not involve macro-level downward causation, then the objection that macrocausal powers of emergents are inherited by their emergent bases cannot get off the ground. Drawing on Broad (1925), Shoemaker’s idea is to account for the causal power of E in terms of micro-latent mi-

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cropowers.53 According to this approach, E’s powers are reductively explainable in terms of micro-level dispositions which are never triggered in contexts described by microphysics. They only become manifest in extremely complex surroundings. Only these emergence-engendering circumstances provide the stimuli needed to trigger them. Those micro-latent powers serve then as a grounding base for the powers of E. Though reducible to micro-level dispositions, the latter are not reductively explainable in terms of microphysical properties, since their grounds, micro-latent micropowers, never come into play in systems studied in microphysics.54 Let me illustrate this idea with an example. Consider a case of strong emergence in biology as discussed in Section 4.3.3 in which certain macromolecules behave in a micro-theoretically unpredictable manner. According to the Broad/Shoemaker-approach, in such cases, the cell fundamentally consists of nothing but elementary particles bearing fundamental properties which constitute certain macromolecules and other chemical entities. When all these chemical elements combine to form a cell, then this context triggers special behavioral dispositions in the ultimate constituents of some molecules. These dispositions only manifest themselves if their bearers are part of a cell. That is, they are micro-latent: when their bearers are in isolation or part of simpler systems, they never come into play, because they are only sensitive to extremely complex cellular environments. Nonetheless, these micro-latent powers do not magically ‘arise’ in biological settings. Rather, they have been existent on the micro-level all along. Physicists cannot detect them, because they never manifest in systems studied in microphysics. According to the Broad/Shoemaker-account, these micro-latent dispositions or powers ground the emergent macrocausal powers of the cell. Now, the reason why we witness dispositions of macromolecules that, in principle, cannot be micro-theoretically predicted is explained by the Broad/Shoemaker-view as follows: these dispositions are grounded in micro-latent micropowers of the particles constituting the macromolecules. The molecular dispositions constituted by the micro-latent powers, in turn, ground the irreducible causal properties of the cell. Note that on this view, there is no irreducible downward causation. If irreducible causal powers are grounded in micro-latent micropowers, then there is no genuine causal interaction between different ontological levels. Everything happens on the micro-level. Problems of downward causation do not arise for this position. The Broad/Shoemaker-account is a very attractive option for explaining strongly emergent behavior in complex systems. But Shoemaker aims for more. He claims, that something analogous [to this theory] has to apply to all cases of emergence, if such cases there be. (Shoemaker 2002: 54)

53 The view Shoemaker develops is indeed already laid-out in Broad’s The Mind and its Place in Nature, but has been widely overlooked in the reception of Broad’s work. 54 Note that Broad and Shoemaker distinguish two versions of the theory: on the first, micro-latent powers are bestowed by different microproperties to those bestowing the micro-manifest powers studied in microphysics. On the second, the same properties bestow both kinds of micropowers. For ease of presentation, I will only discuss the first version of the theory in the following. Nevertheless, everything I say can also be stated in terms of the second version.

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Yet this is premature. The theory is only applicable to cases of strongly autonomous causal structure because only strongly emergent powers can be accounted for in terms of micro-latent micropowers. In contrast, the Broad/Shoemaker-account cannot explain ontologically emergent phenomenal states. The approach cannot account for the intrinsic qualitative features of consciousness, since it only explains irreducible behavior. Proponents of emergent dualism or emergent panpsychism have to adopt alternative approaches in order to account for consciousness. Furthermore, if they allow for interactionist emergence, then they have to account for genuine downward causation as well. The strategy of avoidance of genuine downward causation developed by Shoemaker is of no use to them. The micro-latency approach can thus be classified as a theory of deflationary strong emergence because strongly autonomous high-level causal structure is accounted for without introducing strongly emergent highlevel entities: autonomous causal structure is fully grounded in micro-latent micro-level dispositions. Not being subject to any worries about downward causation, the Broad/Shoemaker-approach seems to be the best theory of strongly autonomous behavior in the literature. For instance, it seems to be superior to the theory of Stephan (2002) who explains causal irreducibility in terms of ’downward’ causal influence exerted by the system itself (or by its structure) on the behavior of the system’s parts. (Stephan 2002: 89) Stephan does not explain how the system or its structure actually performs downward efficacy on its part, but its capability to do so seems to require that it is itself ontologically emer gent. An account which explains causal autonomy by way of downward efficacy of ontologically emergent entities is obviously disadvantaged in comparison with the Broad/Shoemakerapproach which can do without ontological emergence. Note that in contrast to what follows from my classification in Section 4.2. that lists deflationary emergence to be a type of strong emergence, Shoemaker (2007) claims that the microlatency view is compatible with physicalism. In a world featuring deflationary emergence but not ontological emergence, the complete causal structure of the world is grounded in microcausal structure, but part of this grounding base is micro-latent. Shoemaker sees no reason why the fact that part of the macrocausal structure is grounded in micro-latent micropowers should entail the falsity of physicalism as long as the respective micropowers do not involve obviously nonphysical aspects such as fundamental phenomenality. Moreover, as we have seen, in standard cases of causal irreducibility such as the cases discussed from systems biology, micro-latency obvious does not require such suspect mental aspects. If Shoemaker is right and, as I acknowledge, the micro-latency approach is our best theory of autonomous behavior, it follows that deflationary emergence is not a type of strong emergence, but rather of weak emergence.55 However, Wilson (2015) compellingly objects to the micro-latency approach being compatible with physicalism:

55 Note that this assessment is not shared by Broad (1925) who holds that the micro-latency approach has antiphysicalist implications.

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Understanding Emergence [H]ow are we to make sense of the claim that such powers are compatible with Physicalism, given that these powers do not make an appearance in the laws of fundamental physics and given that they cannot be understood as additive combinations of powers which do make such an appearance? What the proponent of micro-latency needs to do in order to establish that non-additivity is compatible with Physicalism is to make a case that fundamental physical laws might themselves entail violations in broadly additive composition laws when micro-entities enter into emergence-engendering combinations. It is unclear how this can be established however, since composition laws (incorporating, e.g., scalar and vector addition, along with other ‘ontologically lightweight’ – boolean, mereological – modes of combination plausibly preserving physical acceptability) appear to exhaustively encode the broadly additive ways in which micro-manifest entities might combine while preserving physical acceptability. At the very least, at present it remains unclear how a ‘micro-latent’ understanding of non-additivity is supposed to conform to the usual understanding of Physicalism as the thesis that all broadly scientific goings-on are nothing over and above the goings-on explicitly (and not just latently) at issue in fundamental physics. (Wilson 2015: 382)

It seems to be an intelligible requirement for any version of physicalism that it entails that the fundamental laws of physics have universal application. After all, physicalism is the view that everything is either directly involved or grounded in the fundamental causal interactions those laws describe: microphysical entities instantiate these fundamental interactions, and everything else can be reductively explained in terms of these interactions. But the micro-latency approach cannot live up to this requirement: ex hypothesis, micro-latent powers cannot figure in the theories of fundamental physics, because they do not manifest at the micro-level. Nonetheless, micro-latent powers instantiate fundamental causal structure. It follows that the laws of fundamental physics are violated in cases of emergence-engendering combinations of microentities, triggering their micro-latent powers. I conclude that the micro-latency approach is not compatible with physicalism. The issue highlights that physicalism is not just the thesis that all mental entities are either themselves microphysical entities or grounded in narrowly microphysical reality (i.e., the causal structure described by fundamental physics), but also that this thesis applies to any concrete phenomena whatsoever. Note, however, that micro-latency might be taken to be compatible with materialism, where materialism is the view that all concrete phenomena are identical to or grounded in structural properties studied by the natural sciences. Materialism thus understood leaves it open whether those structural properties are microphysical properties, or genuine biological or chemical causal powers which are accounted for in terms of micro-latency. Physicalism is thus a variant of materialism, but there are other variants which allow for deflationary emergence as long as deflationary emergent entities are researchable by some natural science. The only class of phenomena ruled out by materialism is entities which cannot be studied by natural sciences for principled reasons, for which the only plausible candidates are fundamental mentality or protomentality. Yet since fundamental (proto-)macromentality cannot be accounted for in terms of deflationary emergence, but only in terms of ontological emergence, it is safe to say that all plausible candidate phenomena for being deflationary emergent are compatible with at least some variants of materialism.

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Solution III: The New Power Condition

In a series of works, Jessica Wilson has argued that there are just two types of emergence to which all emergent phenomena can be assigned. We already encountered one of those types, metaphysical weak emergence, analyzed by Wilson in terms of the proper subset condition. Wilson considers the proper subset condition to be applicable to all weakly emergent phenomena, making them fall under the type of metaphysical weak emergence. Above, I argued that Wilson is right that the proper subset condition represents a genuine type of weak emergence, but that this is not the only type of weak emergence there is: besides metaphysical weak emergence, for which Wilson provides the correct analysis, there is also another, related but independent type of weak emergence, namely epistemological weak emergence. Wilson’s (forthcoming: chapters 2 & 4) second type of emergence is meant to explain all strongly emergent phenomena. As with metaphysical weak emergence, this second type is also analyzed in terms of powers. What Wilson calls the new power condition explains strong emergence in terms of autonomous power tokens: Token apparently higher-level feature S is strongly metaphysically emergent from token lower-level feature P on a given occasion just in case, on that occasion, (i) S synchronically depends on P, and (ii) S has at least one token power not identical with any token power of P. (Wilson forthcoming: chapter 2) Wilson’s approach to strong emergence is best understood by comparing it with metaphysical weak emergence. Wilson claims that in contrast to metaphysically weakly emergent entities, strong emergent entities do not (or at least not only) have an autonomous set of powers, where all token powers in this set are identical to token powers of the emergence base. Rather, a strongly emergent entity has at least one token power which is not identical to a token power of its emergence base. The most obvious problem with this theory of strong emergence is that the new power condition appears not to be capable of accounting for ontological emergence: by solely characterizing strong emergence in terms of powers, the new power condition leaves out what is usually taken to be the central motivation for assuming a phenomenon to be ontologically emergent. Recall that the case against physicalism is driven by epistemic objections such as Chalmers’ two-dimensional argument which aim to establish the ontological autonomy of phenomenal properties not by arguing that they have irreducible powers, but rather by arguing that they have an intrinsic qualitative nature which is not physically explainable. An account explaining the strong emergence of a phenomenon in terms of its possessing autonomous power tokens cannot possibly capture the phenomenal aspect of qualia. Yet it is the phenomenal aspect which antiphysicalists consider to be the root of the autonomy of qualia. The new power condition therefore cannot accommodate the central motivation for viewing consciousness as strongly emergent. To be sure, Wilson’s account explicitly stays neutral on the question as to what powers actually are. She takes her view to be compatible with both dispositionalism and categoricalist views according to which fundamental powers need quidditistic underpinnings (see Section 5.3.1 on the debate between categoricalist and dispositionalist accounts for fundamental dis-

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positional properties). Nonetheless, even if on a categoricalist interpretation, the new power condition might be understood as postulating that cases of strong emergence are characterized by exhibiting at least one autonomous power token plus its categorical base, this approach cannot capture the crucial point of the antiphysicalist case. As seen in the last chapter, antiphysicalists first and foremost argue that the quidditistic aspects of phenomenal states entail their being strongly emergent entities. Their epistemic objections to physicalism merely concern this qualitative dimension of phenomenal states. This is why these arguments are perfectly compatible with epiphenomenalism; indeed, both Jackson (1982) and Chalmers (1996) utilize them to argue for epiphenomenal property dualism. According to the new power condition, however, the fundamental powers of macroproperties serve as crucial criteria for identifying them as strongly emergent, thereby ruling out the possibility of epiphenomenalism from the start without providing any first-order arguments against the view. And even if epiphenomenalism is not tenable for independent reasons, and any fundamental property needs to have causal powers, Wilson’s approach still cannot capture the antiphysicalist’s prime motivation for rejecting physicalism. Now, Wilson herself is a nonreductive physicalist about consciousness, and considers qualia to be merely weakly emergent. She might, therefore, have no reason to assume that ontologically emergent phenomena exist in our world. But a theory of emergence should aim to be so general as to be capable of explaining all possible types of emergent phenomena, regardless of whether they exist in the actual world. As discussed in Chapter 2, physicalism about consciousness is the thesis that in our world all phenomenality is grounded in narrowly microphysical properties, from which it follows that the physical conditions which ground certain phenomenal properties in our world also ground the same phenomenal entities in all other worlds. The thesis is, however, compatible with dualism in other possible worlds. In such worlds, there might be phenomenal properties which strongly emerge from some emergence bases, maybe consisting of alien material which does not exist in our world. Ontological emergence exists in such worlds—provided that, contra Kim, the concept as such is coherent. Since ontological emergence seems at least metaphysically possible, a satisfying theory of strong emergence should be able to account for this type of strong emergence. Furthermore, the question whether consciousness in our world is ontologically emergent or not should be decided by first-order arguments. A theory of strong emergence should not be biased taking stances on substantial controversies in first-order metaphysical debates. It must be broad enough to be able to accommodate all of the views currently on offer in these debates. Yet, while not being capable of accounting for ontological emergence, the new power condition might still be able to explain strongly autonomous macrobehavior. If so, Wilson’s approach to strong emergence shares the fate of her view on weak emergence: while not being capable of explaining all strongly emergent phenomena, the new power condition represents one genuine type of strong emergence. However, as we say in the last section, Shoemaker’s micro-latency approach provides a very attractive interpretation of deflationary emergence which can overcome Kim’s power inheritance objection by avoiding genuine downward causation. Baysan & Wilson (2017) argue that the new power condition, although involving

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downward causation, can also avoid the objection, and is, moreover, preferable to the microlatency approach. In the remainder of this section, I address the question whether the new power condition is indeed preferable to the micro-latency approach as a theory of strongly autonomous behavior. I first discuss Baysan and Wilson’s solution proposal to the power inheritance objection, and then address the question as to which additional reasons there are in favor of one or the other view. The problem with Baysan & Wilson’s (2017) solution proposal to power inheritance argument is that it is obviously based on a misinterpretation. They assume that Kim’s argument runs as follows: if B is the emergence base of E, then any micro-level effect B* caused by E is also caused by B, since B causes E. The important part is the last clause: Baysan and Wilson believe that Kim first assumes that strong emergence is a causal relation, and then, second, argues that a problem of causal inheritance arises, since any power of an emergent feature is also possessed by the emergence base which caused it, thereby rendering the causal contribution of the emergent feature superfluous.56 But this is not Kim’s point: as seen in the last section above, Kim rejects the possibility that emergence might be taken to be a causal relation. And, as argued there, the rejection of causal emergence is a crucial implicit premise of the power inheritance argument. Kim says, it is not possible to view the situation as involving a causal chain from [B] to [B*] with [E] as an intermediate causal link. The reason is that the emergence relation from [B] to [E] cannot properly be viewed as causal. (Kim 1999: 32; italics in original.) Recall that if the emergence relation is causal, then the power inheritance problem does not arise, since, then, B is not the immediate sufficient cause of B*, and E qualifies as an intermediate link in the causal chain from B to B*. Now, Baysan and Wilson’s solution proposal for what they take to be Kim’s objection is to distinguish between direct and indirect powers: Notwithstanding that [B] synchronically necessitates [E], [B] has these powers only in that [B] is a precondition [...] for [E], which is the more direct locus of the power. (Baysan & Wilson 2017: 78–79) B has the indirect power to produce B*, since it can indirectly cause B* by bringing about E. But only the emergent E has the direct power to produce B*, since only E is the immediate sufficient cause of B*. Given the interpretation of Kim’s argument I suggested above, this is obviously a solution that works only if emergence involves a causal relation: only if the emergence of E from B is causal does it make sense to hold that B has only the indirect power and 56 Baysan and Wilson’s discussion is not very clear on that matter for most of its length, but there is one passage which shows that they assume Kim’s objection to be targeting the causal account of strong emergence. In this passage, in which they discuss a potential strategy for avoiding the objection, they explicitly state that Kim’s argument assumes that B causes E: “[E]ven if it is possible to block taking [B] to cause [E] in cases of strong emergence, there would remain a case to be made that [B] inherits any powers of a feature [E] that at least nomologically depends on it.” (Baysan & Wilson 2017: 65; italics added.)

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not the direct power to cause B*. Interpreted thusly, Baysan and Wilson’s proposal is similar to the view of O’Connor & Wong (2005) in taking the emergence relation to be a process of causal production. But while O’Connor and Wong’s account seem to allow for the production of autonomous qualia which might have powers or not, Baysan and Wilson hold that in cases of strong emergence, merely autonomous power tokens are produced, thus denying the possibility of epiphenomenal ontological emergence.57 Again, this is the reason why the new power condition can only qualify as an account of deflationary emergence, but not as a theory of strong emergence tout court. Recall that in deflationary emergence, we merely have to account for the causal autonomy of macrophenomena. As the micro-latency approach shows, the postulate of fundamental macropowers is not necessary to explain such causal autonomy: the apparently autonomous macropowers can be viewed as grounded in micro-latent micropowers. So why invoke genuine strongly autonomous macropowers if causal autonomy at the macro-level can be accounted for by the postulation of micro-latency? Baysan & Wilson (2017) discuss this objection under the heading of dispositional feature inheritance argument. As in the power inheritance objection, the dispositional feature inheritance argument claims that in cases of strong emergence, the seemingly autonomous causal powers of macrophenomena are in fact grounded in, and thus inherited by, microphenomena. The difference between both objections is that the latter argument invokes a new type of microentities, namely micro-latent micropowers, as grounding bases for apparently autonomous macropowers. The dispositional feature inheritance argument is therefore not an objection against the concept of strong emergence, but rather an argument for a certain emergentist view, namely the micro-latency approach. The power inheritance objection, in contrast, is meant to show that interactionist strong emergence is incoherent: any power a strongly emergent entity might have is grounded in powers of its regular microphysical supervenience base—there cannot be new fundamental powers associated with strongly emergent entities over and above the powers studied in microphysics; strong interactionist emergence which postulates such powers is therefore incoherent. The dispositional feature inheritance argument, in contrast, allows for such new fundamental powers, but argues that there is no need to assume that they are macropowers. Viewing them as micro-latent powers rather than as genuine macropowers appears to be more parsimonious and elegant: there is no need to introduce a genuine emergence relation over and above grounding. Note that the new power account must allow for an additional ontological dependence relation at work in strong emergence over and above well-established relations such as realization and constitution at work in various forms of grounding. Also, the micro-latency option can avoid the various problems of downward causation. In addition, the micro-latency approach does not have to postulate an additional ontological category of fundamental highlevel properties in order to explain strongly autonomous behavior in complex systems. While parsimony and avoidance of downward causation speak strongly in favor of the Broad/Shoemaker micro-latency approach, there might of course be other, even more substan57 To be sure, O’Connor & Wong (2005) only discuss the emergence of powerful phenomenal states. Nonetheless, their conception of emergence-causation is also applicable in an explanation of the emergence of epiphenomenal qualia.

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tive reasons for preferring the new power view. Baysan & Wilson (2017) provide three arguments for the new power condition. Yet I shall argue that they cannot counter the two arguments for the micro-latency view, and do not give us compelling reasons to favor the new power condition in accounting for deflationary emergence. First, Baysan and Wilson argue for a distinction between lightweight and substantive emergent dispositions: lightweight emergent dispositions are micro-latent micropowers to bring substantive emergent dispositions, that is, strongly autonomous macropowers. In other words, Baysan and Wilson acknowledge that strong emergence requires the existence of micro-latent micropowers. But, differing from Shoemaker, they hold that the latter are not themselves the locus of strong emergence but only the precondition thereof: micro-latent micropowers serve as emergence base for the production of strongly autonomous macropowers. Only the latter are genuine emergent dispositions. Micro-latent micropowers, in contrast, are lightweight emergent dispositions in the sense that by serving as emergence bases, they play a crucial role in the emergence process, but are not themselves emergent properties. Baysan and Wilson consider this distinction so as to demonstrate how the identification of emergent powers with micro-latent microdispositions can be avoided. However, rather than giving us reason to favor the new power view, the distinction between lightweight and substantive emergent dispositions makes it clear that the new power view cannot do without micro-latency: the new power condition requires the existence of emergence bases which, in turn, have to be explained in terms of micro-latent micropowers, as Baysan and Wilson acknowledge. If so, then why assume that these micro-latent micropowers are only emergence bases, but not legitimate grounds for emergents? They do not provide an argument against such a reductive explanation of emergent dispositions in terms of micro-latent micropowers. They only point out that micro-latent micropowers are not physically explicable such that the micro-latency approach cannot count as a way of making strong emergence compatible with physicalism. As we saw in the last section, this is true. But the same holds for the new power condition. I therefore see no problem for the reduction strategy which, again, enables the emergentist to avoid the postulation of a genuine emergence relation and downward causation, as well as an additional ontological category of fundamental highlevel properties. Their second argument is based on a specific account of powers developed by Wilson (2002), according to which powers are dependent on fundamental interactions. The idea is that entities have powers relative to fundamental interactions: the disposition of the electron to repel other electrons and to attract protons is grounded in the fundamental electromagnetic interaction. This fundamental interaction specifies that there are two electric charges, negative and positive, such that like-charged entities repel each other while opposite-charged entities attract each other. It is because of the electromagnetic interaction that electrons behave in such and such a way in the vicinity of other charged particles. Physics identified four fundamental interactions as of yet: gravity, electromagnetism, the weak interaction, and the strong interaction. This might not be the complete list of all existing physical fundamental interactions, either because novel, additional interactions will be discovered, or some (or even all) of the known interactions might be reduced to even more fundamental interactions. But whatever the

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final list is, all physical powers are dependent on one or several of the fundamental interactions from this list. Now, Wilson and Baysan argue that the new power condition can be specified in terms of the dependence of powers on fundamental interaction: Feature S is strongly emergent from feature P relative to the set {F} of fundamental physical interactions, just in case (i) S broadly synchronically depends on P, and (ii) S has at least one power that is not identical with any power of P that is grounded only in the fundamental interactions in {F}. (Baysan & Wilson 2017: 86) The idea is that emergentists, when postulating a new type of autonomous macropower, are invoking a new fundamental interaction on which those powers depend. The new interaction is a nonphysical interaction, and is added to the list of fundamental interactions which now comprises of both physical and nonphysical interactions: […] (ii) refines the new power condition [...], making explicit that the sense of “new” at issue adverts in part to a fundamental interaction that is new relative to the set of physical fundamental interactions. (ibid.) However, Baysan and Wilson overlook the fact that given interaction relative strong emergence, the postulation of new macropowers requires not one, but rather two new fundamental interactions: one rooting the ‘lightweight’ micro-latent microdispositions of the emergence base, and one rooting the ‘heavyweight’ macropowers. Since they hold that the existence of micro-latency is incompatible with physicalism, both new fundamental interactions are nonphysical. But then it is clear that the interaction-relative strong emergence is compatible with both the micro-latency approach, and the new power condition. The criterion states merely that strongly emergent powers are based on nonphysical fundamental interactions. It does not specify whether the respective emergent powers and nonphysical interactions are micro- or macrophenomena. And as we saw, the new power emergentist needs a new ‘lightweight’ nonphysical micro-interaction and new micropowers anyway so as to account for emergence bases. So, as with the first, the second argument Baysan and Wilson provide also gives us little reason to invoke additional ‘heavyweight’ macrointeractions and macropowers instead of reductively explaining emergent powers in terms of ‘lightweight’ microdispositions which are needed regardless. The third argument Wilson and Baysan provide is based on Baysan’s (2016) thesis that the bearers of powers are not properties, but rather objects: Being knife-shaped has the power to cut bread—conditionally on being instantiated with certain other properties, of course. When we attribute this power to the property of being knife-shaped, do we really mean that the property itself has this power? […] Properties don’t cut bread. Their bearers might. To generalize, properties don’t (literally or fundamentally) have powers; their bearers do. (Baysan 2016: 386)

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If Baysan (2016) is right, then the existence of powers requires objects, functioning as their bearers: it is not the property of being knife-shaped that has the power to cut bread, but rather the knife itself has this power—of course, in virtue of having the property of being knife-shaped. But if so, then it follows that emergent powers also require objects as bearers, as Baysan and Wilson point out: [...] the fundamentally novel powers associated with a strongly emergent feature are in the first instance powers of a fundamentally novel object suited to instantiate the feature in question. This allows for a principled response to the [dispositional feature inheritance argument]: given that in a case of strong emergence, the strongly emergent feature S is understood as having a fundamentally new power, and given that the powers of features are derivative on the powers of objects, the strong emergentist can reasonably maintain that a fundamentally novel object, different from whatever lower-level object P is required to be the bearer of S. (Baysan & Wilson 2017: 92) However, it does not follow from the assumption that emergent powers come with emergent objects that deflationary strong emergence requires the postulation of fundamental macroentities. The Broad/Shoemaker-approach can accept Baysan’s thesis, but, nevertheless, assume that strongly emergent powers are reducible to micro-latent micropowers, and that the objects which bear them are fundamental microobjects. Moreover, recall that the new powers condition also needs micro-latent powers functioning as emergence bases of strongly emergent entities. If so, given that Baysan (2016) is right, these micro-latent micropowers are instantiated by fundamental microobjects. It seems to be perfectly acceptable to reductively explain both emergent powers and emergent objects in terms of ‘lightweight’ micropowers and their bearers. I conclude that none of the arguments Baysan & Wilson (2017) provide in favor of the new power condition gives us any reason to favor it over the micro-latency account of deflationary emergence. 4.6.4

Solution IV: Emergence as Fusion

Humphreys (1997) provides a theory of strong emergence according to which emergent properties are generated by an idiosyncratic diachronic process of fusion. In a fusion process, base-level properties combine in such an intimate way that a new property is produced, but the base-level properties do not individually survive the process. That is, by fusing, the properties constituting the emergence base go out of existence, being replaced by a novel, strongly emergent property. This emergent property is a primitive entity: since the base-level properties have vanished in the fusion process, the emergent property does not have them as parts, but is a literally atomistic, simple entity. Humphreys holds that the microobjects which bear the microproperties being destroyed in fusion stay intact: while only some of their properties fuse, the objects which bore them survive as individual entities. The resulting strongly emergent property is borne by those objects collectively. Note that on the fusion view, strongly emergent properties do not supervene on lowerlevel emergence bases. Rather, what can be considered emergence bases on this view—the

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fusing base-level properties—is destroyed in generating the emergent property. In other words, Humphreys takes strong emergence to consist of a diachronic production process which takes certain low-level properties as input, and generates a higher-level property as output. Importantly, this high-level property comes with its own set of causal powers which are neither numerically nor qualitatively identical with the causal powers of the input properties. Hence, a system in which fusion takes place bears a different overall set of causal powers as result of the generation of a strongly emergent property. Pre-fusion, the system has a set of causal powers which partly consists of the causal powers of the input properties. Post-fusion, both the input properties and their respective causal powers are vanished and replaced by the output property and its characteristic set of causal powers—the overall set of causal powers of the system is modified accordingly. This constitutes the prime reason why fusion qualifies as variant of strong emergence, rather than as variant of grounding. The output property is something-over-and-above the combination of the input properties, since it has different token powers than those the emergence base possessed. Now, it is easy to see how the fusion view can avoid the powers inheritance objection: since strongly emergent entities do not supervene on their emergence bases, the objection cannot get off the ground. Emergent properties, once created, do not supervene on anything, but are rather ontologically independent entities. Accordingly, there are no lower-level candidates for inheriting their causal powers.58 Humphreys assumes fusion to be reversible: a strongly emergent property can be ‘defused’ into its original emergence base such that the former is annihilated, and the properties constituting the latter are restored. As the micro-latency approach and the new power condition, the fusion view appears only capable of accounting for strongly autonomous causal powers but not able to explain the ontological emergence of consciousness, if such there is. For if fusion is understood as production process in which the output is generated by merging the input, then the output cannot be taken to have a radically different nature than the input. But if antiphysicalists are right and the phenomenal character of consciousness belongs to a different highest type than physical matter, it seems to be implausible that phenomenal properties can be generated by merging microphysical properties. In this respect, fusionism appears to be more restrictive than the causal emergence approach of O’Connor & Wong (2005). While both views assume strong emergence to be a diachronic process, causal emergence appears to come with no principled restrictions with regard to what kind of properties might be created in emergence from a given input. Yet the fusion approach seems capable of accounting for the emergence of consciousness in emergent panpsychism: here, the emergence base of consciousness belongs to the same highest type, and it is plausible that macrophenomenal output can be generated by merging microphenomenal input. In fact, the two most prominent versions of emergent panpsychism defended in the contemporary literature, Seager (2010, 2016) and Mørch (2014), are both variants of the fusion view. I shall discuss these approaches at length in Chapter 7. 58 Humphreys (1997) does not develop the fusion view in answer to the power inheritance objection, but as a solution proposal to the causal exclusion problem, as it is directed against emergentism (see Section 5.4.2 for a discussion of the causal exclusion argument). Nonetheless, for the reasons discussed, the approach can also avoid the power inheritance problem.

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However, when it comes to explaining autonomous macropowers, fusionism is clearly disadvantageous to the most plausible account discussed so far, the Broad/Shoemaker micro-latency approach, because the latter position can do without the introduction of a new fundamental process, and does not have to postulate fundamental higher-level properties. In addition to being less parsimonious and elegant than the micro-latency approach, fusionism is also subject to an objection developed by Wong (2006), the problem of basal loss: Consider a system s with emergent property E. The basal properties giving rise to E also constitute myriad nonemergent, structural properties of s. If these lower level properties literally ceased to be in fusing into E, then so, it seems, would those structural properties. These structural properties may include those crucial to the proper functioning of the system. […] Consider when neurophysiological properties N1 and N2 fuse to form [an] emergent (mental) property [...]. Because N 1 and N2 undergo fusion they will cease to exist. But it is plausible that neurophysiological properties are also recruited in local and global excitatory and inhibitory brain states that are nonemergent. These brain states are complex states involving the instantiation of more than one neurophysiological property. Since they are neither emergent nor simple states, they are structural brain states. (By “brain states” I mean collections of dynamic measurable quantities associated with certain anatomical regions of the brain, e.g., V1, or even more fine grained areas.) (Wong 2006: 355) Wong argues that if base-level properties of a system are destroyed in producing an emergent property, then macrofunctions of the system these properties were realizing cannot be maintained. But if functions of the system collapse as a result of fusion, then this might modify the system in a radical way, maybe even destroy it. Thus, it seems that the basal-loss-feature of fusion emergence entails that systems can only have strongly emergent properties at the cost of losing some of their functions. This is, of course, a strong disadvantage in comparison to rival explanations. However, one might think that the problem might be avoided by assuming that only very few basal-level properties constitute the emergence base: if only a handful of fundamental properties of some elementary particles get lost, then this might not cause the collapse of a complete macrofunction of the whole system. The causal role of these properties might be of negligible importance to the maintenance of the system’s functions. But this solution proposal seems untenable. Strongly emergent properties are usually considered to play a causal role for the macrostructure of complex systems. It is plausible that on the fusion view, this is only possible if many properties are involved in constituting the emergence base. For fusion is a production process in which the emergent output is generated by modification of the input. If so, it is plausible that the input must consist of a very great number of fundamental properties in order for the output to have the capacity to play a causal role comparable to macrofunctions realized by a myriad of low-level entities. Humphreys himself presents the another reply to the basal loss problem. Wong reports the following:

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Understanding Emergence In correspondence, Humphreys has responded that properties entering fusion can, and usually will, be complex properties with multiple components. If we assume that properties are individuated by the causal powers they bestow on their possessors, it is correct to say that the fusing properties cease to exist even though many of their components persist. […] Humphreys maintains that such complex properties can both produce emergent properties through fusion and continue to maintain lower-level effects. […] The parts of the original complex property that remain can then play a completely different, and purely basal, causal role from the emergent property. (Wong 2006: 357)

If fusion processes do not take complete properties as an input, but rather only certain aspects of complex properties, then the original properties might survive, lacking the fused aspects, but still having at their disposal their other aspects. The remaining aspects might then be sufficient to uphold the crucial causal work relevant for the system as a whole done by the respective properties. However, I believe that this reply is not convincing for the following reason. Recall that Barnes (2012) compellingly argues that strongly emergent phenomena are fundamental entities. This also seems in line with Humphreys’ assumption that the fusion products are simple, partless entities. If so, it seems that fusion processes can only take fundamental properties as input. For it seems implausible that, by fusing, a derivative input could be transformed into a fundamental output: how should a process of merging be capable of transforming the ontological status of the merged material? Hence, I take it that only fundamental properties can fuse. Yet it is not plausible that fundamental properties have such complex causal profiles that some of their aspects can be fuse while others remain intact. This is at least the case if we assume that the causal profile of fundamental properties is completely described in physics. The fundamental properties of physics, at least the ones discovered so far, are fairly simple dispositions. Take electric charge. The disposition to repel like-charged entities and to attract opposite-charged ones does not seem to have multiple independent aspects such that one of these aspects can fuse while the others can keep up at least some of the functions which the original property maintained. By contrast, if fundamental properties have in addition to their micro-manifest causal profile described in microphysics also micro-latent micropowers, then Humphreys’ reply is plausible. But if so, the fusion view becomes a variant of the micro-latency approach. Yet the fusion-version of the micro-latency view is a rather unattractive variant, since it involves the postulation of fundamental higher-level properties, and a new primitive process, fusion, both of which can be avoided by the original approach of Broad and Shoemaker: that is, the Broad/ Shoemaker-view is considerably more elegant and parsimonious than the fusion view and, therefore, preferable as an account of deflationary emergence. 4.7 Causal Ontological Emergence In the last section, four different approaches for overcoming the power inheritance objection were discussed. I argued that the Broad/Shoemaker micro-latency account is a perfectly satisfactory theory of strongly autonomous macropowers as deflationary emergence. However, since the approach can merely explain macrocausal structure, it is of limited use for the expla-

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nation of the potential emergence of consciousness. I argued that only a causal conception of ontological emergence along the lines of O’Connor & Wong (2005) can reject the power inheritance objection. For it can be avoided that the powers of emergent macrophenomenal states are inherited by their emergence bases iff the dependence relation between them is a causal process; otherwise, a phenomenal state’s emergence base would qualify as immediate sufficient cause for whatever effect the state causes. Recall that merely the interactionist form of ontological emergence is threatened by the power inheritance objection, since only if emergent phenomena have genuine causal powers, there can be an inheritance of those powers by emergence bases. However, I think that despite not being subject to the power inheritance objection, epiphenomenal ontological emergence also benefits from a causal interpretation. For if the emergence dependence relation is not a causal process, then a novel sui generis primitive relation must be postulated, imposing additional costs on the theory. Hence, if it can be shown that the causal approach can satisfyingly explain dependence, then not only interactionist ontological emergence, but also epiphenomenal ontological emergence should be cashed out accordingly because this is the most parsimonious option. However, while the causal emergence view can overcome the power inheritance objection, it is unclear whether it can also provide a satisfactory characterization of the dependence relation of ontological emergence. Recall that as discussed in Section 4.4, Kim (2006) rightly demands that positive accounts of strong autonomy and dependence must be provided. Moreover, Kim points out that traditional characterizations of both concepts in terms of irreducibility and supervenience cannot live up to this demand: they only provide negative criteria for the respective notions. In Section 4.5, I argued that Barnes’ (2012) proposal to account for strong autonomy in terms of a primitive notion of fundamentality is very attractive: on this view, ontologically emergent phenomena are strongly autonomous in virtue of being fundamental higher-level entities, where the primitivist notions of fundamentality at play here is already well-established for reasons entirely independent of the issue of emergence. However, Barnes only provides an account of strong autonomy, but not of strong dependence. It remains a crucial desideratum to develop a characterization of the dependence relation in ontological emergence. Note that the causal account as presented by O’Connor & Wong (2005) can be taken to partly fulfill this desideratum: explaining the nomological supervenience of ontologically emergent entities on their emergence bases in terms of causation is a first step towards a satisfactory characterization of their dependency. As it stands, however, their theory does not fully suffice as an account of dependence. For causation usually does not involve strong dependence of the effected feature on the causing properties: what is different in ontological emergence such that causal processes here involve dependence of effects on their cause? Let me illustrate the crucial difference between ordinary and emergence-causation with Kim’s (1999) model of an emergence system discussed in the last section. An emergence base B generates an ontologically emergent E which downwardly causes the base-level properties B*. B*, in turn, is the emergence base of E*. If E causes B*, it is not impossible for B* to outlive E, or any other property of the same kind that might replace E in the given system. Yet why is the causal relation between B* and E* different? What is the reason that the causal process in

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which B* generates E* is such that E* cannot outlive B*? (Henceforth, I call normal causal processes ‘ordinary causation’, and causal relations at play in ontological emergence ‘emergence-causation’.) In other words, a characterization along the lines of the causal view is only fully intelligible if it is explained how emergence-causation is different from ordinary causation such that emergence-causation constitutes a dependence relation while ordinary causation does not. The question is: why do causal processes constitute relations of strong dependence iff they figure in ontological emergence? Given the causal approach to ontological emergence, the task of developing an account of the ontological emergence relation can thus be understood as the task of explaining how a causal process can constitute a relation of strong dependence. O’Connor & Wong (2005) do not address this issue. As it stands, their theory can thus be considered to provide a fully satisfactory solution to the power inheritance objection, but it is not an account of ontological emergence capable of meeting Kim’s characterization challenge. In the following, I aim to develop a satisfactory characterization of dependence in ontological emergence. I argue that there are several crucial differences between ordinary and emergence-causation which collectively explain why only emergence-causation constitutes a relation of strong dependence of the required kind. I suggest that all of those differences do not concern the nature of causation as such, but rather either the nature of the causal relata, or the way the causal relation is instantiated. I argue that it is therefore plausible to assume that there is the same type of causal relation at play in emergence-causation as appears in ordinary causation: that is, there is a unique kind of causal relation which can be involved in two different types of production processes. Note, however, that this issue cannot currently be finally decided: I shall argue that emergence-causation appears compatible with most of the major views about causation currently on offer; but we lack a consensus on what causation is, and there might be future accounts incompatible with emergence-causation. If so, emergentists might still adhere to the causal conception of ontological emergence. But they would have to allow for two distinct kinds of causal processes, one of which is at play in ordinary causal relations, while the other occurs in ontological emergence. In this case, emergentists cannot adopt existing analyses of causation, but will have to develop a separate theory of emergencecausation. This would render the view less elegant, and potentially involve the postulation of a primitive production relation. But, in my opinion, the resulting position could nonetheless be considered the emergentists’ best option, since there seems to be no other way of avoiding power inheritance. Note that accounting for dependence is not the only requirement for a satisfactory approach to ontological emergence. Another desideratum is to provide an account of emergence bases. We saw in Section 4.6.3—in the context of the discussion of lightweight emergent dispositions in Baysan & Wilson’s (2017) approach—that emergence bases must be considered as consisting of micro-latent micropowers: micro-latent micropowers, given the appropriate stimuli, initiate a causal emergence process which brings about an ontologically emergent phenomenon. Yet the micro-latency approach as developed by Shoemaker (2002, 2007) is a deflationary account of emergence. In order to fully understand the nature of emergence bases, the role of micro-latency in ontological emergence must be further analyzed, and contrasted with micro-latency in deflationary emergence. Since an account of the nature of emer-

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gence bases is an important prerequisite for an adequate understanding of emergence-causation, I begin with this issue. 4.7.1

Micro-Latent Emergence Bases

Prima facie, the contrast between micro-latency in ontological and deflationary emergence is as follows. Ontological emergence involves a causal process, the product of which is an emergent property or substance. Hence, in ontological emergence, the manifestation of micro-latent micropowers does not itself explain emergent phenomena as it does in deflationary emergence. The activation of appropriate micropowers is only the instantiation of the emergence base, which, in turn, gives rise to an emergent property. The ‘job’ of micro-latent micropowers is not to act as grounds for emergents as in deflationary emergence. Instead, they act as emergence bases for the generation of emergent properties which are full-fleshed strongly autonomous entities. That is, instead of allowing for micro-latent grounding bases, as deflationary emergence does, causal ontological emergence invokes micro-latent emergence bases. If this analysis is correct, there must be two types of micro-latent micropowers. The first type, figuring in deflationary emergence, initiates ordinary causal processes. The second type initiates emergence-causation. In other words, ordinary causation itself comes in two flavors, namely with and without micro-latent micropowers, but, additionally, there is a further type of micro-latent micropowers giving rise to processes of ontological emergence. Hence, the causal approach to ontological emergence involves not only ontologically emergent entities— the product of emergence-causation—but also deflationary emergent entities: that is, emergence bases are constituted by special types of micro-latent micropowers which, given appropriate stimuli, produce ontologically emergent phenomena. Since this form of micro-latency qualifies as deflationary emergence (the micropowers constituting emergence bases are only triggered in very complex surroundings, but never in simple systems studied by microphysics), emergence bases themselves are deflationary emergent entities. 4.7.2

Strong Dependence as Causal Relation

As we have seen, the key phenomenon which a theory of dependence needs to explain is that, in contrast to ordinary causation, emergence-causation sustains its products. For ontologically emergent entities are not only caused by their emergence bases, but also strongly depend on them: they cannot exist without being sustained by their emergence bases. Contrast this with a simple case of ordinary causation. Assume that property A causes property B by having the causal power to produce B given an appropriate stimulus. After having been brought into existence, B can persist without the assistance of A. The interaction between two elementary particles might change the position and the momentum of each particle. The interaction thereby brings about novel spatial and kinetic properties of both particles. These spatial and kinetic properties are not sustained by their cause: one particle behaving in a certain fashion causes new kinetic properties of another particle, yet after the causal interaction, these properties do not supervene on the properties of the former particle. By contrast, products of emergence-causation are caused and sustained simultaneously by the same entities. But how to account for such sustainment? Do we have to introduce a primitive dependence relation, sustainment, in order to explain the permanent dependence of emer-

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gents on their emergence bases? Since such a sustaining relation would have to be an additional fundamental relation, it would qualify as a substantial ontological commitment. Invoking such a mysterious and inexplicable sustainment relation would thus render the causal emergence view rather unattractive. However, I think that there is a straightforward way to avoid the postulation of such an additional relation. Note that in the first instance, subjective experiences are events. My experience of having a headache all morning consists of a series of momentary conscious mental events each of which is short-lived and definite in content and temporal grain. That is, human consciousness flows at a certain speed; it is constituted by successive phenomenal events that encompass approximately a hundred milliseconds. If so, there is no need for a separate sustainment relation in addition to the relation of emergence-causation. For the fact that an individual phenomenal event does not persist independently of its emergence base is due to the fact that it only encompasses a very short period of time. More precisely, it only seems to be the case that a subjective experience cannot exist without being sustained by its emergence base; yet, in fact, once brought about, it exists independently but does do so only for a hundred milliseconds or so. In contrast, my headache which I have all morning is in fact sustained by (and ontologically dependent on) its emergence base: a long-term phenomenal state like this is constituted by a series of phenomenal events arising from one and the same emergence base; and the state can only persist if the neural correlate functioning as its emergence base periodically causes headache-experiences. Hence, on this analysis, there is a clear-cut distinction between phenomenal experiences, short-lived events of subjective experience, and phenomenal states, longer-lasting conscious properties constituted by successive phenomenal experiences arising from one and the same emergence base. While the former are brought about by emergence-causation without also being sustained by their emergence bases, the latter can legitimately be described as being sustained. The reason for this is that, with regard to their continued existence, they are dependent on the continuing causal production of phenomenal experiences by emergence bases. It is this continuous causal production of appropriate phenomenal experiences by which emergence bases sustain phenomenal states. Thus, the sustainment of phenomenal states by their emergence bases can satisfyingly be explained by emergence causation without postulating an additional primitive dependence relation. (Having introduced the distinction between phenomenal events and phenomenal states, I will henceforth use ‘phenomenal property’ as an umbrella term for both phenomenal events and phenomenal states.) Figuratively speaking, on the proposed account, emergence-causation has some similarities to holography. Just as a three-dimensional picture is generated by a light field continuously emitting bundles of laser light rays of varying frequencies in a hologram, in the case of ontological emergence, a high-level fundamental entity is generated by an emergence base whose emergence-engendering microdispositions manifest themselves continuously, thereby continuously producing macrophenomenal events and thus sustaining the emergent macrophenomenal state that these macrophenomenal events ground. A core difference between ordinary and emergence-causation is that the latter is irreducibly pluralistic. The reason is the following. Ontological emergence occurs when certain mi-

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croparticles combine in a specific fashion due to their ordinary dispositions. If they stand in an appropriate relationship to each other as a result of such combination, they constitute an emergence base. That is, when being combined in some particular fashion, micro-latent micropowers are triggered in each of them and these dispositions collectively produce an emergent entity. The causal process at play in such cases is pluralistic. For the micro-latent micropowers act together in bringing about an emergent phenomenon, and no single one of them ever causes any effect individually. In this, they sharply differ from dispositions in ordinary causation, both micro-latent and micro-manifest. Ordinary dispositions first and foremost act individually, and produce effects collectively only insofar as, under certain circumstances, several dispositions are triggered simultaneously and the effect is correspondingly different from any effect they could have brought about separately. But this difference is only quantitative. Acting together, each disposition’s contribution adds to those of the others—either amplifying or counteracting the others’ contributions—thus resulting in a much more complex net effect. Yet the net effect can be traced back to the sum of the individual contributions of each participating disposition. In the case of emergence-causation, by contrast, the effect is qualitatively different from anything that could have been produced by a single disposition individually. More precisely, the type of dispositions at play in ontological emergence can only act collectively. Ordinary causation is fundamentally monistic, and only derivatively pluralistic, namely in cases when dispositions act simultaneously all of which could also have acted on their own. Emergencecausation, in contrast, is a fundamentally pluralistic process due to micro-latent micropowers which are only triggered collectively, but never individually. Perhaps the most significant difference between ordinary and emergence-causation concerns the nature of the causal product. Ordinary causal processes generate structural properties, that is, properties concerning the spatiotemporal location and/or the dynamic evolution of their bearer.59 That is, as a result of being involved in causal interactions, objects have new structural properties of various sorts. They might occupy a different location. They might have new kinetic properties such as different momentum from what they had before. They might bear new relations to other objects, for instance, because of combining with other entities and thus becoming part of a complex system. In contrast, emergence-causation produces categorical properties, or quiddities. For if consciousness is an ontologically emergent phenomenon, then macrophenomenal properties are high-level fundamental quiddities. There are crucial differences between structural and categorical properties. As explained in Section 2.2, if categoricalism is true and fundamental dispositional properties have categorical underpinnings, then the categorical properties which realize fundamental microphysical dispositions are not themselves structural properties. 60 Base-level categorical properties play the fundamental causal roles described in physics due to being governed by metaphysically contingent laws. But their intrinsic nature consists either (if physicalism or dualism is true) in quiddities which do not have any positive character be-

59 See Section 2.2 for a discussion of the difference between structural and categorical properties. 60 See Section 5.3.1 for a thorough discussion of the debate between categoricalist and dispositionalist accounts for fundamental dispositional properties

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yond their pure ‘thisness’, or (if Russellianism is true) in proto- or microphenomenality. On both options, they are essentially categorical, and not structural. Note, however, that on emergentist versions of substance dualism, not only higher-level fundamental qualia are produced, but also primitive mental substances functioning as the bearers of qualia. Relatedly, emergent panpsychism also comes in several versions, depending on how ‘substantive’ macrosubjectivity is taken to be. There are respectively versions of emergence panpsychism which come with primitive, substantive macrosubjects, and versions which only allow for fundamental macroqualia, but provide a reductive explanation of macrosubjectivity. I shall discuss this more thoroughly in Chapters 5 and 7. The important point for the issue at hand is that there are emergentist views which not only come with fundamental macroqualia, but also invoke fundamental macrosubjects. Since such macrosubjects obviously have a phenomenal inner nature (after all, they are assumed to function as primitive ‘experiencers’ of phenomenal states), I shall subsume both qualia and subjects under the term ‘categorical entities’ which then encompasses nonphenomenal quiddities, qualia, and primitive subjects. Could the outlined account also explain the ontological emergence of macrosubjects, provided that they in fact qualify as fundamental entities? This seems to presuppose an account of macrosubjects along the lines of the one provided for phenomenal states: that is, macrosubjects must be taken to be constituted by event-like properties. Yet it is not clear whether the assumption that macrosubjects have an event-like nature is intelligible. At least prima facie, a fundamental subject seems to be a substance. But if macrosubjects are substances, then according to the account of ontological emergence I have defended, they cannot be brought about in causal-emergence processes without introducing an additional primitive sustainment relation. Yet this would render emergentism about macrosubjects extremely unattractive. Therefore, I hold that the emergentist must either demonstrate that macrosubjects can be somehow analyzed in terms of events, or provide a functionalist account of them. In this work, I will stay neutral regarding this issue. Given these considerations about macrosubjectivity, one might say that the difference concerning the respective type of causal product between ordinary and emergence-causation is that the former generates structural properties, while the latter generates some type of fundamental categorical entity: either only macrophenomenal properties or macrophenomenal properties and macrosubjects. Given the suggestion that the same kind of causal relation is at play in both ordinary and emergence-causation, the difference in causal product must be due to differences in either the producing causal relatum, or the laws governing the respective causal processes: that is, emergence-causation produces quiddities instead of structural properties because either the microlatent micropowers which constitute emergence bases have special dispositional essences, or because there are special emergence-engendering laws different in content from ordinary laws of nature. On the first view, the microdispositions of emergence bases essentially have powers to collectively produce phenomenal quiddities. These powers constitute a special type of powers, since ordinary powers can only produce structural properties. On the second view, the microdispositions of emergence bases have categoricalist underpinnings. They do not have their emergence-engendering powers essentially, but rather in virtue of being governed by meta-

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physically contingent laws of nature. If so, then it is due to the special form of emergence-engendering laws that, instead of structural properties, macrophenomenal quiddities are produced. The choice between these two options depends on one’s stand in the metaphysics of dispositions: the first option naturally follows from dispositionalism, whereas the second is based on categoricalism.61 Note that the two types of powers at play in ontological emergence—the micro-latent microdispositions constituting emergence bases and the powers of emergent phenomena— correspond to two types of fundamental interactions. As we saw in Section 4.6.3, Baysan & Wilson (2017) compellingly argue that the powers of strongly emergent entities are based on new fundamental interactions. Given their theory of interaction-relative strong emergence, the causal approach to ontological emergence not only comes with a novel type of new fundamental interaction on which the powers of ontologically emergent entities depend; additionally, the collective powers of the constituents of emergence bases to generate ontologically emergent entities is based on another type of novel fundamental interaction. As ontologically emergent entities are assumed to be involved in ordinary causal interactions, it is natural to assume that the fundamental interaction on which the macropowers of ontologically emergent entities depends are of the same type as the fundamental interactions of physics. The fundamental interactions they are based on, though nonphysical, are structurally very similar to physics’ fundamental interactions, since both bring about structural properties. The fundamental interaction at play in the causal emergence process, by contrast, is structurally very different. Here, interaction takes place between fundamental micro-latent micropowers, but the causal products are not new structural properties of the objects which bear the involved disposition. Rather, the causal product is a new high-level categorical entity. What does it mean to say that the fundamental interaction takes place between base properties, but that the product of the interaction is a high-level entity? Consider the stimulus conditions. Each of the dispositions involved in an emergence base is triggered iff it combines with all 61 As will be discussed in Section 5.3.1, categoricalism is compatible with two major views of laws of nature: the nomic necessitation theory, and the best systems account. On the nomic necessitation view (e.g. Armstrong 1983), laws of nature are analyzed in terms of second-order relations among universals. Emergence laws are then second-order relations which connect (on the condition that appropriate stimuli are instantiated) sets of microproperties to high-level phenomenal properties. On the best systems account (e.g. Lewis 1994), a property’s dispositional profile is the result of the spatiotemporal arrangement of the world’s fundamental categorical properties in a certain fashion. The laws are entailed by this arrangement or mosaic of spatiotemporally related quiddities, and describe the latter’s dispositional profiles, that is, the regularities between the quiddities which figure in each optimal axiomatized theory about the world. Now, if consciousness is an ontologically emergent phenomenon, then the mosaic exhibits the production of higher-level phe nomenal quiddities at various spatiotemporal locations. The emergence laws track the regularities between the phenomenal quiddities and base-level properties which figure in the best psychophysical theories of the world. (As will be discussed in the next chapter, it is a controversial matter whether macrophenomenal properties are spatiotemporally located, or inhabit a merely temporally structured mental realm of their own. If the latter is the case, then the theorems of the best psychophysical theories would have to track spatiotemporal as well as merely temporal relations between structural and phenomenal properties.) Given that the onto logical emergence of consciousness already entails that there are higher-level phenomenal quiddities, then it might seem more natural to combine emergentist dualist views with categoricalism about microdispositions. However, there seems to be no prima facie inconsistency in assuming that consciousness is not only special because it has intrinsic qualities beyond pure ‘thisness’, but also because it is the only type of fundamental property which has an intrinsic nature to begin with, all other fundamental properties being pure potencies.

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other dispositions of the emergence base. That is, due to their ordinary dispositions, multiple particles combine. This combination, in turn, serves as the stimulus for the emergence-engendering micro-latent microdispositions each of the particles is bearing. That is, the stimulus for an emergence-engendering disposition is the presence of all other emergence-engendering dispositions which constitute an emergence base together with the former. Hence, the stimulus condition for an emergence-engendering disposition is irreducibly pluralistic. It is triggered iff all other dispositions of the emergence base are in place. The pluralistic nature of stimulus conditions for emergence-engendering dispositions, of course, is the reason for the pluralistic nature of the causal emergence process. Since emergence-engendering dispositions only manifest collectively, the stimulus condition for the collective manifestation must also be pluralistic.62 The following table summarizes the discussed differences between ordinary causation and emergence-causation. Table 4.3: Similarities and Differences Between Ordinary Causation and Emergence-Causation ordinary causation

emergence-causation

causal product

structural events

categorical events

mode of dependence

causal production

causal production

mode of stimulus and manifestation monistic

pluralistic

Finally, we must address the question whether there are two types of causal relations, or one and the same at work in ordinary causation and emergence-causation. The answer to this question depends on which account of causation one endorses. As noted above, since the debate on the nature of causation is wide open, there can only be provided a preliminary answer. Let me briefly discuss the question of applicability to emergence-causation for some of the major accounts of causation.63 It seems that the outlined causal relation at work in ontological emergence is compatible with regularity views and counterfactual accounts. Regularity views come in two variants, the first of which analyzes causal relations as instances of lawful regularities (e.g. Davidson 1967), and the second of which accounts for causation in terms of nomological sufficiency (e.g. Mackie 1965). Both criteria appear to be fulfilled in emergence-causation: there are fundamental emergence-engendering laws which spe-

62 What are the bearers of ontologically emergent properties? On substance emergentist views which allow for emergent macrosubjects in addition to emergent macrophenomenal properties, emergent macrophenomenal properties are borne by macrosubjects. On property emergentist views which do not allow for emergent macrosubjects, if a high-level property is produced in ontological emergence, then that which is generated in the fundamental interaction of an emergence base is a new property of the system as a whole, in which ontological emergence takes place. It is natural to view the phenomenal properties of complex systems such as higher organisms as properties of a superordinate system. It is not uncontroversial whether this system is the encompassing system; in the case of organisms, this would be the animal, or a subsystem such as the brain. This is a delicate question in personal ontology which I cannot discuss here (see Olson 2007 for an overview on the debate in personal ontology). 63 See Hall & Paul (2013) for an overview on the major rival accounts of causation, and their respective merits and weaknesses.

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cific cases of ontological emergence can be subsumed under, and emergence bases are nomologically sufficient for the generation of emergent entities. Furthermore, it is also the case that ontologically emergent entities counterfactually depend on their emergence bases; recall the emergence-model discussed in the last section: if emergence base B had not occurred, then emergent E would not have occurred. Hence, emergence-causation seems to fulfill elaborate counterfactual accounts such as Lewis’ (1973) classic account and his (2000) largely revised theory that define causation in terms of chains of counterfactual dependence or influence.64 The situation seems different when it comes to process theories of causation according to which causal relations essentially require the transference of some quantity. Standard versions of this view, e.g. Salmon (1994) and Dowe (2000), are very narrowly focused on physics, and only allow quantities which figure in fundamental physical laws such as energy, or momentum. It is obvious that these accounts are not applicable to emergence-causation, which is not a type of process describable by physics.65 However, one might argue that this overly restrictive requirement is a major flaw of the approach. As Hall & Paul (2013) rightly remark, “[process] accounts seem to suffer from a surprising lack of ambition” (38): we can obviously conceive of possible worlds that appear to feature causal relations which do not involve the transference of any conserved quantities. Hall and Paul cite the example of a possible world described by Maudlin (2004) featuring fundamental laws similar to the principles of cellular automata such as Horton Conway’s famous Game of Life: here, causal structure is generated in a space-like framework of discrete cells which are either occupied or unoccupied (alive or dead) depending on the status of their neighboring cells according to four simple rules. Such a world obviously does not feature transference of quantities from cell to cell, yet it appears natural to hold that a particular cell’s life or death at a certain time is caused by the pattern of its neighbor-cells. If so, the transference view seems inadequate as a theory of causation. Be that as it may, we can conclude that emergence-causation appears to be compatible with the majority of the current accounts of causation. This provides us with a prima facie reason to hypothesize that there is indeed one and the same causal relation at play in both ordi nary and emergence-causation. If, by contrast, it turns out that ordinary causation in the end requires an analysis which involves the transference of physical quantities or some other criterion not fulfilled by emergence-causation, then the emergentist is free to hold that there are two fundamentally different types of causal relations. Being rooted in a productive process, dependence in ontological emergence could still assumed to be a causal relation, though of a different type to the familiar one. Of course, this would be a much less elegant option, and the emergentist would have to provide an additional account of the type of causation at work in ontological emergence: the power inheritance argument could still be avoided, but the advan64 Given that ontological emergence appears analyzable in terms of counterfactual dependence, it is of course also possible to provide causal models for processes of emergence-causation along the lines of what structural equation theorists such as Hitchcock (2001) and Woodward (2003) have proposed. 65 Note, however, that not all versions of the process approach limit the range of quantities allowed to those studied in physics. For instance, Ehring (1997) provides a version of the view which merely requires that causal processes involve the transference of tropes, wherein the tropes do not have to be narrowly physical properties.

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tage of parsimony would be lost because the emergentist would have to introduce a new type of fundamental dependence relation. However, I do not think that this would render the causal approach to ontological emergence entirely implausible: as we have seen in the last section, a causal conception seems to be the necessarily precondition for avoiding the power inheritance objection, and if such a conception entails that there is primitive causal relation of ontological emergence, then so be it. 4.7.3

The Explicability of Ontologically Emergent Phenomena

As we have seen, ontological emergence is subject to quite technical objections such as the power inheritance objection, and the challenge of providing positive characterizations of autonomy and dependence. Yet besides these elaborate arguments, a more basic concern about the explicability of ontologically emergent phenomena appears to exist. For instance, Kim (1999) claims, [e]mergent properties, unlike those that are merely resultant, are neither explainable nor reducible in terms of their basal conditions (Kim 1999: 20). If Kim is right and explanations for the existence of emergents cannot be provided, then even if the more technical objections can be rejected, there remains a sense in which emergence is mysterious. I think that this impression of the mystery or magic of emergence underpins the concern of many philosophers that there is something fundamentally wrong with the concept of ontological emergence. However, I do not think that this impression is correct. I believe that a merit of the causal approach is that it enables a straightforward means of explaining ontologically emergent entities. For if emergence is a causal process, then causal explanations of emergent entities can be provided in terms of their emergence bases. By contrast, if ontological emergence is a sui generis primitive relation, then the impression of mystery remains: being primitive, ex hypothesis a further explanation of emergence processes and their products cannot be given, besides the postulation of a fundamental dependence relation, which is only negatively characterizable as being not grounding. As a preliminary to discussing the explicability of ontological emergence, I shall analyze at some length the explicability of the other type of dependent entity besides emergents, namely derivatives. This will provide a helpful contrast for understanding what both types of explanatory endeavors have in common, and wherein they differ. As discussed in Section 2.1, proponents of metaphysical grounding take care to stress that what accounts such as physicalism should be taken to assert is that facts concerning derivatives hold in virtue of facts concerning fundamentals. That is, physicalism is taken to be the thesis that facts concerning neural events explain facts concerning mental events. Accordingly, grounding is a genuine kind of metaphysical explanation, and must be distinguished from other kinds of explanations such as causal explanations. Sider’s (2011) representational version of fundamentalism also allows for this kind of metaphysical explanation, but cashes it out in a different way: truths concerning derivative entities are explicable by fundamental truths via their linguistic connections to them.

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Thus, in the discussed fundamentalist frameworks, ontological dependence of derivatives requires that truths concerning the latter are explainable by truths concerning fundamentals. This also appears to be true of the alternatives to the metaphysical fundamentalism. As discussed in Section 2.1, before the rise of metaphysical fundamentalism, supervenience functionalism was the default way to conceptualize physicalism. On this account, dependence is cashed out in terms of metaphysical supervenience, without properly accounting for ontological priority and the asymmetry of dependence. Within this framework, there was a widespread consensus that in order to show that an entity is reductively explainable by others, one must provide a conceptual analysis of the former in terms of a specific functional role. For instance, genes can be reductively explained, since they can be analyzed functionally: being a gene is to fulfill the causal role of transmitting phenotypic characteristics. As it turns out, DNA molecules fulfill this function. 20th century biologists were thereby able to reductively explain genes in terms of DNA molecules.66 Despite utilizing a hyperintensional notion, reductive explanation in fundamentalist metaphysics works in a similar manner to functionalism. An example is Dasgupta’s (2014) view, according to which essentialist facts about the derivative specify a general connection between the latter and certain fundamentals. This general connection can be taken to amount to the specification of a certain functional role.67 From here, reductive explanation takes steps identical to those in functionalism. Dasgupta’s insistence on essentialist rather than conceptual facts can be traced to his acceptance of Fine’s (1994) primitivism about essence. More generally, one can say that on both views it is something about the derivative that is responsible for its being ontologically dependent: on the discussed accounts, this is a functional role that figures in conceptual or essentialist truths about it. I think it can be demonstrated that this is the case according to most versions of metaphysical fundamentalism. For instance, consider the representational accounts of Sider (2011): sentences concerning derivatives have metaphysical semantics such that truths about derivatives are explainable by fundamental truths. Accordingly, reductive explanation fails iff a functional characterization in terms of lowerlevel entities fails, or, according to representational views, iff there cannot be given a metaphysical semantics. There are two possible reasons for such a failure: either the target entity does not allow for a functional characterization (or metaphysical semantics), or there are no micro-level phenomena that fulfill the function (or there is no fundamental sentence to act as metaphysical semantics). Arguably, the latter cases are incidents of deflationary emergence. In such cases, the specified functional role is played by micro-level entities, but they are only capable of playing these roles due to micro-latent micropowers which only manifest under highlevel circumstances. The former, in contrast, are cases of ontological emergence. Kim (1999)

66 It is usually at least conceivable that the function could, in principle, be fulfilled by other kinds of entities as well, making it multiply realizable. The function of transmitting phenotypic characteristics could be fulfilled by other means than those that evolution chose in the actual world. DNA molecules are a realizer of the function, albeit, the only one we encounter in our world, while there are other realizers in other worlds. 67 To be precise, Dasgupta does not speak of functional roles or functional characterization. However, in cases of kinds allowing for multiple realization, it is natural to assume that the general connection specifies a functional role.

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only considers the former case, and, thus, ignores the possibility of deflationary emergent phenomena. As seen above, Kim (1999) concludes from the fact that a functional characterization of ontologically emergent entities cannot be given that they cannot be explained at all. Thereby, Kim seems to assume that metaphysical explanations must involve a functional characterization of the explanandum. Of course, since ontological emergence is a causal and not grounding relation, fundamental facts cannot play an analogous role in explaining ontologically emergent entities to that which they do in explaining dependent derivatives. None of the essentialist or conceptual truths concerning a fundamental yet dependent entity specifies a functional role. Therefore, the route from functionalization of the dependent to identifying fundamentals playing the respective functional role is closed. But there is an obvious reason for this lack of explanatory analogy: if emergence is a causal process, then a causal explanation of dependent fundamentals can only be given in terms of independent fundamentals. In causal explanations, moreover, effects are explained in terms of their causes. And on the causal view of ontological emergence, the cause is the emergence base and the effect the emergent respectively. It follows that it is not something concerning the explanandum (that is, the emergent) that is responsible for its dependency and which, therefore, can provide an explanation of the emergent phenomenon. Rather, it is something concerning the explanans (that is, the emergence base) which accounts for the explicability of the emergent. Correspondingly, I believe the main reason why emergence seems inexplicable and mysterious to many theorists is that they look in the wrong place for explanations of emergents. Being used to the grounding/functionalist model of dependence, they assume that if there is an explanation, then it must be ‘above’, in something concerning the high-level entity. But ‘up there’ nothing useful can be found: ontologically emergent phenomena do not allow for functional characterizations. From this, it is then concluded that emergents are not explicable at all. Kim (1999) is a prime example. What such critics forget, however, is to look ‘at the bottom’. Once this crucial difference between both types of dependence is acknowledged, causal explanations of ontologically emergent phenomena can easily be given. Such phenomena are explicable in terms of a specific type of micro-latent microdispositions figuring in emergence bases and the power of those dispositions to causally produce ontologically emergent entities. Again, there are several options how to cash out this explanation: there is a dispositionalist option which allows for primitive dispositional essences and derives emergence laws from the dispositional profiles of the powers constituting the emergence base; alternatively, there are categoricalist options which provide a reductive explanation of these dispositions in terms of emergence laws, which, given the best systems account, in turn, might themselves be reductively explainable.

5

Alternatives to Physicalism

In Chapter 3, I argued that physicalism is not tenable because neither phenomenal consciousness as such nor the special epistemic gaps of the mind-body domain allow for a reductive explanation in terms of microphysical phenomena. The subject of the chapter at hand is to introduce two alternatives to physicalism: dualism and Russellian monism. Furthermore, I discuss various problems raised in respect to dualism. As will become clear, the constitutive version of Russellian monism can avoid these objections, and therefore seems preferable to dualism. Moreover, I argue that of the two variants of Russellian monism, panpsychism, due to its parsimony and greater explanatory force, is preferable to panprotopsychism. Problems for constitutive Russellian panpsychism, some of which also apply to constitutive Russellian panprotopsychism, are then discussed in the following chapter. Beforehand, some terminological clarifications are in order. I shall make use of Chalmers’ distinction, introduced in Section 2.2, between categorical bases and structural microproperties, that is, the difference between the quidditistic nature and the scientifically examinable profile of fundamental properties. The structural properties studied by (ideal) microphysics can be described as narrowly microphysical properties, while the term ‘broadly microphysical’ denotes the structural plus quidditistic aspects of those properties. I use the term ‘macrophenomenal’ to describe phenomenal states of higher animals. This is in contrast with ‘microphenomenal’, which denotes qualia of elementary particles. I will begin by providing a systematic overview of the accounts of phenomenal consciousness addressed in what follows. This is only meant to provide a rough means of orientation as to the similarities and differences of the various approaches to explaining the production of macroconsciousness. A detailed discussion of the views is then provided in the following sections. 5.1 Varieties of Antiphysicalism As discussed in Chapter 2, physicalism is the view that macrophenomenality is wholly grounded in the structural properties studied by ideal microphysics. Antiphysicalism comes in two broad variants, dualism and Russellian monism, each of which has numerous different versions. Accordingly, dualism has two varieties, Cartesian and emergent dualism. Cartesian dualism allows for a mental realm completely separated from the physical universe, which is inhabited by eternal souls. Those souls are fundamental, ontologically independent mental substances which only occasionally come into contact with the physical world, forming exclusive causal partnerships with a certain animal organism, usually for the whole lifetime of the organism. Emergent dualism, by means of contrast, abandons the idea of a separate mental realm and assumes that macrophenomenality ontologically emerges from structural microproperties. This view may be encountered in two versions: property dualism, which only invokes macrophenomenal properties, and substance dualism, the view that there are also irreducible mental macrosubstances. In the last chapter, we saw that microproperties need addi-

© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2020 F. Klinge, Panpsychism and the Emergence of Consciousness, https://doi.org/10.1007/978-3-662-62258-2_5

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tional structural aspects to those examinable by microphysics in order to act as emergence bases for macrophenomenality. Therefore, dualism cannot be understood as the view that macrophenomenality emerges from the structural properties studied by fundamental physics. However, it is crucial for dualism that only structural aspects of microproperties are involved in producing macroconsciousness. For it is only given this strict criterion that one can make sense of the difference between dualism and Russellian monism. Differing from both physicalism and dualism, Russellian monism takes the categorical bases of microphysical properties as such to be operative in bringing about the consciousness of humans and other animals. The idea is that these categorical underpinnings play two foundational metaphysical roles at once:68 on the one hand, they realize microphysical dispositions such as electric charge, spin, or mass, and, on the other, they generate macrophenomenality. That is, our phenomenal states are not produced by the structural aspects of microphysical properties, but rather by their quidditistic natures. More precisely, Russellian monists are committed to the claim that our phenomenal states are first and foremost produced by quiddities qua quiddities. Importantly, this does not entail that structural aspects cannot also play a role in producing macrophenomenality. On the contrary, most Russellian monists assume that microquiddities only produce macrophenomenality when appropriately combined. That is, macrophenomenality is produced by microquiddities iff their bearers stand in certain spatiotemporal and causal relations to one another. For instance, one might hold that macrophenomenality only arises if elementary particles combine to form certain complex structures such as the brains of higher organisms. If so, not only quiddities qua quiddities but also their structural aspects are instrumental in bringing about macrophenomenality. In the next chapter, we will see that not all contemporary Russellian monists assume that structural aspects play a role in the production of macrophenomenality. Therefore, it is best to characterize Russellian monism as the view that microquiddities as such produce macrophenomenality, perhaps along with structural microproperties. Russellian monism comes in two variants: panpsychism and panprotopsychism. Panpsychism is the view that the microquiddities which generate macrophenomenality are themselves phenomenal states, while panprotopsychism holds that they are nonphenomenal. Panprotopsychism can only be negatively characterized in terms of quiddities which are not phenomenal properties, as panpsychism assumes; indeed, panprotopsychism claims that their nature is not epistemically accessible to us. Nonetheless, panprotopsychism takes quiddities as such to produce macrophenomenality—hence the name ‘protophenomenal’. Both variants of Russellian monism come, in turn, in two versions, depending on which type of ontological dependence relation they invoke: constitutive Russellian monism is the view that macrophenomenality is grounded in micro- or protophenomenality, while emergent Russellian monism is the view that macrophenomenality ontologically emerges from microor protophenomenality. As with dualism, emergent panpsychism and panprotopsychism have two versions: one which only invokes macrophenomenal properties, and one which also allows for macromental substances. 68 Russell (1927) was one of the first to develop this idea, hence the name ‘Russellian monism’. The eminent astronomer Eddington (1928) was another early proponent of the strategy.

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Constitutive Russellian monism has attracted considerable attention in the last few years, since it appears to be capable of avoiding the most severe objections to dualism. Hence, it is this version, rather than the emergentist one, which will primarily be discussed in this chapter. Note that there are also non-Russellian versions of panpsychism and panprotopsychism. For one can assume that elementary particles have categorical aspects which produce macrophenomenality, but which are different, in turn, from those categorical aspects which realize microphysical dispositions. Yet such views have no chance of overcoming dualism’s problems, as will become clear in the following. To my knowledge, there are no contemporary proponents of these positions. Besides emergent panpsychism, there are two other non-constitutive versions of panpsychism: identity and autonomous Russellian panpsychism. Identity panpsychism holds that every token macrophenomenal state is identical to a singular token microphenomenal property. Autonomous panpsychism assumes that there is both fundamental micro- and macrophenomenality, but denies any ontological dependence between them. In this chapter, I shall ignore both of these views, and concentrate on constitutive and emergent versions of Russellian monism; I will instead address them in Chapter 7, where I argue that both are not tenable. Table 5.1: Accounts of the Production of Macrophenomenality view

mode of production

nonreductive physicalism

grounding

emergent dualism

ontological emergence

constitutive Russellian panpsychism constitutive Russellian panprotopsychism emergent Russellian panpsychism emergent Russellian panprotopsychism

production base

producing entities

structural properties studied by structural produc- (ideal) microphysics tion base structural microproperties microphenomenality (perhaps along with structural microproperties)

grounding categorical production base ontological emergence

protophenomenality (perhaps along with structural microproperties) microphenomenality (perhaps along with structural microproperties) protophenomenality (perhaps along with structural microproperties)

identity Russellian panpsyidentity chism

microphenomenality

Cartesian dualism autonomous Russellian panpsychism

none

none

none

Here is a detailed plan for the following sections. I begin with a short section on the two versions of dualism, namely substance and property dualism. In Section 5.3, I then discuss the Russellian strategy, and analyze how Russellianism is embedded in the more general controversy between the two major theories as to the nature of fundamental dispositional properties, namely dispositionalism and categoricalism. I argue that the traditional formulations of both views face severe difficulties, but that the Russellian version of categoricalism can reject these

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problems. If so, then, in addition to providing an attractive take on the mind-body problem, there are also independent reasons for adopting Russellianism. In Section 5.4, I address the various problems that have been raised against dualism. While I think that—contra to what is widely believed—the most prominent objections, the pairing problem and the causal exclusion argument, can be rejected (at least in the form in which they are usually presented), I put forward a novel problem, the fundamental interaction problem, which I take to be more severe. In Section 5.5, I discuss constitutive Russellian monism’s account of macromental downward causation. In the last section, I argue that of the two versions of Russellian monism, panpsychism is preferable to panprotopsychism. 5.2 Dualism As has been seen, dualism comes in two broad variants, substance and property dualism. On the former view, the bearer of macrophenomenal properties—and perhaps other mental states —is a primitive mental substance. Traditional versions of substance dualism such as Descartes’ usually take this substance to be an immortal soul which inhabits a separate, nonspatial realm and only contingently comes into contact with the physical world. On this view, the soul is an eternal, self-sustaining being which forms an intimate causal connection to a specific organism for a certain period of time only. The soul survives the death of the organism and, on views allowing for reincarnation, might even enter a causal partnership with a new organism at a later time. Moreover, a soul’s causal relationship to a certain material being is an exclusive connection: my soul only interacts with my body, and not with yours. As we will see, it is a considerable challenge for the substance dualist to provide an account of this exclusive causal connection. There are also emergentist versions of substance dualism, a prominent proponent of such an approach being Lowe (2008). According to such views, the soul is not an eternal, self-sustaining substance, but rather ontologically emerges from an appropriately structured organism or other type of system; it is viable to hold that non-organic entities such as future AI systems might also constitute emergence bases for mental substances, though it seems that most substance dualists would resist such claims. The emergent soul is not a substance in the sense of being purely self-sustaining—after all, it ontologically depends on its emergence base. So, in what sense might then the soul be a substance? It is a substance in the sense of being the bearer of phenomenal properties and perhaps other mental kinds. Although a material system gives rise to the soul, it is the latter (and not the former) which instantiates phenomenal properties. It is not the material system, but rather only the emergent soul that is a subject of experience. The traditional dualist has plausible reasons for postulating mental substances. For it is only so that she can ensure the immortal life of souls. But why invoke them on an emergentist view? Is it not redundant to postulate emergent mental substances in addition to emergent mental properties if both are taken to be ontologically dependent on material objects? Arguably, as has been seen in Chapter 3, in order to explain phenomenal consciousness, it suffices to invoke irreducible macrophenomenal properties. Why not just assume that the brain or some other appropriate material system bears them? Of course, in difference to other prop-

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erties of the brain, phenomenal properties are emergent. But this only means that they are fundamental higher-level properties, and not—as ordinary macroscopic properties the brain bears —reducible to microphysical phenomena. Prima facie, the assumption that a material system can bear such properties does not seem problematic. However, in Chapter 3, we saw that the dualist might have to allow for a genuine mental operation of acquaintance being at play in the application of direct phenomenal concepts. It is not clear whether the bearer of this acquaintance relation can be a physical entity such as the human brain. It might be plausible to suppose that a physical entity bears nonphysical properties. But is it plausible that a physical object can also bear an intimate, physically inexplicable intrinsic relation of acquaintance to those properties? If not, property dualism might have to give way to substance dualism. To my knowledge, this question has not really been addressed in the literature on qualia. In this work, I will stay neutral regarding this issue. Nevertheless, it must be addressed by antiphysicalists in order to provide a fully satisfying account of consciousness. Note that the issue is also of importance to emergent Russellian monism. For it is also here that we encounter fundamental macrophenomenal properties. If they cannot be borne by physical systems, then the emergentist Russellian monist has to invoke emergent macrosubjects, too. 5.3 Russellian Monism Russellian monism is a specific version of categoricalism about fundamental dispositions. In order to fully understand the commitments the position possesses qua being a version of categoricalism, it is useful to discuss the debate about the nature of dispositions. This debate concerns two major accounts, dispositionalism and categoricalism, that have been provided for explaining fundamental dispositional properties. This analysis reveals, as I shall argue, that Russellian monism is the most promising theory of fundamental dispositions. For both dispositionalism and categoricalism are subject to severe problems, respectively. Yet the Russellian version of categoricalism can avoid the objections to categoricalism. In addition to the arguments from the debate about consciousness, this provides further strong reasons for endorsing Russellianism. I begin by focusing on dispositionalism and the differences between it and categoricalism, before then discussing what I regard to be the most severe objections to both views respectively. 5.3.1

Dispositionalism and Russellian Categoricalism

It is widely agreed upon that many of the properties figuring in microphysics are dispositions. For instance, electric charge is the disposition to repel like and to attract opposite charge. Generally speaking, dispositions are causal role properties of exhibiting a certain type of behavior—the manifestation of the disposition—in reaction to a specific type of affection by other properties—the stimulus of the disposition. For instance, charge has the manifestation properties of attracting or repelling behavior which is triggered by stimuli of like or opposite charge. Taking their justification from cases such as charge, dispositionalists commit themselves to the following claims: first, that all fundamental properties are dispositions, and second, that

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fundamental properties have their dispositional profiles essentially, and do not have a nontrivial nature beyond the causal roles they play. However, it not obvious that all properties figuring in fundamental physics can be characterized dispositionally. The most problematic case is arguably spatiotemporal properties, which appear prima facie not to be dispositional. Yet microphysics invokes spatiotemporal properties, since elementary particles occupy spatiotemporal locations. We therefore have good reason to assume that spatiotemporal properties are fundamental. Hence, the dispositionalist has to provide an analysis according to which they nonetheless turn out to be causal powers. Such accounts have indeed been developed; for instance, Bird (2007a: chapter 7) argues that General Relativity can be taken to imply a dispositional view of spatiotemporal properties: [According to General Relativity] [e]ach spacetime point is characterized by its dynamical properties, i.e. its disposition to affect the kinetic properties of an object at that point, captured in the gravitational field tensor at that point. The mass of each object is its disposition to change the curvature of spacetime, that is to change the dynamical properties of each spacetime point. Hence all the relevant explanatory properties in this set-up may be characterized dispositionally. (Bird 2007a: 166) On Bird’s view, mass and spatiotemporal properties are ‘causal partners’, playing the roles of stimulus and manifestation for each other. This is certainly an interesting idea. Yet I do not know whether it is ultimately tenable. Furthermore, we simply do not know whether all properties studied by not only contemporary but also ideal physics allow for a fully dispositional characterization. But if so, dispositionalism is a promising candidate for a general theory as to the intrinsic nature of fundamental properties. An advantage of this view is that it takes physics to reveal the full nature of fundamental properties, these being purely narrowly microphysical dispositions. Moreover, dispositionalism has the merit of allowing for an attractive account of laws, according to which the laws of microphysics are entailed by the nature of fundamental dispositions. For instance, the laws of electromagnetism are derived from facts such as that charge by its nature has the power to repel like and to attract opposite charge. Since laws are grounded in dispositions, which have their causal profiles essentially, on this view laws are metaphysically necessary: that is, in all worlds featuring electromagnetism, electric charge repels like and attracts opposing charge. As we will see, this is a key difference to categoricalist views of laws which take them to be metaphysically contingent. One can argue that dispositionalism is perfectly parsimonious and elegant, since it takes physics to fully disclose fundamental reality. Dispositionalists allow microphysics to reveal the full nature of fundamental properties and the laws by which they are governed such that they have the characteristics discovered by physics not only in the actual, but also in all other worlds they inhabit. Even if it turns out that only some but not all fundamental properties figuring in ideal physics are dispositions, one can still assume that those which, in fact, allow for dispositional characterizations are essentially purely dispositional, while the other fundamental properties are accounted for differently. Such a mixed view is a version of dispositional essentialism, the view that those fundamental properties which are dispositions are essentially purely disposi-

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tional. This might still be considered an attractive view, providing a parsimonious account of fundamental dispositions, according to which physics reveals their full nature. Nonetheless, the majority of theorists in the debate on fundamental dispositions believe that dispositions cannot be primitive, but must rather have a non-dispositional intrinsic nature. One consideration in particular plays a crucial role here: essentially dispositional properties come with primitive modality, but most philosophers believe that our fundamental ontology should be non-modal, and we therefore must allow for reductive accounts of modal relations. For one thing, Armstrong (1997) argues the modal nature of brute dispositions makes them Meinongian: a primitive disposition permanently has a fundamental manifestation property, even if this manifestation is not triggered; in fact, the disposition even has it if the manifestation is never triggered. Hence, by accepting primitive manifestation properties, the dispositionalist is committed to fundamental non-existent entities. Another reasoning is provided by Lewis (1986a), who famously argues for a reductive account of modality in terms of purely actual properties, and—in order to account for counterfactuals—properties instantiated in other possible worlds. However, Lewis’ account involves modal realism, the thesis that all possible worlds concretely exist. Armstrong (1997), in contrast, believes modal reductionism can be achieved by grounding the dispositional nature of properties in second-order nomic necessitation relations between universals. On behalf of dispositionalism, Bird (2007a: chapter 5) replies that Armstrong’s solution cannot dismiss primitive modality since nomic necessitation itself is a modal relation, while modal realism comes at the cost of an extremely inflated ontology, hardly a price worth paying. However, contra Bird and Lewis, one might hold that full-blown realism about possible worlds is not necessary for a solution along the lines of Lewis’ proposal—however, this is part of a complicated debate as to the nature of modality which I cannot enter into here. In the end, the debate is between two opposing principled stances: some find the idea of primitive modality deeply unintelligible, while others see no problem with such a view. Instead, I shall discuss an argument which more narrowly focuses on the specifics of dispositionalism, without invoking grand metaphysical convictions. But, before this, a few words on alternatives to dispositionalism are necessary. Critics of primitive dispositions adopt to categoricalism, according to which fundamental dispositional properties have categorical grounds, intrinsic features which realize their dispositional profile. How can we make sense of these quidditistic underpinnings? As Bird (2007a: chapter 4) points out, ‘categorical’ must be understood in negative terms. That is, a categorical property does not confer of necessity any power or disposition. […] Properties [...] have no essential or other non-trivial modal character. [...] The essential properties of a natural property are limited to its essentially being itself and not some distinct property. (Bird 2007a: 66–67) On categoricalism, the nature of fundamental properties is independent of their dispositional profile. In fact, this intrinsic nature constitutes their only non-trivial essential character-

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istic. It merely consists of the brute fact that the property is identical to this property and distinct from all other properties. Note that this is different on Russellian versions of categoricalism. Here, quiddities are taken to be proto- or microphenomenal properties: they have a positively characterizable essence, being either some kind of subjective experience, or a protophenomenal feature capable of constituting qualia. While it is only in the case of panpsychism that we possess a positive concept of these features (with regard to their general characteristics they resemble the qualia we enjoy), in the case of panprotopsychism, they also have specific qualitative characteristics beyond their mere being themselves and not a different property—we merely lack any cognitive access to these qualities. But what about the dispositional features of properties? Categoricalism supposes that the dispositional profiles of fundamental properties are assigned to them by the metaphysically contingent laws of the world they are located in. While in the actual world, negative charge acts as the power to attract positive charge, there are other possible worlds in which negative charge repels positive charge. Within the categoricalist framework, two major theories of laws have been developed: the nomic necessitation theory and the best systems account. On the nomic necessitation view as developed inter alia by Armstrong (1983), laws are second-order relations between fundamental properties (Armstrong takes them to be universals), thereby enabling causal connections between them. That is, a fundamental law of nature is a second-order universal that relates first-order universals. Armstrong uses ‘N’ to symbolize such second-order relations. A fundamental disposition D is then analyzed as follows: N((D&S),M), where S is the stimulus, and M the manifestation property of D. N((D&S),M) entails lizax((Dx&Sx)→Mx), but not vice versa, since there might be accidental true generaliza tions not being rooted in causal relations. Importantly, the fact that N holds is metaphysically contingent: in other worlds, D has stimulus and manifestation relations to other properties. On the best systems account proposed by Lewis (e.g. 1994), in contrast, a property’s dispositional profile is the result of the spatiotemporal arrangement of the world’s fundamental categorical properties in a certain fashion. The laws are entailed by this arrangement or mosaic of spatiotemporal related quiddities, and describe their dispositional profiles. That is, there are one or several theories which systematize the local facts about the mosaic in a fashion which achieves an optimal trade-off between strength of explanatory force and simplicity of assumptions. Fundamental laws are all those true generalizations about a world w which figure as axioms or theorems in these ‘best systems’ describing w. That is, given that lizax((Dx&Sx)→Mx) is a true generalization in w, it is a fundamental law of w iff it is an axiom or theorem in a best theory about w. As the physicalist version of categoricalism, Russellian monism is compatible with both accounts of laws, the difference being that proto- or microphenomenal quiddities are amongst the categorical properties connected by fundamental laws. Note that Russellian monists are only committed to the thesis that at least some categorical properties are proto- or microqualia, yet they can allow for quiddities which are not proto- or microphenomenal. For instance, electric charge might be grounded in microqualia, while spin is realized by quiddities which do not come with nontrivial positive essential characteristics.

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The Circularity Objection to Dispositionalism

Besides general considerations regarding modality, what might be wrong with dispositionalism? A number of commentators, among them Robinson (1982) and Lowe (2006), have argued that dispositionalism due to its identity criteria for fundamental properties faces a problem leading to a vicious circle; here is Lowe’s version of the argument: [On dispositionalism] each power is the very property that it is at least partly in virtue of being a power for a certain kind of manifestation. But if all properties were powers, then all manifestations of powers—being properties of their bearers —would themselves be powers, likewise ‘getting their identity’ from their manifestations. The problem here is […] that no property can get its identity fixed, because each property owes its identity to another, which in turn owes its identity to yet another—and so on and on, in a way that, very plausibly, generates either a vicious infinite regress or a vicious circle. (Lowe 2006: 138) Take an arbitrary fundamental type of property A. According to dispositionalism, the essence of A is given by its having a certain dispositional profile, that is, by the fact that in reaction to a certain stimulus, A instantiates a certain manifestation. The manifestation of A, in turn, is another type of property, B. Given dispositionalism, B also has no nature beyond having a certain dispositional profile which determines its manifestation of another property, C, given certain types of stimuli. It follows that C also manifests another property which, in turn, manifests another property, and so on. Since it is implausible that there is an unlimited number of kinds of fundamental properties, this chain of interdependent dispositions is not an infinite regress, but rather a circle, in which some link N has as manifestation A, thus completing the circle. In order to get his argument off the ground, Lowe has to (implicitly) assume that the identity of a property is fixed by its essence. I take it that this is a plausible assumption. Yet if the identity of A is fixed by its relationship to N and B, then A can only have a determinate identity if some property in the chain of interdependent types of properties, of which A, B, and N are parts, has a determinate identity. But every link in the chain owes its identity to its relationship to other links which—themselves owing their identity to further links—also do not have a determinate identity. The last link N then (partly) owes its identity to A whose lack of determinate identity was the root of Lowe’s problem. It follows that there is no type of property which can fix A’s identity. However, if the identity of A cannot be derived from its dispositional profile, then A must have a nature beyond this profile. Yet if A has non-trivial essential features either in addition or instead of its dispositional character, then dispositionalism is false. In conclusion, the root of this problem is that dispositionalism does not take the identity of fundamental properties to be primitive but, rather, to be dependent on other entities. Lowe argues that this idea cannot be made intelligible; if the identity of dispositions depends on other dispositions whose identity, in turn, depends on others, then we either face a regress or a vi cious circle.

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In reply to the objection, Bird (2007b) argues that the dispositionalist can avoid this conclusion by assuming that the identity of A does not depend on the individual stimulus and manifestation relations it bears to other dispositions. Rather, A’s identity is grounded in the whole pattern these relations form with the stimulus and manifestation relations of all other fundamental properties.69 As Bird points out, this pattern of interdependent stimulus and manifestation relations can be represented by a graph wherein the relations are visualized by the edges, and the dispositions themselves by the vertices of the graph. If the graph is asymmetric, and therefore not automorph, then the vertices’ identity is grounded in the graph’s structure, which, in turn, is determined by the pattern of the edges. In order to represent various other essential characteristics of a stimulus-manifestation pattern, Bird (2007b) introduces a number of additional constraints which I cannot go into here. The important point is that there are graphs which fulfill all of these desiderata. Bird demonstrates that there are indeed structures of dispositions which are circular but which, nonetheless, can satisfyingly ground the identities of the involved dispositions. Of course, the tenability of this approach depends on the contingent empirical fact whether the fundamental properties stand in a structure with the right characteristics. But this question can only be decided by ideal physics. Hence, Bird’s solution can only reject the circularity objection by making dispositionalism vulnerable to potential empirical refutation. While vulnerability to potential empirical refutation might be considered a somewhat weak point of Bird’s proposal, I think that there is a more severe problem facing the account. As has been seen, the identity of a fundamental property depends on the whole structure of relations with other fundamental properties it has due to its stimulation and manifestation relations. But then, there cannot be electric charge in other worlds featuring an additional fundamental property, Γ, which does not exist in the actual world. For some such worlds, this might be plausible. For instance, assume that in w2, there is a property, charge#, which has an analogous dispositional profile as charge except for the fact that its manifestation is not repelling behavior but another property, namely Γ. If so, then it is plausible that charge# is not identical with charge. Yet consider w3 in which there is charge* which has an analogous dispositional profile as charge, yet Γ occupies a remote link in the chain of stimulation and manifestation relations of which charge* is a part. That is, charge* has analogous stimulus and manifestation properties as charge—it is merely the case that at some remote link in the overall stimulus-manifestation pattern of fundamental properties, there occurs a link, Γ, which has no analogon in the actual world. If this is the case, then it seems plausible that charge* is identical to charge. However, Bird cannot allow for such identity, since the overall pattern fundamental properties stand in is different from the one of the actual world. Let me illustrate this with an example. Suppose that physicalism is true about our world. In contrast, w3 is a world inhabited by Cartesian souls. But besides that, w3 features analogues of all of the fundamental dispositions of the actual world, having exactly similar stimulus and manifestation properties to the ones of our world—except for mass*, which has the same dispositional profile as mass but, in addition, also interacts with Cartesian souls. Let Γ be a fun69 At least, this conception works for the circular case where the relations build a closed structure, and not a infinite line of relations as in the regress case. But again, since it is plausible that there is a finite number of fundamental property types, the circular case is the one which concerns us here.

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damental mental force those souls possess. Again, Γ does not directly interact with charge* but only with mass*. To be sure, mass* is then not identical to mass, since their dispositional profiles diverge. But I consider it plausible that charge* is identical to charge: charge* has exactly analogous stimulus and manifestation conditions to charge—it is only the case that mass* is triggered differently than mass due to the influence Cartesian souls have on mass*. Why should this difference in the stimulation conditions of mass* in comparison to mass entail that charge* is not identical to charge, although charge and charge* have exactly analogous stimuli and manifestations? Again, Bird cannot allow for the identity of charge and charge*. Since the identity of charge supervenes on the complete structure of its stimulation and manifestation relations and the pattern charge*’s identity supervenes on is slightly different because it encompasses one additional link, Γ, charge and charge* cannot be identical. That is, Bird’s proposal entails an extreme holism with regard to the identity of fundamental dispositions: if only one dispositional profile in the whole pattern of stimulus and manifestation relations is slightly modified, then the identity of all fundamental dispositions is altered—regardless of whether they stand in direct relation to the modified disposition or not. I do not say that one could not defend such a view; however, such an extreme form of holism with regard to the identity of fundamental dispositions strikes me as highly counterintuitive, and thus a prima facie reason for abandoning dispositionalism. Note that the circularity problem only concerns dispositionalism, but not mixed views which allow for both primitive dispositions and fundamental properties with categorical grounds. For on such views, the identity of the primitive dispositions is secured by the categorical properties to which they stand in manifestation and/or stimulus relationships. 5.3.3

The Power-Swapping Problem for Categoricalism

The power-swapping problem is a well-known argument against categoricalism which has inter alia been put forward by Black (2000) and Lewis (2001). I discuss the version presented by Bird (2007a: chapter 4). For the sake of simplicity, Bird frames the objection in terms of universals. But it can also be directed at versions of categoricalism which assume that fundamental properties are tropes instead of universals. The argument is based on the following case of transworld property-identity: assume that in the actual world, w1, universal F is mass and universal G is electric charge, and that the possible world, w2, is alike to w1 in every respect except for the fact that F plays the charge-role and G plays the mass-role. That is, in w2 the charge-role is played by mass, whereas the mass-role is played by charge. Now, Bird complains regarding w2, “[...] it is just the actual world plus a decision to swap the names ‘gravitational mass’ and ‘charge’” (Bird 2007a: 75). In addition to transworld power-swapping, categoricalism also allows that two types of properties in one and the same world can have the same powers. For if the identity of a property has nothing to do with it possessing certain powers, then it cannot be ruled out that two different types of properties realize the exactly same powers. In other words, the following is a genuine possibility if categoricalism is true:

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Again, the only criterion for their being different universals is that both F and G have the primitive property of being essentially the properties they are and different from any other universal. It is easy to see that Russellian versions of categoricalism can avoid the power-swapping objection. On Russellian monism, quiddities as such have a determinate qualitative nature beyond their being identical to the property they are and distinct from other quiddities. For on both Russellian panpsychism and Russellian panprotopsychism, quiddities as such are capable of producing macrophenomenality because they have a substantive nature which qualifies them for being production bases of macrophenomenality. This is evident in panpsychism, where quiddities are phenomenal properties. Also on panprotopsychism, it is assumed that certain types of quiddities must combine in order to generate macrophenomenality. However, does this allow protophenomenal properties to avoid the power-swapping argument? Do they have a positive nature beyond their brute identity? I think that they have to have substantive essences because it is only due to some type of qualitative—though nonphenomenal—nature that they are capable of producing macrophenomenal states. Let me analyze this more thoroughly. On constitutive panprotopsychism, it is obvious that the qualitative character of macrophenomenal states derives from the character of a specific combination of microquiddities. Therefore, they must have a certain qualitative yet nonphenomenal nature. Furthermore, since there is a variation in macrophenomenal character depending on which combination of microquiddities serves as a production base, different types of microquiddities must have varying qualitative characters. It is then natural to assume that one type of quiddity, sharing a certain qualitative nature, realizes electric charge, while another type, also sharing the same character, realizes mass. If there is a world which is identical to ours except for the fact that the powers of these types of quiddities are swapped, then this world is qualitatively very much different from our world. Moreover, since the production of macrophenomenality is at least partially dependent on the specific qualitative character of the microquiddities serving as production base, then facts about macrophenomenality will also be extremely different in this world. For similar reasons, emergent Russellian panprotopsychism is also not subject to the power-swapping objection. Moreover, on this view, the production base of different macrophenomenal states consists of specific combinations of types of microquiddities such that in any world with swapped powers, there will be different macrophenomenal states than in our world. It follows that no versions of Russellian monism is subject to the power-swapping objection. This can be considered an important argument for the view. Usually, the commitment to the counterintuitive idea of the existence of micro- and protophenomenality is considered a high ontological cost for Russellian monism. But, as has been seen, the assumption that quiddities have a nontrivial qualitative character is not only vindicated by allowing for an attractive solution to the mind-body problem. Rather, it is also required to solve a severe problem for categoricalism. The Russellian monist can therefore argue that this is a cost which propo-

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nents of physicalist versions of categoricalism also have to incur in order to avoid the powerswapping objection—the difference between physicalist and Russellian versions of ‘qualitative’ categoricalism being that only the latter take quiddities as such to ground macrophenomenality. Of course, physicalists can bite the bullet and accept the conclusion that there are qualitatively identical worlds which nonetheless do not coincide in all their nontrivial intrinsic facts. Yet it can legitimately be argued that this is at least as counterintuitive as the assumption that quiddities have qualitative characteristics. I take it that the power-swapping argument is of considerable help to Russellian monists in fighting the ‘the incredulous stare’ attitude physicalists so often display towards panpsychism and panprotopsychism—in light of powersswapping, it can legitimately be answered with a ‘tu quoque’. 5.4 Problems for Dualism Most of the prominent objections that have been raised against dualism concern mental downward causation. Qualia appear to cause various sorts of physical events: my headache seems to make me take pain-killers and the prospect of experiencing an orgasm appears to make me have sex. Already raised by Elisabeth of Bohemia in a letter to Descartes, perhaps the oldest concern with the causation of mental substances is the lack of an appropriate nexus between fundamentally mental and physical properties that could root a causal relation between them. 70 However, this concern stems from a process approach to causation according to which causal relations require the transference of some quantity. If so, it is hard to envisage how a nonspatial, purely mental substance could possibly interact with physical systems; for both kinds of entities belong to different ontological categories which do not have any nontrivial properties in common—and if there is no nontrivial type of property both can possess, then there are no quantities which could possibly be transferred between them. However, the process view of causation is highly contentious, and the argument can easily be rejected if the dualist adopts another theory of causation which does not require the transference of quantities such as the counterfactual analysis. Another traditional worry, famously raised by Leibniz against Cartesian dualism, is that the causal impact of fundamental mental properties is incompatible with the principle of the conservation of energy. According to laws of conservation, certain physical quantities are conserved during causal interactions. If so, souls can affect physical systems only in such a way that there is no change in the total amount of the quantities that have to be conserved. Whether this makes mental causation impossible obviously depends on the question as to which kinds of physical quantities must be conserved. Papineau (2001) provides a detailed historical survey of the conceptions of the conservation principle during different scientific periods. Papineau explains that Descartes thought of conservation in terms of scalar, that is, nondirectional, quantities such as motion, while Leibniz took the principle to require the conservation of vectorial, that is, directed, quantities such as momentum and kinetic energy. 70 For ease of presentation, I discuss the following two objections as being directed against substance dualism. With minor modifications, they can, however, also be leveled against property dualism.

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There is no problem for mental causation if scalar quantities are to be conserved. However, if vectorial quantities must be conserved, then mental causation seems impossible. For if so, then mental causation cannot change the direction of physical causal pathways on pain of violating their vectorial characteristics: conservation of energy in combination with conservation of momentum wholly determines the direction and speed of the motion of particles. But if mental causal impact can neither change the direction nor the speed of physical pathways, then there is no way for a mental property or substance to influence the behavior of the body it is connected to. In contrast to its predecessors, Newtonian physics does not come with such strict conservation laws. This stems from the fact that the concept of force Newton introduced into physics superseded the old mechanical paradigm, according to which there is only one way a physical entity can impact another, namely via direct contact. Furthermore, after Newton’s detection of gravity, other fundamental forces have been discovered such as electromagnetism, and there is no principled restriction on the number of fundamental forces or interactions in contemporary physics. To every force there corresponds a certain type of energy, whereby types of energy can be transformed into one another. As discussed in the last chapter, the dualist is free to introduce novel fundamental forces. Such mental forces are then added to the list of the fundamental interactions physics invokes; and conservation merely requires that the total amount of energy is preserved. As Papineau points out, the dualist can assume that mental interaction comes with its own type of energy such that mental energy is transformed into various kinds of physical energy and vice versa. Hence, the conservation principle in its contemporary form is no threat to interactive dualism.71 However, in the last decades, these traditional arguments against dualist mental causation have been refined. The pairing problem is a modification of the causal nexus worry. In contrast to the latter, it is not based on a contentious theory of causation but describes a general problem for the intelligibility of mental causal powers independently of any specific conception of causation. As the conservation argument, the causal exclusion problem is based on an empirical premise justified by scientific findings, though this premise is entailed from con71 More precisely, Papineau argues that deterministic mental causation is not ruled out by conservation laws. Yet he argues that this principle nonetheless rules out spontaneous mental causation as figuring in libertarian free will: “The content of the principle of the conservation of energy is that losses of kinetic energy are com pensated by build-ups of potential energy, and vice versa. But we couldn’t really speak of a ‘build-up’ or ‘loss’ in the potential energy associated with a force, if there were no force law governing the deployment of that force. So the very idea of potential energy commits us to a law that governs how the relevant force will cause accelerations in the future” (Papineau 2001: 25). However, Rauschenberger (MS) points out that there are cases of physical causation in which there is no transfer of energy. An straightforward example is a space station which orbits a planet and is thereby affected by the gravitational pull of the planet. Yet the gravitational pull transfers no energy whatsoever; Rauschenberger explains: “The energy communicated to it would be equal to the work performed on it by the gravitational force. But the work performed by a force on a body is defined as the scalar product of the force vector and the vector representing the displacement of the body. If the space station does perfect circles around the planet, the displacement vector is always perpendicular to the force vector, which means that their scalar product is always zero. No work is being done, no energy is being communicated” (Rauschenberger MS). As the example demonstrates, physical causation does not necessarily require any transfer of energy, and therefore also not necessarily the conservation of any communicated amount of energy. Yet if this is not a requirement for physical causation, then it could hardly be one for mental causation. Hence, it seems that libertarian mental causation cannot be ruled out by complaining about its violation of the conservation principle.

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temporary research. I shall argue that there prospects for dualism to avoid both problems. However, I will develop another more severe mental causation problem for the position, namely the fundamental interaction problem. 5.4.1

The Pairing Problem

The pairing problem was first developed by Foster (1968), but rose to prominence thereafter in Kim’s (e.g. 1973, 2005) formulation. The problem as presented by Kim is directed against substance dualism. However, I shall argue that it also applies to property dualism. Kim argues that causation requires an extrinsic framework that comes with external relations which pair causes to their effects. In the case of ordinary macroscopic causation, it is spatial relations which serve as pairing-relations. Consider the case of Susie and Steven who simultaneously both throw a rock. As a result, two windows, A and B, break. Now, what determines which rock caused which window to break? In order to answer this question, it seems we have to trace the spatial relations from A’s breaking to Susie’s and Steve’s throwing respectively, and the same has to be done for B’s breaking. Suppose that Susie’s throwing stands in the correct spatial relation to A’s breaking, but Steve’s throwing does not. If so, this establishes the fact that her throwing, rather than his, caused A to break. Kim suggests that this method can be generalized: not only in everyday cases of macroscopic causation, but in all possible causal processes, there must be extrinsic pairing relations which root the causal facts. To support this thesis, Kim considers potential cases of causation in a purely mental world without a spatial but with a temporal dimension, only to find that causation cannot possibly exist in such worlds. Consider a mental world which features two mental substances C and D that, at time t0, have exactly similar intrinsic properties, amongst them the power to cause property f in souls with certain characteristics g. A moment later, at t1, soul E, which has g, acquires f. Suppose further that it was D which caused f in E. Yet what is the fact of the matter that determines that D rather than C caused E to have f? It seems that this causal fact cannot be brute, but rather requires a plausible explanation. In contrast to the above rock-throwing case, causation in a purely mental world takes place in a merely temporal framework, lacking any spatial dimension. As the example suggests, this seems not to suffice for rooting causation: in order to uniquely pair effects to their causes, it appears to require a full-blown spatiotemporal framework. As Kim explains, [c]ausal relations must be selective and discriminating, in the sense that there can be two objects with identical intrinsic properties such that a third object causally acts on one but not the other, and, similarly, that there can be two intrinsically indiscernible objects such that one of them, but not the other, causally acts on a third object. We believe that objects with identical intrinsic properties must have the same causal powers or potentials, both active and passive [...]. However, objects with the same causal powers can differ in the exercise, or manifestation, of their powers, vis-à-vis other objects around them. This calls for a principled way of distinguishing intrinsically indiscernible objects in causal situations, and it is plausible that spatial relations provide us with the principal means for doing this. (Kim 2005: 85)

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The problem carries over to the interaction between mind and body. Suppose that there are two mental substances with exactly similar intrinsic properties. Both perform exactly similar mental doings m1 and m2. M1 causes the physical effect p1, while m2 causes p2. Here, we encounter a similar pairing problem to that in the purely mental case. If there is no extrinsic spatiotemporal ordering relation, then there seems to be no fact of the matter which can ground the respective pairings. Note that in contrast to the causal nexus worry discussed above, the pairing problem cannot be avoided by adopting the counterfactual analysis of causation. As Bennett (2007) explains, […] if [p1] counterfactually depends on m1, we can always ask why – and our answers are tightly constrained by the fact that m2 and [p1] are not so connected. Why does [p1] counterfactually depend on m1, given that it does not counterfactually depend on m2? (Bennett 2007: 320) For similar reasons, other reductionist accounts such as the nomological subsumption approach are also of no help to the dualist. However, as long as the problem only concerns substance dualism, this might not be any great cause of concern for the antiphysicalist. For, as discussed above, the standard antiphysicalist arguments seem only to entail that there must be a dualism of properties, but not of substances. Yet, contra what Kim suggests, I think that the pairing problem also applies to property dualism. Of course, on this view, there are no selfsustaining mental entities, but merely ontologically dependent emergent macrophenomenal properties. But, as explained above, the fact that macrophenomenality is emergent by itself does not explain how macroqualia can causally interact with physical properties. If they are not located in spacetime, they are obviously subject to the pairing problem.72 The pairing problem is a considerable challenge to all versions of interactive dualism. In reply to Kim’s argument, O’Connor (2000) aims to develop an intelligible case of nonspatial causation. If O’Connor succeeds in providing such a case, then this demonstrates that causal relations between objects not inhabiting a common spatiotemporal framework are indeed possible. This, in turn, would rescue substance dualism from the paring problem. O’Connor considers a nonspatial mental world in which souls are located by a mathematical ordering system that consists in the souls’ having information of their respective location in the system. Furthermore, each soul can form intentions for changing its location as well as the location of other souls in the order. These intentions function as causes, and bring about variations in the structure of the system by relocating individual souls. However, the problem with O’Connor’s case is that the intentions and location-informations are purely intrinsic properties. Yet as Kim points out, our concept of causation seems to allow for selective causal pairings between entities with identical intrinsic properties. By assuming a quasi-spatial ordering rooted in location-information and intentions of souls, O’Connor rules out the possibility of such selective pairing of entities with identical intrinsic features from the very start. Those in72 Note that it is not inconsistent to assume that a material system such as an animal brain can have nonspatial immaterial properties. If these properties are ontologically dependent on a specific state of the system such that they expire if this state is not in play, then it makes sense to regard them as properties of the system in question, even if they are not located in spacetime.

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tentions and the information souls have about their location are intrinsic properties of the souls, and ex hypothesis two souls cannot have the same intrinsic properties. For if two souls have the same intrinsic properties, then they would inhabit the very same location in the world’s ordering framework, making it impossible for them to cause numerically different effects by having the same intentions. To summarize, the pairing problem is based on two core premises. First, causation requires external relations which uniquely pair causes to their effects. Second, spatial relations are necessarily part of causal pairing—in particular, temporal relations by themselves do not suffice for pairing. Accordingly, there are two solution approaches available to the dualist: either she attacks premise one, or premise two. The first strategy, defended by Audi (2011) and Bailey et al. (2011), amounts to taking causation to be a brute relation: causal relations do not require external pairings, because they are irreducible, primitive relations which by themselves provide unique pairings between causes and their effects. Causal primitivism, or causal singularism, as the view is also called, has been defended for reasons that have nothing to do with mental causations. Tooley (1990) argues that there are cases of physical causation involving probabilistic laws which cannot be accounted for by reductionist theories about causation but only by causal primitivism. Consider, for instance, a world in which it is a fundamental law that a certain type of particle A having property f has a 50% change of bringing about property g in nearby particles of type B. Suppose that in this world, two intrinsically indiscernible particles of type A which both have f are equidistant from a particle of type B. A moment later, the latter particle acquires g. What makes it the case that one of the former particles caused the latter to have g rather than the other? We can neither cite differences in non-trivial intrinsic properties, nor relevant differences in spatiotemporal location—both type-A particles do have different spatial locations, but they are equidistant from the type-B particle—in order to establish that one of them was the cause while the other was not. It seems that there are causes of purely physical causation for which the pairing problem arises. Now, Audi and Bailey and colleagues point out that the dualist can argue that the pairing problem is not unique to the mind-body case, requiring a general solution in terms of causal singularism: certain cases of probabilistic physical causation and additionally certain causes psychophysical interaction demonstrate that causation is not accountable in terms of noncausal facts, but rather primitive. It is just a brute fact that a causal relation holds between certain events but not others—it is a not further explainable fact that one of the two type-A particles causes the type-B particle to have g, and that m1 causes p1, while m2 does not. However, the problem with this reply is that causal singularism is widely rejected. The standard account of cases of physical causation for which the pairing problem arises, defended inter alia by Lewis (1986b) and Schaffer (2008), is that there is no fact of the matter which of several equally qualified candidate-events causes a certain effect. Yet this is no option for the dualist: in contrast to cases of probabilistic physical causation where it does not make a substantial metaphysical difference which of two equally qualified events in facts causes a certain effect, it does make a substantial metaphysical difference whether m1 or m2 causes p1. The difference is especially severe if embodiment, that is, the exclusive causal partnership between a particular soul and a certain organism, is accounted for in causal terms, as

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is done by many dualists, among them Foster (1991) and Audi (2011). However, if we account for pairing problems for physical causation without invoking causal singularism, it appears somewhat ad hoc to postulate singularism merely to explain psychophysical causation. Moreover, this move makes dualism incompatible with many of the most widely endorsed theories of causation. I conclude that the first strategy comes at the considerable cost of committing the dualist to a contentious theory about causation. It might therefore be preferable to evaluate the remaining option of attacking premise two instead of premise one. This strategy has been opted for by Foster (1991) and Unger (2006) who argue that there are individualized laws connecting specific minds and bodies. The idea is that, due to these individualistic laws, we get custom-fit pairings of minds and bodies. My body is the only material object which has the disposition to interact with my mind and vice versa, while your body has an exclusive access to your mind.73 Note that this solution proposal is based on a rejection of causal generality for mind-body interactions. There are neither two bodies, nor two mental substances with exactly similar intrinsic properties. All bodies are different since even if they share all possible qualities they can share, they still differ in their special individualized dispositions. The same is true for minds. Therefore, we do not need extrinsic pairing relation in the mind-body domain. An exclusive causal pairing is already guaranteed by the internal make-up of the respective causal partners. Wong (2007) provides an extensive discussion of various ways to cash out the individualized dispositions/laws approach. Arguably the strongest version is an emergentist view, according to which the individualistic dispositions are not taken to be primitive. Rather they are rooted in general dispositions of bodies to acquire individualized dispositions for the particular mind they produced. Hence, the matching of causal partners is entailed by the emergence process in which a particular body brings about a particular mental substance. Wong describes the causal pairing connection as […] a kind of sui generis singular relation that holds between an individual and the system that generates it, which then provides the basis for selective interaction. (Wong 2007: 188) But the fact that a certain emergence base generates a specific mind is merely a historical emergence fact. I do not see how such a fact could ground an exclusive causal pairing between emergence base and emergent. If ontological emergence is a type of causation, as argued in the last chapter, it is not plausible why a causal relation as such—the one between emergence base and emergent—should be capable of grounding an exclusive channel for future causal interaction for the emergent. In order to provide the emergence relation with such power, we would have to enrich the relation with additional content over and above being a specific type of causation (as described in the last chapter). 73 Unger (2006) defends the idea in terms of individualized powers, instead of laws. But this is just a dispositionalist versions of the same account, grounding laws in dispositions instated of reducing dispositions to laws. For easy of presentation, I will henceforth discuss the approach in terms of dispositions but anything I say could be translated in law-talk.

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I see no other way how this might be done besides the following. Note that individualistic dispositions are fundamental causal powers, or at least they must be grounded in fundamental powers. In particular, their individualist nature is primitive. The reason is this. It cannot be the case that a number of general microdispositions constitute a fully unique individualistic macrodisposition. For any group of particles with the general dispositions in question could ground this macrodisposition, rendering it not individualistic. Hence, the fundamental dispositions at play in the constitution of an individualistic macrodisposition must themselves be individualistic. But the following can legitimately be the case: each particle of the universe comes with its own individualistic disposition; when particles combine in order to form an emergence base for a mental substance, the combination of their individualistic dispositions grounds an individualistic macrodisposition for the whole organism of which they are parts, which is then uniquely paired with the emerged mind via this particular disposition. The individualistic macrodisposition can be interpreted as being part of the causal process, or as a process which acts alongside emergence. Both interpretations are possible, though I tend to favor the latter because it does not require a revision of last chapter’s theory of emergence. This version of the individualistic law approach does, therefore, entail that each and every elementary particle in the universe comes with a unique individualistic disposition. However, as Wong points out, there is a major empirical problem for such a view. Organisms are not stable systems. Rather, they are subject to continuous metabolic overturn, changing large numbers of their ultimate constituents on a daily basis. Hence, it does not suffice for the dualist to account for the initial generation of individualistic psychophysical pairings; she must also explain how later instantiations of the organism in question constituted by different particles can come to have its special individualized macrodisposition. Wong discusses different forms this problem can assume depending on what mereological theory (e.g. nihilism or restricted composition) the dualist accepts. But, to make a similar point as above, I think it is safe to say that, regardless of the mereological details, the individualized disposition of the organism must in any case be grounded in dispositions of its ultimate constituents. For as long as the organism is a derivative phenomenon, it is plausible that it inherits its causal powers from the set of powers of its ultimate constituents in a somewhat similar way to that in which functional properties inherit their powers from their realizers (see Section 4.3.2). Hence, elementary particles which are part of an organism connected to a particular mind must also have individual dispositions in order to ground the mind-body pairing. The problem is then that all elementary particles in the universe must be capable of acquiring all individualistic dispositions which allow for causal interaction with all existent or even (nomologically) possible minds. For a particle which is now in my brain can in the future be part of your organism, and might already have been a constituent of Aristotle’s body. Wong concludes that this entails a gigantic proliferation of individualistic dispositions: each elementary particle of the universe must possess as many individualistic dispositions as there are nomologically possible minds. These dispositions are most of the time latent, and only when a particle joins a certain organism does the particular individualistic disposition matching the mind-body pairing of the organism become activated. In other words, due to metabolic turnover, there is a continuous switch of the individual components of the emergence base. When a certain particle is removed from the system and a

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new particle takes its place, then this particle has to assume its role in order to sustain the individualistic macrodisposition rooting the psychophysical pairing of the system. But the new particle can do so iff it possesses an exactly similar individualistic disposition to the former particle. For only then can it replace the former because this very individualistic disposition (and only this disposition) is required to fill the place of the former. This entails that all particles must have myriads of latent individualistic dispositions which qualify them to interact with all possible minds in the history of the universe. This is a very counterintuitive assumption to say the least. I doubt that it could be taken to be part of an attractive version of dual ism.74 There is an alternative way to cash out the individualistic laws approach. Instead of assuming that the individualistic causal powers of its fundamental constituents qualify a specific material object to exclusively interact with a certain soul, the dualist might postulate psychophysical laws involving haecceitistic facts.75 Given the emergentist account discussed above, this would mean that psychophysical laws specify that a given soul interacts only with the parts of the body it emerged from. That is, given haecceitism, the particular material entity which functions as emergence base for a certain soul has an individual essence. 76 Now, for every soul, there is a psychophysical law specifying that the soul can only interact with the particular material entities from which it emerged. That is, upon emergence, a certain soul is exclusively connected to a particular material object due to a custom-fit psychophysical law that this particular soul can only interact with the fundamental constituents of this particular object, whereby the law specifies the haecceitistic essence of both the soul and the physical object from which it emerged. At the core of haecceitism is the thesis that entities with individual essences can change their parts without losing their identity. If so, the particles constituting the object at a given time do not need to have individualistic causal powers in order to be capable to interact with the soul. Rather, their being part of a object whose individual essence figures in a particular law renders them able for causal interaction with a particular soul. Hence, on this account, an explosion of individual causal powers can be avoided.77 I think that this version of the individualistic laws approach faces several serious concerns. First, it is based on the truth of haecceitism about both medium-sized material objects and souls. Yet haecceitism is a contentious doctrine which is not widely accepted (see Cowling 2016). 74 Unger (2006) argues that minds are capable of conveying individualistic dispositions on physical entities such that they provide the bodies they are about to establish a causal connection with the required features. However, such transmitting already is a causal notion; conveyance of individualistic dispositions on physi cal entities requires that the latter already possess individualistic dispositions. 75 In the literature, it is often not distinguished between these two ways to cash out the individualistic laws ap proach. However, I think both accounts are clearly distinct: on the first, we assume that fundamental parti cles exhibit individualistic causal powers only allowing them to interact with a certain soul having the right answering power. Here, there is no reference to primitive haecceitistic essences at play. On the second, in contrast, there are psychophysical laws which mention individual essences of particulars such as souls and ordinary objects. On the second approach, it might not be possible to reduce laws to fundamental disposi tion, at least, I cannot see how it might be done. The first approach, in contrast, can probably be cashed out either in terms of primitive fundamental powers, or in terms of some reductive theory of powers. 76 Material entities functioning as emergence bases for souls might be either whole organisms, or relevant part of an organism such as its brain. 77 Although it is not entirely clear, Foster’s (1991) proposal seems to correspond to a Cartesian (that is none mergentist) version of the haecceitistic approach.

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Second, even if haecceitism about such entities is true, and there are, in fact, individual essences of the appropriate kind, then it seems highly implausible that psychophysical laws do mention such haecceitistic facts. For haecceitistic facts about derivative phenomena are not fundamental facts: they concern the individual essences of derivative entities. It seems strange if nonfundamental facts figure in fundamental laws. Recall Sider’s pureness requirement for fundamental facts as discussed in Chapter 3. The pureness requirement seems also to apply to fundamental laws since fundamental laws are ingredients of fundamental reality, or at least grounded in fundamental facts. At this point, the dualist might adopt a somewhat analogous move to that of Dasgupta’s approach of the grounding of grounding facts: she might argue that haecceitistic facts are autonomous in Dasgupta's sense.78 But, in contrast to Dasgupta's account of the grounding of grounding facts, the haecceitistic laws approach takes autonomous facts to figure in fundamental facts as such. Since psychophysical laws govern the causal interactions of irreducible souls, they are fundamental laws of nature, and as such part of fundamental reality. It appears strange to have the fundamental theory of fundamental reality mention all sorts of haecceitistic facts: while on Dasgupta’ account, grounding facts are grounded in autonomous facts, on this interpretation of the haecceitistic laws account, autonomous facts figure among the facts which are part of fundamental reality. For fundamental laws are obviously part of fundamental reality. But then our fundamental theory about fundamental reality would mention all sorts of autonomous facts about the individual essences of ordinary objects. Note that this is not the case on Dasgupta’s account of grounding. Here, autonomous facts merely figure as grounds of grounding facts. Those grounding facts, being themselves grounded, are not part of fundamental reality, and neither are autonomous facts. Hence, on Dasgupta’s account, fundamental reality complies to the purity requirement. But even if the dualist rejects purity and allows for autonomous facts to figure in fundamental laws, the account seems unattractive. For it entails an explosion of fundamental laws and corresponding fundamental interactions. The reason is that each individualistic psychophysical law is fundamental, because it is irreducible to more basic laws. While there is a general law-formula along the lines of the one given above (a given soul interacts only with the parts of the body it emerged from) individual psychophysical laws securing unique pairings for particular souls have to mention particular individual essences. This makes them irreducible to a general psychophysical law along the lines of the law-formula. It follows that ideal theory about fundamental reality must mention myriads of fundamental psychophysical laws and corresponding fundamental interactions in addition to a few fundamental laws and corresponding interactions invoked by fundamental physics. Such gigantic proliferation of fundamental laws and interactions massively inflates fundamental theory: the list of fundamental laws and interactions would have the size of a rather weighty tome. I conclude that none of the solution proposals to the pairing problem discussed seems promising. Yet there is an easy way to provide immaterial macroqualia with spatial location. The dualist has just to adopt the Russellian strategy, according to which phenomenal states realize structural properties. If so, macroqualia are macroquiddities which realize certain struc78 Note that Dasgupta himself would not allow for such an application of his framework, since he rejects haecceitism (see Dasgupta 2009).

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tural properties in the same way that according to Russellian panpsychism, microphenomenal properties realize microphysical dispositions. In contrast to Russellian panpsychism, what might be termed Russellian dualism does not equip microqualia with the tools to realize microphysical dispositions. Rather, on Russellian dualism, macroqualia act as quiddities for additional nonphysical structural properties. Yet this they do in much the same way as Russellian panpsychism’s microqualia ground microphysical structural properties. I conclude that the pairing problem can be avoided if the dualist allows for such a Russellian account of macrophenomenal properties. Note that this solution can also be applied to substance dualism. The only difference between Russellian property and Russellian substance dualism is that the bearers of macrophenomenal quiddities are not physical systems, but rather mental substances. 5.4.2

The Causal Exclusion Problem

The causal exclusion argument has been put forward by various philosophers under a variety of names and comes in various versions. Kim’s (e.g. 2005) version is probably the most influential of these. It can be directed against both nonreductive physicalism and dualism, but also against other emergentist views such as emergent Russellian monism. On all those views, mental kinds have a certain autonomy: they are not straightforwardly identical to physical kinds but merely supervene on them, yet for different reasons respectively. Recall that on nonreductive physicalism, mental states are grounded in physical properties and thus metaphysically supervene on them, while on dualism and emergent Russellian monism, qualia emerge from certain microproperties—which are either physical or proto(micro)phenomenal —and thus nomologically supervene on them.79 On all views, there is reason to assumes that their ontological autonomy gives rise to causal autonomy; that is, given that certain mental properties are irreducible, they will also have irreducible causal powers. Now, the causal exclusion argument objects to the causal autonomy of supervenient phenomena. In the following, I will discuss Kim’s (2005) version of the argument, albeit somewhat deviating from his presentation. I discuss the problem as it applies to nonreductive physicalism and dualism. In this chapter, I ignore the way that emergent Russellian monism might deal with the problem as this will instead be discussed in Chapter 7. Kim’s version of causal exclusion argument has two stages. First, Kim argues that when a supervenient macroproperty causes another property, it must downward-causally impact properties of the lower level it supervenes on, regardless of the caused property being micro or macro. Assume that a supervenient property E causes another supervenient property E* inhabiting the same ontological level. In order to cause E*, E has to bring about E*’s supervenience base B*, since E* is ontologically dependent on B*: in order to get the former, one must bring about the latter. It follows that same-level causation from E to E* involves downward causation from E to B*. In the second stage of the argument, the premises Completeness and No Overdetermination are introduced. Completeness claims that any caused microphysical event has an immediate sufficient microphysical cause.80 No (systematic) Overdetermination allows that there be 79 Recall that most dualists allow for standard functionalist analyses of mental states other than qualia. 80 The qualification ‘caused’ is due to the fact that certain quantum events do not have a determinate cause.

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cases of contingent overdetermination: for instance, the case of a barn that burns down because someone commits arson and it is simultaneously struck by lightning (where both causes are sufficient for the barn’s destruction) qualifies as contingent overdetermination. The principle denies the existence of systematic overdetermination. A case of overdetermination is systematic if certain types of causal chains sufficient for a certain type of effect (for instance, from mental to physical) always co-occur with other types of causal chains (for instance, from physical to physical) which are also sufficient for the same type of effect.81 Both dualism and nonreductive physicalism assume supervenience of qualia—and probably other mental kinds—on microphysical properties. Given Completeness, it follows that any effect a mental property might have systematically overdetermines some microphysical event. On both views, macrophenomenal causation is therefore subject to the causal exclusion argument. There are three potential ways to object to the argument: either one denies Completeness, one denies No Overdetermination, or one bites the bullet and gives up on the idea that mental states have causal powers. Questioning No Overdetermination is the standard strategy adopted by proponents of nonreductive physicalism; there is a widespread agreement that this strategy succeeds, although physicalists have developed different competing versions of it.82 All versions utilize a variant of the idea that the higher-level causation of mental states is in some sense coarse-grained in comparison to micro-level causation, arguing that overdetermination is unproblematic in such cases.

81 Note that the causal exclusion argument as I present it corresponds to Kim’s (2005: Chapter 2) second version of what he calls the supervenience argument. There are some differences between mine and his formulation of the second stage, most of them merely terminological and stylistic. A more substantial difference concerns Completeness: Kim’s analogous set of premises (the role played by Completeness in my formula tion is played by two premises in Kim’s formulation) require that any caused physical event has a sufficient physical cause at time t for every t. But if so, the argument cannot rule out a case of mental downward cau sation involving synchronic causation that Lowe (2008: Chapter 2) describes. (I discuss a slightly simplified version of Lowe’s case.) In this case, the physical event B*, occurring at t2, has a sufficient physical cause B at t1, no causes in the timespan between t1 and t2, and only physical causes before t1. However, B causes B* via two routes: partly by means of directly causing B*, and partly by means of synchronically causing a mental event E, which due to being synchronically caused occurs at the very same point in time as its cause, namely at t1. Now, E is a cause of B*, and B* would not have occurred if E had not occurred. Thus, E does not overdetermine B*. Nevertheless, B* has a sufficient physical cause at t1, since it suffices to bring about B at t1 in order to cause B*. Yet there is still non-overdetermining mental causation in the picture, because B partly causes B* by bringing about E. Moreover, since B* has no causes after t1, and only physical causes before t1, the situation complies with Kim’s requirement that B* has a sufficient physical cause at every point in time at which it has a cause. Hence, Kim’s version of the argument cannot rule out cases of mental causation involving synchronic causation of the described kind. One could object to possibility synchronic causation, but, as argued in the last chapter, ontological emergence involves synchronic causation. Indeed, on the causal conception of ontological emergence, downward causation by an ontological emergent entity is somewhat similar to the situation Lowe describes. A better way to avoid the problem is to abandon reference to time, and formulate Completeness in terms of the requirement that any caused physical event has an immediate sufficient physical cause: although B* has no causes after the occurrence of B, B is not the immediate sufficient cause of B*, because B partly causes B* via the intermediate causal link E. Since E is synchronically caused, this link is not temporally intermediate such that Kim’s formulation cannot rule it out as a non-overdetermining cause of B*; but it is, nonetheless, causally intermediate such that the alternative formulation of Completeness can rule it out as a nonoverdetermining cause of B*. 82 Note, however, that Kim himself does not think that these physicalist replies are successful.

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In their survey article on mental causation, Robb & Heil (2018) distinguish autonomy and inheritance solutions. Autonomists such as Jackson (1996) argue that macro- and micro-level causation does not compete because both types are responsible for different properties of the same effect respectively: the former for the effect’s macroproperties, and the latter for its microproperties. Both causes thereby provide two different yet compatible explanations for one and the same effect: one for its coarse-grained macrofeatures and one for its fine-grained microfeatures. Proponents of inheritance solutions criticize that according to autonomy accounts, micro- and macrocausation appear somewhat unrelated, although the former grounds the latter. Inheritance accounts aim at a closer connection between macro- and microcausation that does justice to the grounding relation they bear to each other; the idea is that the former ‘in herits’ its efficacy from the latter by way of being constituted by it. There are a number of suggestions how to cash out inheritance. For instance, Yablo (1992) argues that the realization of functional properties can be accounted for in terms of the determinable-determinate relation. The idea is that in the same way as red is a determinable of scarlet and a determinate of color, some physical properties act as determinates of coarsegrained mental properties. If so, then, analogous to how there is no inconsistency in assuming that both the wine’s redness and its being scarlet caused me to have a certain visual experience, mental properties and their physical grounds can unproblematically cause the same effect. A similar solution can be derived from the subset view of realization defended by Shoemaker (2001, 2007) and Wilson (e.g. 1999, 2011, forthcoming: chapters 2 & 3).83 The subset view was thoroughly discussed in the last chapter, where its implications for theories of weak emergence were examined. Recall that according to this approach, functional kinds essentially have a certain set of causal powers. On every occasion of realization, this token set is identical to a proper subset of the realizer’s token powers. It is argued that the fact that the set of powers of the functional property S is not identical to the whole power-set of its physical realizer P but rather only to a proper subset of it makes functional properties causally autonomous. Nonetheless, each individual token power of S is identical to a token power of P. Yet S’s complete power profile is not identical to P’s power profile, since the latter encompasses powers which do not figure in the former. Hence, S’s power profile is irreducible to P’s but, nevertheless, fully explainable in terms of the latter: any token power figuring in the former is derivable from a token power figuring in the latter qua being identical to it. Since any token power of S is identical to a token power of P, S can be taken to inherit its full causal efficacy from P. The ideas of non-rival autonomy or inheritance between macro- and microcausation do not seem to be applicable to the dualist case because the mental properties in question are not taken to be physically grounded. Again, on this view, certain types of mental causes systematically co-occur with certain types of physical causes, both of which are sufficient for the same type of physical effect. It seems that this can only be accounted for by the assumption that in a case of phenomenal efficacy, there are two interlinked yet fundamental laws of nature:84 one is 83 In fact, Wilson (2011) claims that the subset view is compatible with the determinable-determinate view, providing a more abstract account of the same relation. 84 The microphysical causing of overdetermined microphysical effects is probably not only due to one, but indeed several laws of physics: for instance, both electromagnetic and gravitational features of the causing entities might play a role in bringing about the effect. For the sake of simplicity, this will here be ignored.

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mental-to-physical, the other physical-to-physical, and both govern the production of the very same effect. Being fundamental, each law is primitive so that they are not reducible to each other. But, nonetheless, they somehow interact in such a strange way that each of them independently mandates the generation of effects which would also have been brought about by the other law acting in isolation. What is wrong with the postulation of such an intertwining of physical and mental laws? In the literature, one does not find much elaborate critique, since most commentators regard the whole idea as obviously absurd dismissing it out of hand. Melnyk (2003) is a notable exception; he provides a more careful consideration in which he compares the intertwined laws thesis with an analogous scenario in another domain. In the contrasting case, a platoon independently receives orders from both its captain and a colonel, and yet the orders always have the exact same content. As Melnyk points out, [we] would not be content to treat such a case as mere coincidence; we would insist on an explanation, if one could possibly be got. Likewise, I suggest, in the case of the two causal laws mandating the occurrence of the very same kind of effect: unless explained, it is an intolerable coincidence. (Melnyk 2003: 291) Now, plausible explanations for the agreement of the officers in the platoon-case are indeed available. Melnyk lists two: One way [of explaining the agreement of the officers] would be to suppose that whenever the colonel issues orders to the platoon he sends a copy of them to the craven captain, who always reissues the orders to the platoon, and who always fears issuing any independent orders of his own. Another way would be to suppose that, because they received identical training at Staff College and receive exactly the same information about their strategic and tactical circumstances, the colonel and the captain independently arrive at the same conclusions as to what the platoon should do. (Ibid.) However, explanations along these lines are clearly not applicable to the dualist law-case: There is no way in which the [physical] causal law […] could bring about the mental causal law […]; nor are causal laws the sort of things that can have undergone identical training regimes. (Ibid.; italics in original) Melnyk rightly concludes that it is not a plausible option for the dualist to reject No Overdetermination. In contrast, some theorists consider it a viable option to accept epiphenomenal dualism, the view that emergent qualia have no causal powers whatsoever. This used to be the preferred strategy of ‘new wave’ dualists like Jackson (1982) and Chalmers (1996). But Jackson (2007) became a type-A physicalist. And Chalmers (2003a, 2013) also came to acknowledge the unattractiveness of epiphenomenalism—and, in my opinion, rightly so, since epiphenomenalism is radically counterintuitive. As Fodor (1989) famously said,

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Furthermore, even if epiphenomenal dualists allow for functional accounts of propositional attitudes (so that my wanting and my believing qualify as genuine causes), it would nevertheless be quite astonishing were the disagreeability of the subjective experience of pain not responsible for my attempt to avoid injuries and were the pleasure that lies in the experience of an orgasm not responsible for my pursuit of sex. I therefore consider epiphenomenalism to be the least attractive antiphysicalist option. It should be avoided as long as there are tenable alternatives. Thus, it seems that the best choice among the bad options the dualist faces is denying Completeness. This has been the preferred strategy of dualists like O’Connor & Wong (2005) and Lowe (2008). However, the causal completeness of microphysics is widely regarded as an irrefutable empirical fact which philosophers of all persuasions are bound to accept. Yet it is not always clear what is taken to justify this strong conviction in Completeness beyond the vague indication that it somehow follows from contemporary physics. Papineau (2001) is at pains to provide an elaborate argument for the thesis. In a historical survey, he finds that Completeness has only been widely accepted since the 1950’s. His explanation is that extensive physiological research only became available then, and that these findings made Completeness extremely plausible. Before that, researchers succeeded in reductively explaining a large number of macroscopic phenomena in other domains, but the molecular-level mechanisms operative in higher organisms were largely unknown. Hence, at the time, it was not an implausible assumption that irreducible mental forces are at work in the brains of humans and other animals, downward causally influencing their behavior. Yet once the workings of cells were better understood, the existence of such mental forces should have been be empirically detectable. Particularly important in this regard was the major progress in cell biology during the first half of the 20th century. Papineau provides the following account of the crucial breakthroughs: […] the catalytic role and protein constitution of enzymes were recognized, basic biochemical cycles were identified, and the structure of proteins analyzed, culminating in the discovery of DNA. In the same period, neurophysiological research mapped the body’s neuronal network and analyzed the electrical mechanisms responsible for neuronal activity. (Papineau 2001: 31) None of this research, Papineau points out, showed any trace of irreducible macrocausation in human organisms: all microbiological processes studied were fully explainable in terms of physicochemical interactions. This motivated and justified belief in the full causal completeness of microphysics, as the last domain which presented a plausible candidate for irreducible macroscopic causal structure turned out to provide no evidence for such causal influence. Hence, from the lack of recognizable irreducible mental forces in the brain, Papineau

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derives (and endorses) an empirical argument for Completeness. Since, despite extensive investigations, biological research never revealed any signs of the existence of irreducible macrocausal powers in biological organisms, we have strong inductive reasons to accept the full explicability of all neural processes in terms of physicochemical forces: You could in principle accept the rest of modern physical theory, and yet continue to insist on special mental forces, which operate in as yet undetected ways in the interstices of intelligent brains. And indeed there do exist bitter-enders of just this kind, who continue to hold out for special mental causes, even after another halfcentury of ever more detailed molecular biology has been added to the inductive evidence that initially created a scientific consensus on completeness in the 1950s. [...] However, I see no virtue in philosophers refusing to accept a premise that, by any normal inductive standards, has been fully established by over a century of empirical research. (Papineau 2001: 32–33) As plausible as it prima facie appears, I do not think that this is a compelling argument. Papineau disregards that molecular biology has undergone substantial changes within the last couple of decades. Contra Papineau, careful study of recent developments in microbiology reveals that the unimpaired success of reductive explicability of microbiological processes no longer seems so certain. Especially since the rise of systems biology in the 1990’s, researchers explicitly take into consideration strong emergence as a plausible explanation for the often experienced failure of reductive explanations in cell biology. The purely reductive aspirations characterizing the research programs of the 1950’s and 1960’s gave way to more liberal approaches recognizing genuine biological mechanisms, that is, macrocausal structures irreducible to purely physicochemical explanations. Boogerd et al. (2005) is an especially interesting article, featuring authors from systems biology, philosophy of biology, and metaphysics respectively. They argue that in unicellular organisms such as E. coli, various macromolecules acting as enzymes in biochemical networks processing substrates have other kinetic properties than those we would expect from studying them in isolation or within simpler systems. That is, certain macromolecules exhibit a qualitatively different behavior when acting as enzymes in a cellular environment than we would expect from studying them in simpler contexts or in isolation. Hence, contra Papineau, there does indeed appear to be empirical evidence for irreducible macrocausal structure in cells. Note, however, that cells feature such irreducible macrocausation not because they have irreducible biological macroproperties, but because the micropowers of some of their molecular constituents change in certain ways iff they are part of a cell. The behavior of certain macromolecules appears to be microtheoretically unpredictable: if studied in vitro, then they show no trace of the behavior in question. Chemistry informs us as to certain behavioral dispositions of these molecules which should allow us to predict how the molecules behave in complex settings with a great number of causal influences. However, when studied in situ, they behave differently from what we would expect given our physicochemical knowledge. Note that this cellular behavior is nevertheless regular and, thereby, predictable for microbiologists who have studied the respective biological mechanisms. Yet it is not predictable given

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only physicochemical knowledge and information about initial conditions. In other words, the mechanisms at play in such irreducible macrocausal structure have been successfully modeled and predicted, but they cannot be reductively modeled and predicted. Importantly, Boogerd et al. (2005) do not interpret this unpredictability as being due to epistemic limitations of our current research methods, but rather as a consequence of strongly emergent behavior. Boogerd and colleagues are not the only theorists arguing for emergent causal powers in cellular contexts. Noble (2012), an eminent cardiovascular physiologist and pioneer of systems biology, argues for a similar view in the case of heart cells. Kaiser (2011) provides an overview of cases of causal irreducibility in microbiology. Other works arguing for strong emergence in biology include Bechtel & Richardson (2010), and Powell & Dupré (2009). Note that the issue in all of these cases is not that predictions are impossible because of high sensitivity to initial conditions, as in chaotic systems; predictions of cell behavior are, in fact, possible, and various cellular mechanisms have been thoroughly investigated. The point is, however, that the behavior which certain macro-molecules exhibit in the course of these mechanisms is not predictable from what would be expected from studying them in simpler systems or in isolation. Accordingly, Richardson & Stephan (2007) develop an account of explanations in cell biology allowing for nonreductive yet mechanistic explanations of strongly emergent behavior. In a similar vein, Kaiser (2015) sharply distinguishes reductive explanations from mechanistic explanations in biology. Note that regardless of potential implications for the tenability of dualistic mental causation, emergent macrobehavior as such (also when it figures outside the mind-body domain such as in the case discussed by Boogerd and colleagues) is incompatible with physicalism. 85 For should there be such behavior, then it is due to microphysically inexplicable causal powers. In Chapter 3, such strongly autonomous causal structure in complex systems was described as one of two potential problems for grounding physicalism, the other being phenomenal consciousness. In the last chapter, I already examined what kind of emergence is at play in irreducible macrocausal structure, and discussed in more detail why and how exactly physicalism is threatened by its possible existence. Although the kind of evidence from cell biology as presented by Boogerd and colleagues is not directly linked to the mind-body domain, it might nevertheless be taken to justify cautious optimism on the part of the dualist. She might argue analogously to Papineau (2001) as follows: in the same way as Completeness of microphysics was both historically motivated and justified by microbiological research of the 1950’s and 1960’s, Incompleteness of microphysics is motivated and justified by novel research in systems biology today. If new evidence in biology points towards strongly emergent behavior, then this should justify Incompleteness in the same way as biological evidence in the past was taken to justify Completeness. Of course, this line of reasoning is highly speculative. While some currently available biological evidence seems to challenge Completeness, I think it is safe to say that the matter is far from clear. We currently lack sufficient detailed empirical knowledge of microbiological mechanisms to draw any firm conclusions. Cellular mechanisms turned out to be massively more complex than was expected by the pioneers of microbiology in the 1950’s. 85 Although it is not necessarily incompatible with materialism, see Section 4.3.3.

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In summary, it seems that the causal exclusion argument rests on a highly speculative premise. We currently cannot determine whether it is sound or not. But the widespread belief within the philosophy of mind that Completeness is beyond question is clearly false. For the time being, we should concentrate on core philosophical reasoning, that is, a priori arguments; microbiology is not yet developed enough to give us reliable evidence for or against Completeness. Also, for matters of complexity, we currently do not know whether irreducible macrocausation also exists in neurons. As of yet, irreducible systemic causation has only been demonstrated in much simpler prokaryotic cells. Nevertheless, it might not be unreasonable to suspect that there might also be strongly autonomous causal structure in neurons. Of course, it is currently far from clear whether such autonomous behavior exists. Indeed, even if there is such behavior, it would have to be instrumental in influencing the firing-rate of neurons in such a way that the information structure in neural networks is modified: only then could autonomous causal structure be taken to count as evidence for mental downward causation. But dualists are free to provide theories of how qualia might possibly affect macromolecules in neurons such that they show divergent behavior in certain contexts leading to deviant neuronal firing patterns, thus influencing the behavior of the organism. Nevertheless, it appears that, in principle, interactionist dualism could be ruled out empirically if we find no traces of macromental downward causation in the brain. Since downward causation changes the behavior of physical goings-on, future scientists, having studied the complete causal structure of the brain, should be able to tell whether there happens anything which is not in accordance with the laws of physics. However, even this might not be the case. Downward causation might be empirically undetectable as it could be indistinguishable from chaotic behavior.86 As the neuroscientist Christof Koch explains, [g]iven the nonlinear and cooperative nature of [...] neural networks, their behavior is chaotic to a high degree. (Koch 2009: 37) And from this he concludes that, [y]our actions are not, and never will be, predictable. (Ibid.: 45) If there is a high degree of chaotic behavior in neural networks, then dualists can argue that downward causation effects only tiny changes in the micro-evolution of neural systems: it might only have to slightly influence the firing-rate of the neurons located at functionally crucial spots in a certain neural pattern in order to produce significant changes in macrobehavior via the butterfly effect. Such miniature changes to initial conditions will never be empirically detectable, since they do not result in major changes of energy transmission detectable via modeling neural behavior. It is generally empirically undecidable whether nonlinear systems are fully micro-deterministic or not: a theory which assumes that nonlinear outcomes are due to macromental intervention is as empirically adequate as the assumption that they are due to 86 As discussed in Section 4.3.1, nonlinear macrodynamics in chaotic systems are epistemologically emergent: that is, due to their high sensitivity to small changes in initial conditions which cannot be captured in model ing, they are, in principle, not predictable and derivable from underlying processes.

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micro-deterministic chaos. While inference to the simplest explanation might in most cases justify the assumption that such systems are fully micro-determined, when we have independent reasons to question full micro-determinism such as in the case of the brain, this reasoning does not apply. For in such cases (at least if we accept the case for emergentist antiphysicalism), there is reason to expect mental downward causation in the brain, and it might thus appear plausible to take nonlinear dynamics on the neural level to be partly determined by genuine macrophenomenal causes.87 Note that it is currently a hotly debated question whether neural networks are in fact chaotic.88 However, the mere existence of this debate illustrates once again that our knowledge of the causal structure of the brain is not nearly as developed as many philosophers seem to believe. It could also very well turn out, contra my suggestion in the last paragraph, that neuroscientists find evidence for causal structure in the brain which is not in accordance with the laws of physics. If so, philosophical accounts—amongst them physicalism—which imply Completeness are empirically falsified.89 87 I further discuss the ‘chaos-approach’ to macrophenomenal downward causation in Footnote 90 and Footnote 117. 88 See Bishop (2017: 78) for an overview about the empirical literature on chaos in the brain. 89 Note that a very principled refutation of Completeness can be derived from the standard interpretation of quantum mechanics: according to the Copenhagen interpretation, the deterministic Schrödinger equation describes the world in terms of a wave function which takes physical systems to often be in superimposed states that cannot be directly observed. Upon procedures of experimental measurement, the deterministic evolution of the wave function for a certain system non-deterministically collapses into a non-superimposed state, and the system acquires a definite (classical) location. Importantly, the collapse of the wave function is brought about by measurement, whereas measurement involves observation by conscious subjects. Hence, it seems that a fundamental microphysical dynamic is caused by macromental intervention. An interpretation along these lines was already suggested by some of the pioneers of quantum mechanics such as Bohr and Heisenberg, and it also appears in the classic formulation of quantum mechanics by von Neumann (1955). In recent years, a number of physicists and neuroscientists have argued that there exist superimposed states at certain places in the macrodynamics of neural networks, and that the wave function of those states collapses due to the intervention by macroqualia of the organism, thus influencing the organism’s behavior. The two most prominent quantum consciousness theories are the accounts by Stapp (1993) (see also Schwartz et al. 2005) and Hameroff & Penrose (1996, 2014). Hameroff and Penrose suggest that macrophenomenally induced quantum collapses occur within microtubuli (protein structures in the cytoskeloton of neurons responsible for transportation processes inside individual neurons). Stapp, in contrast, assumes that quantum state reduction takes place in ion channels in nerve terminals. Both accounts are highly contested, and it is has been questioned whether quantum events of the required sort for influencing the information structure of neural networks via quantum reduction really exist in the suggested places (see e.g. Atmanspacher 2015 for an overview on the respective problems of these approaches). Moreover, there are al ternative interpretations of quantum mechanics such as Bohm’s ‘hidden-variable’ theory and Everett’s ‘many-worlds’ account that do not invoke quantum collapses. Hence, in principle, quantum approaches can only succeed if an interpretation of quantum mechanics which allows for quantum collapses is correct. (We currently do not know which theory is correct: although collapse and non-collapse interpretations yield slightly different predictions, those differences are so subtle that they cannot currently be measured.) A particular interesting feature of quantum consciousness approaches is that they can be understood as effectively arguing that there is no need for postulating a novel fundamental mental interaction in addition to physical interactions in order to allow for emergentist downward causation, because fundamental physics by itself requires a fundamental mental interaction in addition to gravity, electromagnetism, the weak interaction, and the strong interaction (recall Wilson’s account of interaction-relative strong emergence discussed in Section 4.6.3). Hence, if a particular version of the quantum approach to consciousness is indeed correct, then antiphysicalists need not to introduce an additional fundamental interaction, but can rely on the ones that quantum physics already invokes. (Furthermore, this quantum consciousness theory would provide antiphysicalists with a detailed account of the mechanics of macrophenomenal downward causation.) Note that the ‘chaos-account’ of downward causation that I discussed above is different from quantum consciousness

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In conclusion, I think it is fair to say that we are currently completely in the dark concerning the question whether there is strongly autonomous macrocausal structure in the brain or not. Papineau (2001) argues that we have strong reason to believe in Completeness, since microbiology and extensive physiological research since the 1950’s never revealed any evidence whatsoever for strongly autonomous macrocausal structures. Well, in the light of the evidence discussed in this section, this seems to be at best anachronistic. While it is certainly true that the reductionist research program in microbiology which took its start from the discovery of the DNA in the 1950’s was very optimistic towards full reductive explicability of all biological mechanisms, this is certainly no longer the case. It is the defining conviction of novel subdisciplines such as systems biology that a purely reductive approach is incapable of explaining all microbiological mechanisms. While, in some cases, failure of reductive explicability might merely be due to extremely high complexity and the existence of various feedback loops, some failure might very well be due to genuine causal autonomy. We simply do not know for sure at this point. It is currently not justifiable to oppose views involving fundamental downward causation for the mere reason that they violate Completeness. 5.4.3

The Fundamental Interaction Problem

In Section 5.3.1, I argued that the pairing problem not only, as usually assumed, concerns substance dualism, but also property dualism. Yet by adopting an analogy of the Russellian strategy for macrophenomenal states, dualism can sidestep the problem. In the last section, we saw that current empirical evidence provides some prospects for the dualist to reject the causal exclusion argument by questioning Completeness. Thus, it seems that there is a dualist position, Russellian dualism, which might reject all of the common mental causation arguments. Nevertheless, I do not believe that Russellian dualism is tenable. For, as I shall argue in this sec tion, the position faces another severe challenge, the fundamental interaction problem. Recall that Russellian dualism takes macroqualia to realize novel fundamental dispositions; that is, phenomenal properties qua being quiddities inhabit an inner dimension (what might be called the ‘intrinsic nature’ of the world) which as such is not part of the physical spatial framework. But if phenomenal states have causal powers, they ground structural dispositions which occupy certain spatiotemporal locations. Otherwise, phenomenal properties are completely causally isolated from physical entities, and also from each other. While both employ the Russellian strategy, an important difference between constitutive Russellian monism and Russellian dualism is the following: constitutive Russellian monism assumes that micro(proto)phenomenal properties perform all the fundamental causal work and, furthermore, in doing so realize microphysical dispositions, while macrophenomenal properties are just derivative combinations of microphenomenality. Russellian dualism, in contrast, has macrophenomenal properties directly play causal roles in the physical world. approaches in that this view does not rely on the existence of superimposed states in neural macrodynamics. Rather, according to this approach, macrophenomenal downward causation interacts with neural patterns that are in fully non-superimposed ‘classical’ states via a novel fundamental mental interaction which is not invoked in fundamental physics; yet because of epistemologically emergent nonlinear macrodynamics in these neural networks, the downward causal impact is, in principle, empirically undetectable (see also Footnote 117). (Of course, this approach does only work if there is in fact chaos of the right sort in the brain, which is controversial.)

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Moreover, these causal roles do not correspond to microphysical dispositions, but are additional causal powers which interact with physical causal structure. For dualistic macrophenomenal states are strongly emergent entities, and must thus have nonphysical causal powers. As has been seen in the last chapter, according to Wilson’s (2002, forthcoming: chapter 5) theory of interaction-relative strong emergence, causation by strongly emergent entities such as dualistic phenomenal states must be understood as fundamental causal process. This causation therefore presupposes the existence of a novel nonphysical fundamental interaction. That is, physicists so far discovered four fundamental interactions; if the Russellian dualist postulates a new type of fundamental properties possessing genuine powers, then she effectively postulates a novel nonphysical fundamental interaction. It is added to the list of fundamental interactions such that the list now consists of physical and irreducibly psychophysical interactions. Furthermore, recall that Kim’s (2005) causal exclusion argument shows that all types of macrocausation in strong emergence involve downward causation. The reason is that in order to cause emergent E*, emergent E has to cause E*’s emergence base B*. Hence, all causal efficacy of emergent macroqualia is directed towards the microlevel. Taking into account interaction-relative strong emergence, it follows that that the downward causation exerted by macroqualia is dependent on a new type of interaction. Now, I believe that taken together, Kim’s insight that emergent causation is downward causation and Wilson’s finding that emergent causation represents a new fundamental interaction create a serious problem for the intelligibility of mental causation in Russellian dualism. For if dualistic downward causation is based on a novel fundamental interaction, then it directly interacts with elementary particles. To see this, recall that physicalist solutions to the causal exclusion problem argue that there is a harmless overdetermination at play in mental downward causation. Mental states ‘inherit’ their efficacy from their physical realizers by way of being constituted by them. While there are a number of ways to cash out the details, it is universally acknowledged that derivative properties are not causal rivals to fundamental microphysical properties (and thereby not problematic overdeterminers of physical effects) because they only possess derivative causal powers. The dualist’s macroqualia, in contrast, do not qualify as harmless overdeterminers since they have no grounding base from which they could possibly inherit derivative causal powers —their causal powers are fundamental. Hence, if macroqualia possess fundamental powers rooted in a novel psychophysical fundamental interaction, then their causal interactions are of the fine-grained type only suited for interaction with other fundamental properties. That is, the physical entities entering causal relations with macrophenomenal properties have to be fundamental. Hence, it seems that dualistic downward causation has to be directed at individual elementary particles, rather than being directed at more complex physical systems. However, if macroqualia directly interact with microphysical properties, then it seems that they can only have the size of an elementary particle. For how else would they be able to directly interact with inhabitants of the basal ontological level if they themselves are anything but quantum-sized? If so, a macroquale might be located in one part of a neuron of the neural pattern which constitutes its emergence base. But if a macrophenomenal property merely occupies a tiny spot in the quantum realm, then it seems that it can only influence a few nearby particles. However, it is implausible that by interacting with only a few particles in one neu -

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ron, the global information structure of a whole neural pattern can be modified. Yet phenomenal states have to modify global information in order to play a causal/functional role in the macrostructure of the brain. And this is what mental causation should be all about: interactionist dualism is not the view that our phenomenal states are capable of influencing the behavior of a few elementary particles in the brain; rather, it is the view that qualia are crucial causal factors for the determination of the behavior of the whole organism. It follows that even rejecting Completeness and postulating a fundamental interaction between macrophenomenal states and elementary particles does not help the dualist in explaining phenomenal causation, or, at least, it does not allow for a phenomenal causation which is worth the name. How could the dualist reply to this concern? I can think of three promising approaches. First, she could assume that macroqualia are complex phenomena with multiple parts, by way of which they can interact with many different particles at a time. I see two problems for this view: first, if such complex qualia are big enough to modify global information structure in the brain, then they are probably empirically detectable even by current methods; second, if qualia are complex, then they are subject to the combination problems for constitutive panpsychism which I discuss in the next chapter. For given Russellianism, if they are structurally complex, then it appears they also must be phenomenally complex, and the latter complexity gives rise to a number of combination problems, as will become clear in the next chapter. Second, one might suggest that macroqualia are fields which, by way of permeating a whole neural pattern, can simultaneously influence the behavior of many of the pattern’s basic constituents. The idea here is that fundamental physics not only discovered various types of fundamental particles, but also fields which can be understood as the media which root different fundamental interactions between the particles. Also here, a problem comes to mind. In contemporary physics, fields are media of causal interactions, but not causal powers themselves. It seems that macroqualia would have to be local excitation properties of such a novel field in order to qualify as causal relata. But then, the fundamental interaction problem arises all over again. And if the qualia are assumed to instantiate multiple excitation properties of the field simultaneously, then the second problem for complex qualia arises again: the view is subject to combination problems. At this point, one might suggest that qualia are not causal agents themselves such that they have to be properties of a novel field. In contrast, they are fields as such and only provide a new medium for interaction between particles which was not possible as long as the field was not yet existent; however, once the field comes into being, multiple particles, having dispositions which make them suitable for interacting via the field, enter novel causal relations with one other that are not possible without the field. This raises the question whether there can be local fields. At least in contemporary physics, fundamental fields appear to be holistic. That is, there are not multiple primitive electromagnetic fields at various locations of the universe, but only one such field which regulates the interaction between all charged objects. But this might not be too big a problem—who says that mental fields have to abide to the model of physical fields? However, even if there can be local fundamental fields, a similar problem as for the individualistic dispositions account discussed above arises. For every type

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of quale that animals or humans could possibly entertain, there has to be a separate field. A field as such—being merely a passive medium for interaction—has only limited power to influence the behavior of particles. Therefore, it is plausible that the very different reactions which are caused by such different qualia as pain and joy have to correspond to different fields. But there are presumably only a small number of types of fundamental particles. Therefore, it seems that many fields have to act on the same particles. But then, every particle needs an appropriate disposition for many possible fields in order to interact via the field. However, then we are back to a problem similar to the one we encountered in the context of individualistic dispositions as a solution to the pairing problem. If particles must have separate fundamental dispositions for the interaction with each and every potential type of qualia in the universe, an explosion of micro-latent dispositions of elementary particles is the consequence. A potential solution to this problem might be to assume that mental fields are internally structured. If so, the dualist can hold that there is only one type of field, which can have lo cally quite different qualities. Various types of macroqualia instantiate the same type of field, yet differ respectively on how the field is structured. Thus, elementary particles must only have a singular disposition to interact with this one type of field—the different causal profiles of different types of qualia are rooted in differing field structures. But this view also faces a problem. The structured fields approach appears to be subject to the structural mismatch argument. As will be discussed in the next chapter, the structural mismatch argument is one of the most severe objections to constitutive Russellian panpsychism. The worry is that on Russellianism, we should except that there is isomorphism between dispositional-dynamical structure and the phenomenal structure of the quiddities realizing the former. But if fields possess complex dispositional-dynamical structure, then this structure is not mirrored by phenomenal structure. Whatever dispositional-dynamical structure the pain-field must have in order to bring about downward causally pain-behavior, it is obvious that this structure is very different from the structure of what-it-feels-like to be in pain. I shall postpone further discussion of this problem to Section 6.7, where I discuss the structural mismatch argument. However, is the dualist even forced to accept the charge? Why not just reply: it’s magic— macroqualia affect as many dispersed elementary particles as they have to. They just somehow manage to show up at the right spots at the right time, never mind the details. Of course, this answer is available. Yet it is not so much an explanation as a label for a mystery. I take it that if there is an antiphysicalist view which can give a more elaborate account of mental causation, then this view is preferable. We therefore have good reason to evaluate other antiphysicalist views.90 5.5 Mental Causation in Russellian Monism In the last section, we saw that dualism is subject to severe problems of mental downward causation and emergence. Proponents advertise Russellian monism as an antiphysicalist alter90 Moreover, in Section 6.7 (after we have discussed the structural mismatch argument at length) I shall argue that the simple field account and the ‘mystery-approach’ are also subject to a certain aspect of the structural mismatch problem. If so, this constituted additional reason for supposing that these proposals are not tenable.

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native to dualism which can avoid these problem. Above, we already saw that dualism can avoid the pairing problem by adopting the Russellian strategy. It is therefore clear that the problem does also not arise for Russellian monism. With regard to the causal exclusion problem, theorist have shown that Russellian monism in combination with the thesis of phenomenal constitution manages to reject the objections. The resulting view is constitutive Russellian monism, which can overcome the objection in two consecutive stages. First, Russellian monism furnishes (proto)-consciousness with the foundational metaphysical role of realizing micro-physical dispositions. This allows the view to integrate the (proto-)phenomenality of elementary particles into the order of the natural world in such a way that worries about the causal exclusion for proto- or microphenomenal do not arise. The idea is that by employing microphenomenal properties as realizers of microphysical dispositions, the view gives microphenomenal properties a causal role without letting them compete with physical causation: by grounding physical causation, they bring about physical causation, rather than interfering with it. Hence, the problem of overdetermination does not arise for micro- and protophenomenal properties: every caused microphysical event has just one sufficient cause and this cause is microphysical. Yet mental causation still figures in this picture. It is micro- or protophenomenal properties which play the causal roles involved in physical causation. Physics just describes causal structure, and microphysical properties as described by the laws of physics are pure dispositions. Yet the latter are realized by phenomenal properties standing in the causal relations described by these laws. Second, as a consequence of phenomenal constitution, macrophenomenality is grounded in combinations of micro- or protophenomenal states. With regard to macrophenomenal causation, constitutive Russellian monists can adopt the standard reply of nonreductive physicalists to causal exclusion arguments, namely rejecting No Overdetermination: macrophenomenal states inherit the causal powers of their microconstituents, thereby having causal efficacy which does not involve downward causation and is thus not subject to the causal exclusion argument. As we saw in Section 5.3.2, while physicalists have developed a number of competing versions of this strategy, there is a widespread agreement that some version of the strategy succeeds. The constitutive Russellian monist is free to apply whatever version of the strategy might turn out to be correct. Since all variants of the strategy are silent on the nature of the grounding relata, there is no reason why power-inheritance should not work in the case of phenomenal constitution if it does in the case of physical constitution. Furthermore, since Russellian monists take macrophenomenal states to be grounded in a large number of microphenomenal properties, the fundamental interaction problem does not arise. Assume that pain correlates with C-fiber vibration. If so, pain is grounded in the ultimate microphenomenal constituents of this neural pattern. Hence, pain inherits its causal powers from the combined powers of those myriad microphenomenal states such that pain’s powers correspond to the causation exercised by the global information structure of C-fiber vibration. Hence, constitutive Russellian monism can avoid both the antiphysicalist arguments and the problems of mental causation dualism faces. Moreover, by grounding both microphysical dispositions and macrophenomenality in micro- or protophenomenal states, the view can re-

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tain physicalism’s parsimonious monistic outlook. It thus appears to combine the strengths of its rivals, physicalism and dualism, while avoiding their weaknesses. However, constitutive Russellian monism faces severe problems of its own. There have been raised a number of objections to phenomenal constitution. These so-called combination problems are the subject of the next chapter. There, I will argue that constitutive Russellian monism cannot overcome a number of these objections. 5.6 Panpsychism or Panprotopsychism? In Section 5.2, we saw that according to physicalist categoricalism, the nature of quiddities is exhausted by the fact that a given quiddity is identical to this very quiddity it happens to be and distinct from all other properties. And this lack of any positive essential qualities makes physicalist categoricalism fall prey to the power-swapping objection. In contrast, Russellian monist versions of categoricalism can avoid this objection by allowing for positive essential features of qualities which are either micro- or protophenomenal. However, the panprotopsychist variant of Russellian monism is threatened by another problem concerning its account of the nature of quiddities which the other two versions of categoricalism can avoid. This is the problem of noumenalism. The concern is that panprotopsychism leaves us completely in the dark as to the nature of quiddities; we are told that quiddi ties have positive non-trivial essences that are themselves not phenomenal, but which qualify quiddities to produce macrophenomenality. As Goff (2017: chapter 7) points out, panprotopsychism’s characterization of quiddities is partly negative—they are not phenomenal—and partly indirect—they are capable of producing macrophenomenality—but fails to provide any substantive positive account of their nature: We ask the big question, ‘What is fundamental reality like, and how on earth does it give rise to consciousness?’; the panprotopsychist seems to answer, ‘I’ve no idea what fundamental reality is like, but whatever it’s like it somehow gives rise to consciousness.’ (Goff 2017: 167) Prima facie, panprotopsychism’s noumenalism about quiddities renders the view disadvantageous in comparison to its two competitors, physicalist categoricalism and panpsychism, both of which provide substantive characterizations of quiddities, taking them to have no positive character beyond their essentially being themselves, and being distinct from all other properties or taking them to essentially being phenomenal properties respectively. However, Chalmers (2003a) and Pereboom (2011) have argued that it is conceivable that panprotopsychists might be able to infer a positive concept of their nature from introspection, perhaps with the help of some sort of as yet unimaginable conceptual revolution. After all, the panprotopsychist qua antiphysicalist holds that we are acquainted with the full nature of our phenomenal states. It might be possible to explore the nature of their microconstituents by means of thorough introspective analysis of our phenomenal properties. In this regard, panprotopsychism has some similarities with type-C physicalism. 91 As typeC physicalism, the view comes in two variants. One claims that we are in principle incapable 91 Type-C physicalism was discussed in Section 3.1.1.

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of knowing how the microconstituents of our phenomenal states realize them because of the limitations inherent in our cognitive design. The other holds that this is very possible, yet it requires considerable scientific progress. The latter variant, given that the required conceptual revolution indeed materializes, can avoid the problem of noumenalism.92 Hence, panpsychism seems prima facie more promising than panprotopsychism. Panpsychism is clearly preferable to the noumenalist variant of panprotopsychism, because it provides us with a positive account of the nature of quiddities. Moreover, it appears preferable to explore whether there is a consistent version of panpsychism—an endeavor which can currently be undertaken, since all required resources are readily available—than to await a conceptual revolution which is uncertain to ever materialize. However, there is a version of panprotopsychism which does not suffer from the problem of noumenalism: Russellian panqualityism assumes that the categorical grounds of microphysical dispositions are unexperienced qualities; that is, in difference to Russellian panpsychism, this position does not invoke microsubjects, but rather assumes that qualities that could be instantiated in subjective experiences appear ‘naked’ (without being borne by an experiencer) on the micro-level. If so, the panprotopsychist’s microquiddities are of the same type as the qualities of our experiences. Hence, we are provided with a positive account of microquiddities, and the threat of noumenalism is avoided. Panqualityism is, in fact, a very popular version of panprotopsychism, and has been defended by influential historical figures such as Mach (1984/1886), James (1904), and Russell (1921). Today’s leading proponent of this position is Coleman (2012, 2014, 2015, 2016). However, one can have serious doubts as to whether the view is intelligible. If microproperties of the same type as the qualities that we experience realize microphysical dispositions, then the question arises whether such microqualities can be instantiated without being experienced by a subject. Is it intelligible to assume that, for instance, micro-pain realizes charge, but there is no associated feeling? It seems that the qualities of our phenomenal states are essentially properties characterizing certain subjective experiences. But then, they cannot be instantiated without being borne by a subject. If so, then it seems not conceivable that there could be micro-analogues of such qualities appearing unexperienced. (Goff 2017: section 6.2.3 provides a similar argument.) Moreover, as Chalmers (2013: section 7) points out, Russellian panqualityism falls prey to versions of most of the combination problems for constitutive Russellian panpsychism: it can, in fact, only avoid those combination problems which concern the combination of microsubjects. In the following chapter, I will focus on constitutive Russellian panpsychism and the position’s tenability in the light of several serious combination problems advanced against phenomenal constitution. I will argue that at least some of these arguments succeed, and that constitutive panpsychism is false. As we will see, most of the problems phenomenal constitution faces are also applicable to protophenomenal constitution (including panqualityist constitu92 The difference between type-C physicalism and panprotopsychism is of course that the former takes the ground of macrophenomenality to be microphysical structure, while the latter takes the ground to be micro quiddities as such (perhaps alongside microphysical structure). Chalmers (2003a) takes the analogy between the two positions even further. He argues that type-C physicalism is an instable position, and that views like those of McGinn (1989), who is the prime proponent of the noumenalist version of type-C physicalism, are really variants of panprotopsychism.

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tion) with minor modifications. Hence, panprotopsychism cannot profit from panpsychism’s failure with regard to phenomenal constitution. Yet I will argue in Chapter 7 that emergent Russellian panpsychism is a promising alternative version of panpsychism.

6

Problems for Constitutive Russellian Panpsychism

In the last chapter, the rationale panpsychists provide for the view that there are microsubjects bearing microphenomenal properties which act as both realizers of microphysical dispositions and grounding bases for macrophenomenality was discussed. We saw how this proposal avoids severe problems of mental causation as well as emergence, and that it renders categoricalism intelligible. But the postulation of microphenomenality gives rise to a crucial question: how do microsubjects and their microphenomenal properties combine in order to constitute macrosubjects and their macrophenomenal properties? This is the so-called combination problem.93 6.1 Multiple Combination Problems As Chalmers (2016) points out, the combination problem is not a single problem but, rather, a complex of multiple problems. One can distinguish between different types of combination problems, answering to the three dimensions of phenomenology, quality, subjectivity, and structure. As we saw in Chapter 3, every experience involves a certain phenomenal character, the specific quality of what-it-feels-like: this is the qualitative dimension of phenomenology. Qua being an experience, a phenomenal state has to be experienced by someone. That is, it has to have a bearer, its subject. Moreover, every experience comes with a certain phenomenal structure; it is its structure which makes an experience attributable to a certain sensory modality such as vision or sound. The respective structure is then a structure within the visual or the auditory field or within some other modality. Now, for all three dimensions, the question arises as to how they can combine. As we will see, there are various reasons why combination might seem problematic for a phenomenal dimension. This turns the combination argument into multiple arguments which attack different problematic aspects of combination respectively. In the following nine sections, I discuss the most prominent combination problems, and potential replies to them. I argue that some of them are solvable, while others are not. Sections 6.12 to 6.15 are then devoted to a problem of mental causation for Russellianism, the problem of structural exclusion, which Mørch (forthcoming) raises, as well as Mørch's solution proposal to this problem. I shall argue that Mørch's argument is sound, but her solution is wanting. Yet a revised version of her account can avoid the objection. However, this revised version gives rise to a new combination problem. 6.2 James’ Original Argument The combination problem has its historical origins in James (1950/1890), who argued against phenomenal combination as follows:

93 The term ‘combination problem’ was coined by Seager (1995).

© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2020 F. Klinge, Panpsychism and the Emergence of Consciousness, https://doi.org/10.1007/978-3-662-62258-2_6

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Problems for Constitutive Russellian Panpsychism Take a hundred [phenomenal states], shuffle them and pack them as close together as you can (whatever that may mean); still each remains the same feeling it always was, shut in its own skin, windowless, ignorant of what the other feelings are and mean. There would be a hundred-and-first feeling there, if, when a group or series of such feelings were set up, a consciousness belonging to the group as such should emerge. And this 101st feeling would be a totally new fact; the 100 original feelings might, by a curious physical law, be a signal for its creation, when they came together; but they would have no substantial identity with it, nor it with them, and one could never deduce the one from the others, or (in any intelligible sense) say that they evolved it. Take a sentence of a dozen words, and take twelve men and tell to each one word. Then stand the men in a row or jam them in a bunch, and let each think of his word as intently as he will; nowhere will there be a consciousness of the whole sentence. We talk of the 'spirit of the age,' and the 'sentiment of the people,' and in various ways we hypostatize 'public opinion.' But we know this to be symbolic speech, and never dream that the spirit, opinion, sentiment, etc., constitute a consciousness other than, and additional to, that of the several individuals whom the words 'age,' 'people,' or 'public' denote. The private minds do not agglomerate into a higher compound mind. (James 1950/1890: 160)

In this passage, James seems to argue that something about phenomenology prevents consciousness from combining in a similar manner to that in which material composition works. While it is possible to build a wall by combining hundred bricks, it seems to be impossible to produce a macrosubject by combining hundred microsubjects. However, a closer reading of James (1950/1890) reveals that what drives his argument against phenomenal constitution is a quite general objection to combination. For James, the result that phenomenal composition is impossible is a consequence of his argument for general compositional nihilism. Phenomenal combination is not criticized as such, but rather as a special case of material composition. But if the combination problem does only arise as a consequence of a case against composition in general, it seems that it can be fended off easily. Nihilism is a hotly contested view, and constitutive panpsychists are not obliged to accept it. Nevertheless, the passage quoted has inspired many philosophers to believe that phenomenal combination is problematic as such, even if we accept physical aggregation. 6.3 The Conceivability Argument Redux Chalmers (2016) argues that an obvious way to interpret James’ quote is to read it as a conceivability argument. Here is again what James has to say about the product of phenomenal combination: [T]his [...] feeling would be a totally new fact; the [...] original feelings might, by a curious physical law, be a signal for its creation, when they came together; but they would have no substantial identity with it, nor it with them, and one could never deduce the one from the others, or (in any intelligible sense) say that they evolved it.

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The argument seems to be that the fact that macrophenomenal states are not deducible from microphenomenal states entails that phenomenal combination is impossible. Now, given this reading, the objection can be developed into an argument similar to the conceivability argument against physicalism except for adding microphenomenality to the grounding base. The original conceivability argument claims that it is conceivable that the conjunction of currently instantiated physical facts is in place without an arbitrary currently instantiated phenomenal fact—e.g. the fact that I have such and such visual experience right now—being in place (see Chapter 4 for a thorough discussion). In contrast, the version of the conceivability argument against constitutive panpsychism claims that it is conceivable that the conjunction of the world’s physical and microphenomenal facts—which includes all facts about microsubjects and their experiences the constitutive panpsychist postulates—are in place without me having such and such visual experience. It is then argued that conceivability entails metaphysical possibility which, in turn, entails that constitutive panpsychism is false. This is Chalmers’ formulation of the argument. PP represents the conjunction of all physical and microphenomenal facts, and Q an arbitrary macrophenomenal fact such as my current visual experience. (1) PP&~Q is conceivable. (2) If PP&~Q is conceivable, it is metaphysically possible. (3) If PP&~Q is metaphysically possible, constitutive panpsychism is false. ______________ (4) Constitutive panpsychism is false (Chalmers 2016: 187) How can the constitutive panpsychist respond to this argument? In Chapter 4, we saw that physicalist replies to the original conceivability argument concentrate on the contentious claim of premise (2) that, in the case of consciousness conceivability, entails metaphysical possibility. Solution proposals such as the phenomenal concept strategy grant the existence of special epistemic gaps, but deny that those gaps are indicative of an ontological gap. However, this route seems to be closed for the constitutive panpsychist. The conceivability argument against physicalism is at the core of the case against physicalism. If the constitutive panpsychist does not accept the thesis that in the case of consciousness, conceivability entails metaphysical possibility, then she seems not to be able to defend the original argument. Moreover, without the conceivability argument against physicalism, she loses the core motivation for adopting panpsychism in the first place. 6.4 Phenomenal Bonding and Consciousness+ However, there is a crucial difference between the both arguments: in the original argument, the grounding base is purely physical and, therefore, transparent to us. Physics reveals to us the essence of physicality. Only because of the assumption that we have transparent access to both the physical grounding base and macrophenomenality does the argument at all get off the ground. But in the case of constitutive panpsychism, it is less clear that the grounding base is fully transparent. It is obvious that microphenomenal properties and microsubjectivity are transparent to us since they belong to the same natural kinds as our phenomenal states and our

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subjectivity. Nevertheless, there might be dimensions of microphenomenality over and beyond microsubjects and their experiences. Goff (2016) speculates that there might be a nontransparent phenomenal bonding relation such that if microsubjects bear this relation to each other, then phenomenal combination occurs and a macrosubject is constituted. Now, if this relation were to be transparent to us, then we would realize that there is an a priori entailment from microsubjects standing in this relation to macrosubjects. But since we do not know the full nature of the phenomenal bonding relation, we can conceive of microsubjects standing in this relation without any macrosubjects being constituted—yet no metaphysical possibility corresponds to this conception. However, in order to make the suggestion intelligible, Goff has to provide some account of this relation. What kind of relation could the phenomenal bonding relation be? Goff (2016) suggests that the phenomenal bonding relation is the categorical nature of the spatiotemporal relation. Identifying the phenomenal bonding relation with the intrinsic nature of the spatiotemporal relation seems to be the perfect choice, since, in this way, the panpsychist can account for the quidditistic nature of the spatiotemporal relation. As Goff points out, while standard constitutive Russellian panpsychism provides microphenomenal grounds for microphysical dispositions, the deep nature of the spatiotemporal relation is left unexplained. Physics only provides mathematical models of it. But if we believe that physical dispositions need categorical natures over and above their dispositional profile, then we might by the same reasoning infer that the spatiotemporal relation also needs to have a categorical underpinning. Goff’s idea is that the phenomenal bonding hypothesis can provide us with an account of the categorical nature of the spatiotemporal relation and, at the same time, explain the non-transparency of phenomenal combination, thereby rejecting the conceivability argument against phenomenal combination: the categorical nature of the spatiotemporal relation is the phenomenal bonding relation (the relation that makes microsubjects that stand in it constitute macrosubjects); yet since we do not have a transparent conception of the latter, we lack a transparent conception of phenomenal constitution. Moreover, as Goff explains, this view provides an attractive account of the categorical nature of the world, given the plausible assumption that the only fundamental relation is the spatiotemporal relation: the categorical nature of fundamental properties is consciousness, and the categorical nature of fundamental relations is phenomenal bonding. However, there is a serious downside to Goff’s proposal: if the phenomenal bonding relation is the intrinsic nature of the spatial relation, then this entails universal phenomenal combination. Since all microsubjects in the history of the universe bear spatiotemporal relation to each other, there is a macrosubject for all possible sums of different microsubjects. This is a highly counterintuitive result. Panpsychism is already committed to the existence of microconsciousness which is hard to swallow. But if it turns out that there are not only trillions of microsubjects corresponding to elementary particles, but also macrosubjects corresponding to all possible sums of microsubjects of all times, then the position might seem to be fully incredible. At the very least, the phenomenal bonding strategy comes at a very high price. Yet Goff (2017: section 7.3.2) provides a second solution proposal to the conceivability argument against constitutive panpsychism, namely the hypothesis of consciousness+. The idea is to add a protophenomenal dimension to microphenomenology. On this proposal, mi-

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crophenomenal grounding bases consist not only in microsubjects and their respective phenomenal states. Rather, microphenomenal states are parts of more encompassing properties which, in addition to a phenomenal component, also exhibit a protophenomenal dimension, the ‘+’-component. The nature of this additional protophenomenal dimension is completely opaque to us. But the constitutive panpsychist can assume that knowledge of its nature would reveal to us that there is an a priori entailment from appropriate combinations of micro- to macrophenomenality. If we had a transparent concept of the component, then it would not be conceivable that microsubjects do not combine under appropriate circumstances. The conceivability argument against phenomenal combination only seems plausible to us because we are ignorant of the +-component. Note that consciousness+ induces a noumenal dimension within panpsychism: part of the grounding base of macrophenomenality is opaque to us. If so, it is not clear whether the view is all that much preferable to panprotopsychism. Goff acknowledges that the consciousness+version of constitutive panpsychism is not as attractive as the pure version. Nonetheless, he thinks that it is preferable to panprotopsychism because, according to this view, at least some elements of the nature of the micro-grounds of macroconsciousness, namely the phenomenal dimensions of consciousness+, are transparent to us. Panprotopsychism, in contrast, leaves us completely in the dark as to the ground of ordinary consciousness. But it is hardly obvious that the consciousness+ hypothesis performs better than panprotopsychism. Instead of labeling it consciousness+, the position could equally well be named panprotopsychism+, the view that the micro-grounds of human consciousness involve protophenomenal elements plus microconsciousness. What makes this view more plausible than pure panprotopsychism? Why not hold that the protophenomenal elements themselves suffice to ground ordinary consciousness? We do not know anything whatsoever about this highest type, besides that it is neither phenomenal nor physical. I think that this proposal can hardly count as a panpsychist solution to the conceivability argument. Instead of explaining phenomenal constitution, Goff postulates that there is an explanandum, labels it ‘+’, and tells us that it is conceptually inaccessible to us. I believe that the consciousness+-hypothesis is better described as a version of panprotopsychism rather than panpsychism, since the bulk of the explanatory work regarding phenomenal constitution is ascribed to protophenomenal elements. Moreover, panprotopsychism seems preferable to the consciousness+ hypothesis for reasons of parsimony. Both introduce a noumenal highest type and are thereby less parsimonious than panpsychism. Yet the consciousness+ hypothesis holds that there is microconsciousness in addition to macroconsciousness, while panprotopsychism can do without microconsciousness. This has important consequences: panprotopsychism views both physical properties and consciousness as derivative and grounded in fundamental protophenomenal properties; Goff’s panpsychism+, in contrast, assumes two kinds of fundamental entities, namely proto- and micro-phenomenal properties. While ordinary panpsychism and panprotopsychism can do with only one highest type, phenomenality or protophenomenality, respectively, panpsychism+ is committed to two fundamental categories, phenomenality and protophenomenality.94 94 As seen above, also the phenomenal bonding solution adds an element of noumenalism to constitutive panpsychism, namely the phenomenal bonding relation, which falls under a novel highest type of property. One might therefore think that this proposal has the same disadvantages vis-à-vis standard panprotopsy-

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I conclude that both the phenomenal bonding strategy and the consciousness+ hypothesis succeed in fending off the conceivability argument. But they come at a considerable prices respectively: phenomenal bonding entails universal phenomenal combination, and the consciousness+ solution transforms constitutive panpsychism into a version of panprotopsychism which might be considered weaker than other forms of panprotopsychism. In my view, the phenomenal bonding solution is preferable, since it can avoid the introduction of fundamental protophenomenal properties. 6.5 Coleman’s Anti-Subject-Summing Argument Coleman (2014), while advocating for quality-combination, provides an interesting argument against the possibility of subject-combination. In contrast to the conceivability argument, Coleman’s objection does not infer from a negative criterion such as an epistemic gap that combination is not possible, but rather provides positive evidence for the incoherence of subject-summing. His argument is based on the analysis of a particular case of subject constitution involving the two microsubjects Blue and Red producing the macrosubject or, as Coleman calls it, über-subject Ub: Consider the [micro-subjects’] points of view. One—Blue’s—is pervaded by a unitary blueness, the other—Red’s—by redness, and that is all they experience, respectively. To say these points of view were present as components in the experiential perspective of the über-subject (‘Ub’) would therefore be to say that Ub experienced a unitary phenomenal blueness and a unitary phenomenal redness, i.e. had synchronous experiences as of each of these qualities alone, to the exclusion of all others. For it is these qualities each on their own that characterise, respectively, the perspectives of the original duo. Experience excludes, as well as includes. […] Ub doesn’t experience red-to-the-exclusion-of-(blue-and)-all-else, nor blue-to-theexclusion-of-(red-and)-all-else, let alone—impossibly—both together. (Coleman 2014: 33; italics in the original.) Coleman’s anti-subject-summing argument is based on an analysis of subjecthood from which it is inferred that subject-combination is incoherent. He argues that subjects essentially are discrete points of views, and qua essentially being discrete points of view, they cannot combine. For one cannot combine several phenomenal perspectives as such, since a perspective is defined by being precisely limited to exhibiting such and such phenomenal content exclusively. Of course, it might plausible that it is possible combine the content of several perspectives, that is, the phenomenal properties they instantiate. But this would be a combination of phenomenal qualities. Subject-summing, however, concerns the combination of subjects, chism as the consciousness+ hypothesis. Yet, in contrast to adherents of consciousness+, proponents of phenomenal bonding can justify their commitment to an additional highest type of relational quiddities by argu ing that it is not only required to explain phenomenal constitution, but also to account for the deep nature of the spatiotemporal relation. If it can be compellingly argued that spatiotemporal relations have a categorical nature, then the commitment to this novel highest type does not amount to additional ontological costs be cause panprotopsychists must also allow for similar relational quiddities. I stay neutral on the question whether the case for such a category of relational quiddities is sound. But even if so, constitutive panpsychism cannot be made intelligible, because it runs into other unsolvable problems, as will become clear in the following.

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and it is not possible to combine perspectives as such. Coleman thus claims that we have direct access to an essentialist fact about subjecthood rendering subject combination impossible, namely that it involves exclusive perspectives. In contrast to the conceivability argument, the anti-subject-summing objection does not argue that there is no a priori entailment and that constitution is, thereby, under-determined. Rather, the objection is that we know something positive about the nature of subjectivity which rules out the possibility of subject combination. The problem is not that there is an epistemic gap we cannot close, but, rather, that entailment is not possible because of something we know a priori about the nature of subjectivity. Hence, Goff’s solution proposals discussed in the last section are of little help here, these postulating additional microentities (phenomenal bonding relations or protophenomenal properties) in order to bridge an epistemic gap. However, Goff (2017: section 7.3.3) develops a separate reply to Coleman’s argument: [C]onsider a standard form of panprotopsychism. On this view, a given [macro]experiential state is constituted of certain protophenomenal properties, but those protophenomenal properties don’t themselves characterise the resulting [macro]experience. [...] It seems coherent, therefore, to hold that a property can play a role in constituting a given experience without playing a role in characterising that experience. [...] [O]nce we have allowed that partial characterising and partially constituting can come apart [in protopanpsychism], it seems that we can coherently suppose that they can come apart in the case of the relationship between the microlevel phenomenal and the [macro]-phenomenal. […] We might see [Coleman’s] arguments against subject-summing as relying on an ambiguity in the phrase ‘being part of what it’s like to be subject.’ A given microexperience can be ‘part of what it’s like to be me’ in the sense that it constitutes my experience, or can be ‘part of what it’s like to be me’ in the sense that it characterises my experience. Distinguishing these two meanings disarms the arguments. […] [O]ne could hold that Blue and Red constitute (i.e. partially ground) the Ub’s point of view, but without being phenomenally present in that viewpoint (i.e. without ‘showing up’ in Ub’s experience); and hence avoid the incoherent scenario of Ub experiencing both red-to-the-exclusion-of-(blue-and)-all-else and blue-to-theexclusion-of-(red-and)-all-else. (Goff 2017: 190–191; italics in the original.) Goff argues that there is a difference between constitution and characterization. In claiming that microsubjects can constitute macrosubjects, the constitutive panpsychist does not necessarily commit herself to the further claim that macrosubjects are characterized by their grounds. That is, the phenomenal point of view of a macrosubject does not have to feature the perspectives of the microsubjects constituting it. Hence, the fact that their points of views are discrete does not render them incapable of combining: they do not have to bequeath the discreteness of their perspectives to their constitutive product. Thus, there is no reason for thinking that subject-combination is impossible.

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However, I believe that Goff’s reply is not convincing. As I see it, the problem is that it changes the topic. Coleman claims that it is part of the nature of subjectivity that it comes only in discrete units, and that this essentialist fact about subjects makes it impossible for them to combine. Instead of attacking this claim or demonstrating that the discreteness of subject-perspectives is no obstacle to subject-combination, Goff discusses the experiences of the macrosubjects, and claims that they do not have to be characterized by the microphenomenal states grounding them. Let me explain this point in more detail. Consider the above quote. Goff claims that microsubjects can constitute a macrosubject “without being phenomenally present in [its] viewpoint (i.e. without ‘showing up’ in [the macro-subject’s] experience)” (italics added). But Coleman’s claim is not that subject-combination is not possible, because the experience of the macrosubject shows no trace of the microsubjects. Here again is a portion of the quote from Coleman cited above: To say these points of view were present as components in the experiential perspective of the über-subject (‘Ub’) would […] be to say that Ub experienced a unitary phenomenal blueness and a unitary phenomenal redness. (Italics added) Contra Goff’s interpretation, Coleman does not state regarding the experience of a macrosubject that it cannot feature the perspectives of microsubjects, but rather regarding the perspective of the macrosubject that it cannot be composed of the perspectives of microsubjects. Instead of defending subject-combination, Goff effectively argues that Coleman’s argument does not render quality-combination impossible. This is true, but beside the point. A successful reply to Coleman’s argument would have to attack his analysis of subjecthood. This might be a viable possibility. I find it intuitive that the nature of subjecthood involves phenomenally exclusive discreteness, but this thesis might very well be criticized. Nevertheless, as long as no competing analysis of subjecthood compatible with subject-combination is developed, we have good reason to regard Coleman’s argument as successful. 6.6 The Palette Problem The palette problem is a variant of the quality combination problem. It concerns an apparent mismatch in the number of types of micro- and macroqualities. Physics tells us there are only a few types of elementary particles bearing a few types of microphysical dispositions. Moreover, Russellian panpsychism assumes that every type of fundamental disposition has just one type of microphenomenal realizer. It seems thus plausible that there are exactly as many types of microphenomenal as types of microphysical properties. But—given the vast complexity of human phenomenal experience—how can it be that the richness and diversity of the phenomenal qualities we enjoy is the result of the combination of just a handful of microqualities? The palette problem is that macrophenomenology seems too rich and diverse for being traced back to a few microphenomenal qualities. Here is Chalmers’ formulation of this objection: (1) If constitutive panpsychism is correct, macrophenomenal qualities are constituted by microphenomenal qualities.

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(2) If Russellian panpsychism is correct, there are only a few microphenomenal qualities. (3) Macrophenomenal qualities are too diverse to be constituted by a few microphenomenal qualities. ______________ (4) Constitutive Russellian panpsychism is incorrect. (Chalmers 2016: 189) A number of solution strategies to the palette problem have been provided within the literature. Chalmers categorizes them into large- and small-palette solutions. Large-palette solutions reject premise (2), and hold that there already are myriad different types of microphenomenal properties. If so, it is not difficult to explain how such a huge number of microqualities can give rise to our rich phenomenal life. 95 The problem with large-palette solutions is that they appear to be incompatible with Russellianism. They postulate far more types of microqualities than there are types of microphysical dispositions. Hence, not all of these microqualities can act as realizers for those dispositions. But then, problems of mental causation arise for those types of microqualities excluded from acting as realizers. Here, the panpsychist faces two options. Either they have causal powers, or they do not. If they have causal powers, then it seems that they are subject to the causal exclusion problem. If they do not have causal power, then they are epiphenomenal. Both options do not seem to be acceptable to constitutive panpsychists who reject dualism, since they consider neither systematic overdetermination of physical effects, nor epiphenomenalism of phenomenal states to be tenable. Large-palette solutions thus come at the price of sacrificing constitutive panpsychism’s core advantage over dualism, a price which can hardly be worth paying.96 It seems that the constitutive panpsychist must provide a small-palette solution. Small-palette solutions reject premise (3). Although macrophenomenal states display very rich and diverse qualitative profiles, they, nonetheless, can be derived from qualitatively meager grounding bases. In order to derive such large output from such small input, the constitutive panpsychist has to postulate some sort of phenomenal blending. At this point, the blending of macrophenomenal color experiences and tastes is often taken as an analogy of how blending of microqualities might work. Coleman (2012) describes the blending of phenomenal colors as follows: In painting, one deploys qualitative elements which can, in arrangement, alter one another’s intrinsic character. This mutual conditioning is part and parcel of the integration of the qualitative elements into a whole, with systemic powers all its own: the overall phenomenological upshot of all the composing elements. Qualitatively distinct elements can combine into a smoothly variegated qualitative whole. This, a painted canvas, is the model I suggest we have in mind when we think of phenomenal combination. (Coleman 2012: 157–8) 95 Lewtas (2017) defends a solution along these lines. 96 Proponents of large-palette solutions might argue that while contemporary physics only allows for a small number of fundamental physical properties, this might not be the case for ideal future physics which might feature a great number of fundamental particles and dispositions. However, it seems implausible that the world is nearly as complex at the very bottom as the richness of human phenomenology appears to require. At least, this is a large gamble on the future of scientific inquiry which is better avoided if possible. We thus have good reasons for evaluating the prospects of small-palette solutions.

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As becomes clear from this quote, phenomenal blending is based on an extreme form of phenomenal holism, the idea that the qualitative character of a phenomenal state is partly altered by other phenomenal states it is co-conscious with. The idea is the following: we know that phenomenal holism exists since we know from everyday experiences such as Coleman’s painting case that the characters of macrophenomenal states can be influenced by their phenomenal surroundings. Yet if macroqualities blend into each other when experienced together, then we also have reason to assume that the same is true of microqualities. Just as—in another example Coleman provides—the tastes of roast beef and red wine differ when they are consumed together from their separate consumption, so changes the qualitative character of microphenomenal properties depending on their respective combinations with other microqualities. In this way, a small number of microqualities can produce a much greater number of macroqualities. However, in contrast to most of the familiar examples of the blending of coconscious macroqualities, microphenomenal blending must be so extreme that we cannot distinguish different phenomenal inputs. Here, certain cases of the blending of color experiences might be telling, wherein, for instance, the experiences of redness and yellowness at the same location produce the experience of orange in such a way that we are unaware of the phenomenal inputs (see Chalmers 2016: 205). However, the tenability of solution proposals along these lines has been challenged for very principled reasons. Basile (2010) argues that by subscribing to phenomenal holism, the constitutive panpsychist commits herself to two incompatible assumptions. The first is phenomenal essentialism, the thesis that the nature of a phenomenal state is what-it-feels-like. Phenomenal essentialism follows from the fact that direct phenomenal concepts give us a transparent account of the essences of our phenomenal states (see Chapter 3): those concepts reveal to us the complete nature of our phenomenal states—and what they reveal is their phenomenal character. The second assumption is what Basile calls the sharing principle, the thesis that the same phenomenal state can simultaneously be experienced by two different subjects. He argues that constitutive panpsychism qua allowing for phenomenal constitution is committed to the sharing principle. The idea is that if by combining microphenomenal states a, b, and c a macrophenomenal state P is grounded, the latter is identical to the sum of the former. It follows that experiencing P involves experiencing a, b, and c simultaneously. That is, by experiencing P, the macrosubject inter alia experiences a, an experience it shares with one of the microsubjects of its grounding base. But if phenomenal holism is true, and the phenomenal character of a is changed when it blends with b and c, then the macrosubject feels something different in experiencing a as part of experiencing P than the microsubject which, say, experiences a without simultaneously having any other experiences. However, given phenomenal essentialism, a is essentially what-it-feels-like. Therefore, a as experienced by the macrosubject is not identical to a as experienced by the microsubject. Yet phenomenal constitution entails that a is part of the grounding base and part of P. It follows that constitutive panpsychism is incoherent. Can the constitutive panpsychist avoid this incoherency? Note that Basile’s objection (implicitly) presupposes what I shall call a conception of constitution as composition from which the sharing principle is derived. According to this view, the constituted entity is composed of its grounding base in a narrow sense such that the parts of the former are identical to parts of

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the latter: if p1 partly constitutes P, then P has a part which is identical to p1. But, as Goff (2017: section 8.1) argues, the constitutive panpsychist is not necessarily committed to such an account of constitution. It therefore does not necessarily follow from the fact that microphenomenal property e1 is part of the grounding base of macrophenomenal state E that a macrosubject experiencing E thereby experiences, among others, e1.97 She is only committed to the thesis that macrophenomenal states are grounded in microphenomenal states bearing appropriate relations to each other. Moreover, accounts of realization have been provided according to which grounded properties do not have parts which are identical to their grounds. Note that these accounts are usually developed for functional properties, yet—on antiphysicalist views—phenomenal states are not functional properties. However, the constitutive panpsychist might argue that phenomenal constitution works in a similar fashion to functional realization. As discussed in Section 4.3.2, e.g. Pereboom (2002) provides an account of realization which does not involve identity of the parts of the constituted entity with features of the ground. But this is not uncontroversial: other theories of realization entail the sharing principle. For instance, the Shoemaker-Wilson subset-view takes functional states to have token powers identical to some of the token powers of their realizers, while the latter also have additional powers not shared by the former. Hence, in order to avoid the sharing principle, the constitutive panpsychist must demonstrate that (at least) phenomenal constitution can be accounted for in terms of non-compositional constitution. Goff fails to provide a detailed account of non-compositional phenomenal constitution, but constitutive panpsychists might be able to develop such a theory and reject the sharing principle. At the least, this appears the be a promising strategy for the dismissal of Basile’s objection. Note that an account along these lines is somewhat analogous to Goff’s reply to Coleman’s anti-subject-summing argument. In the last section, I argued that Goff’s response does not succeed against Coleman’s critique of subject-subjection. What might be different in the case of the palette problem so that this reply proves more promising here? In quality-combination, the phenomenal characters of qualia are blended. There is no logical problem in thinking that phenomenal characters can combine. Their characteristic qualities can enter combination, though by phenomenal blending these qualities change considerably when mixed with other qualities. In subject-combination, by contrast, discrete perspectives with exact phenomenal boundaries have to be combined—at least this is what Coleman claims. But boundaries as such cannot mix. Boundaries qua boundaries cannot enter combination with other boundaries because they exclude each other. If my point of view consists of such and such experiences to the exclusion of all other possible experiences, then this point of view cannot mix with other points of view. The reason is that the respective exclusion-properties are incompatible with each other unless it is the exact same perspectives. Goff is right that constitution does not necessarily entail that the constituted entity has parts which are identical to its constituents. Hence, the constitutive panpsychist might be able to provide good reasons for rejecting the sharing principle. Note that this principle concerns the product of constitution. Basile’s argument questions the coherence of quality-combination 97 Goff (2017) does not explicitly discuss Basile (2010), but argues against phenomenal constitution as composition in another context.

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because of the assumption that the product of combination obeys phenomenal essentialism and the sharing principle. By rejecting one of them, the sharing principle, we can avoid the incoherence to which they give rise. Coleman’s argument against subject-combination, on the other hand, makes an assumption about the inputs to combination which renders constitution impossible. It is obvious that Goff’s considerations about the output of constitution cannot possibly dismiss Coleman’s worry. As I argued in the last section, one must attack Coleman’s analysis of subjecthood in order to reject his argument. This might be an option. But unless one can provide a more convincing analysis than Coleman, we have good reason to accept his argument. Back to the palette problem. Even if we acknowledge that there is no identity between micro- and macroqualia, we still need to be told how microphenomenal blending works. It has not only to be explained as to how a handful types of microqualia can plausibly give rise to the rich diversity of macrophenomenal properties, but also demonstrated as to how the seemingly simple character of a macroquale such as the experience of red can result from a combination of multiple microqualia. The constitution hypothesis has to make sense of the fact that the phenomenal character of the former intelligibly results from the phenomenal characters of its constituents without bearing any identifiable traces of this inheritance. Furthermore, blending has the counterintuitive implication that there is no gap between different sensory modalities such as auditory and visual experience. For phenomenal constitution entails that experience of these different modalities share the same phenomenal constituents. But an auditory experience such as hearing the sound of a piano seems to have phenomenologically nothing in common with a visual experience such as experiencing a certain shade of redness. Now, while it is a considerable challenge to provide a detailed account of phenomenal blending, such a theory might be in the cards. First steps in this direction have inter alia been taken by Roelofs (2014, 2015: chapter 5), and Coleman (2015). Roelofs develops an account based on the concept of phenomenal confusion endorsed by Spinoza and Leibniz in order to explain why we cannot identify the traces of microqualities in our phenomenal experiences, while Coleman elaborates on the work of Hartshorne (1934) in order to provide an account of how the apparent phenomenal gap between sensory modalities might be bridged. I conclude that there is no principled reason to think that the palette problem cannot be overcome by a developed version of the small-palette solution. 6.7 The Structural Mismatch Problem Both physical and phenomenal properties come with specific structural aspects. They have mathematically describable structures stemming from both their internal complexity as well as their associated quality spaces. Chalmers (2016) distinguishes two dimensions of structure, internal and external structure, where internal structure is the internal complexity of states, and external structure is the structure of the quality spaces in which they partake. Both dimensions are exhibited by experiences and physical states but take on very different respective forms. Physical states of material systems possess certain internal geometrical structures resulting from the spatial arrangements of the systems’ parts. The auditory and visual fields we experience also have specific internal spatial structures: my visual experience might feature a

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red object over there and a blue object over here with a brown object located in the middle between them. Furthermore, each of our sensory modalities comes with a characteristic quality space. Part of the visual modality is color experience, which comes with an external structure corresponding to the location of phenomenal colors in color space. As discussed in Section 3.4, phenomenal colors have at least three external structural dimensions: lightness, saturation, and hue (and maybe also others such as warmth). The combination of levels of intensity of the scalar dimensions of lightness and saturation (and perhaps warmth) allows for locating a given hue within color space. Moreover, microphysical properties have external structure: mass, for instance, has a scalar structure, and charge a binary structure. Now, the structural mismatch problem identifies a sharp discrepancy between the structure of micro- and macrophenomenal properties following from Russellian assumptions. Recall that Russellian panpsychism ascribes to microqualia the role of realizing microphysical dispositions. If so, it seems that in order to be able to play those roles, microqualia have to be structurally isomorphic to microphysical properties. For if microqualia act as quiddities, it seems that in order to realize those properties, they must have a structure sufficiently similar to the microphysical properties with which they are associated. But then, the quiddity of mass has a scalar structure, and the quiddity of charge a binary structure. As discussed in Chapter 5, there are different ways to cash out Russellian panpsychism. On some such views, microphysical dispositions are identical to their microphenomenal quiddities, while, on others, they bear a relationship of realization to their categorical grounds which does not involve identity. It is obvious that if microqualia are identical to microphysical dispositions, then both must be isomorphic. However, even if they are not identical, it seems that a microquale needs to have a binary structure in order realize charge. The upshot is then that according to Russellian panpsychism, microphenomenal structure must have the same form as microphysical structure. Yet on constitutive panpsychism, macrophysical as well as macrophenomenal structure is constituted by microphysical and microphenomenal structure. Hence, macrophenomenal structure must be sufficiently similar to microphenomenal structure that it is derivable from it. But macrophenomenal states seem to be structurally very different from the micro- and macrophysical structure of the brain. As discussed in the previous paragraph, macrophenomenal properties exhibit idiosyncratic forms— such as the structure of the visual field—that seem to have little in common with physical structure—such as the scalar structure of mass or the binary structure of charge. It is hard to see how such macrophenomenal structure can be derived from microphenomenal structure given that the latter is largely isomorphic to physical structure. Hence, there is a problem of structural mismatch between micro- and macrophenomenality. Here is Chalmers’ formulation of the argument: (1) If Russellian panpsychism is true, microphenomenal structure is isomorphic to microphysical structure. (2) If constitutive panpsychism is true, microphenomenal (and microphysical) structure constitutes macrophenomenal structure. (3) Microphysical structure constitutes only macrophysical structure.

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Problems for Constitutive Russellian Panpsychism (4) If microphenomenal structure is isomorphic to microphysical structure, then any structure constituted by microphenomenal structure (and microphysical structure) is isomorphic to a structure constituted by microphysical structure. (5) Macrophenomenal structure is not isomorphic to macrophysical structure ______________ (6) Constitutive Russellian panpsychism is false. (Chalmers 2016: 206)

One might question premise (1) on the ground that microphenomenal properties might have structure over and above the structure qualifying them to realize microphysical dispositions. But it is not clear whether this suggestion really helps in avoiding structural mismatch. Even if there is such surplus microphenomenal structure, the original microphenomenal structure would still have to figure within macrophenomenal structure. Yet we find no trace of it in our direct phenomenal concepts. Moreover, if the surplus structure is not relevant in grounding microphysical dispositions, the features of microqualia which exhibit the surplus structure must be either epiphenomenal or otherwise those features are threatened by causal exclusion. Both options seem problematic because macrophenomenal states inheriting those features are then either partially epiphenomenal, or partially causally excluded. As Chalmers explains, the best strategy for the constitutive panpsychist is to deny premise (5): despite initial appearances, there is indeed macrophysical structure isomorphic to macrophenomenal structure. This results from the following line of reasoning: whenever we enjoy a macrophenomenal state, there is a corresponding psychological state of which our cognitive system is aware. The fact that we can report on the details of our phenomenal experiences entails that every phenomenal information embedded in our conscious states corresponds to cognitive information available for verbal report and global control. Take color experience which involves (at least) the three dimensions of hue, intensity, and saturation. The visual system needs a similar three-dimensional information structure in order to be able to process visual information which can later be reported as, for instance, the experience of seeing the yellow line in Kandinsky’s Composition IX. Correspondingly, whenever there is psychological awareness in the sense of cognitive information available for global behavioral control and verbal report, there is isomorphically structured phenomenal information. Chalmers (1996) therefore postulates the principle of structural coherence, according to which the structure of consciousness is mirrored by the structure of [psychological] awareness, and the structure of awareness is mirrored by the structure of consciousness (Chalmers 1996: 225).98 Now, how might the principle of structural coherence allow us to reject premise (5)? The answer is that because states of psychological awareness qua being neuronal states are consti98 In chapter eight of his (1996), Chalmers develops the foundations of a theory according to which the princi ple of structural coherence can be derived from an underlying principle of informational coherence (though he does not use this term). The problem with the principle of structural coherence is that it can hardly figure in a fundamental theory of consciousness, since ‘structure of awareness’ is a high-level notion, and, as such, far too vague to be applicable to a fundamental theory. But according to Chalmers, the concept of informa tion developed by Shannon (1948) is suitable for this task. By utilizing this concept of information, one can take information as being involved in both physics and phenomenology. Thereby, information can serve as a common ground in both realms for the formulation of a principle of coherence.

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tuted by microphysical states, they qualify as macrophysical states in a broad sense of the term. Correspondingly, Chalmers suggests a distinction between narrowly and broadly macrophysical structure: narrowly macrophysical structure is macroscopic structure characterized in terms of physics: for example, in terms of space, time, mass, charge, and so on. Broadly macrophysical structure is any structure constituted by microphysics: for example, chemical, biological, and computational structure. (Chalmers 2016: 208; italics in original) Hence, macrophenomenal structure is isomorphic to one sort of broadly macrophysical structure, namely the structure of psychological awareness. But it is not clear whether the constitutive panpsychist can exploit this fact in a solution to the structural mismatch problem. Of course, broadly macrophysical structure is derivative from narrowly macrophysical structure which, in turn, is directly grounded in microphysical structure. But the constitutive panpsychist views macrophenomenal structure as being directly grounded in microphenomenal structure in much the same way as narrowly macrophysical structure is directly grounded in microphysical structure. If so, then why is macrophenomenal structure isomorphic to one sort of broadly macrophysical structure which is only indirectly grounded in microphysical structure? If microphenomenal structure is isomorphic to microphysical structure and directly grounds macrophenomenal structure—would it not be plausible that macrophenomenal structure is isomorphic to the type of macrophysical structure directly grounded in microphysical structure? But if it follows from the core assumptions of constitutive panpsychism that macrophenomenal structure is isomorphic to narrowly macrophysical structure, then the structural mismatch problem arises all over again.99 Goff (2017: section 8.2) offers a solution to this dilemma. He argues that structural mismatch can be avoided if it is assumed that there are both macrophenomenal structure isomorphic to narrowly macrophysical structure and macrophenomenal structures isomorphic to all sorts of broadly macrophysical structure respectively: 99 Given this thorough analysis of the structural mismatch argument and its implications, we can easily see that the problem also threatens the simple field proposal and the ‘mystery-approach’ for solving the fundamental interaction problem discussed in Section 5.4.3: both accounts invoke microphysical structure of some kind, and it is hard to imagine that this structure (whatever it might be) is isomorphic to macrophenomenal struc ture. In Section 5.4.3, it was argued that the structure of complex microphenomena such as structured fields is far too intricate and fine-grained for being isomorphic to macrophenomenal structure. This is one aspect of the structural mismatch argument. The other aspect is that as we saw in this section, also macrophenomenal structure has a complex idiosyncratic structure stemming inter alia from the external structure of the quality spaces in which our phenomenal properties partake, and their respective location within those spaces. But then, it is hard to see how this idiosyncratic structure can be isomorphic to the simple structure of the postulated microstructural entities: how can macroqualia realize simple microstructural properties, or uniform fields, given that they have such rich macrophenomenal structure? At this point, the Russellian du alist might resort to a similar reply as the one (discussed above) that the constitutive panpsychist might give in response to premise (1): macroqualia have surplus phenomenal structure that is not involved in realizing those simple microstructural entities. But then, the problem arises again that if so, this surplus structure is epiphenomenal. It seems that, therefore, (contra to what was suggested in Section 5.4.3) also the simple field approach, and even the idea to invoke microstructural properties which affect neural patterns globally in an inexplicable manner are subject to the structural mismatch problem.

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Problems for Constitutive Russellian Panpsychism If we suppose that there is a vast multiplicity of kinds of consciousness corresponding to a vast multiplicity of structures in the brain, the mystery as to why there is a form of consciousness mirroring a seemingly quite arbitrary brain-structure disappears; many macro-level brain structures correspond to phenomenology, and the information states corresponding to [human consciousness] are just one amongst this many. If we suppose that there is one, or few, kinds of consciousness at the macro-level of the brain, it is extremely odd that there should be consciousness corresponding to high-level information states. This given us strong reason to suppose that there are in fact many forms of consciousness instantiated in the macro-level brain. […] [Human consciousness] is special from the perspective of those interested in human society. But from the God’s eye view it may be a highly arbitrary and uninteresting slice from a world teeming with phenomenology. (Goff 2017: 207–208 )

As with the phenomenal bonding strategy discussed in Section 6.4, the problem with this solution is that it multiples the number of macrosubjects and macrophenomenal properties beyond all limits. This makes the position rather unattractive. At the very least, the overwhelming abundance of kinds of macroconsciousness gives us reason to look out for alternatives to constitutive panpsychism. Moreover, in the next section, I shall discuss a version of the combination problem, the revelation argument, which has, as it will turn out, even more disastrous consequences for constitutive panpsychism. 6.8 The Revelation Argument The revelation argument is based on the thesis that the full nature of our consciousness is revealed to us by our direct phenomenal concepts. As was discussed in Chapter 3, this thesis— Goff calls it Direct Phenomenal Transparency—is crucial to all of the major arguments against physicalism about consciousness. The panpsychist qua antiphysicalist can therefore be expected to be committed to it. Yet if constitutive panpsychism is true, then our phenomenality is constituted by a vast number of microsubjects and their respective microphenomenal states. But introspection does not reveal to us that our conscious states have microphenomenal constituents. Therefore, constitutive panpsychism is false. This is the simplest version of the revelation argument. Note that this version of the argument appears to presuppose a conception of constitution as composition. It seems that knowledge of the full nature of a macrophenomenal state reveals the microphenomenal constituents of this state iff the microphenomenal constituents of a macrophenomenal state are identical to its parts. For it is only if so that revelation of the full nature of the state involves revelation of the nature of its parts. In turn, those parts are identical with microphenomenal states. Hence, there being microphenomenal constituents to our phenomenal states would have to be revealed by introspection. However, in Section 6.6, we saw that the constitutive panpsychist might be able to reject this conception of phenomenal constitution. She might very well be able to demonstrate that while macrophenomenality is grounded in microphenomenality, no part of a macrophenomenal state is identical to any of the properties of its microphenomenal ground. But then, there is no reason to think that our di-

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rect phenomenal concepts reveal to us that macrophenomenality has a microphenomenal grounding base. However, Goff (2015, 2017: section 8.3)—who himself, as we saw, questions phenomenal combination in this narrow sense—has developed versions of the revelation argument which utilize accounts of constitution that are neutral on the question whether constitution involves combination. Hence, the above reply does not bear against these versions of the objection. For they are compatible with non-combinational accounts of constitution. Goff’s version of the revelation argument, he calls it subject irreducibility argument, comes in two variants. Both utilize a theory of metaphysical fundamentalism. In Chapter 2, I introduced metaphysical fundamentalism and its commitment to a hyperintensional notion of ‘nothing-over-and-aboveness’. While we have good reasons to accept the basic rationale for fundamentalism and the hyperintensional turn in metaphysics behind it, there are a number of rival fundamentalist approaches and it is controversial which of them is preferable to the others. Goff is therefore right in providing two forms of his argument each of which is cashed out in one of the leading theories of metaphysical fundamentalism, namely the Fine-Dasgupta account of metaphysical grounding, and Sider’s view respectively (for an overview on these accounts, see Section 2.1.3 and 2.1.4).100 I begin with discussing the former (Goff 2017: section 8.3). Goff aptly calls the Fine-Dasgupta account of grounding grounding by analysis. Recall from Section 2.1.4 that Dasgupta claims that grounding relations themselves need to be grounded in essentialist facts concerning the grounded entity: if an entity is grounded in underlying phenomena, then the essence of the former reveals how and why it is grounded in the latter. Here is an example Goff uses to illustrate this point: part of the essence of ‘party’ is the fact that a party occurs iff an event occurs that involves various people reveling. Therefore, the fact that Mike, Mary, Anthony, and George revel in Mike’s apartment grounds the fact that there is a party in Mike’s apartment. The particular grounding fact concerning the events in Mike’s apartment holds in virtue of the general connection between the act of reveling and party-events that the above essentialist fact about parties establishes. Thus, the particular grounding fact is itself grounded in an essentialist fact concerning parties. Again, as was discussed in Chapter 3, all of the major antiphysicalist arguments involve the premise that it is our direct phenomenal concepts which completely reveal to us both the essence of our phenomenal states, and the essence of being a subject experiencing these states. However, on introspection, we realize that our phenomenal concepts do not reveal to us that our macrophenomenality is grounded in microphenomenality. Given grounding by analysis, it seems to follow that macroconsciousness is not grounded at all, but rather fundamental. For according to the Fine-Dasgupta view, the first-order grounding fact that my consciousness is grounded in the combinations of such and such microsubjects exhibiting such and such microphenomenal states would itself have to be grounded in an essentialist fact about macroconsciousness. Yet given Direct Phenomenal Transparency, I have fully transparent access to the complete nature of my consciousness. I can form direct phenomenal concepts about my sub100 Goff (2019) develops a version of the argument utilizing the the framework of truthmaker fundamentalism as defended by e.g. Cameron (2008, 2016) (see Section 2.1.3, Footnote 10 for a short discussion of truthmaker fundamentalism).

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jecthood as well as my various phenomenal states which provide me with irrefutable knowledge of all the essentialist facts about my subjectivity and the phenomenal states I enjoy. When I retrieve this knowledge, I do not encounter any propositions about microphenomenality of any kind. Therefore, the first-order grounding fact about my consciousness to which constitutive panpsychists are committed does not hold. It follows that constitutive panpsychism is false. By way of illustration, Goff considers the case of the human subject Jane. Here is his formulation of the argument: Premise 1 – The fact that Jane exists as a conscious subject is grounded by analysis in the micro-level facts only if the micro-level facts logically entail what is essentially required for Jane to exist as a conscious subject. (This premise follows from the definition of grounding by analysis). Premise 2 (Subject irreducibility) – What is essentially required for there to be an x such that x is a conscious individual cannot be analysed into facts not involving x. Conclusion 1 – The fact that Jane exists as a conscious subject can be grounded by analysis in the micro-level facts only if the micro-level facts logically entail the existence of Jane. Premise 3 – Jane is a macro-level entity, and hence her non-existence is logically consistent with the complete micro-level facts. Conclusion 2 – The fact that Jane exists is not grounded by analysis in the microlevel facts (Goff 2017: 217) Premise 2 is crucial. On the Finean account of essence, an analysis of human subjectivity has to be given in terms of its real definition or essence. This real definition encompasses all essentialist facts about subjectivity. Our direct phenomenal concepts reveal to us that these essentialist facts do not specify any general connection between subjecthood and micro-facts. Rather, we know that subjecthood is not analyzable in terms of anything non-macrophenomenal. It follows that there is no general connection which could ground first-order groundingclaims about macrosubjects. Yet if brute essentialism is true, then any potential grounding claim has to be grounded in such a general connection. As there is no such connection, constitutive panpsychism is false. This is the first version of Goff’s argument. The second version of the subject irreducibility argument (Goff 2015) utilizes Sider’s approach as follows. As discussed in Section 2.1.3, Sider (2011) defends a representational view about connecting facts. Proponents of metaphysical grounding usually take grounding to be a relation between worldly entities, since its relata are usually assumed to be facts, and facts are worldly entities. On Sider’s view, on the other hand, there are strictly speaking no derivative entities. The extra-linguistic world only inhibits fundamental reality, while derivativeness is a purely linguistic phenomenon. Derivative entities only exist in the sense that certain sentences of non-fundamental languages about derivative entities are true. Sider’s means of connecting the fundamental and the derivative are metaphysical truth conditions which hold between true sentences of non-fundamental languages, and sentences of the fundamental language. Only

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the fundamental language carves reality at its joints, its linguistic expressions exactly mirror the structure of fundamental reality such that fundamental sentences can provide fully correct descriptions of fundamental reality. Goff’s second version is not directed at constitutive Russellian panpsychism, but rather at constitutive Russellian monism, the general view encompassing both constitutive Russellian panpsychism and constitutive Russellian panprotopsychism. As discussed in Chapter 5, not only panpsychism, but, in fact, all versions of Russellian monism are committed to the assumption that there is no a priori analysis of macrophenomenal facts in terms of microphysical facts: macrophenomenal truths cannot be a priori entailed from a complete knowledge of microphysical truth. However, Russellian monists assume that the complete truths about the microrealm allow for an a priori entailment of the macrophenomenal truths, wherein the complete micro-truths encompass not only microphysical, but rather all truths about the microrealm. On constitutive Russellian panprotopsychism, these truths also involve protophenomenal truths in addition to microphysical truths, while they involve microphysical and microphenomenal truths on constitutive Russellian panpsychism. But if there cannot be given a causal or otherwise physical analysis of macrophenomenal truths, it is hard to see as to how there could be given an analysis in terms of notions which are not macrophenomenal. Note that the first version of the subject irreducibility argument can also be directed against Russellian monism in general: essentialist facts about macroconsciousness involve protophenomenal facts just as little as they involve microphenomenal facts. This point is analogous to premise 2 of the other version of the argument: our direct phenomenal concepts grant us a priori access to all essentialist facts about our macrophenomenality. But we cannot analyze these facts in terms of concepts not involving macrophenomenal notions. It follows that they are not reductively explicable in terms of anything else. According to Sider, this entails that macrophenomenal truths are isomorphic to their metaphysical truth conditions. Recall that on Sider’s view, any true sentence has a metaphysical truth condition in terms of a sentence of the fundamental language which provides its metaphysical analysis. But if a true sentence cannot be analyzed in terms of a sentence with different linguistic expressions, then the sentence is itself part of the fundamental language. Since the fundamental language mirrors fundamental reality, the fact described by this sentence is part of fundamental reality. Hence, macrophenomenal facts are fundamental. But according to Russellian monism, macrophenomenal facts are derivative. It follows that Russellian monism is incoherent, and thus false. The up-shot is that as Goff demonstrates, if we accept Direct Phenomenal Transparency (a thesis to which all antiphysicalists are committed), then constitutive Russellian monism is false even if constitution does not involve combination—at least, this is what two of the major approaches to metaphysical fundamentalism suggest. Of course, it is currently controversial whether one of those accounts is sound. But since they are among the most developed theories of constitution, Goff’s argument gives us considerable reason to question constitutive Russellian monism. Moreover, antiphysicalists can only allow for such alternative accounts of nothing-overand-aboveness which allow for transparency of connecting facts from knowledge of the nature of a derivative entity: that is, knowledge of general connections between a grounded en-

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tity and its ground can be derived from knowledge of the essence of the grounded entity. For it is only if knowledge of the essence of a given entity allows one to derive a priori facts about the grounding relations which that entity bears to other phenomena that the antiphysicalist can reject physicalism. If, in contrast, grounding is opaque, and knowledge of the nature of a phenomenon does not allow one to derive information about the metaphysical dependence relations this phenomenon bears to other entities, then the antiphysicalist cannot rule out that phenomenal states of which we know the essence are physically grounded. It is thus their featuring transparency of connecting facts which render both the Fine-Dasgupta view and the Sider-model (adopting the form of metaphysical grounding or metaphysical truth conditions respectively) suitable for the Russellian monist. Yet it is also transparency of connecting facts which plays the core role in the subject irreducibility argument: if Direct Phenomenal Transparency reveals connecting facts, we can a priori know whether our consciousness is grounded in micro(proto)phenomenality—it does not matter for the tenability of the argument how exactly we account for the metaphysical connection. Hence, it seems that any other account of nothing-over-and-aboveness which the Russellian monist might possibly adopt as an alternative to the two accounts we discussed could still also be employed in the subject irreducibility argument. So, the question is as follows: is there a way for the constitutive Russellian monist to reply without rejecting transparency of connecting facts? In fact, Roelofs (forthcoming) aims to develop such a reply to the revelation argument. 6.9 Revelation and Phenomenal Confusion Roelofs (forthcoming) argues that full knowledge of the nature of an entity is necessary but not sufficient for knowing whether the entity is reducible to something else or not. He claims that in order to know whether there is a grounding relation between a certain entity and some thing else, I not only have to know the nature of the former, but also the nature of the latter. Only if I have access to both essences am I in a position to discern whether there is a constitutive relation between them. Knowledge of the nature of an entity is a necessary, but not sufficient condition for knowledge of its ontological status vis-à-vis some other entity. Knowledge of the nature of the latter is the additional necessary condition: only having knowledge of both provides me with the sufficient conditions for knowing whether one of them grounds the other. Roelofs argues for this thesis about the sufficient conditions for knowledge of constitution by considering a case involving functional properties: To be a clock is, more or less, to be something made to tell the time. Substances with many different properties could constitute a clock—metal hands, glass displays, quartz crystals, stone sundials, etc. What can we know a priori about the constitution of clocks, given that we know the nature of being a clock? Here is something we cannot know: all the possible things that might constitute a clock. (Roelofs forthcoming) It is certainly true that our knowledge of the nature of the functional property of playing the clock-role does not provide us with a priori knowledge of some (or even all) potential and

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actual realizers of the clock-property. Our knowledge of the nature of the clock-property does not a priori entail knowledge about actual existing clocks. Yet if one not only knows the essence of the clock-property, but also the nature of a certain entity, then one can infer whether this entity is a clock. If so, it seems that only knowledge of both the nature of the clock property and the entity is sufficient for knowing whether the entity is a clock. Now, Roelofs argues that this has crucial implications for constitutive Russellian monism. We arguably know the nature of physical entities. This is so because we know the nature of the physical which is revealed to us by physics. Therefore, antiphysicalist arguments succeed; they can show that we can infer from the knowledge of both the nature of our phenomenal states and the nature of physical states that they do not stand in a grounding relation. But according to Roelofs, constitutive Russellian monists have no reason to hold that we know the nature of micro- or protophenomenal states. In contrast to the physical, we have no science which studies the micro(proto)phenomenal realm. For Russellian monism assumes that micro(proto)phenomenal states act as quiddities for microphysical properties. Qua being quiddities, they cannot be studied by science. But if we do not know the nature of micro(proto)phenomenal properties, then we do not know whether they ground our macrophenomenal states—even under the assumption that the nature of the latter is fully revealed to us. If so, Roelofs argues, it is a viable possibility that we are radically confused about macroconsciousness. We know the nature of our conscious states, and we wrongly assume them to be fundamental, since we know that they are not grounded in the only other kind of entities of which we know the nature, namely physical properties. But once we acknowledge the possibility of there being micro(proto)phenomenal properties, we have to concede that we only have limited knowledge about the ontological status of macroconsciousness. While we can rule out that macroconsciousness is grounded in the physical, we have no means to decide whether it is, in fact, fundamental. In order to be able to decide that question, we would have to have access to the nature of the additional types of entities which are potential candidates to act as grounding bases for macrophenomenal states. But as long as there is no science of the micro(proto)phenomenal, we cannot rule out that macroconsciousness is derivative after all. As seen in the last chapter, arguments from categoricalism, mental causation, and emergence suggest that panpsychism has great advantages over dualism. And since antiphysicalist arguments can be defended while the revelation argument can be rejected, we seem to have compelling reasons to accept constitutive panpsychism, and to assume that macroconsciousness is derivative on microconsciousness. I believe that this argument is problematic for at least two reasons. Firstly, Roelofs does not distinguish between generic and objectual essence. Our knowledge about the nature of functional properties concerns their generic essence. We know what it takes for something to be a clock. Of course, knowledge of the nature of the property of being a clock does not entail knowledge of every kind of object which realizes this property. The reason is that this knowledge concerns the generic essence of being a clock, that is, what necessary and jointly sufficient conditions something has to fulfill in order to be a clock. However, Direct Phenomenal Transparency does not only involve knowledge of the generic essence of our phenomenal states but also knowledge of the objectual essence of the phenomenal properties we enjoy, that is, the essence not of the type to which a certain token

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states belongs, but the essence of the particular token as such. If the nature of my phenomenal state q is fully revealed to me, then this does not only to imply that I know the essential properties of the phenomenal type to which q belongs, but also that I know the nature of this particular token of this type, namely the objectual essence of q. As discussed in Section 3.4, any tenable version of antiphysicalism must allow for us being acquainted with (some of) our phenomenal states: in employing a direct phenomenal concept of a certain quale, we ‘take up’ its phenomenal character into our concept, as Chalmers (2003b) frames it—a mental process which obviously reveals not only the generic, but also the objectual essence of this quale. And if one knows the objectual nature of a particular phenomenal state (or a particular clock for that matter), one also knows how it is constituted. Hence, Direct Phenomenal Transparency entails knowledge of the objectual essences of macrophenomenal states, and, since constitutive Russellian monists are committed to this thesis, the have to allow that we can a priori know whether macroconsciousness is derivative or fundamental. The revelation argument seems vindicated. Secondly, even if we assume for the sake of argument that we only know the generic essence of our conscious states, Direct Phenomenal Transparency would even then reveal to us whether there is a general connection between phenomenal properties and other fundamental properties. Take grounding by analysis and the case of parties. The Fine-Dasgupta account of grounding assumes that first-order grounding facts are grounded in general connections between grounding base and grounded entity which are specified in essentialist facts about the grounded entity. This concerns the generic essence. The fact that there is a party in Mike’s apartment right now is grounded in the fact that Kilian, Caro, Stevie, and Anja are reveling. This first-order grounding fact itself, in turn, is grounded in the essentialist fact about parties in general that a party occurs iff an event occurs involving various people reveling. And this essentialist fact is clearly part of the generic essence of the property of being a party. It follows that even under the assumption that we only know the generic essences of our conscious states, we still would know what necessary and sufficient criteria entities have to fulfill in order to act as grounding bases for conscious states. But as the subject irreducibility argument shows, we do not have such knowledge. Hence, macroconsciousness is fundamental. I conclude that Roelofs’ reply cannot reject the revelation argument. Is this the final verdict on constitutive Russellian monism? Goff himself does not think so. In chapter eight of his (2017), he put forward a version of constitutive panpsychism, cosmopsychism, that he claims can overcome the subject irreducibility argument. In the next section, I discuss this view. I shall argue that Goff is wrong in thinking that cosmopsychism can avoid the revelation argument. A version of the argument also applies to this position. 6.10

Cosmopsychism

We saw in the last section that Russellian monists qua being antiphysicalists have to allow for an approach to nothing-over-and-aboveness which involves transparency of connecting facts, yet any such account can be taken as a basis for the formulation of the subject irreducibility argument. The only potential escape route open to the constitutive Russellian monist seems then to be to search within those frameworks for a grounding relation of macroconsciousness

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which is not ruled out by Direct Phenomenal Transparency. That is, constitutive Russellian monism is only tenable if our consciousness has a grounding base which is not revealed by our direct phenomenal concepts. But how could it possibly be the case that connecting facts are transparent and consciousness is derivative, yet we cannot a priori acquire knowledge of its derivativeness, although we know the nature of our qualia? Prima facie, this seems impossible. However, Goff (2017: chapter 9, 2019) argues that there is a general ontological view, priority monism, which can provide panpsychism with a grounding base for macroconsciousness that is not revealed to us via introspection, although connecting facts are transparent. Priority monism is the view that not the smallest entities, but rather the biggest object is fundamental: the cosmos grounds all smaller entities.101 This contrasts with the standard view, priority pluralism, according to which elementary particles are fundamental. But how does this ontological controversy relate to the debate about panpsychism? Now, if priority monism is true, then this has important implications for constitutive panpsychism. In the broadest sense of meaning, panpsychism is the view that consciousness is ubiquitous. While panpsychists disagree about which kinds of objects are conscious, they agree that, besides animals, at least some entities of the fundamental ontological level are. Given priority pluralism (he view that has been implicitly presupposed in this work so far), this means that some or even all elementary particles have phenomenal states. But given priority monism, this means that the cosmos enjoys fundamental phenomenal properties. Hence, constitutive panpsychism comes in two flavors, micropsychism and cosmopsychism. Micropsychism is the view that some (or even all) elementary particles have fundamental phenomenal properties which ground all other forms of consciousness. 102 Cosmopsychism, in contrast, is the view that the cosmos has fundamental phenomenal states which ground all other forms of consciousness. Until recently, almost all panpsychists were smallists. Only as a consequence of the rising popularity of priority monism due to the work of Schaffer (e.g. 2009b, 2010), have panpsychists such as Shani (2015), Nagasawa & Wager (2016), and Goff (2017: chapter 9, 2019) developed cosmopsychist alternatives to micropsychism. But Goff is the only panpsychist who adopts cosmopsychism because he believes that cosmopsychism comes with a different form of grounding—he calls it grounding by subsumption—which does not require that grounded entities are analyzable in terms of their grounds. Goff’s view is based on a certain version of priority monism, namely the account of Schaffer (2010). I shall begin by introducing Schaffer’s version of priority monism and its cosmopsychist adaption, and then argue that the view has to allow for microphenomenality in order to have the same theoretical values as micropsychism. In Section 6.10.2, I will argue that the existence of microconsciousness in cosmopsychism gives rise to a version of the subject irre101 Note that the usual usage of ‘monism’ in the philosophy of mind is different from its usage in ‘priority monism’: while monism in the latter sense concerns the number of basic token entities (and claims that there is only one fundamental token entity), monism in the former concerns the number of highest type of entities: accordingly, dualism is the view that there are two highest types of entities (mentality and matter). See Schaffer (2018: section 1) on the different usages of ‘monism’. 102 In Section 4.1, I introduced the terms ‘smallism’ for describing views according to which everything is either some sort of micro-stuff, or grounded in this sort of micro-stuff. Both physicalism and micropsychism are smallist views.

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ducibility argument, even under the assumption that there is an alternative form of grounding at play. While Goff thinks that the most elegant version of cosmopsychism does not involve microphenomenality, he also prepares for the case that cosmopsychism might be forced to accept it. Hence, he develops an alternative version of his approach which allows for microconsciousness. This position utilizes a third form of grounding in order to avoid the subject irreducibility argument. I will also address this view, and aim to show that it involves highly implausible assumptions which render it a rather unattractive position. 6.10.1 Priority Monism, Cosmopsychism, and Microphenomenality Priority monism takes the whole universe as such to ground all smaller entities in the world. A prime challenge for the view is thereby to account for the apparent heterogeneity of priority monism’s fundamental entity. Usually, fundamental entities, while grounding the complex structure of the world, are assumed to be homogeneous themselves. But then, if the cosmos is fundamental, the universe is a homogeneous object. However, this is obviously not the case; the universe is internally structured, having very different properties at various regions. In answer to this problem, Schaffer (2010) provides three approaches for explaining how a fundamental property can be heterogeneous. His favored one is the concept of distributional properties. On this account, the cosmos has one overarching internally structured fundamental property that grounds all the local properties that we find in the world. Consider a polka-dotted dress. It might be intuitive to think that the fact that the dress is polka-dotted is grounded in the fact that it has green dots at various regions while being homogeneously white otherwise; but the grounding relation might instead be the other way round. The fact that the dress is green polka-dotted could be taken to ground the fact that it has a green dot here as well as the fact that is white over there. In the same manner, Schaffer argues, the cosmos might be taken to possess a very sophisticated distributional property that is the ultimate ground of all derivative properties in the universe. If so, the heterogeneity of the universe is then due to the fact that the cosmos has a distributional property which is the ultimate ground of all derivative properties. Now, the panpsychist version of priority monism takes the universe’s distributional property to be least partly phenomenal. And according to Russellian cosmopsychism, this distributional property involves cosmophenomenal states which realize at least some of the world’s physical properties such that the view is compatible with the causal completeness of physics. Like Russellian micropsychism, Russellian cosmopsychism takes phenomenal properties to realize microphysical dispositions. But in contrast to micropsychism, those phenomenal properties are not fundamental but grounded in cosmophenomenal states which are aspects of the distributional property of the cosmos. As mentioned above, Goff’s favorite version of cosmopsychism only involves cosmo- and macroconsciousness. Note that in order to exclude microconsciousness, Goff has to assume that cosmophenomenality is isomorphic to the sum of the macrophenomenal states that occur in the world. That is, the distributional property of the cosmos is such that it is ‘consciousness-dotted’—so to speak—at those and only those regions of the universe where we find animals. But this assumption is not plausible. Russellianism entails that fundamental consciousness realizes at least parts of the world’s basic causal structure. But according to the causal

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completeness of microphysics, basic causal structure exclusively appears on the microphysical level. And in animals, we find the same particles having the same causal powers as anywhere else. Yet if cosmophenomenality is only present in regions where animals are located, then there is basic causal structure on the macro-level. It follows that if we subscribe to the causal completeness of microphysics—what constitutive panpsychists of all sorts should be expected to do, since the principle is crucial for their case against emergentist views (see Chapter 5)—there are far more cosmophenomenal states than macrophenomenal states. In other words, Russellianism together with the completeness of microphysics entails that at least one types of microphysical property has to be grounded in phenomenal properties. And I believe that this, in turn, entails that there is microconsciousness. For phenomenal states which realize microphysical dispositions cannot be macrophenomenal states. A phenomenal state such as human pain cannot act as a realizer of microphysical dispositions such as spin or charge: I do not nearly have enough token qualia to ground all the myriad tokens of just one type of the microphysical properties occurring in my brain. Therefore, Russellian cosmopsychism has to allow for microphenomenal properties which are themselves grounded in cosmophenomenality. 6.10.2 Overcoming the Combination Problem Via Grounding by Subsumption? As noted above, Goff believes that by grounding macroconsciousness in cosmoconsciousness the subject irreducibility argument can be rejected because of the special form of grounding at play in priority monism. Goff’s account is largely influenced by Schaffer’s view which describes grounding in priority monism as follows: [t]he derivative entities, in order to be an ‘‘ontological free lunch’’ and count as no further addition, ought to be already latent within [their grounds]. In other words, the grounding relations should just be ways of separating out aspects that are implicitly present from the start. (Schaffer 2009a: 378) If a derivative entity is already latently present in its ground as an aspect, then grounding seems not to require that the grounding relation is grounded in essentialist facts concerning the derivative entity. Rather, an analysis of the fundamental entity which discloses its aspects should reveal the grounding fact.103 Correspondingly, Goff (2017: section 9.2) provides the following toy-example of grounding macroconsciousness in cosmoconsciousness (facts are denoted by sentences in curly braces): {subject BIG feeling pain, anxiety and experiencing red} grounds by subsumption {subject LITTLE1 feeling pain}, {LITTLE2 feeling anxious}, and {subject LITTLE3 experiencing red}. (Goff 2017: 228) This example nicely illustrates that for grounding by subsumption to work, derivative entities must have isomorphic correlates in the fundamental unity. Goff does not explicitly discuss 103 As discussed in Chapter 3, Schaffer has recently changed his view. He now (e.g. Schaffer 2017) defends a view involving nontransparent grounding facts. As discussed, the constitutive panpsychist cannot follow him in this direction, since she is committed to the transparency of grounding. We have, therefore, good reasons to stick to Schaffer’s former view of grounding in priority monism.

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this but the difference between grounding by analysis and grounding by subsumption is not that only the former requires that grounding is backed by an analysis. Rather, the difference is that the analysis concerns the other relatum. While grounding by analysis requires that the nature of the grounded entities reveals a general connection to its grounding base, grounding by subsumption requires that the ground reveals why and how it grounds the grounded entity. Cosmoconsciousness grounds macroconsciousness because it has a part that is isomorphic to the macrophenomenal state it grounds. Correspondingly, LITTLE1’s macro-pain is grounded in cosmo-pain. It seems that without this phenomenal state, cosmoconsciousness could not ground LITTLE1’s macro-pain: an essentialist fact concerning cosmo-pain, what-it-feels-like, is be responsible for its being capable of grounding macro-pain. That is, their isomorphism seems to consist in their having the same phenomenal character. All of this is in accordance with Schaffer’s view that in priority monism “the grounding relations should just be separating out aspects that are implicitly present from the start.” I take it that being “implicitly present from the start” means that an analysis of the grounding entity reveals parts that ground isomorphic derivative entities. Hence, if there are microphenomenal states, they are grounded in the cosmos as micro-aspects of its overarching, at least partly phenomenal distributional property. Moreover, grounding by subsumption requires cosmophenomenal properties to be isomorphic to microphenomenal properties. It is plausible that some microphenomenal properties are grounded in cosmophenomenal properties that also ground macrophenomenal properties. If at least some of the microphysical dispositions in my brain are grounded in microphenomenal properties, then the cosmophenomenal state C that grounds my overall macrophenomenal state O has phenomenal parts which have to be isomorphic to the respective microphenomenal state they ground. And an analysis of C reveals these parts. Yet C is isomorphic to O. Therefore, the micro-parts should not only show up in an analysis of C but also in an analysis of O. It follows that a direct phenomenal concept of O must reveal that it has such micro-parts. It seems therefore that cosmopsychism falls prey to the same worry as micropsychism does. Both entail that macrophenomenality is analyzable in terms of the phenomenal character of microphenomenal states, the difference being that the direction of grounding is opposite, not the latter grounding the former, but the former the latter. In reply to this objection, could the cosmopsychist not assume that the cosmic distributional property has a complex texture such that, at the same location, there exist both cosmophenomenal state C which grounds O, and a great number of other cosmic states which ground the microphenomenal properties inhabiting this region? If so, while C and O are phenomenally isomorphic, there is no need to assume that they share the phenomenal characters of those other cosmic states. However, I believe that this proposal renders macrophenomenality subject to the causal exclusion problem. For if macrophenomenal states have causal powers, those powers do not stand in a grounding relation to microphysical dispositions because microphysical properties are grounded in cosmic states which themselves do not stand in any constitutive relation to macrophenomenality. But then, macrophenomenal states must either directly interact with the microphysical properties realized by those other cosmic states, thereby violating the causal completeness principle, or be epiphenomenal. Both options are

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unacceptable to the constitutive panpsychist, since they would sacrifice constitutive panpsychism’s advantage over emergentist dualism. But even if macrophenomenal states ground microphenomenal states—does grounding by subsumption in fact necessarily entail phenomenal isomorphism? Could it not be the case that a macrophenomenal property grounds some microquale with which it does not have anything in common phenomenologically? First of all, I believe that it is plausible that grounding by subsumption does involve an analysis qua being a transparent grounding relation. Panpsychists qua being antiphysicalists are committed to transparent grounding. And transparency entails that an analysis of one of the essences of the involved entities has to reveal the metaphysical connection between the grounded entity and its ground. Grounding by subsumption and grounding by analysis differ on which essence reveals the grounding fact. But if both approaches are variants of transparent grounding, then knowledge of the nature of one of the entities involved must reveal their metaphysical connection. On top of that, the cosmopsychist seems to be forced to commit herself to phenomenal isomorphism. For if there can be grounding by subsumption without phenomenal isomorphism, then physicalist priority monism can account for macroconsciousness. The reason is this. Assume that the phenomenal profile of the macroquale grounded by subsumption in a cosmophenomenal state could not be a priori entailed from knowledge of the phenomenal character of the latter. How, then, could the physicalist’s proposal that a purely physical cosmic state grounds the macroquale be rejected? The only way to deny this possibility is to insist that there is a priori entailment from cosmic-state character to macro-state character which is only the case if the former is a phenomenal state. But then we also have to assume that the phenomenal characters of the microqualia which are grounded by subsumption in macroqualia are revealed by knowledge of the essences of the latter. In contrast, other properties of microphenomenal states such as their causal powers do not have to be transparent to us. Microphenomenal states might have their causal powers due to contingent laws, and there is no reason to assume that these laws are accessible via human phenomenal transparency. Given Direct Phenomenal Transparency, it is just the phenomenal characters of microqualia grounded in macroqualia which must be revealed to us. Goff does not believe that the cosmopsychist has to allow for microconsciousness in the first place. But he acknowledges that if macroconsciousness would ground by subsumption microconsciousness, then phenomenal transparency would require that we are aware of the latter. Yet I have argued above that it follows from Russellianism and the principle of the causal completeness of the microphysical that cosmopsychism cannot do without microconsciousness. Otherwise, microphysical properties could not be realized by phenomenal states. While his official version of cosmopsychism does not assume microconsciousness, Goff (2017: section 9.3.2), nevertheless, prepares for the case that cosmopsychism might be forced to accept microphenomenality, developing an alternative version of cosmopsychism. On the alternative version, macroconsciousness is grounded in such a way that it does not have to ground microphenomenal states. This view comes with two different types of consciousness. The first can have parts, and can itself be part of other consciousnesses. This is the type of consciousness we encounter in familiar versions of panpsychism. But additionally, there is a second type which functions as determinable of other consciousnesses. Consider the follow-

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ing analogy: ‘Red’ is a determinable of ‘scarlet’, and a determinate of ‘color’. The fact that something is scarlet grounds the fact that something is red which in turn grounds the fact that it is colored. According to Goff’s alternative version of cosmopsychism, macroconsciousness is a determinable of the consciousness of the brain—call it brain-consciousness—in a similar way as red is a determinable of scarlet. Brain-consciousness is grounded by subsumption in cosmoconsciousness and, in turn, grounds microconsciousness. It has a very rich phenomenal character, and is thus capable of grounding the myriad microphenomenal properties of the brain. Human macroconsciousness is an abstraction from this rich phenomenal structure in a similar way as red is an abstraction from a specific color such as scarlet. Direct Phenomenal Transparency reveals to us only this abstracted, simplified phenomenal character, but not the full phenomenal structure of brain-consciousness. On this view, there is a mereological phenomenal order from comic- over brain- to microconsciousness, but also additionally a ‘determinable-determinate’ phenomenal order from brain- to human macroconsciousness. While this is a very interesting and creative idea to avoid the subject irreducibility argument, I think it is not tenable for the following reasons. Firstly, how could there be two different ordering relations for the same kind of entity? How can there be subjects that cannot have parts due to their nature, since they are abstractions, and subjects that have parts and are parts of other subjects, but both belong to the same natural kind ‘subject of experience’? Secondly, ‘determinable-determinate’-relations normally do not multiply the number of properties of the same kind that an object has. If an object is homogeneously scarlet, then it has just one color and not three, ‘scarlet’, ‘red’, and ‘color’. In contrast, if my consciousness is an abstraction from brain-consciousness, then my brain would have two different subjects with two different experiences, brain- and human macrophenomenality. Thirdly, the solution seems also to be open to micropsychism. Why not assume that microconsciousness ground by analysis brain-consciousness whose determinable is human macroconsciousness? Fourthly, it is unclear whether knowing the nature of a determinable does not involve knowing the nature of at least some of its determinates. Could Jackson’s Marry be taken to know the determinable ‘color’ without knowing any specific color such as red or blue? By analogy, can we really be taken to know the nature of our phenomenal states if we do not know any of the determinates of which these states are determinables? To conclude, I have argued that adopting a panpsychistic version of priority monism does not help the panpsychist in avoiding the subject irreducibility argument. If cosmopsychism adheres to Russellianism, then it has to allow for microconsciousness. This, however, entails that macroconsciousness has to be analyzable in terms of microconsciousness. Moreover, macroconsciousness’ being thus analyzable gives rise to Goff’s subject irreducibility argument. While Goff’s alternative version of cosmopsychism is not subject to this objection, its taking macroconsciousness as determinable of brain-consciousness gives rise to a number of severe problems which render the view rather unattractive.

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6.11 The Limits of Phenomenal Combination The rejection of the cosmopsychist escape route for the subject irreducibility argument ends my discussion of the most prominent versions of the combination problem. Let us take stock. The prospects of solving the quality combination problem are good. A theory along the lines of Coleman’s and Roelofs’ accounts of phenomenal blending could probably solve the palette problem. The combination of qualities seems to be possible. Structural combination, in contrast, seems implausible. While the possibility that macrophenomenal structure is constituted by microphenomenal structure cannot be directly ruled out, solutions to the structural mismatch argument entail that there are a huge number of macrosubjects present in each organism, an assumption which is highly counterintuitive. Even more dramatically, the best solution to the conceivability argument against phenomenal combination, the phenomenal bonding thesis, entails that universal phenomenal combination is true, according to which there is a macrosubject for every group of material objects across space and time. Finally, the combination of subjects is impossible. The subject irreducibility argument shows that macrosubjects are not constituted by microsubjects. Furthermore, the anti-subjectsumming argument can be taken to explain why micro-subject cannot combine. Arguably, both arguments complement each other. Note that Goff’s argument on its one cannot explain why subjects do not combine. By way of analyzing what a grounding relation between subjects would entail for us to know about our conscious states, Goff can rule out subject-combination: we do not have the knowledge we would need to have in order for subject-grounding to be true. But this merely establishes the finding that macrosubjects are not grounded without giving any explanation of the fact that microsubject cannot combine. In contrast, Coleman’s argument seems able to explain why they cannot combine: their being essentially discrete perspectives renders subjects incapable of composition. In this way, both arguments together might be taken to provide a compelling case against subject combination. However, these various combination problems do not exhaust the challenges for constitutive panpsychism. While the combination problems attack constitution in panpsychism, there is also a severe problem for the Russellian theory of mental causation upon which constitutive panpsychism is based. The structural exclusion problem for Russellianism is the subject of rest of the chapter. 6.12

Structural Exclusion

Recall the Russellian strategy discussed in the last chapter. By employing microphenomenal states as realizers of microphysical dispositions, Russellian panpsychism gives them a genuine causal role. Most importantly, the constitutive panpsychist can escape the causal exclusion argument by making use of this strategy. Since microphenomenal properties are realizers of microphysical dispositions, they have genuine causal efficiency, but do not compete with physical causation. By grounding physical causation, they bring about physical causation rather than interfering with it. Moreover, microphenomenal states ground macrophenomenal states which, thereby, inherit their causal efficiency. Hence, the causal exclusion problem for macromental causation does not arise. Every caused microphysical event has just one suffi-

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cient cause, and this cause is microphysical. But there is still mental causation in this picture. It is microphenomenal properties which play the causal roles involved in microphysical causation. Physics just describes causal structure: microphysical properties as described by the laws of physics are pure dispositions. In turn, the latter are realized by microphenomenal properties standing in the causal relations described by the laws. Mørch (forthcoming) provides the following objection to Russellianism: [On Russellian panpsychism,] physical dispositions will mainly depend on the structure of the phenomenal laws, whereas the phenomenal qualities they apply to will be irrelevant. Granted, dispositions will also depend on there being some phenomenal categorical properties (and enough types and instances of them) because otherwise there would be nothing for the laws to apply to and relate. But from this it only follows that phenomenal properties are explanatorily relevant qua categorical (and perhaps qua their type/instance cardinality) not qua phenomenal. (Mørch forthcoming) The fact that a microphenomenal property realizes a specific microphysical disposition has nothing to do with its specific phenomenal character; rather, it solely depends on the fact that the microphenomenal property is connected to other microphenomenal properties by certain fundamental laws. Moreover, recall that on categoricalism, laws are not metaphysically necessary: there are possible worlds with completely different laws. It is a metaphysically contingent fact as to which law governs which microphenomenal property. Therefore, the causal role of a feeling like pain is not in any way due to what-it-feels-like to be in pain; rather, it is solely due to the contingent fact that pain’s microphenomenal constituents are governed by certain laws. And these constituents could have been governed by different laws: there is a possible world in which you ‘jump for joy’ every time you are in sharp pain, because, in that world, pain’s microconstituents bear different causal relationships to on another. This is a highly counterintuitive consequence. As Mørch points out, it is not the kind of causal relevance to which panpsychism should aspire. Phenomenal entities should be causally relevant qua being phenomenal not qua being connected by contingent laws. But the standard version of Russellianism excludes them from being genuine phenomenal causes. Yet microsubjects should have real phenomenal agency. Rather than being blind cogs in a net of fundamental laws governing their behavior by ascribing contingent causal roles to their phenomenal states, their behavior should be determined by the phenomenal character of their experiences —the what-it-feels-like dimension of their feelings should be the reason why they behave the way they do. Note that Mørch does not argue that panpsychism’s microphenomenal properties are not causally efficacious. They are causally efficacious qua being categorical—yet they are not efficacious qua being phenomenal. Structural exclusion is therefore not a threat to the general causal efficacy of microphenomenal properties, but rather to their phenomenal efficacy in a narrow sense. Hence, panpsychists might accept structural exclusion and be content with nonphenomenal efficacy of microphenomenal states (see Brüntrup 2016). However, as Mørch points out, structural exclusion gives Russellian panpsychism a disadvantage vis-à-vis physi-

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calism and interactive dualism, both of which are not subject to the worry. For physicalism takes phenomenal properties qua phenomenal to be identical to physical or functional properties, and dualism postulates psychophysical laws which causally connect their phenomenal aspects to certain physical properties. 6.13

Mørch's Phenomenal Powers Panpsychism

Mørch suggests that microphenomenal states can be taken to be causally relevant qua their phenomenal characters if we assume that those characters as such ground specific causal powers. This approach combines the two major theories of fundamental dispositions. Recall that on categoricalism, fundamental properties are not purely dispositional, but have categorical bases. Moreover, they have specific dispositional profiles only contingently qua being governed by certain laws. On dispositionalism (e.g. Bird 2007a), in contrast, fundamental properties have their dispositional profiles essentially, and do not have any non-trivial essential features beyond the causal roles they play. Rather than establishing contingent causal relations between properties, laws of nature are entailed by the nature of dispositions, and thus metaphysically necessary. Now, Mørch argues that phenomenal properties qua being phenomenal are purely categorical properties, yet in virtue of their specific phenomenal characters, they ground dispositions: If phenomenal properties have causal powers, they could [...] ground dispositions. But if they have their powers contingently, they would seem explanatorily relevant in virtue of their powers not but in virtue of their phenomenality, i.e., it would bring back the exclusion problem. Phenomenal properties must therefore have their powers necessarily. [...] [F]or some phenomenal properties, their powers do not seem contingent. Consider what it is like to feel pain. It does not seem contingent that something that feels like pain makes subjects who experience it try to avoid it, as opposed to try to pursue more of it or remain indifferent. Pain seems to make us try to avoid it because its phenomenal character is just intrinsically disagreeable and repulsive. (Mørch forthcoming) According to Mørch's analysis, pain in virtue of what-it-feels-like grounds the intention to avoid this experience. This intention is the phenomenal power of pain. Mørch suggests that analogously to the case of pain, microphenomenal properties also ground phenomenal powers. In turn, those microphenomenal powers serve as grounds for microphysical dispositions. Thus, microphysical dispositions are grounded in phenomenal powers which, in turn, are entailed by the phenomenal character of microphenomenal states. This seems to qualify as genuine microphenomenal agency. Hence, Mørch's phenomenal powers panpsychism appears to avoid the structural exclusion problem by tracing the efficacy of microphenomenal states back to their phenomenal characters. However, I shall argue that this solution is not tenable. My argument can best be stated with the help of a formal analysis of dispositions. I shall use Bird’s (2007: 24) formalism—already familiar from the last chapter—which represents the simple conditional analysis of dispositions. Let ‘D(S,M)x’ be the abbreviation for ‘x has the disposition to manifest property M in response to stimulus property S’. Let ‘↦’ be the symbol for the counterfactual conditional’ be the symbol for the counterfactual conditional

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such that ‘Sx ↦’ be the symbol for the counterfactual conditional Mx’ is the abbreviation for ‘if x was S, then x would be M’. Thus, dispositions can be formalized as follows: D(S,M)x ↔ Sx ↦’ be the symbol for the counterfactual conditional Mx. Now, as we saw, Russellian panpsychism takes microphysical dispositions to be grounded in microphenomenal properties. However, in order to realize these dispositions, microphenomenal properties must be standing states: if microphenomenal properties serve as categorical bases for microphysical dispositions, they must be permanently instantiated. For if an entity has a certain disposition, it also possesses the disposition at times when the disposition does not manifest. Hence, operating within the Russellian framework, Mørch must allow for microsubjects to permanently have certain feelings. These feelings realize microphysical dispositions. Assume that microphenomenal property P realizes microphysical disposition D. If microsubject x bears P, x manifests property M iff stimulus S occurs. What makes D a microphysical disposition is the fact that M is a type of microphysical behavior. Standard Russellian panpsychism assumes that it is contingent laws which ascribe D to P. Mørch objects to this, and suggests that P realizes D because its phenomenal character essentially grounds a specific phenomenal power. This power, in turn, grounds D. But how can it be that the phenomenal character of P as such makes x react in a certain fashion to the occurrence of S given that this phenomenal character does not change in response to S? Recall Mørch's pain case. By claiming that pain grounds the power of painavoidance, Mørch seems to mean the following: when a feeling of pain arises in a macrosubject, its phenomenal character makes the subject act in a certain way, namely to try to avoid pain.104 In this example, pain is clearly not a standing mental state. Rather, pain arises in the subject because the feeling is triggered by a stimulus and pain’s phenomenal character instantly makes the subject try to avoid pain. Thus, it is not the case that in virtue of pain’s phenomenal character, the subject has the disposition to avoid pain iff a certain additional stimulus occurs—pain’s phenomenal power is not itself a disposition. For if it were, then the manifestation of the intention to avoid pain would be conditional on an additional stimulus. We can construct a somewhat analogous microphenomenal toy example. Take P to be micro-pain, x to be an electron, and D to be negative charge. S is the presence of another negative-charged particle, and M repelling behavior. Since electrons are at least nomologically necessarily negatively charged, x bears micro-pain permanently during its whole existence. If P realizes D, then P’s phenomenal character qua what-it-feels-like cannot be the reason why x manifests M iff S occurs. Since x bore P prior to the occurrence of S, x has the exact same experience after being affected by S as it had before. The presence of another electron y—constituting stimulus S—cannot be the reason why x qua having an experience which is intrinsically disagreeable tries to avoid the stimulus. X was in micro-pain all along—for micro-pain is the categorical basis for D. And repelling y does not make micro-pain go away, because x does not lose D by manifesting M. 104 More precisely, pain’s phenomenal character is a causal factor for pain-avoidance. There might be other mental states such as certain desires which counteract this factor such that the subject does ultimately not try to avoid pain.

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It follows that if microphenomenal states are taken to serve as categorical bases for microphysical dispositions, then the assumption that microphenomenal properties realize microphysical dispositions in virtue of being governed by contingent laws cannot be avoided—and neither can structural exclusion. For if they act as such categorical underpinnings, then their phenomenal character as such cannot play any explanatory role with respect to the fact as to which microphysical dispositions their bearers possess. It must be contingent laws ascribing to them their causal roles, since the latter cannot possibly be entailed by the phenomenal essences of microqualia. Hence, a solution to the structural exclusion argument is incompatible with the core assumption of standard Russellianism: viewing microphenomenal properties as categorical bases of microphysical dispositions renders their phenomenal character incapable of having explanatory relevance. 6.14

Impure Russellian Powers Panpsychism

I argued in the last section that what I called the core assumption of standard Russellianism (i.e. microqualia act as categorical bases for microphysical dispositions) renders microphenomenal properties incapable of avoiding structural exclusion. A solution therefore requires a substantial revision of the Russellian strategy. In this section, I develop a non-standard version of Russellianism which can avoid this objection. Before going into detail, some terminological clarifications are needed. Chalmers (2019) distinguishes between pure and impure versions of Russellian panpsychism. On pure Russellian panpsychism, microsubjects have micromental properties which realize microphysical dispositions, and have no micromental states other than those. On impure Russellian panpsychism, microsubjects also have other micromental properties (in addition to the former states) which are not direct grounds of microphysical dispositions. The account which I propose is a version of impure Russellianism. I argue that if microsubjects possess (in addition to microphenomenal properties and their powers) certain other types of mental states, then structural exclusion can be avoided. Let me begin by returning to Mørch's analysis of macro-pain’s phenomenal powers: Consider what it is like to feel pain. It does not seem contingent that something that feels like pain makes subjects who experience it try to avoid it, as opposed to try to pursue more of it or remain indifferent. Pain seems to make us try to avoid it because its phenomenal character is just intrinsically disagreeable and repulsive. (Mørch forthcoming) If we are to take this analysis seriously, then we must acknowledge that micro-pain must behave analogously to macro-pain in order to avoid structural exclusion. Consider again our toy example, in which P stands for micro-pain, x is an electron, D is negative charge, S is the presence of another negative-charged particle, and M is repelling-behavior. If P behaves analogously to macro-pain, we must allow that P’s microphenomenal character has the power to make x act in a certain way. But then, P cannot be the categorical base of D. Rather, it must be the stimulus of D. For the causal order of the macro-pain-case is as follows: the subject expe-

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riencing pain is disposed to act in a certain fashion, namely to try to avoid pain. That is, the stimulus for this disposition is pain’s phenomenal character qua being intrinsically disagreeable. Applying this to the micro-pain case, x must have the following disposition: D(P,M)x: Px ↦’ be the symbol for the counterfactual conditional Mx. Thus, according to our toy example, the correct analysis of negative charge is: x is disposed to react with repelling behavior to the stimulus of micro-pain. However, the analogy to the macro-pain case is as of yet incomplete. Macro-pain is not a permanently instantiated state, but only arises when specific circumstances occur. Analogously, micro-pain cannot be a permanent state of x, but must rather be caused by S, the presence of another negative-charged particle. Only if P is not permanent can repelling behavior be understood as intention to avoid micro-pain by removing its cause. It follows that x additionally has the following disposition: D(S,P)x: Sx ↦’ be the symbol for the counterfactual conditional Px. That is, x is disposed to have the experience of micro-pain if another negative-charged particle is present. In conclusion, micro-pain acts as stimulus for a behavioral disposition of a microsubject iff micro-pain itself is the manifestation property of another disposition of the microsubject. For micro-pain can be a non-permanent property of x iff it is not the categorical base but the manifestation property of a disposition of x. I take it that one can generalize the findings of the micro-pain case and explain other microqualia analogously. Hence, my proposal is the following. First, instead of taking microphenomenal properties to be categorical bases of microphysical dispositions, we must allow for microphenomenal properties to be manifestation properties of additional dispositions. Second, microphenomenal properties, in turn, act as stimuli for yet other dispositions which have microphysical behavior as manifestation properties. Microphenomenal properties as such are categorical properties which ground microphenomenal powers in order to act as stimuli. Thus, my analysis of microphenomenal properties and their powers differs from Mørch's in two respects. First, the powers grounded by microphenomenal properties are not dispositions, and, therefore, they themselves cannot realize microphysical dispositions. For if they were dispositions, then they would only cause effects when they are triggered by a further stimulus. This is not the case. Once a microphenomenal property is instantiated, its phenomenal powers immediately trigger another disposition of the microsubject. Consider again our toy-example: micro-pain, once instantiated, immediately causes microsubjects to try to avoid it (pain-avoidance is the triggered disposition)—no additional stimulus is required for it to do so. Second, and following from the first point, I take microphenomenal states to be embedded in relations to two additional types of dispositions of the microsubject. One of those brings about microphenomenal properties in the microsubject, while the other realizes microphysical dispositions. In the case of micro-pain, then, x has the disposition D(S,P)x: Sx ↦’ be the symbol for the counterfactual conditional Px which makes it experience micro-pain in the presence of other negatively charged particles. Moreover, it has the disposition D(P,M)x: Px ↦’ be the symbol for the counterfactual conditional Mx which makes it try to avoid micro-pain. Since the cause of pain is the presence of another electron, the second disposition's manifestation property pain-avoidance behavior can be taken to realize a microphysical disposition, namely repelling-behavior.

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I think it is plausible to assume the two additional types of dispositions are fundamental mental entities, because they are borne by the same microsubjects which also bear microphenomenal states. Taking them to be irreducibly mental appears to be the most parsimonious option; indeed, this is required for the view to qualify as a version of panpsychism. Furthermore, I believe that the two types of dispositions must be primitive dispositional properties which have their dispositional profiles essentially without having any categorical grounds. The reason is the following. Assume that they have categorical grounds. If so, then these quiddities must be microphenomenal properties. For if they are not qualia, then the view would not qualify as panpsychism. However, if the micromental dispositions have phenomenal bases, then the structural exclusion problem applies to these microqualia all over again and with it my critique of Mørch's approach from which it follows that there must be even more fundamental mental dispositions which have these properties as manifestations. For these micromental dispositions the question as to their metaphysical status also arises—thus, we enter into an infinite regress which can best be blocked by assuming that the original micromental dispositions I invoked are primitive dispositional properties. My version of impure Russellianism therefore violates pure categoricalism. It is a mixed view about fundamental dispositions involving both primitive micromental dispositions and microphenomenal quiddities.105 Returning to the micro-pain-case, D(S,P)x: Sx ↦’ be the symbol for the counterfactual conditional Px can be regarded as the disposition to experience micro-pain given S. With regard to D(P,M)x: Px ↦’ be the symbol for the counterfactual conditional Mx, I suggest that it plays a somewhat analogous role in microsubjects to that which intentions play in our mental architecture. That is, D(P,M)x: Px ↦’ be the symbol for the counterfactual conditional Mx is the microintention of pain-avoidance behavior given micro-pain. The idea is that just as macro-pain causes the intention to avoid macro-pain, so does micropain cause the intention to avoid micro-pain.106 In a human macro-case of intending, there are usually further mental states involved which might counteract the causal factor represented by pain. We might have certain strong desires which make us ultimately endure pain, although pain as such causes us to try to avoid it. Also, the specific content of an intention to avoid a specific experience of pain is usually partly determined by certain beliefs about what can be done to make the feeling go away. For instance, I might have a headache and the belief that I can make my headache go away by taking a certain drug. But I also have the desire to only take drugs if it is really necessary, since I think that taking too many drugs is unhealthy, and I have the desire to stay healthy. So, I might end up with the intention to endure my headache although the phenomenal character of my headache was a strong causal factor for making me intend to counteract my pain. It is a natural assumption that fundamental microsubjects lack such an elaborate mental architecture. Having no brains, they clearly cannot think, and do not possess propositional atti105 Since my account is a mixed view which allows for primitive dispositions and categorical properties, it is not subject to the circularity objection against dispositionalism which has been discussed in Section 5.2.2. 106 In the philosophy of action, there is no consensus about what intentions are, and how they can be explained, for instance, whether they are reducible to other kinds of mental states or not. I basically argue that phenomenal powers panpsychism needs to allow for primitive micromental states of choosing such and such behavior in response to microphenomenal stimuli. I call this type of state microintention, but one could also speak of microchoices or microvolitions, if one believes that intentions have to be analyzed in a way incompatible with this manner of using the term.

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tudes. It is therefore natural to assume that microphenomenal properties serve as the immediate and sole stimuli for the forming of certain intentions to certain courses of action. Since there are no propositional attitudes involved, we might regard microintentions as simple urges for a certain course of action in reaction to phenomenal experience. One might worry that because of the introduction of primitive microintentions, the view violates Completeness: microintentions realizing microphysical dispositions are caused by microphenomenal properties such that every caused microphysical property does not have an immediate sufficient microphysical cause, but rather an immediate sufficient microphenomenal cause. However, I believe that it is in this case natural to reinterpret the causal completeness of microphysics as causal completeness of the microrealm, where the microrealm comprises microphysical and micromental entities. This might seem to make a crucial difference. But microphysical causation was grounded in micromental causation from the beginning; the grounding base has merely been enlarged. Instead of one micromental state serving as ground for a microphysical property, three micromental states are involved. The interaction between these states can therefore be considered as extended grounding base for microphysical properties. I see no reason why a constitutive version of this variant of impure Russellian panpsychism should not be considered to have evaded the causal exclusion argument. 6.15

A New Combination Problem

I think that the version of impure Russellian powers panpsychism I defended in the last section gives rise to yet another combination problem. For if the panpsychist allows for a novel kind of fundamental mental state, then the question of combination arises for these states, too. First of all, it is unclear if fundamental intentions can combine. As we saw above, there are at least models for experiential combination, but it is much harder to even image what intention combination would amount too. Could a theory of blending for intentions be developed? While there might be a palette problem for microintentions, I think that there is an even more pressing problem for the view: constitutive panpsychism arguably has to assume that macrophenomenal states are grounded in microphenomenal states and microintentions. The reason is the following: if any macrophenomenal state is constituted by a multitude of micromental goings-on, then it seems plausible that some of the latter are purely phenomenal states, while others are microintentions. This is so, since microsubjects continuously switch between bearing purely phenomenal states and bearing intentions such that for any multitude of microphenomenality which plausibly constitutes a macrophenomenal state, some of the former are in ‘phenomenal-mode’, while others are in ‘intention-mode’. If, for instance, pain is constituted by the multitude of microphenomenality involved in C-fiber vibration, then arguably some of the properties of the microphenomenal grounding base are microphenomenal states, while others are microintentions. C-fiber vibration is a causal-functional pattern, and its causal properties are ultimately grounded in microintentions. Hence, it must exhibit a certain amount of microintentions at any time. But if macrophenomenal states are partly grounded in microintentions, then they should have at least some intentional dimension themselves. How could they be partly constituted by primitive intentions without inheriting something of the essential character of intentions? However, their lack of intentional character is obvious—our

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direct phenomenal concepts do not reveal that they involve any sort of willing or volition for a certain course of action. This is can best be illustrated by revisiting Mørch's pain example. How can the phenomenal character of pain as such be taken to ground the intention to avoid pain? How can the intention to avoid pain be ‘nothing over and above’ what-it-feels-like to be in pain? Mørch is clearly right when she says that “[p]ain seems to make us try to avoid it.” But, contra Mørch, I believe that we have to interpret ‘making’ here as a causal notion. ‘Trying to avoid pain’ can only be the intention of pain-avoidance. The phenomenal character of pain grounds pain’s power to cause such an intention to avoid pain. But pain’s phenomenal character is not able to ground the intention to avoid pain. This character as such is too meager to be capable of grounding so elaborate a mental state as the intention to avoid something. The intention of avoiding pain has a complex representational structure which, amongst other things, represents the phenomenal character of pain. How can a mental state involving the full representation of pain plus the urge of avoiding this experience be nothing-over-and-above pain? Of course, pain qua phenomenal state might have a representational dimension, as proponents of the phenomenal intentionality theory claim (see Bourget & Mendelovici 2019). But it seems incoherent to assume that a state involving the full representation of pain and over-and-above that the urge of avoiding pain—that such a state is nothing-over-and-above pain. This is the intention combination problem. How can the constitutive panpsychist reply to this problem? Is there the possibility to claim that we have a case of constitution while in the constitution microintentions are canceled out? It does not seem so, since this would be a fairly complex process, much too complicated for counting as purely additive or aggregative. As seen above, Goff argues that constitution does not necessarily entail identical phenomenal character if we accept a grounding view of constitution rather than a conception of constitution as identity. In the same manner, could the panpsychist claim that while macrophenomenal states are party constituted by microintentions, there is no need to assume that the microintentional character must show up in the macrophenomenal state? Note that this is a far stronger claim than that of Goff. He holds that the phenomenal character could significantly differ between macro-states and their microconstituents. Nevertheless, macro-states inherit their mental-mode from their mental constituents: the fact that the latter are phenomenal entails the fact that the former are also phenomenal. So, while the exact phenomenal character of the former can differ from those of the latter (and this opens the possibility for accounts of phenomenal blending), macrophenomenal states plausibly inherit some phenomenal profile. But were macro-states which are partly constituted by microintentions not to have any intentional dimension whatsoever, then this would mean that they do not inherit anything of the mental-mode of some of their mental constituents. Thus, the assumption that while microphenomenal states combine, no combination of microintentions exist seems not to be tenable, since it would be arbitrary that only one kind of fundamental mental states combines while the other gets lost. Also, the causal role of microphenomenal states is much weaker on impure Russellian powers panpsychism, since it is only indirectly involved in bringing about microphysical dispositions. If macrophenomenal states are only constituted by microphenomenal states, then

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they would inherit only this weak form of mental causation. It is unclear whether this is enough to secure an attractive version of causal efficiency of macrophenomenal states. I conclude that the intention combination problem is a serious threat for constitutive panpsychism. The view must adopt the impure Russellian powers view I argued for in order to overcome the problem of structural exclusion. But then, the intention combination problem arises, since macrophenomenal states seem to have to possess a volitional dimension if they are partly constituted by microintentions.

7

Emergence in Panpsychism

In the last chapter, I argued that constitutive Russellian panpsychism is false, since several of arguments against phenomenal constitution are sound. Yet it follows from the findings of Chapters 3 and 5 that there are strong reasons for assuming that some form of Russellian panpsychism must be true: physicalism seems incapable of overcoming epistemic objections such as Chalmers’ two-dimensional argument, and dualism faces apparently irresolvable difficulties with regard to mental causation. Russellian panpsychism, by contrast, is not subject to antiphysicalist objections, and avoids dualism’s mental causation problems for microphenomenal causal efficiency. However, it is not clear whether any other version of Russellian panpsychism besides its constitutive form can also avoid problems of mental causation for macrophenomenality. We thus face a crucial question: is there a version of Russellian panpsychism invoking an ontological dependence relation between micro- and macrophenomenality other than constitution that can circumvent problems for mental causation for macrophenomenality? Put differently: is there an ontological dependence relation other than constitution which can plausibly hold between micro- and macrophenomenality and which, moreover, does not give rise to irresolvable arguments against macromental causation? In this chapter, I argue that such a dependence relation does indeed exist, namely ontological emergence. I begin by discussing the prospects of all three non-constitutive versions of Russellian panpsychism (autonomous, identity, and emergent Russellian panpsychism) for meeting this challenge. I argue that emergent Russellian panpsychism appears prima facie preferable to the other two approaches. In Section 7.2, I consider two versions of this position, resulting from different ways of conceptualizing the ontological emergence relation at work in the position: fusionist emergent panpsychism, which is based on Humphreys’ (1997) account of emergence, and causal emergent panpsychism, which invokes a causal emergence relation along the lines of the view which I suggested in Section 4.7. I argue that the causal approach is preferable to the fusionist account. Sections 7.3 to 7.5 are then devoted to addressing mental causation problems for the causal version of emergent Russellian panpsychism, all of which, I argue, are either solvable, or are currently not decidable due to a lack of sufficient empirical knowledge, but at least have some prospects of being solvable in the future. 7.1 Non-Constitutive Versions of Panpsychism 7.1.1

Autonomous Panpsychism and Identity Panpsychism

Identity and autonomous panpsychism can be understood as representing two extremes on a continuum: identity panpsychism holds that the dependence relation between micro- and macrophenomenality is even closer than grounding, namely identity, while autonomous panpsychism denies any ontological dependence of macro- on microphenomenality, whatsoever. There are two versions of autonomous panpsychism. On the first version, macrophenomenality does not depend on microphenomenality, but microphenomenality depends on macrophenomenality. There are, in turn, two variants of this first version. One is constitutive

© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2020 F. Klinge, Panpsychism and the Emergence of Consciousness, https://doi.org/10.1007/978-3-662-62258-2_7

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cosmopsychism which views macrophenomenality as being dependent on cosmophenomenality while microphenomenality depends on macrophenomenality. The other is constitutive macropsychism, the view that macrophenomenality is both fundamental and ontologically independent, and, moreover, grounds microphenomenality. We saw in Section 6.10 that views on which microconsciousness depends on macroconsciousness fall prey to a version of the subject irreducibility argument. Hence, we can rule out both variants by means of the reasoning therein discussed. On the second version of autonomous panpsychism, both microphenomenality and macrophenomenality are fundamental, but there is no relation of dependence between them whatsoever. This view is somewhat similar to nonemergent dualism with the difference that it allows for micro- in addition to macrophenomenality. Besides problems for macromental causation faced by the view, one might wonder where macrophenomenality comes from if it does arise neither from micro- nor cosmoscopic dependence bases. Presumably, this approach must postulate a purely mental realm inhabited by macromental substances. If so, it closely resembles substance dualism, but additionally invokes microphenomenality. But then, the question arises as to why one should postulate microphenomenality in addition to macrophenomenality if the former plays no rule in producing the latter. Perhaps the existence of microphenomenality helps in handling problems of macromental downward causation: it might be easier to solve these problems if downward causation is mental-to-mental instead of mental-to-physical. Indeed, I shall argue in the following sections that a specific form of mental-to-mental downward causation can avoid the familiar problems of mental causation. However, as will become clear in the course of the following sections, mental-to-mental downward causation is only capable of avoiding these concerns if macrophenomenality emerges from microphenomenality. Hence, it appears to yield no benefits to postulate micro- in addition to macrophenomenality if they do not stand in some relation of ontological dependence upon each other. Identity panpsychism assumes that every conscious macroentity is identical to a conscious microentity: that is, my consciousness is identical to the consciousness of an elementary particle, for instance, one of the quarks in my brain. This view has a historical predecessor in Leibniz’s theory. Chalmers (2016) lists a number of problems facing identity panpsychism: There are obvious worries here about this quark’s stability (what happens when it disappears?) and about its causal role (how could its properties play the rich causal role that macroexperiences seem to play?). [...] [T]he quark is presumably microphysically like other quarks, so it will also be microphenomenally like those quarks, yielding a vast manifold of subjects of experience, just like me, throughout the brain and throughout the universe. And given the simplicity of the microphysical structure of a quark, it is hard to see how the corresponding microphenomenology could have anything like the complexity of our macroexperience. So unless this view is combined with serious revisions to physics, it is probably best put aside. (Chalmers 2016: 195) The stability problem might be solved by assuming that the microbearer of my consciousness regularly switches: if the quark which realizes my consciousness disappears from my brain, then another quark takes over and realizes my phenomenology. But as is already clear

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from the vocabulary I just used, this view is not a version of identity panpsychism. My consciousness being associated with different quarks on different times cannot be identical to the subjectivity of one of these quarks. Rather, in order to be ‘switchable’, the relation between my consciousness and any of the subjectivities of the quarks must be realization. Note also that as Chalmers indicates, an especially severe version of the structural mismatch problem arises for identity panpsychism. According to identity panpsychism, the structure of my phenomenal states is identical to microphenomenal structure. But given Russellianism, microphenomenal structure is very different from macrophenomenal structure. In order to avoid this problem, identity panpsychism would have to abandon Russellianism, but if so, then the view is vulnerable to the causal exclusion problem. I take it that this and the other problems Chalmers mentions provide more than enough reason to discard identity panpsychism. 7.1.2

Emergent Panpsychism

Emergent panpsychism assumes that the ontological dependence relation between micro- and macrophenomenology is ontological emergence. In Chapter 4, I argued that ontological emergence, if cashed out correctly, is a coherent concept, and that general concerns about its unintelligibility are misplaced. In this chapter, I shall argue that it can provide Russellian panpsychism with the required resources for explaining the dependence of macro- on microconsciousness, but, nonetheless, allow for an intelligible account of macromental causation which can avoid mental causation problems. Since on emergent panpsychism, macrophenomenal causation is not grounded in microphenomenal causation, the view faces the same worries regarding macromental causation as dualism. However, I shall argue that emergent panpsychism has more helpful resources as dualism: having at its avail microphenomenology allows for a solution to the causal exclusion problem. Moreover, this solution also renders the account immune to other core objections such as the pairing problem. 7.2 Two Variants of Emergent Panpsychism Emergent panpsychism is the view that macrophenomenality ontologically emerges from microphenomenal emergence bases. There are several ways to cash out the view, depending on which account of ontological emergence is taken as a basis. In Chapter 4, we saw that there are several accounts which pass the ‘litmus test for strong emergence’ consisting of overcoming the power inheritance objection. However, as I argued, only one of them qualifies as a theory of ontological emergence, namely the causal emergence approach. Yet given the assumption that emergence bases are microphenomenal, there is a further option in the case of emergent panpsychism: Humphreys’ (1997) fusionism can also account for this form of ontological emergence, since input and output of the emergence process are now of the same highest type. (Recall that fusion appears to be a quasi-mechanical process in which an input is transformed into an output such that both need to be sufficiently similar for this process to work.) I argued in Chapter 4 that the causal view is superior to fusionism as a general account of processes of strong emergence for reasons of parsimony and the avoidance of various problems only the fusion account faces. However, the situation might be different in the context of panpsychism, since the peculiarities of phenomenal-to-phenomenal emergence might tip the

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balance in favor of fusionism: for all we know, there might be reasons why the assumption of microphenomenal emergence bases for macroconsciousness is better accounted for in terms of fusion than causation. Hence, we have reason to re-evaluate the controversy between causal emergence and fusionism within the panpsychist framework. In the contemporary literature, Seager (2010, 2016) and Mørch (2014) have defended emergent panpsychism.107 Both their views are, indeed, variants of the fusion-view. I shall argue that both accounts are untenable, albeit for different reasons. Furthermore, there is no principled problem for cashing out emergent panpsychism in terms of causal emergence such that this appears to be the preferable option. 7.2.1

Against Fusionism

Seager’s (2010, 2016) account is a straightforward panpsychistic application of Humphreys (1997). Recall from Section 4.6.4 that Humphreys assumes fusion to be an idiosyncratic diachronic process of combination of base-level properties. What sets fusion apart from regular forms of combination is that the fusion process is so intimate that the base-level properties do not individually survive the process of generating a new property. That is, in fusing, the emergence base vanishes, being replaced by a novel, strongly emergent entity that is simple and partless. On Humphreys’ original account, only properties fuse. The objects which bear those properties, however, are not impaired by fusion processes: while some of their properties fuse, they themselves survive as individual entities. Furthermore, the fused property is borne by the objects which bore the input properties collectively. Now, Seager’s version of emergent panpsychism has microphenomenality fuse and produce macrophenomenality according to Humphreys’ model. Like Humphreys’ original account, Seager’s approach is subject to Wong’s (2006) problem of basal loss: if base-level properties of a system are destroyed in producing an emergent property, then the macrofunctions of the system these properties were realizing cannot be maintained. But if functions of the system collapse as a result of fusion emergence, this might modify the system in a radical way, maybe even destroy it. Thus, it seems that the basal-loss-feature of fusion emergence entails that systems can only have strongly emergent properties at the cost of losing some of their functions. I argued in Section 4.6.4 that this problem can only be avoided if it is assumed that the fusing properties are micro-latent: that is, elementary particles possess ‘excess properties’ which do not play any causal roles in the complex systems those particles constitute; it is these excess properties which enter fusion, and their causal powers only come into play once they are fused into the macrocausal powers of the fused property. Analogously, on Seager’s view, one would have to postulate that microsubjects possess two types of microphenomenal properties: regular microqualia, which realize microphysical dispositions, and ‘excess microqualia’, which are not involved in realizing microphysical properties, and only come into play in processes of fusion. 107 Another recent proponent of emergent panpsychism is Rosenberg (2004, 2015). Rosenberg develops his form of emergent panpsychism on the basis of a quite idiosyncratic theory of causation largely influenced by Whitehead’s (1978/1929) panpsychist process metaphysics. While Rosenberg is at pains to develop his view within the framework of the analytic tradition, his version of emergent panpsychism is, nonetheless, heavily presuppositional. It is therefore beyond the scope of this work to discuss his position.

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This might be an option when it comes to quality fusion, but it does not seem to work in the case of subject fusion. A microsubject cannot have ‘excess subjectivity’ such that its overall subjectivity can be ‘split’, with merely some of it fusing while the rest of it remains intact. Subjectivity seems not to be a feature of which microsubjects could possibly possess several: that is, it seems implausible that a microsubject could have several ‘subjectivities’ only some of which fuse and are involved in producing a macrosubject, while others remain in order to preserve the microsubject’s survival. Additional whole microsubjects would have to be introduced which do not realize any microphysical causal structure. Only these ‘micro-latent microsubjects’ are then inputs to fusion processes. But this renders the view extremely unattractive, since the core Russellian assumption is sacrificed, according to which the same sort of microphenomenology both realizes microphysical dispositions, and produces macrophenomenology. Moreover, the postulation of micro-latent microsubjects in addition to those microsubjects which realize microphysical causal structure involves additional theoretical costs, making the view less parsimonious. Furthermore, as a result of the separation between the type of microphenomenality which realizes microphysical properties, and that sort which enters fusion processes in order create macrophenomenality, the view is in an analogous situation with regard to problems of mental causation as dualism. For if micro-latent microphenomenality fusion-produces macrophenomenality, then the same worries arise as for dualistic emergentist macrophenomenality. With regard to these problems, it does not make any difference whether macrophenomenality is taken to emerge from microphysical causal structure, or from micro-latent microphenomenality. In both cases, macrophenomena arise with novel powers which have downward causal interactions with fundamental entities, be they purely microphysical or (partly) microphenomenal. As in the case of dualism, while there is some prospect that the causal exclusion argument might be avoidable, Seager’s fusionism encounters severe difficulties with regard to the other mental causation problems discussed. If macrophenomenality is not spatially located, then the view is subject to the pairing problem. If macrophenomenality is spatially located, then the view faces the fundamental interaction problem. The solution strategies open to panpsychistic fusionism are identical to the ones emergent dualism can employ. In Chapter 5, I argued that there is no plausible strategy for emergent dualism to overcome these problems. I take the same to be true for Seager’s version of panpsychistic fusionism for analogous reasons which I will not repeat here.108 Mørch's (2014) account differs from the Humphreys-Seager approach in that it replaces ‘basal loss’ with ‘switching fundamentality’: that is, in fusing, the microsubjects and microphenomenal properties constituting the emergence base do survive, but not as fundamental entities; rather, they lose their ontological status of being fundamental, becoming derivative parts of the emergent macrosubject and its phenomenal properties. This can be considered priority monism on a small scale: in fusion, a macrosubject is generated that is a complex entity with a myriad of microsubjects as parts to which it is ontological prior; the former is fundamental, while the latter are derivative from it.

108 See Sections 5.4.1 and 5.4.3 for a detailed discussion of potential solution strategies and their problems.

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However, the very idea of switchable ontological status seems to be problematic. I believe that it is incompatible with standard accounts of metaphysical fundamentalism that fundamental entities can lose and regain their ontological status. 109 The problem is especially grave in the case of ‘defusion’, when a strongly emergent property is decomposed into its original emergence base such that the former is annihilated, and the properties constituting the latter are restored. It does not seem to make sense that a property is derivative on some other property such that it is strongly ontological dependent (in Barnes’ [2012] sense) on its ground, but that if its ground disintegrates, then the derivative property survives and is transformed into a fundamental property: that is, switching from being derivative to being fundamental appears to be incompatible with the very concept of derivativeness, according to which a derivative entity is strongly ontological dependent such that it has to be sustained by its ground, and therefore cannot outlive the latter. Yet even given that the idea of switching fundamentality can be made intelligible, there is another severe problem: when fundamentality is switched from the input to the output of the fusion process, then microphenomenal properties are grounded by subsumption in macrophenomenal properties. Therefore, Mørch’s version of fusionism falls prey to the revelation argument against cosmopsychism which I developed in Section 6.10. I argued that the regular revelation argument is sound, and that it also applies to case of phenomenal grounding by subsumption, and not only to cases of grounding by analysis as Goff (2017) suggests. I will not repeat this argument here, but if I am right, then this rules out Mørch's version of emergent panpsychism. 7.2.2

Causal Emergent Panpsychism

The alternative to fusionism is a ‘layered’ form of emergent panpsychism, according to which microphenomenal entities produce macrophenomenal entities while fully retaining their identity and metaphysical status. That is, microsubjects and their phenomenal states combine in a certain fashion so that they constitute an emergence base for a macrosubject and its experiences while remaining fully intact fundamental entities. The macrosubjects generated and their macrophenomenal states are additional and separate fundamental macrophenomena which neither replace their emergence bases (as on Seager’s view) nor stand in any constitutive relation towards them (as on Mørch’s account); nevertheless, they are strongly ontologically dependent on them: the emergent cannot survive the disintegration of its emergence base. More precisely, it cannot survive the functional disintegration of its emergence base: because of metabolic turnover, it is plausible that some of the microsubjects participating in the emergence base of a longer-lasting experience such as a headache are removed after a certain amount of time. In such a case, the neural correlate’s microconstituents and their intrinsic microphenomenal dimensions serve as emergence base for the macrosensation; and, as long as the neural correlate of the headache persists, vanishing microconstituents are replaced by other microsubjects which take over their respective functions. In Chapter 4, I argued that ontological emergence has to be cashed in terms of a causal emergence process in order to avoid the power inheritance objection. Therein, I also provided a detailed account of the causal emergence process, and how it differs from ordinary causa109 See Section 2.1 for an overview on distinct versions of metaphysical fundamentalism.

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tion. I take it that the layered version of emergent panpsychism should utilize this causal approach of ontological emergence, and, in the rest of this chapter, I presuppose the causal emergence view. However, while causal emergent panpsychism can avoid the power inheritance objection, the position—qua invoking fundamental macromental causal powers—is potentially subject to the three mental causation problems discussed in Chapter 5: the causal exclusion problem, the pairing problem, and the fundamental interaction problem. In the following sections, I analyze whether these problems also apply to emergent panpsychism and, if so, whether there are promising strategies for solving them. In Chapter 5, I argued that there is some plausibility for the strategy of rejecting the first premise of the causal exclusion problem, although this is largely an empirical question which we currently lack sufficient data to evaluate, and which can only be decided once cellular mechanisms are much better understood. In Section 7.3, I shall argue that there is a version of emergent panpsychism which can avoid this problem altogether: this position can accept both premises of the argument, and, nonetheless, circumvent its conclusion. If so, then emergent panpsychism can only be attacked by question-begging formulations of the causal exclusion argument. Moreover, as I argue in Sections 7.4 and 7.5, this view can also avoid the pairing problem, the problem of fundamental interaction, and the structural mismatch problem. However, before addressing the problems of mental causation, let me analyze the specificities of macrophenomenality on emergent panpsychism, and its similarities and differences to microphenomenality. 7.2.3

The Architecture of Emergent Macrophenomenality

In Section 6.14, I argued that in order to avoid the structural exclusion problem, Russellian panpsychists have to allow for two types of fundamental micromental states in addition to microqualia: primitive micromental dispositions which have as their manifestation properties microqualia, and microintentions which are caused by microqualia, and, in turn, realize microphysical dispositions. In contrast to other forms of panpsychism, emergent panpsychism takes not only micro- but also macrophenomenality to be fundamental; the question therefore arises whether macrophenomenality also features all three types of mental states. 110 In order to answer this question, one must analyze general similarities and differences between microand macrophenomenality: this allows one to see the postulation of which types of micromental states the specificities of macrophenomenality require. The following analysis will reveal that emergent panpsychism does not need to invoke a macro-analogon to the first type of micromental state, because its role (bringing about macrophenomenal states) is already played by emergence-engendering micro-latent dispositions of microsubjects. Moreover emergent Russellian panpsychism can adopt functionalist analyses with regard to macrointentions, and 110 Note that as explained in Section 6.13, structural exclusion is not a threat to the general causal efficacy of microphenomenal properties, but only to their phenomenal efficacy in a narrow sense. Panpsychists could, in principle, accept structural exclusion, and be content with nonphenomenal efficacy of microphenomenal states; yet structural exclusion lends Russellian panpsychism a disadvantage vis-à-vis physicalism and interactive dualism, both of which are not subject to the concern. Moreover, as we will see in the next section, in order to fully avoid the causal exclusion problem, emergent panpsychism must allow for microintentions. Hence, panpsychism in its emergentist version has additional benefit to be gained from invoking those micromental states. I take it that emergent panpsychism should, therefore, allow for them.

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thus take them to be physically grounded. However, there is one interesting exception to this verdict: as I shall discuss in a short excursus at the end of this section, there is strong reason to assume that versions of emergent Russellian panpsychism allowing for libertarian free will require primitive macrointentions. Let me briefly recapitulate the strategy for avoidance of the structural exclusion problem developed in Section 6.14. I argued that if microphenomenal properties are realizers of microphysical dispositions, then they cannot be causally efficacious qua their phenomenal character. For if they act as realizers of microphysical dispositions, then microsubjects possess them permanently: an electron is negatively charged during its whole lifetime, and if negative charge is grounded in a microqualia, then the electron experiences the respective feeling permanently. Hence, the feeling as such cannot be the reason why the electron repels a likecharged particle. The presence of the particle has nothing to do with the feeling—it neither brings about the feeling in the electron, nor does its repelling-behavior make the feeling go away. Therefore, as I argued, we should allow for two additional type of micromental states: first, if microphenomenal properties are manifestation properties of micromental dispositions, then they are not permanent states, but rather only arise when triggered by certain stimuli such as the presence of a like-charged particle, departing once such a particle is repelled; second, for the reasons named, microphenomenal properties cannot be categorical grounds of microphysical dispositions. Rather, these grounds have to be additional micromental states of microsubjects; I argued that these states are somewhat similar to human intentions, calling them ‘microintentions’. Microintentions have microphenomenal properties as stimuli, and microphysical behavior as manifestation properties. Now, what implications does this account of microphenomenality have for a plausible conception of the phenomenal architecture of macrosubjects? The first thing to note is that there is a quite general distinction between micro- and macrophenomenality: differing from microqualia, macrophenomenal properties, though fundamental, are ontologically dependent. Hence, the question of their permanent instantiation does not arise. A macrophenomenal property is brought about iff an appropriate emergence base is formed by microsubjects combining in a certain way, and it vanishes once the emergence base disintegrates. Therefore, the emergent panpsychist has no need to introduce primitive macromental dispositions possessing macrophenomenal properties as manifestation properties—the putative role these states would be introduced to play is already fulfilled by emergence-engendering micro-latent microdispositions: that is, macrophenomenal states are not manifestation properties of fundamental macromental disposition, but rather the manifestation properties of emergence-engendering micro-latent microdispositions of microsubjects; they are the product of the causal emergence-process enacted by those microdispositions, and can as such be taken to be the manifestation properties of the latter. Next, consider macrophenomenal properties. I take them to have phenomenal powers qua their phenomenal character, in an analogous manner as microphenomenal properties have microphenomenal powers.111 But, differing from the latter, macrophenomenal properties do not 111 After all, Mørch's (forthcoming) structural exclusion argument is based on an analysis of macrophenomenal states which is then applied to the micro-case in order to argue that microphenomenal states ground phenomenal powers. Hence, if the argument can successfully be applied to the micro-case, it must also work for

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cause properties of the same ontological level. Recall that Kim’s (2005) causal exclusion argument demonstrates that when an emergent macroproperty causes another property, it must downward-causally impact properties of the lower level it supervenes on, regardless of the caused property being micro or macro. For if an emergent property causes another emergent, it must bring about the latter property’s emergence base. With regard to macro-level intentions, I believe that the emergent panpsychist can adopt a standard functionalist account. Note that in the philosophy of action, it is controversial as to what intentions are (see e.g. Setiya 2018). For instance, there are distinct views on whether they are reducible to other kinds of mental states or not. Yet it seems plausible that if they are a genuine kind of mental phenomenon, then they are propositional attitudes. Moreover, if they are reducible to other types, then it is plausible that those states are propositional attitudes. Thus, either way, it appears uncontroversial that intentions are in some sense analyzable in terms of propositional attitudes. Furthermore, there is a broad consensus that propositional attitudes allow for functional analyzes, and, thereby, are physically explainable. Hence, emergent panpsychists seem to lack any reason for allowing for ontologically emergent macrointentions. Excursus I: Macrointentions and Free Will However, I believe that there is an important qualification to the above conclusion: there are good reasons for assuming that versions of emergent panpsychism allowing for libertarian free will cannot adopt functional analyses of intentions, but must rather take them to be fundamental, thus mirroring microintentions in this regard. The rationale for this is the following. At the heart of the debate on free will is the question whether free will and moral responsibility are compatible with determinism. Libertarians deny this compatibility. Three broad variants of libertarianism can be distinguished, event-causal approaches, agent-causal accounts, and non-causal theories, on the basis of how they account for the causal role of intentions, and their relations to other mental states (see Clarke & Capes 2017); but those differences do not need to concern us here. Usually, theorists of free will do not thoroughly analyze what metaphysical status of free agency their respective accounts imply. Yet more metaphysically inclined philosophers such as Merricks (2001), O’Connor (2009a), and Wilson (forthcoming: chapter 8) have provided forceful arguments for the thesis that libertarianism has to be understood as an emergentist doctrine.112 Wilson’s reasoning is here particularly insightful. Wilson argues that—regardless of how the specificities of the function of intentions and their relations to other mental kinds are cashed out in detail, and which of the distinct versions of libertarianism one accordingly adopts—all variants of libertarianism must allow for a specific kind of strongly emergent causal power on which free intending is based. According to Wilson, what sets this type apart from other types of causal powers is that it is nomologically transcendent: that is, while causal powers are usually governed by laws which determine their dispositional profile, the intentional power of free agents is not.113 Crucially, Wilson’s distinction between law-governed and nomologically transcendent agency is orthogonal to the dismacrophenomenal states, provided that they are fundamental. 112 Merricks (2001) does not explicitly describe his view in emergentist terms, but it is obvious from his argumentation that his position implies that free will is a strongly emergent phenomenon.

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tinction between determinism and indeterminism. Note that laws of nature are not necessarily strictly deterministic, but might also be probabilistic, as, for instance, the laws of quantum physics are. However, as Wilson points out, the distinction between deterministic and probabilistic laws has led to the confusion that libertarianism’s rejection of determinism is merely opposed to the thesis that human agency is governed by strictly deterministic laws such that free will can be cashed out in terms indeterministically law-governed intentions.114 As Wilson explains, the Libertarian is under no obligation to suppose that the only alternative account of choices as nomologically deterministic is one according to which they are nomologically indeterministic. On the contrary: to my mind, the natural opposition to the purported incompatibility between free agency and Determinism is one according to which agents are transcendentally free—that is, free, in at least some of their choices, from either deterministic or indeterministic laws. (Wilson forthcoming: chapter 8) If Wilson’s take on determinism and free will is correct, then libertarian free agency requires the existence of intentional powers which are not governed by strict laws at all, neither deterministic, nor indeterministic. Rather, these intentions transcend any nomological restrictions such that the agent is free to choose particular courses of action for any given reason she might have, or even for no specific reason at all. Moreover, if intentions are nomologically transcendent, then they must be ontologically emergent. For if intentions are derivative, then they inherit their causal powers from their physical grounds; and since the powers of the latter are law-governed, so are the powers of intentions. Of course, also on libertarian views, human persons are not totally free in their agency, but limited by a number of psychological and physiological restrictions stemming from the physical and functional design of their organisms: they can only act on reasons, desires, and ideas they actually possess, and merely perform bodily movements of which their organism is capable; but within this nomologically determined range of options, they have considerable free, that is, nomologically transcendent, behavioral capacities.115 113 Of course, the dispositionalist account of laws has it the other way around, that is, that primitive dispositional profiles determine the content of laws; however, this merely implies a minor modification to the concept of nomological transcendence: given the dispositionalist account, nomologically transcendent powers do just not have a determinate dispositional profile, and thus cannot ground specific laws. 114 Note that only proponents of indeterministically law-governed intentions such as Kane (1996) are subject to the much-discussed argument from luck: roughly, if an action of intending or choosing is indeterministically determined by antecedent events, it cannot be the case that it is up to the agent whether she chooses to do so; rather, it is simply a matter of luck whether she performs the action or not. It is a major advantage of Wilson’s emergentist conception of libertarian free agency, and one of its core motivations, that it appears to avoid this objection. 115 Recent findings in neuroscience are often interpreted as showing that libertarian free will is incompatible with well-established empirical data. Especially the pioneering work of Libet (1985), and subsequent studies such as Haggard et al. (2002) are cited in this regard. Libet found that the reported experience of intending some course of action is preceded by activity in relevant regions of the brain by approximately 400 milliseconds. This is taken as demonstrating that apparent voluntary action is in fact initiated by unconscious brain processes, and the action is only later (incorrectly) interpreted by the brain as being caused by conscious willing. However, O’Connor (2009b) provides an extensive discussion of Libet’s experiments and compellingly argues that their setup is too artificial for deriving any general results about all forms of conscious

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I am inclined to agree with Wilson’s reasoning. Yet for the issue at hand, it does not matter whether the case for emergentist libertarianism is sound. My point is merely that if libertarianism is true, and, moreover, has to be cashed out in terms of nomologically transcendent emergent powers of intending, then emergent panpsychism has to allow for a closer analogy between micro- and macrophenomenal architecture: there is not only fundamental micro- but also fundamental macrointentions. If so, it is plausible that only the macrointentions (and not the microintentions) are nomologically transcendent in the described manner. For we have no reasons to assume that microsubjects are free agents. Moreover, the downward causation of macrointentions can be understood as functioning similar to the downward causation of macroqualia: both mental kinds modify the information-structure of certain neural patterns, thus indirectly bringing about deviant behavior of the organism. In the following sections, I develop a detailed model of mental downward causation in emergent panpsychism. I restrict myself to discussing the causal impact of macroqualia, but everything I say could also be applied to fundamental macrointentions. 7.3 Solving the Causal Exclusion Problem In Section 6.14, I argued that the problem of structural exclusion developed by Mørch (forthcoming)—if microphenomenal states act as realizers for microphysical dispositions qua being governed by contingent fundamental laws, then they are not causally efficacious qua being phenomenal—can only be solved if we allow for the following revisions to standard Russellianism: microphenomenal states are embedded in relations to two additional types of primitive dispositions borne by microsubjects. One of these dispositions brings about microphenomenal properties in the microsubject, while the other realizes microphysical properties. Furthermore, I suggested that the latter type of micromental disposition can be understood as a micromental analogy of intentions: it can be regarded as primitive urge of microsubjects for a certain course of action in reaction to the phenomenal experience they undergo. In this section, I argue that in addition to being required for a solution to the structural exclusion problem, this type of micromental state also provides emergent panpsychism with a solution to the causal exclusion problem. Like property dualism, emergent panpsychism views macrophenomenal properties as ontologically emergent, the difference being that their emergence bases are not microphysical but microphenomenal properties. However, the nature of the emergence base does not seem to make a difference with regard to causal exclusion. Either way, macrophenomenal properties supervene on their respective emergence bases, thus giving rise to the objection. Yet I shall argue that the nature of the emergence base does make a crucial difference: it allows emergent panpsychism to avoid the causal exclusion problem by invoking a specific type of mental-tomental downward causation.

choice. Moreover, Wilson (forthcoming: chapter 8) argues that even if we take Libet’s results at face value, there are plausible interpretations of the results compatible with the existence of libertarian free will. To be clear, I do not intend to defend libertarianism in the work at hand. Yet I hold that the case for libertarianism is not as easily dismissed as many seem to think. If so, it is a worthwhile endeavor to evaluate as to how lib ertarianism could be cashed out within a panpsychistic framework.

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I believe that intentions are a very special type of mental state: they are essentially dispositional, but do not have any specific disposition essentially. Consider the case of humans: it seems at least to be the case that we have a free choice to form intentions with different contents in reaction to the very same reasons. That is, the concept of intentions allows for the metaphysical possibility that exactly identical circumstances can give rise to intentions with different contents. Imagine you look out of the window, and you see a close friend walking past the house. The belief forms that this would be the perfect opportunity to personally invite her to a party. Furthermore, the desire arises to go out and invite her. It seems inconceivable that there is world in which the exactly identical situation occurs, but wherein your counterpart does not form this belief-desire pair: if the counterpart sees the friend and has otherwise identical beliefs, desires, preferences, etc. to those which you have, then the counterpart must also have this belief-desire pair. The reason is that beliefs and desires appear to be functional states which are individuated by the specific causal relations they bear to other mental states, to sensory stimuli, and to behavior. Beliefs and desires essentially have such causal relations to other states that, within the described circumstances, a belief and a desire with the content described forms. In contrast, it is conceivable that you form the intention to go out on the street and invite your friend and therefore do so, while your counterpart forms the intention to stay in and therefore does so. If this is right, then intentions do not essentially have specific causal relations to other states. For if they had, then all of your counterparts would necessarily form the same intention as you do. Of course, the question is highly contested as to whether the ‘power to do otherwise’— in exactly the same circumstances—is a nomological possibility: for the nomological possibility entails the actual existence of libertarian free will. Fortunately, the account I develop does not rely on the truth of libertarianism. We might not have the power to do otherwise. For the purposes at hand, it suffices that the libertarian conception of intentional powers is not incoherent. But the coherence of the libertarian conception is not questioned in the debate on free will. Compatibilists reject the actual existence of libertarian free will on grounds such that it is not compatible with determinism, and that it is not needed to account for moral responsibility and ownership. Yet the coherence of the libertarian conception is not thereby denied. Now, I suggest that macrophenomenal properties have a specific type of causal power by which they influence the dispositional profile of the microintentions of certain microsubjects. That is, given the same microphenomenal stimuli, my macro-pain causes microsubjects in my brain to react in a slightly different fashion: it downwardly causes microintentions of a number of microsubjects in my brain to change their dispositional profiles in certain ways. Since microintentions ground microphysical properties in virtue of their dispositional profile, this modification makes them ground different microphysical properties. For instance, downward-causal intervention might modify the microintention of a microsubject playing the role of an electron in such a way that, as a result, the microsubject attracts a like-charged particle rather than repels it. In this case, all token stimuli are exactly the same as if no downward causation had occurred: in both cases, the presence of another electron triggers the manifestation of the electron’s electromagnetic disposition—only that in the sec-

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ond case, due to macromental intervention, this very disposition has temporarily changed its profile from ‘repel-mode’ to ‘attraction-mode’. Thus, the microphysical causal chain of events has been changed by macromental intervention without violating either Completeness or No Overdetermination: every microphysical effect has an immediate sufficient micro-cause, without there being any systematic overdetermination of micro-effects. Rather than directly causing any microproperty, mental-to-mental downward causation causes microsubjects to cause different properties to those they normally do. Hence, every effect of the microcausal chain has an immediate sufficient micro-cause, as Completeness requires. But since the direction of the chain is altered (because the dispositional profiles of microintentions are modified), downward causal intervention does not overdetermine micro-effects: due to downward intervention, different micro-effects occur to those which would have occurred without downward intervention. We can illustrate this graphically. I take an arrow pointing at a property to symbolize that the respective property is caused by the property the arrow originates from. Figure 7.1 represents a regular case of downward causation in which a macrophenomenal property, E1, causes a microproperty, e2, which is also caused by another microproperty, e1. This case either violates Completeness or No Overdetermination, depending on whether e1 is a sufficient cause of e2. Figure 7.2, by means of contrast, represents a case of mental-to-mental downward causation: here, e1 is a microintention and E1 manipulates which effect e1 causes, rather than causing a micro-effect itself. This is illustrated by the downward arrow not pointing at one of the microproperties—this would symbolize that E1 causes the microproperty as such—but rather pointing at the arrow connecting e1 and e2; this I take to symbolize that E1 influences which effect e1 causes. In this case, Completeness is not violated, because e1 is the immediate sufficient cause of e2. No Overdetermination is not violated, because e1 would have caused another event—call it e2’—had E1 not intervened. E1

e1

e2

Figure 7.1: Mental-to-Physical Downward Causation

E1

e1

e2

Figure 7.2: Mental-to-Mental Downward Causation

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Again, in a case of mental-to-mental downward causation, the overall causal chain might be fully deterministic. The only contrast to constitutive panpsychism is that this determinism is not pure micro-determinism, but rather involves macrophenomenal states which downwardcausally modify microintentions. However, even if one accepts my solution, one might think that it is nothing more than a technical trick to abide to the letter of the causal exclusion argument, hardly able to count as fulfilling the spirit of the principles upon which the argument is based. For also on my account, there is macromental intervention ‘messing’ with the laws of fundamental physics. But this complaint implicitly relies on the much stronger principle of microphysical causal closure, the thesis that microphysical causal chains are not only complete (for every microphysical effect, there is an immediate sufficient microphysical cause), but that there is no non-microphysical causal intervention with those chains whatsoever. While many physicalists are prepared to also accept this stronger principle, the crucial point is that it does not allow for a non-question-begging objection to genuine downward causation. For invoking causal closure implies outright denying macromental downward causation: arguments with causal closure as a premise rule out interactive versions of emergentism from the very start by rejecting any potential nonphysical influence on microphysical causal structure. Of course, the trick is to provide an argument that only has premises which proponents of the target position also have reasons to accept, and to demonstrate that the premises entail a thesis incompatible with the target position. I take it to be a major advantage of my version of emergent panpsychism in comparison to dualism that it seems that this cannot be accomplished : there is no way for the physicalist to provide a non-question-begging causal exclusion argument against the position I developed in this section. While the version of emergent panpsychism proposed complies with Completeness, as we saw, it nonetheless violates the stronger principle of microphysical causal closure. Thus, emergent panpsychism could be ruled out empirically if we find no traces of macromental downward causation in the brain. For since downward causation changes the behavior of physical goings-on, future scientists, having studied the complete causal structure of the brain, should be able to ascertain whether anything not in accordance with the laws of physics occurs. However, there is some empirical evidence that neural dynamics are to a large extent chaotic. If so, then downward causation might be empirically undetectable since it is indistinguishable from chaotic behavior. I argued at length at the end of Section 5.4.2 that it is presumably possible to cash out downward causation in a manner such that it would appear empirically indistinguishable from deterministic chaos. Emergent panpsychism can adopt this strategy of accounting for downward causation.116 However, the question whether neural dy116 In Section 5.4.2, I argued that dualists can interpret certain outcomes of nonlinear dynamics in neural networks (given that the brain is chaotic) as being due to macrophenomenal intervention. Since nonlinear macrodynamics in chaotic systems are epistemologically emergent (see Section 4.3.1), it is, in principle, empirically undecidable whether chaotic systems are fully micro-deterministic or not; thus, the assumption that a certain nonlinear outcome is due to macromental intervention is as empirically adequate as the assumption that it is due to micro-deterministic chaos. However, we have seen that in light of the fundamental interaction problem, dualism cannot maintain such an account of downward causation, since dualist downward causation is incapable of invoking sufficiently holistic interventions on the micro-level. By contrast, emergent Russellian panpsychism can arguably allow for an account along these lines: if there is a high degree of chaotic behavior in neural networks (yet recall that this is currently controversial

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namics are in fact chaotic is controversial, and currently hotly debated in neuroscience. Generally, as explained in 5.4.2, we do not possess sufficient scientific evidence for evaluating empirical hypotheses such as closure. It seems therefore currently not possible to invoke arguments against macromental downward causation based on empirical premises. 7.4 Pairing and Fundamental Interaction As we have seen in Chapter 5, besides the causal exclusion argument and the causal closure objection, there exist a number of other problems for irreducible macromental downward causation, the most severe of which are the pairing and the fundamental interaction problems respectively. Since emergent Russellian panpsychism invokes irreducible downward causation, this view is prima facie also subject to those objections. However, in what follows, I shall argue that due to the special form of categoricalism at play in Russellian monism, my version of emergent Russellian panpsychism can avoid these problems in a way which dualism cannot. I thoroughly discussed Kim’s (2005) version of the pairing problem in Section 5.4.2. Thus, I shall here merely provide a short recapitulation of the main issues. Kim argues that causes can be ‘paired’ to their effects iff they are part of an external ordering framework such as spacetime, making them stand in spatial relations to one another: that is, causation requires the existence of a spatial framework (or a quasi-spatial framework, invoking external relations analogous to spatial relations) in order to secure a unique pairing of causes and effects. Suppose that Susie and Steven simultaneously throw a rock respectively, and as a result two windows, A and B, break. Which rock-throwing caused which window to break? As Kim points out, in order to answer this question, we have to trace the spatial relations from the event of the breaking of window A back to the two events of Susie’s rock-throwing and Steve’s rock-throwing, and the same for the event of the breaking of window B. If Susie’s rock-throwing stands in the right spatial relationship to A’s breaking, but Steve’s does not, then this establishes the fact that Susie’s rock-throwing, rather than Steve’s, caused A to break. Furthermore, Kim demonstrates that the existence of spatial relations (or some analogous link

among neuroscientists), then this position can assume that downward causation effects merely tiny changes in the micro-evolution of neural systems. As I have argued in Section 5.4.2, downward causal intervention might only have to slightly influence the firing-rate of the neurons located at functionally crucial spots in a certain neural pattern in order to produce significant changes in macrobehavior via the butterfly effect. Such miniature changes to initial conditions will never be empirically detectable, since they do not result in major changes of energy transmission detectable via modeling neural behavior. However, in addition, downward causation might have to ‘shield’ targeted neural patterns from random noise, in order to secure stable out comes. For if neural patterns are in fact chaotic, then even the minutest amounts of external influence can lead to changes in initial conditions counteracting the macromental intervention. Yet such shielding might very well be accomplishable, given that downward causation in emergent Russellian panpsychism disposes of means for holistically modifying neural networks: macromental intervention might have to constantly ‘scan’ a certain targeted neural pattern for noisy external factors, and counteract them such that the desired outcome occurs. Let me clarify that, of course, these remarks are nothing more than a very preliminary (and quite speculative) discussion of the mechanics of downward causation. However, I take it that a full-blown emergentist account of macromental downward intervention must address these (and similar) issues, and amongst other things provide a plausible explanation as to how downward causation might work within a nonlinear neural environment, given that it is a real possibility that here is a high degree of chaos in neural networks.

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between cause and effect) is not only necessary for cases of derivative causation involving ordinary objects such as rocks and windows, but also for fundamental causal processes. Now, if phenomenal properties are fundamentally mental entities, then they prima facie do not inhabit spatial locations. The question therefore arises how we can pair phenomenal causes to their physical effects if they do not bear spatial relations towards each other. In Section 5.4.1, I argued that dualism can easily avoid the pairing problem by adopting the Russellian strategy. The resulting position, Russellian dualism, takes macroqualia to realize structural properties in the same way as Russellian panpsychism takes microqualia to realize microphysical properties, the difference being that Russellian dualism has macroqualia realize dispositions which are not microphysical properties, but rather fundamental properties that exist in addition to the properties described by microphysics. Nonetheless, on Russellian dualism, macroqualia realize dispositions which are part of the physical spatiotemporal framework, and, therefore, they can straightforwardly be paired to their physical causal partners. However, as I further argued in Section 5.4.3, Russellian dualism is subject to the fundamental interaction problem: being fundamental entities, the dispositions realized by macroqualia must participate in fundamental causal interactions, and in order to do so, they must interact with microphysical properties. For only the latter qualify as fundamental physical entities. This, in turn, seems to entail that macroqualia themselves cannot be bigger than elementary particles. But if so, then they presumably can only locally interact with some nearby particles; this, however, does not seem to suffice for modifying the global information structure of neural patterns in the brain. Hence, dualistic interaction cannot bring about the right sort of causal effects: macroqualia can only effect tiny changes in the microstructure of neural patterns, yet they cannot influence large-scale information processing in the brain; but then, they cannot influence the behavior of a whole organism. In Section 5.4.3, I discussed various solution strategies the Russellian dualist might adopt, arguing that all promising options render her position subject to a version of the structural mismatch problem. Yet the structural mismatch problem is one of the most severe objections to constitutive Russellian panpsychism, and if Russellian dualism is subject to it, then that severely jeopardizes this position. Thus, dualism faces a dilemma: the pairing problem is only avoidable by strategies rendering the view vulnerable either to the fundamental interaction argument, or the structural mismatch problem. Now, the question arises as to whether emergent Russellian panpsychism can sidestep dualism’s dilemma. In the following, I shall argue that it can, indeed, avoid this complex of problems. For the Russellian strategy at work in emergent Russellian panpsychism invokes a specific relationship between macroqualia and microqualia allowing for a solution to the pairing problem which does not render this view subject to the fundamental interaction argument: the specificities of the version of categoricalism at play in this position provides it with quasispatial frameworks uniquely matching macroqualia to the microqualia of their respective emergence bases; hence, there is no ambivalence with regard to the question with which causal partners macroqualia interact because each macroquale inhabits its individual framework determining that it can only interact with its own emergence base. A quick word on the linkage between the argument of this section and the reasoning of the last section: in the last section, I argued that by employing a specific form of mental-to-mental

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downward causation, emergent Russellian panpsychism can avoid the causal exclusion problem; in this section, I provide yet another argument for the merit of mental-to-mental as opposed to mental-to-physical downward causation. I argue that mental-to-mental downward causation follows naturally from the most plausible model of phenomenal emergence. Moreover, this model entails that macroqualia can only interact with the microqualia of their respective emergence bases, and this, in turn, allows emergent Russellian panpsychism to avoid both the pairing and the fundamental interaction problem. 7.4.1

Categoricalism’s Intrinsic Dimension

Let us begin by analyzing what distinguishes variants of Russellian monism from other versions of categoricalism. This recapitulates some of the issues already discussed in Chapter 5, but for the most part focuses on some further aspects not addressed so far. In contrast to Russellian dualism, Russellian monism holds that not only macrophenomenal properties come with a phenomenal categorical nature, but that also (at least some types of) microphysical properties have (proto)phenomenal quidditistic essences. This entails that (proto)phenomenality plays the roles of at least some of the fundamental physical causal structure of the world. However, the assumption that microphysical properties have a categorical nature beyond their dispositional profiles is not unique to Russellian monism. As we saw in Section 5.3.1, this is indeed the defining assumption of all versions of categoricalism: the physicalist version of categoricalism also holds that microphysical dispositions have quidditistic natures. Yet what sets physicalist categoricalism apart from versions of Russellian monism is that quiddities as such are assumed to have no metaphysically substantive intrinsic nature to them: a physicalist quiddity has no non-trivial essential qualities over and above its being identical to this property and not some other property; it does not possess any qualitative essential features, but merely exhibits pure ‘thisness’, as one might say. Nonetheless, physicalist quiddities do have an intrinsic nature beyond their dispositional profiles. Note that it is only the dispositional profiles of physicalist quiddities which can be studied by physics. Moreover, there is strong reason to assume that this is not merely due to the fact that physicalist quiddities as such do not possess any qualitative features such that there is not much to be studied about them; rather, and more crucially, even if these quiddities had qualitative essential features, those features would be beyond the reach of empirical investigation. For given categoricalism, qualitative essential features as such would also not be part of the behavioral inclinations of their bearers, yet it is merely behavior which can be studied by empirical sciences: only the behavior of entities (and not their quidditistic nature) is observable in experiments, and allows for mathematical or computational modeling. If so, we are ignorant of categorical properties as such. Let me discuss this important issue more thoroughly. The thesis that we are ignorant of the nature of fundamental properties has most prominently been defended by Langton (1998): Langton argues that objects affect us in virtue of their causal powers, and it is therefore merely those causal powers that we can study; yet we cannot find out anything about the categorical properties grounding these powers.117 Lewis (2001) endorses Langton’s thesis, and 117 Langton (1998) traces this thesis back to Kant, interpreting Kant’s noumenalism in terms of our ignorance of the categorical grounds of physical causal powers.

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backs it with an argument of his own: he points out that physicalist categoricalism entails Ramseyan Humility, the thesis that we cannot know the nature of fundamental properties since the fundamental causal structure of the universe can be multiply realized (recall the powerswapping cases discussed in Chapter 5).118 On account of this multiple realizability, we cannot find out which quiddities in fact realize the causal structure of the actual world. Bird (2007a: chapter 4) agrees with Lewis’ reasoning, but argues that the multiple realizability of the universe’s causal structure has serious consequences for categoricalism: indeed, as discussed in Section 5.3.3, two distinct types of quiddities might realize the same type of microphysical disposition in the actual world. But then, our fundamental theoretical terms would fail to refer: if there are, in fact, two distinct types of quiddities playing the mass role, then our term ‘mass’ refers to neither of them (and hence fails to refer tout court) since this term denotes the (single) mass-type. Thus, for principled reasons, we cannot know whether our fundamental theory is true.119 I take it that the arguments of Langton, Lewis, and Bird convincingly demonstrate that quiddities qua quiddities are not empirically accessible. Furthermore, our principled ignorance of categorical properties seems also (implicitly) to be taken for granted in the debate on Russellian monism: indeed, Russellian panprotopsychism takes microquiddities to possess nonphenomenal qualitative essential features of some kind, and it is widely agreed upon that these features are not accessible to empirical research. Now, given our principled ignorance of the nature of fundamental properties, I consider it a plausible assumption that on physicalist categoricalism, microphysical properties are only directly located in spacetime insofar as their dispositional profiles are concerned: their categorical natures as such are, strictly speaking, not part of the physical realm of spacetime. For if the categorical aspects of microphysical properties were as such involved in the physical spatial framework, then physics should, in principle, be capable of studying them: it is plausible that if an entity is part of the spatiotemporal structure of the physical universe, then it must in principle be explorable by physics or some other natural science. Yet, physics leaves us completely in the dark about quidditistic essences. Hence, I take it that it follows from the defining commitments of categoricalism that what could metaphorically be called a concrete intrinsic realm, or intrinsic dimension exists beyond the extrinsic dimension of the universe, partaking in the framework of physical spacetime. Furthermore, what distinguishes Russellian monism from physicalist categoricalism is the fact that the former assumes that the categorical aspects of microphysical properties as such engage in substantial metaphysical work, while the latter denies this: Russellian monism comes in two variants, panpsychism and panprotopsychism, that hold that the categorical aspects of microphysical dispositions are either micro- or protophenomenal properties; both po118 The power-swapping scenarios discussed involve quiddities realizing different physical properties in other worlds than they do in ours. But then, different quiddities could also realize the causal structure of our world. Hence, the latter is multiply realizable. 119 Bird’s argument is another interesting objection to categoricalism that has not been discussed in Section 5.3.3. Note that powers Russellian panpsychism can avoid Bird’s objection, since microqualia and microintentions have their phenomenal powers essentially. For if so, then the fundamental causal structure of the world is not multiply realizable (at least with regard to those microphysical dispositions which are grounded in microphenomenal powers; this, in turn, suggests that the powers panpsychist should hold that all rather than merely some of the microphysical dispositions are grounded in microphenomenal powers).

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sitions assume—and this is crucial to the Russellian idea of providing microquiddities as such with substantial metaphysical work—that microquiddities qua their categorical nature bring about macrophenomenality (perhaps only if they bear appropriate causal and/or spatial relationships to each other).120 On physicalist categoricalism, in contrast, macrophenomenality is wholly grounded in microphysical causal structure: that is, categorical underpinnings generate macroconsciousness qua playing microphysical causal roles; yet categorical underpinnings qua their quidditistic essences are provided with neither any role in bringing about consciousness, nor any other metaphysical task. Thus, Russellian monism is not distinct from physicalist categoricalism by means of invoking an intrinsic dimension of microphysical properties; it is distinct in allowing for positive essential characteristics of quiddities beyond their pure thisness, and ascribing to these characteristics substantive metaphysical tasks. Yet this is not the only crucial difference between both views: another distinction concerns their conception of the structure of the intrinsic dimension. Again, physicalist categoricalism takes microphysical properties to have an intrinsic categorical dimension to them, but does not ascribe to its inhabitants (qua categorical) any metaphysical role; on Russellian monism, in contrast, the inhabitants (qua categorical) have a metaphysical role, namely generating macroconsciousness. A consequence is that Russellian monism’s intrinsic dimension is complexly structured. For it inhabits both micro(proto)phenomenal quiddities and their phenomenal products, namely macrophenomenal entities: that is, intrinsic dimensions have a complex structure insofar as it is not only the case that individual microphysical dispositions have their respective intrinsic categorical underpinnings, but also the case that quiddities as such combine and collectively generate macrophenomenal entities additionally inhabiting the respective intrinsic dimensions of those collections of quiddities. Note that while for the sake of simplicity, I often speak like if there was only one intrinsic dimension, I take it that on categoricalism, each token microphysical disposition has its own intrinsic dimension represented by its quiddity. Moreover, on Russellian monism, combinations of microquiddities have collective intrinsic dimensions represented by the macrophenomenal entities they constitute. 7.4.2

Russellian Monism’s Two-Layered Intrinsic Dimension

Let us analyze the structure of Russellian monism’s intrinsic dimension more thoroughly: I consider it natural to assume that the relationship between micro(proto)phenomenality and macrophenomenality is such that macrophenomenal entities inhabit a second layer of the intrinsic dimension of the microrealm.121 If so, then macrophenomenal entities can be taken to qualify as the intrinsic natures of their production bases: that is, when certain microphenomenal entities combine and generate a macrophenomenal entity, then the latter represents the 120 Of course, depending on the version of Russellian monism, the production relation is either grounding, or emergence. Note that when I speak of ‘bringing out’, ‘producing’, ‘generating’, and the like in the following, I mean to cover both grounding and emergence. Moreover, I shall primarily discuss the production of macroqualia, ignoring, for the most part, the generation of macrosubjects: since macrosubjects have their causal powers due to the macromental properties they possess, macrosubjects as such do not directly play a role in the discussion of macromental downward causation, and can therefore be ignored in what follows. 121 To my knowledge, this issue not been addressed in the literature as of yet. Hence, there is no existing debate on the question whether Russellian monism comes with a complexly structured intrinsic dimension.

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collective intrinsic nature of the former. For if combinations of micro(proto)phenomenal entities qua being quiddities generate macrophenomenality, then this is a production process which exclusively concerns the intrinsic aspect of nature. Hence, macrophenomenality is a purely categorical phenomenon: macrophenomenal entities stand in no direct contact to physical spacetime. This is the core reason why constitutive Russellian monism can assume that macroqualia have causal powers, but violate neither Completeness nor No Overdetermination: macroqualia inherit their causal powers from their categorical grounding bases, and it is only the latter which directly play causal roles in the physical universe by realizing microphysical dispositions. In order to fully understand why macrophenomenal entities qualify as purely categorical phenomena, it is helpful to examine constitutive Russellian panpsychism’s strategy of avoiding causal exclusion more closely (for the sake of simplicity, I ignore panprotopsychism for the moment; nevertheless, the strategy is analogous for both positions). In Section 5.5, it was discussed that constitutive Russellian panpsychism can adopt a strategy analogous to nonreductive physicalism for rejecting the causal exclusion argument: since macroqualia are grounded in microqualia, the former inherit the causal powers of the latter in a similar manner to the manner in which functional properties inherit the causal powers from their physical realizers. However, there is a crucial distinction we have not discussed so far. Functional properties are purely structural properties: by being realized by physical properties, they inherit some or even all (depending on which account of realization one adopts) of the causal powers of the latter. In contrast, on constitutive Russellian panpsychism, macroqualia are categorical properties. If they are grounded in microqualia, then they inherit first and foremost their categorical nature from their microphenomenal grounding bases. For instance, macro-pain is constituted by a great number of different types of microqualia, inheriting its phenomenal character from the combined phenomenal characters of the latter. Now, only due to inheriting microphenomenal characters, it also inherits certain causal powers, namely (some of) the causal roles which those microqualia play. 122 Hence, by contrast to functional realization, in phenomenal constitution, inheritance of causal powers occurs merely indirectly, mediated through the inheritance of phenomenal character. That is to say, because macro-pain qualifies as the intrinsic nature of its grounding base, thus inheriting its combined phenomenal character, it also inherits microphysical causal efficacy. By contrast, if macro-pain was not the intrinsic nature of some combination of microqualia but nonetheless powerful, it would have to stand in some form of direct contact with the physical world such that it can play a causal role within the framework of physical spacetime. Yet if so, then the macroquale would be subject to the causal exclusion problem. For it would have to realize a structural property additional to those described by fundamental physics, since the latter are microproperties, and a macroquale, because of being a macro122 It is an interesting question whether in phenomenal constitution, all or only some of the powers of the grounding base are inherited by macroqualia. Recall from Section 5.4.2 that the Shoemaker-Wilson subset view of realization merely allows for partial inheritance. Yet even if this account is correct, it targets functional realization, and might not be directly applicable to phenomenal constitution. It is a desideratum for theories of phenomenal constitution to specify whether this type of grounding involves partial or full inheritance of causal powers. To my knowledge, this question has not been addressed in the literature on panpsy chism as of yet.

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level entity, cannot realize dispositions of the lowest ontological level. Moreover, causal interventions of the structural property realized by macro-pain would either violate Completeness or No Overdetermination; constitutive Russellian panpsychism would then fall prey to the causal exclusion problem for the same reason as Russellian dualism does. Therefore, I hold that constitutive Russellian panpsychism must assume that when microqualia combine and form a grounding base for the constitution of a macroquale, a second layer of the intrinsic dimension comes into being, namely the collective intrinsic nature of the grounding base, and on this second layer, a macroquale is located which inherits its causal powers from the grounding base. spatiotemporal dimension

intrinsic dimension, first layer

intrinsic dimension, second layer

macrophysical

grounding microphysical

macrophenomenal

grounding

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Figure 7.3: Extrinsic and Intrinsic Dimensions in Constitutive Russellian Panpsychism

7.4.3

Phenomenal Emergence Within the Two-Layered Structure

Now, emergent Russellian panpsychism deviates from this model only insofar as the dependence relation between microphenomenal production base and macrophenomenal product is assumed to be ontological emergence rather than constitution. If so, it remains the case that there is no direct causal interaction between macroqualia and physical properties. Of course, as a consequence of the fact that the dependence relation is ontological emergence rather than grounding, macroqualia cannot inherit their causal powers from the microphenomenal level; rather, macroqualia have strongly autonomous powers. Yet given the outlined model of the intrinsic dimension, macroqualia can only downward causally interact with the entities of their respective emergence bases. For if a macroquale is the collective (emergent) intrinsic nature of its emergence base, then it is completely causally isolated except for its relationship to the latter.123 (Note that if macrophenomenal entities ontologically emerge from combinations of microphenomenal entities, then they cannot, strictly speaking, qualify as their intrinsic nature, given that ‘nature’ is understood as describing the essence of an entity. For being emergent 123 Of course, such causal interaction cannot possibly affect the micro-latent microdispositions which emergence-produce a certain macroquale because if it did, then the emergent macroquale would be annihilated. Rather, downward causation by macroqualia can only impact other properties of their emergence bases. This is in line with the argument provided in the last section: there, we saw that downward causation must affect microintentions in order to avoid the causal exclusion problem.

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makes them stand in a causal relation to their production bases, and this is obviously not an essentialist connection. For the purpose of illustration, I shall, nonetheless, continue to use the terms ‘intrinsic nature’, albeit it must be understood in a loose sense when applied to emergent macrophenomenal entities.) spatiotemporal dimension

intrinsic dimension, first layer

intrinsic dimension, second layer

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grounding microphysical

macrophenomenal ca

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tio usa

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Figure 7.4: Extrinsic and Intrinsic Dimensions in Emergent Russellian Panpsychism

How does this model of phenomenal emergence help emergent Russellian panpsychism in dealing with the pairing problem? I hold that the structure of the intrinsic dimension allows for precise pairing relations in mental-to-mental downward causation: the two layers of an intrinsic dimension provide a space-like framework allowing for exclusive pairing relations. Since each microphenomenal emergence base has an individual emergent intrinsic nature, there is a separate intrinsic dimension for each emergence base such that each two-layered framework of an intrinsic dimension constitutes a closed system: in contrast to non-Russellian versions of dualism, my position does not assume that macroqualia inhabit a separate yet common mental realm (such that all macroqualia are located in one and the same nonspatial but nonetheless temporally ordered mental framework), but rather that each macroquale inhabits its own individual framework which it exclusively shares with the entities of its emergence base. Hence, there is no problem in matching several simultaneous causes to their respective effects: each two-layered structure constitutes an external pairing framework which only disposes of one cause-effect-pair at a time; due to its location in a certain framework, a macroquale can only downward causally influence the entities with which it shares a common framework, namely its own emergence base. For instance, my current headache causally interacts with the microphenomenal quiddities of the microconstituents of its neural correlate serving as its emergence base; and since the headache exclusively partakes in the particular framework which connects it to its emergence base, no problem arises in matching these causal partners. However, even if emergent Russellian panpsychism can avoid the pairing problem in the manner described, it is not obvious that the position can also avoid the fundamental interaction problem: that is, even if mental-to-mental downward causation occurs within the framework of a two-layered intrinsic dimension, it must nevertheless be demonstrated that macro-

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qualia can affect the global information structure of the neural patterns that function as their emergence bases, and not merely local effects in a few of the microsubjects constituting these patterns. Thus, the question arises: how can mental-to-mental downward causation be holistic enough to affect a very large number of microsubjects in an emergence base simultaneously? Here is my response. Recall that it was argued in Section 4.7.2 that ontological emergence is a process of irreducibly pluralistic causation. Now, I see no reason why we cannot suppose that downward causation is also pluralistic, but rather in the reverse direction: rather than having a plurality of causes acting collectively in order to produce a single emergent property, there is a single macrophenomenal cause in mental-to-mental downward causation which simultaneously brings about a plurality of effects; due to the specific structure of the intrinsic dimension, a macroquale can simultaneously act on a great number of microintentions.124 In contrast to Russellian dualism, on which only quantum-scale local intervention is possible (because macroqualia must realize structural properties that partake in quantum-level fundamental causation), emergent Russellian panpsychism can allow that its specific type of mental-to-mental downward causation is sufficiently holistic to modify the global informationstructure of neural patterns: that is, we are free to hold that there is an idiosyncratic type of downward causation between macroqualia and their emergence bases allowing for pluralistic interaction with a great number of microintentions of the emergence base simultaneously. Moreover, since this interaction takes place within a two-layered intrinsic dimension, no concerns regarding structural mismatch arise. Recall that I argued in Section 5.4.3 that on Russellian dualism, in order to influence a great number of microphysical properties simultaneously, a macroquale would need to have a very complex phenomenal structure: presumably, it needs to be a field with a complex pattern of local features structurally very similar to microphysical quantum phenomena. Yet because the intrinsic dimension is not spatially ordered, I believe that on emergent Russellian panpsychism, we must not invoke an analogous complex phenomenal structure of macroqualia in order for them to be capable of pluralistic downward causation of the sort described: being the combined intrinsic nature of a great number of microphenomenal entities, we can unproblematically assume that macroqualia possess idiosyncratic causal powers rendering them capable of bringing about this sort of pluralistic effect merely in virtue of their phenomenal character. Let me explain this downward causal mechanism in more detail. Given the phenomenal powers account defended above,125 we can assume that a macroquale’s phenomenal character as such grounds phenomenal powers which are lawfully tied to myriads of microintentions in its emergence base; moreover, this sort of downward causation is based on a fundamental mental-to-mental interaction which specifies how those microintentions are altered as a function of the specific phenomenal character of the macroquale:126 that is, the law governing 124 Recall that in order to avoid the causal exclusion argument, mental-to-mental downward causation must take on the form described in Section 7.3. Hence, macroqualia cause changes in the dispositional profiles of mi crointentions borne by microsubjects of their emergence bases. 125 Mørch's phenomenal powers panpsychism was originally discussed in Section 6.13. The modification I argued for was advanced in Section 6.14. 126 In accordance with Wilson’s (2002) conception of interaction-relative strong emergence, mental-to-mental downward causation is based on a novel fundamental interaction. See Section 4.6.3 for a thorough discussion of interaction-relative strong emergence.

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mental-to-mental downward causation determines how a large number of microintentions in the emergence base of a certain macroquale are simultaneously modified depending on the specific phenomenal character of the macroquale. If the emergence base is a neural pattern, then it is easily conceivable that the global information structure of this pattern is significantly changed by this kind of downward causation. Importantly, on my view, macrophenomenal powers are not structural properties, as in Mørch's (forthcoming) account, but purely quidditistic phenomena: macrophenomenal powers do not directly play a causal role in physical spacetime as structural properties would do; rather they merely specify how the microintentions of a macroquale’s emergence base are influenced given that the macroquale has such and such phenomenal character. In other words, since macroqualia do not ground structural causal powers, but phenomenal powers of the described sort, they must not have a phenomenal structure which renders them capable of realizing quantum-level structural properties. Hence, the structural mismatch problem does not arise. 7.4.4

The Model’s Inapplicability to Emergent Dualism

However, is not the solution to the pairing problem I developed for emergent Russellian panpsychism also open to emergent Russellian dualism? Let me stress that according to my analysis, it is not ontological emergence which is responsible for the unique pairing of downward causation to its micro-effects, but rather the extrinsic pairing relations of the two-layered structure of Russellian monism’s intrinsic dimension. It is therefore not the case that any emergentist position can secure unique pairing of downward causal efficacy: rather, only versions of emergentism which come with a comparable two-layered structure can solve the pairing and the fundamental interaction problem in the manner described. Hence, emergent Russellian dualism cannot solve these problems merely by using the tools of the emergence relation it invokes. However, even if so, cannot dualists assume that macroqualia emerge from microphysical emergence bases but interact with the constituents of the latter according to the model I provided? Why not assume that an idiosyncratic framework is created via the emergence process wherein the emergent macroquale is located such that no problem arises in matching effects in the emergence base with downward causal interventions by the macroquale? The problem with this proposal is that it is incompatible with dualism’s commitment to physicalism about the microrealm. Emergent dualism is the view that the microrealm is fully explicable in microphysical terms, yet the physical microrealm gives rise to ontologically emergent phenomenal properties (or even mental substances). One consequence is that dualism is compatible with dispositionalism about the microrealm. Even Russellian dualists can be dispositionalist about microphysical properties and hold that macroqualia are the only fundamental properties possessing a quidditistic nature (which is phenomenal). But if dualists adopt full-blown categoricalism about all fundamental properties, then they are committed to physicalist categoricalism about microphysical properties—otherwise their view would collapse into a version of Russellian monism. For nonphysicalist forms of categoricalism about microphysical properties are, by definition, variants of either panpsychism or panprotopsychism.

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Now, as I argued in Section 2.2, physicalist categoricalism involves what I called the nocausation-by-quiddities-qua-quiddities constraint: as I explained in this section, it is plausible to hold that physicalism involves the claim that the full metaphysical and causal story of the world can be accounted for in terms of the structural properties ideal microphysical theory invokes. And even if one does not adopt full-blown physicalism but only to physicalism about certain types of phenomena, as dualists do, one is still obliged to allow for a full explanation of the phenomena in question in narrowly microphysical terms. Moreover, this verdict receives additional justification from our above discussion of physicalist categoricalism, which clarified that physicalist quiddities as such do not have any positive characteristics. Yet without such positive characteristics, they cannot have causal powers (not even passive ones) qua their categorical essences. For their very having causal powers qua being quiddities would amount to possessing nontrivial positive quidditistic characteristics because their possession of those powers would qualify as such a positive characteristic. It follows therefore that dualists qua being physicalist categoricalists (or dispositionalists) about microphysical properties cannot allow that the categorical underpinnings of microphysical dispositions qua their quidditistic nature causally interact with macroqualia. Again, the reason is that if they participate in causal interactions qua their quidditistic nature, these interactions cannot be accounted for in microphysical terms because microphysics can merely study structural causal powers.127 7.5 Solving the Problem of Structural Fit Almost all variants of the combination problem do not arise for emergent Russellian panpsychism. More precisely, all arguments based on quality and subject combination are straightforwardly avoided by this position. Yet as we will see in what follows, the situation is different with regard to the structural mismatch problem: a modified version of that objection also applies to this view. 7.5.1

The Structural Mismatch Problem for Constitutive Russellian Panpsychism

Let me begin by briefly recapitulating the original structural mismatch problem for constitutive Russellian panpsychism as discussed in Section 6.7. Chalmers (2016) provides the most elaborate version of this argument; here is again his formulation: (1) If Russellian panpsychism is true, microphenomenal structure is isomorphic to microphysical structure. 127 Matters are a bit more complicated than is suggested in the main text. Emergent dualism, in fact, involves what one could call a physicalism+-account of the microrealm. For, as explained in Section 4.7.1, emergent dualism has to allow for micro-latent microdispositions of elementary particles such that they can act as emergence bases for macrophenomenality. In addition, interactionist dualism has to allow for a new funda mental interaction between macrophenomenal states and microentities. This also requires micro-latency. But micro-latent causal powers are not narrowly microphysical properties because they cannot be accounted for by microphysics. Therefore, emergent dualism cannot adopt full-blown physicalism about the microrealm, but rather must allow for these additional micropowers. Yet it is crucial to emergent dualism that these additional micropowers are the causal powers of structural properties. Again, if dualists take those dispositions to be powers which quiddities essentially have qua their categorical nature, then their view collapses into a version of Russellian monism. (Given that those categorical natures would have to be qualitative but nonphenomenal, emergent dualism would collapse into a version of emergent Russellian panprotopsychism.)

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Emergence in Panpsychism (2) If constitutive panpsychism is true, microphenomenal (and microphysical) structure constitutes macrophenomenal structure. (3) Microphysical structure constitutes only macrophysical structure. (4) If microphenomenal structure is isomorphic to microphysical structure, then any structure constituted by microphenomenal structure (and microphysical structure) is isomorphic to a structure constituted by microphysical structure. (5) Macrophenomenal structure is not isomorphic to macrophysical structure ______________ (6) Constitutive Russellian panpsychism is false. (Chalmers 2016: 206)

Before addressing available response strategies, let me note that the problem is slightly different for versions of panpsychism which allow for impure powers Russellianism:128 the existence of microintentions appears to make a difference with regard to this problem, since given impure powers Russellianism, we have no reason to assume that microphenomenal structure as such must be isomorphic to microphysical structure. Since on this view, microphysical structure is directly realized by microintentions, while microqualia merely act as stimuli for them, we should expect that only microintentions must bear mental structure mirroring microphysical structure. Yet the constitutive version of this view must allow that macrophenomenality is constituted by both microqualia and microintentions. Otherwise, there could be no inheritance of micromental causal powers, since microintentions bear the main share of the work of grounding microphysical causation. But if macrophenomenality inherits both structure isomorphic to microphysical structure and structure of an additional kind, then it must be at least partly isomorphic to macrophysical structure: that is, while it probably has surplus structure of a different kind (due to being partly constituted by microqualia), microqualia must also have structure mirroring macrophysical structure (due to being partly constituted by microintentions). However, it seems not to be the case that macrophenomenal structure is even partly isomorphic to microphysical structure; the structural mismatch problem therefore also arises for the impure powers version of constitutive Russellian panpsychism. With this clarification in mind, let us return to the question as to how the constitutive Russellian panpsychist can respond to this argument. As Chalmers (2016) points out, the most promising strategy is to deny premise (5). This can be done because there is not only one, but many different macrophysical structures in the brain. In this vein, Chalmers distinguishes between narrowly and broadly macrophysical structures. The former only comes in one version, namely macrostructure characterized in physical terms. By contrast, there is a great variety of broadly macrophysical structures. A given macrostructure qualifies as broadly macrophysical if it is derivable from microphysical structure. This, at least, encompasses all structures studied in the special sciences such as biological, chemical, or psychological structure.129 Given this understanding of macrophysical structure, it turns out that macrophenomenal structure is, in fact, isomorphic to one variant of broadly macrophysical structure, namely the structure of psychological awareness: as is captured by what Chalmers (1996) calls the principle of struc128 Recall that in Section 6.14, I argued that in order to avoid the structural exclusion problem, panpsychists have to adopt a version of impure powers Russellianism according to which microphysical dispositions are not merely grounded in microphenomenal properties, but rather in microphenomenal properties and microintentions. 129 Of course, this does not apply to strongly emergent phenomena in the special sciences if there are any.

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tural coherence, every macrophenomenal state has a corresponding psychological state of which our cognitive system is aware; that is, every phenomenal information of our conscious states corresponds to cognitive information available for verbal report and global control. This is entailed by a number of empirical data such as that we can report on the details of our phenomenal experiences. Yet, as we saw in Section 6.7, the principle of structural coherence is not of much help to constitutive Russellian panpsychism: if microphenomenal structure is (partly) isomorphic to microphysical structure, then the question arises as to why macrophenomenal structure which is directly constituted by microphenomenal structure is not (partly) isomorphic to the kind of macrophysical structure which is directly constituted by microphysical structure, namely narrowly macrophysical structure. Moreover, why instead is it fully isomorphic to one arbitrary variant of broadly macrophysical structure, namely psychological awareness? Recall that Goff (2017: section 8.2) points out that these questions can be satisfactorily answered if we assume that there are multiple types of macrophenomenal structure. On Goff’s view, for any variant of macrophysical structure both narrow and broad, there is a corresponding isomorphic type of macrophenomenal structure. If so, it comes as little surprise that there is also one type mirroring the structure of awareness. However, this explanation comes at considerable theoretical costs because it entails that there is a great number of different types of macrosubjects bearing different types of macrophenomenal states in my brain, of which I am only one. Nevertheless, the constitutive Russellian panpsychist does not have much in the way of alternatives as this seems to be the only solution open to this position. 7.5.2

The Problem of Structural Fit for Emergent Russellian Panpsychism

Now, a somewhat similar problem concerning macrophenomenal structure also arises for emergent Russellian panpsychism. Yet, here, the question is not as follows: why is macrophenomenal structure not isomorphic to narrowly macrophysical structure? There is no reason to suppose that is should be given that macrophenomenality is not grounded in microphenomenality. The question is rather as follows: why does the principle of structural coherence hold? That is, why is macrophenomenality structurally isomorphic to the structure of psychological awareness, and not to some other macrophysical structure? In other words, while constitutive Russellian panpsychism must explain why macrophenomenal structure is not isomorphic to narrowly macrophysical structure, the fact requiring explanation in emergent Russellian panpsychism is that macrophenomenal structure is not just sui generis, but rather isomorphic to one specific type of broadly macrophysical structure: the problem of structural mismatch is thus transformed into the problem of structural fit between macrophenomenal structure and the structure of psychological awareness. Isomorphism between macrophenomenal structure and the structure of awareness seems remarkable since the structure of awareness is just one of many distinct broadly macrophysical structures in the brain. Macrophenomenality could, in principle, be isomorphic to any of these macrophysical structures, or even have a completely idiosyncratic structure unrelated to any physical structure at all. One might argue that it is natural to assume that macroqualia have a structure mirroring the information structure of their neural correlates because the latter function as their emergence bases, and it is plausible that macroqualia inherit their phenomenal structure from their

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emergence bases. Hence, we should expect that macrophenomenal structure corresponds to psychological awareness. But this reply is unsatisfactory for familiar reasons: the neural correlates of macrophenomenal states exhibit all kinds of macrophysical information structures, only one of which corresponds to psychological awareness. However, as I shall argue in the following, in contrast to constitutive Russellian panpsychism, emergent Russellian panpsychism can indeed provide a straightforward solution to its problem of macrophenomenal structure not involving any highly implausible assumptions: since on emergent panpsychism, macrophenomenal states have strongly autonomous causal powers, an evolutionary explanation is open to this position. 7.5.3

An Evolutionary Explanation of Structural Fit

The idea is the following. First of all, it is plausible that in phenomenal emergence, the emergent product inherits some type of phenomenal structure from its emergence base; otherwise, we would not expect there to be a fit between macrophenomenal structure and any type of macrophysical structure: if macrophenomenality emerges from microphenomenal emergence bases, but does not inherit any type of phenomenal structure, then we would expect macrophenomenal structure to be completely idiosyncratic, having no similarity to any type of physical structure whatsoever. We therefore have good reason to assume that there is some kind of inheritance between micro- and macrophenomenal structure. It is therefore a plausible assumption that the emergence law governing the production of macroconsciousness involves a rule about how macrophenomenal structure is inherited from the microphenomenal structure of the emergence base. Furthermore, since the emergence law is a fundamental law of nature, this rule is presumably fairly simple. It directly applies to primitive microqualia, governing the process by which aspects of their collective phenomenal structure are inherited given that they constitute an emergence base. Note that it is crucial that what is inherited is not individual, but collective phenomenal structure. If the phenomenal structure of the individual constituents of an emergence base would be inherited, then the emergent macrosubject would have experiences with (partly) narrowly macrophysical structure. For, as discussed above, Russellian panpsychism entails that the experiences of microsubjects mirror the structure of microphysical dispositions. Hence, macrophenomenality must inherit some variant of the phenomenal structures resulting from the combination of individual microphenomenal structure. However, this does not explain the apparently amazing coincidence that in the case of higher animals, the inherited structure happens to mirror the structure of awareness. The emergence law looks suspiciously fine-tuned for generating just the right match between macrophenomenal and psychological structure in this very complex setting. Why should fundamental laws be such that a specific outcome for a highly complex application is built into them from the start? This smacks of intelligent design. Yet there is an easy way to avoid the assumption that there is such suspicious fine-tuning: suppose that some random simple rule for phenomenal structure inheritance; now, genetic mutations bring about all kinds of organisms coming with different types of emergence-engendering microstructures, and these microstructures, in turn, give rise to a variety of types of macrophenomenal structures depending on the specificities of our chosen rule of phenomenal

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structure inheritance. But then, it is plausible to assume that of these organisms, only those were able to survive in which, by chance, macrophenomenal structure happened to be isomorphic to the structure of awareness. For in all other types of organisms, macrophenomenal causation is based on the ‘wrong’ sort of information, leading to downward causal intervention which does not enhance, but rather diminish the prospects of survival and selection. If macrophenomenal structure is isomorphic to some type of macrophysical structure other than psychological awareness, then macroqualia do not possess the sort of information required for targeted influencing the global control of behavior. If, for instance, macrophenomenal structure mirrors chemical macrophysical structure, then phenomenal downward causation would target the wrong sort of macrophysical causal structures for modifying the behavior of the whole organism: if the macrosubject has subjective experience with a structure that is isomorphic to chemical processes in neural networks, then such experience does not qualify the macrosubject to influence the organism in any survival-enhancing way, for instance by interacting with the external world. To use an illustrative example, the subjective experience of seeing a lion in front of me makes me react in a survival-enhancing manner; yet a subjective experience with the phenomenal structure corresponding to the chemical information of the neural pattern that, in fact, emergence-causes the lion-seeing experience would not have made me react thusly. If so, then at an early stage of the biological evolution of higher organisms, only those organisms were selected which had the right sort of fit between macrophenomenal structure and the structure of psychological awareness. Of course, it is not clear whether very simple organisms also possess macroconsciousness, or only higher animals. Whatever is true, and at whatever stage of biological complexity macroconsciousness arises, beginning at this stage, biological evolution selected for viable types of macrophenomenality because only the types with the right sort of structural fit are survival-enhancing. One might object to this reasoning that an evolutionary explanation of phenomenal fit involves highly speculative claims about the empirical details of biological evolution. Is this not problematic, since it might clash with empirical findings? Yet these speculations will never be empirically falsifiable, because they concern macrophenomenal details, and their causal interventions with microstructure in organisms which is impossible to model, or to experimentally reconstruct. The evolutionary account for explaining macrophenomenal structure is therefore guaranteed to be empirically adequate—or, more precisely, adequate with the findings we are capable of gathering.130 Note that the problem of structural fit arises for all emergentist views of macroconsciousness, and therefore also for dualism. Interactionist versions of dualism can adopt the evolutionary solution I developed for emergent panpsychism because they allow for mental downward causation. Of course, these cannot assume that phenomenal structure is inherited because on their views, there is no microphenomenal structure from which the former could be inherited. Rather, dualists have to invoke an emergence law involving a rule about which macrophenomenal structure materializes, depending on certain microphysical specificities of 130 Note that this lack of empirical falsifiability does, to a certain extent, hold for all evolutionary theories about the development of a certain trait.

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the emergence base. But from here, their evolutionary explanation is analogous to that of emergent panpsychism. Epiphenomenal dualism, however, denies that macrophenomenal properties have causal powers. Therefore, the criterion of the survival-enhancement of downward causation for natural selection of types of macrophenomenal structure cannot be applied to the view. Hence, it runs into similar problems in explaining macrophenomenal structure as those of constitutive Russellian panpsychism: the fact that macrophenomenal structure mirrors psychological awareness appears to be an amazing coincidence. However, in contrast to constitutive panpsychism, epiphenomenal dualism can invoke an emergence law determining structural inheritance. Yet epiphenomenal dualism cannot avoid the fine-tuning problem discussed in the preceding paragraphs. Since (interactionist) emergent panpsychism can solve it, this position is also superior to constitutive panpsychism and epiphenomenal dualism in this respect.131 Excursus II: The Emergence Law Let me close my discussion of emergent Russellian panpsychism with a brief speculative excursus on what the emergence law of this position might look like, given our current empirical knowledge. As was noted in the Introduction, there is a leading neuroscientific theory of consciousness, the Integrated Information Theory (IIT), which implies a form of panpsychism. Since IIT arguably provides the currently most promising account of the physical correlates of consciousness, this theory might help us in narrowing down the character of the emergence law. However, in its official form, IIT is incompatible with Russellian panpsychism. Mørch (2018) has recently suggested two modifications to IIT for rendering the theory reconcilable with Russellian panpsychism. One of them is prima facie also applicable to my version of emergent Russellian panpsychism.132 In what follows, I discuss whether IIT in this modified form might provide us with criteria which systems must fulfill in order to qualify as emergence bases for macrophenomenality. I shall argue that a problem for such an integration of Mørch’s proposal into the framework of my position arises, yet I develop an alternative modi131 In their discussion of Chalmers’ (1996) version of epiphenomenal dualism, Hill & McLaughlin (1999: 450– 451) complain that on Chalmers’ view, the emergence laws must be extraordinary complex and very high in total number: for every phenomenal kind, there has to be a separate law governing its production. I consider this to be an unwarranted accusation: emergentists of all color need not to postulate more than one fundamental emergence law governing the production of macrophenomenality, and determining a general rule by which macrophenomenal states inherit a specific type of structure. However, in contrast to interventionists, epiphenomenalists have to assume that it is either an astonishing coincidence, or the result of some kind of deliberate fine-tuning that macrophenomenal structure happens to be isomorphic to the structure of psychological awareness. Furthermore, note that my evolutionary solution and my criticism of epiphenomenalism must not be confused with a very different evolutionary objection to epiphenomenal dualism, provided inter alia by Popper (1978), arguing that epiphenomenal qualia could not have evolved, since they are useless. As Jackson (1982: 133–134) rightly points out, consciousness must not itself be survival-enhancing in order to evolve, but could just as well be a by-product of the evolution of survival-enhancing traits. My critique is a different one: it concerns the point that given epiphenomenalism, it seems hard to explain why macrophenomenality happens to have phenomenal structure isomorphic to psychological awareness. 132 By contrast, Mørch's second modification, while also compatible with constitutive Russellian panpsychism, fits the fusion version of emergent Russellian panpsychism particularly well. It what follows, I shall ignore this proposal.

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fication of IIT which can avoid this problem. It is this latter interpretation of IIT which can be taken to (partly) characterize the emergence law of emergent Russellian panpsychism. I shall begin with a rough outline of IIT’s main assumptions. 133 IIT takes phenomenality to be correlated with (maxima of) integrated information, symbolized as Φ. Information is defined as the measure of the extent to which the immediate past and future states of a system are constrained by its internal causal structure: that is, information specifies to what extent past and future states of a system can be predicted given only knowledge of its present state, while holding external influences fixed. Integration is defined as the measure of the extent to which the information of a system results from the causal interconnection between its parts: that is, the amount of integration is the higher, the more information gets lost by cutting the system in two via its weakest causal link; thus, a feed-forward structure corresponds to low integration, while the existence of complex feedback loops entails high integration. IIT provides a mathematical apparatus for precisely measuring the exact amount of Φ for a given system. Now, IIT takes such systems within a complex object to possess consciousness that qualify as local maxima of integrated information (Φmax). Other systems in the object overlapping with the system possessing local Φmax (by sharing parts with it) do not possess consciousness, regardless whether those systems are on the same, a higher, or a lower ontological level; this includes the parts of the complex with Φmax, and also larger systems of which this complex is itself a part. Consciousness therefore ‘switches’ from one system to another when a complex with local Φmax becomes part of a system with even higher Φ (such that the former loses its status of having local Φmax): while the complex used to possess consciousness, once it is part of this larger system, it loses its consciousness, while the larger system gains consciousness. This is the so-called Exclusion postulate of IIT, specifying that only local maxima of integrated information possess consciousness. In comparison with other neuroscientific theories of consciousness, IIT has considerable advantages. It can elucidate formerly (simultaneously) inexplicable data such as why consciousness arises in the cerebral cortex, but not in the cerebellum, despite the fact that the latter possesses far more neurons, and why consciousness is absent during deep sleep, general anesthesia, and epileptic seizures, although neural activity is still intense during these mental episodes.134 Another important empirical validation of IIT concerns the callosal syndrome: IIT predicts that in split-brain cases, there exist several consciousnesses in a single brain resulting from several local maxima of Φ in the brain; the existence of multiple consciousnesses in such cases has indeed been experimentally confirmed. Moreover, since IIT invokes a very general criterion for entities to qualify as correlates of consciousness that is not restricted to features only neural patterns can possess, it implies a 133 My outline of IIT closely follows that of Mørch (2018: section 1). Note that the criteria I describe merely represent rough approximations of precisely defined quantifiable measures. For a detailed nontechnical introduction to IIT, see Tononi & Koch (2015). Oizumi et al. (2014) provide the latest version of the mathematical formulation of IIT. 134 Other theories of consciousness can merely explain some of those phenomena individually, but not all of them simultaneously, since they propose neural correlates which are either present in certain cases where consciousness is absent, or absent in specific cases where consciousness is present (or even both) (See Tononi & Koch 2015: section 3).

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form of panpsychism: an entity is a correlate of consciousness iff it possesses a local maximum of Φ, and also systems other than neural networks can have local Φmax. Indeed, even elementary particles such as protons and neurons qualify as systems coming with a small amount of Φ (since they consist of causally interconnected triads of quarks) such that IIT takes them to possess microconsciousness, provided they are not part of systems with higher Φ. By means of contrast, aggregates, ordinary objections, and even the artificial intelligence systems and computers we currently construct (since they are largely based on feed-forward information processing) do not possess amounts of Φ surpassing those of their microconstituents. Hence, IIT takes those systems not to possess higher-level consciousness. However, in its current form, IIT is incompatible with Russellian panpsychism for at least two reasons. First, from IIT’s definition of information, it follows that only complex systems can possess integrated information because only such systems have parts; but then, those elementary particles which appear to be simples such as electrons and quarks cannot be conscious. Second, and more importantly, IIT’s Exclusion postulate determines that lower-level systems lose their phenomenality when they become part of a superordinate system with higher Φ. But if microphenomenality functions as ultimate ground of microphysical properties, then there must be consciousness in elementary particles of the lowest ontological level at all times: that is, if microconsciousness is fundamental and grounds microphysical properties, then it seems not to be possible that phenomenality can ‘switch’ between different ontological levels. For quantum-level systems cannot lose their microphenomenality if this phenomenality functions as ground of their fundamental microphysical properties.135 Now, of the two potential modifications of IIT rendering the theory compatible with Russellian panpsychism which Mørch (2018) provides, one consists in modifying the Exclusion principle. It is this proposal which is particularly interesting for the purpose of specifying the emergence law in emergent Russellian panpsychism. Here is Mørch's revision of the Exclusion principle: Instead of saying that consciousness never overlaps, IIT could say that (1) consciousness never overlaps within the same spatiotemporal grain, and (2) there is consciousness only at grains with higher Φ than any grain below. This would entail that the brain, regarded as a coarse-grained system, will have overlapping consciousness at the finest, microphysical grain (as systems at the finest grain vacuously satisfy clause (2) given that there is no grain below). (Mørch 2018: 14; italics in original) 135 Mørch (2018) provides a somewhat different account of IIT’s incompatibility with Russellian panpsychism. Note that Mørch is not opposed to the concept of switchable phenomenality per se. Indeed, her alternative modification of IIT does allow for such switching (this is the reason why it is not compatible with my version of emergent panpsychism). Recall that Mørch's (2014) fusionist emergent panpsychism invokes the switching of fundamentality, and the problem I identified with the idea of switchable phenomenality stems from the fact that microphenomenality is fundamental. Thus, the objection I provided against the idea of switchable fundamentality is the deeper reason why I also oppose switchable phenomenality. By contrast, Mørch's fusionism seems perfectly compatible with the switchability of phenomenality; indeed it seems nat ural to assume that if microentities lose their status of being fundamental when fusing in order to produce a macrophenomenal entity, then they also lose their microphenomenality: while this is not part of Mørch's (2014) original conception of fusionism, it seems plausible that by becoming derivative, they also lose their microphenomenality, given that Russellian panpsychism takes microphenomenality to be a fundamental phenomenon.

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According to Mørch's modification, Exclusion is relativized to individual spatiotemporal grains, and consciousness arises at a certain grain iff there is higher Φ at this grain than at any lower grain (for the purpose of discussion, we can identify ‘spatiotemporal grain’ with ‘ontological level’): that is, given that a system at a certain ontological level has local Φmax, this system is conscious, and no other system of the same level overlapping with the former pos sesses consciousness; yet all entities on the lowest level, including partless elementary particles, can possess consciousness, since they vacuously fulfill the criterion that there is no lower ontological level with higher Φ. Moreover, as a result of relativizing Exclusion, there can also be systems at intermediate levels possessing consciousness, given that they have local Φmax with regard to all lower levels; that is, in quantifying Φmax, we only take into account the same level, and lower levels, but not higher levels: even if there is higher Φ at a higher level, this does not rule out that a system at a lower level might possess consciousness given it fulfills the named criterion. Hence, while the relativized Exclusion principle rules out ‘horizontal overlapping’ at one and the same ontological level, it allows for ‘vertical overlapping’: that is, a macroconscious system might have microconscious lower-level parts. While Mørch herself does not make use of her proposal in this particular way, her modification allows us to interpret IIT as narrowing down the character of the law which governs the production of macrophenomenality in emergent Russellian panpsychism. Recall that on my version of this position, elementary particles (realized by microsubjects) possess micro-latent microdispositions which given appropriate stimuli (of the sort described in Section 4.7), produce macrophenomenal properties; now, the stimulus for an emergence-engendering disposition is that the microsubject bearing this disposition is part of a system (at a certain ontological level) with higher Φ than any other overlapping system on the same level, or at a lower level. Let me explain this in more detail. We saw in Section 4.7 that the micro-latent microdis positions constituting emergence bases have pluralistic stimulus conditions: each of these dispositions is triggered iff its bearer combines with other microsubjects which, taken together, bear all other dispositions required for the instantiation of an emergence base. That is, due to their ordinary dispositions, multiple particles/microsubjects combine; this combination, in turn, serves as stimulus for the emergence-engendering dispositions which each of the particles/microsubjects bears. Hence, the stimulus condition for an emergence-engendering disposition is irreducibly pluralistic: it is triggered iff all other dispositions required for the instantiation of an emergence base are in place. Now, Mørch's proposal can be taken to specify the stimulus condition for emergence bases: emergence-engendering micro-latent microdispositions of elementary particles are triggered iff (1) those particles are elements in a system possessing local Φmax at the ontological level the system inhabits, and (2) the system’s amount of Φ is higher than the amount of Φ present in any lower-level systems it overlaps with. That is, the stimulus condition of an emergence-engendering disposition of a particle is the presence of other particles which are thus causally interconnected with the former particle and among each other so that the system they compose has so defined local Φmax. As a result, a macrophenomenal entity emerges that is annihilated once the system loses its so-defined Φmax.

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However, there is a problem with this account of emergence laws: the same micro-latent microdispositions might sustain two distinct macrophenomenal properties simultaneously if they are part of a system having local Φmax with regard to the same and lower levels, but another system they partake in is composed at a higher level possessing even higher Φ. Since on my account, ontological emergence is assumed to be a causal process, this seems problematic because one and the same cause seems incapable of producing two completely distinct effects simultaneously. Furthermore, Mørch's proposal appears quite gerrymandered, and too arbitrary and complicated in order to characterize a fundamental law: intuitively, fundamental laws should be fairly simple and straightforward; but then, it seems implausible that the emergence law would feature a clause, namely (2), which is only in place in order to be vacuously fulfilled by some phenomenon, namely microconsciousness. I think that there is an easy solution to this problem: given the framework of emergent Russellian panpsychism, IIT can be taken to not provide an account of the physical correlates of consciousness, but rather of the correlates of the emergence of macroconsciousness from microphenomenal emergence bases: that is, on this reading, IIT does not provide criteria for the instantiation of microconsciousness at all, but rather only for the conditions that have to be in place for the production of macroconsciousness. This modification seems to be compatible with the core empirical findings supporting the case for IIT: these findings exclusively concern data about the occurrence of macroconsciousness; we do not possess (and possibly never will possess) any empirical data about microconsciousness. Now, on my proposal, IIT is interpreted as providing the physical criteria which have to be in place for the instantiation of an emergence base for macroconsciousness: a macroqualia emerges iff there exists a system with local Φmax. On this proposal, the Exclusion postulate can be fully retained in its original form except for the fact that it only concerns macroconsciousness but not microconsciousness: if a complex with local Φmax becomes part of a superordinate system with even higher Φ (such that the former loses its status of having local Φmax), then it loses its consciousness, whereas the larger system gains consciousness. Hence, emergence-engendering dispositions do not have to sustain more than one distinct macrophenomenal state simultaneously. Furthermore, this proposal can qualify as putting forward a simple and elegant fundamental law: if elementary particles constitute a system with local Φmax, then they (due to their emergence-engendering dispositions) collectively produce and sustain a macroqualia (which, given the model of emergent panpsychism I provided in Section 7.4, qualifies as their collective intrinsic nature); and if those same particles happen to become part of a superordinate system with even higher Φ, then they (in companion with the other particles of the superordinate system) collectively produce a novel macroqualia instead of the former (which qualifies as the collective intrinsic nature of all those particles which compose the superordinate system). This sort of ‘switching’ of consciousness is compatible with Russellian panpsychism because it only concerns macroconsciousness: microphenomenality is never annihilated; hence, there is no problem of loss of the grounding bases of microphysical properties. Of course, the emergence law also has to specify how macrophenomenal character is inherited from a microphenomenal emergence base. Such phenomenal inheritance rules might be empirically inaccessible. Yet, arguably, something along the lines of the above sketch is

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currently our best empirically informed guess about the fundamental law governing the emergence of consciousness. Let me clarify that I am not suggesting that either IIT or my modification provides us with a correct theory of correlates of (macro)consciousness. My aim was merely to explore how the version of emergent panpsychism defended in this work might incorporate a currently promising account of the physical correlates of (macro)consciousness.

8

Re-Evaluating the Antiphysicalist Options

In this final chapter, I take stock and evaluate the options available to antiphysicalists in the light of the considerations provided in this work. While none of the available theories of phenomenal consciousness comes without severe shortcomings, of the two which appear most promising, emergent Russellian dualism and emergent Russellian panpsychism, the latter view seems overall clearly preferable. The main reason is that as I have argued in the last chapter, this position can achieve a better score in handling mental causation problems. However, there is another important issue mentioned only in passing thus far. Perhaps surprisingly, considerations of general theoretical elegance and parsimony might also speak in favor of panpsychism: by grounding microphysical dispositions in microqualia, Russellian panpsychism appears to be a promising antiphysicalist candidate for retaining a worldview as parsimonious as that of physicalism; that is, while physicalism grounds all concrete derivative phenomena in fundamentally microphysical entities, Russellian panpsychism might be capable of grounding everything in fundamentally mental entities. For in contrast to dualism, Russellian panpsychism appears merely to require one highest type, namely mentality. If so, this renders emergent Russellian panpsychism considerably more elegant than anything dualists might hope to achieve, arguably making it the best possible choice for antiphysicalists, also from an ontological point of view. However, fundamental physics invokes not only dispositions, but also spatiotemporal properties. Yet while it seems that microphysical dispositions can, indeed, be accounted for by the Russellian strategy, it is not obvious whether spatiotemporal properties also allow for such treatment. But only if it can be demonstrated that these properties are grounded in microphenomenality might panpsychism qualify as being more parsimonious than dualism. I shall argue that there are, indeed, good prospects for a Russellian account of spatiotemporal properties, albeit the details remain to be worked out: building on recent considerations from Chalmers (2019), I argue that the cosmopsychist variant of emergent Russellian panpsychism seems especially promising in this regard. I proceed as follows. In Section 8.1, I summarize what I take to be emergent Russellian panpsychism’s best options for solving the problems of mental causation. I also recapitulate my take on other crucial obstacles, such as the counterintuitiveness of microphenomenality. In Section 8.2, I consider whether and under which conditions this position might allow for a purely monistic worldview. 8.1 Mental Causation and Phenomenal Emergence As we have seen in Chapter 5, constitutive Russellian panpsychism can claim a clear advantage over dualism: by grounding macroconsciousness in microphenomenal entities which also realize microphysical dispositions, this variant of panpsychism can avoid the sundry problems of mental causation to which dualism is subject. Yet panpsychism’s advantage over dualism is no longer so obvious once it is acknowledged that the view must allow for phenomenal emer-

© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2020 F. Klinge, Panpsychism and the Emergence of Consciousness, https://doi.org/10.1007/978-3-662-62258-2_8

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gence: by invoking irreducible downward causation, emergent Russellian panpsychism is subject to the very same problems of mental causation by which dualism is threatened. I have argued in Chapter 7 that, nonetheless, emergent Russellian panpsychism is preferable to dualism, since the former view possesses considerable advantages in handling these problems. 8.1.1

Microphenomenality and the Metaphysics of Dispositions

Before reviewing the mental causation problems, let me begin with panpsychism’s major disadvantage in comparison to dualism, namely the counterintuitiveness of the existence of microphenomenality. While this strikes many as an utterly incredible postulation, I argued in Section 5.3 that it has considerable virtues when it comes to well-known dilemmas in the metaphysics of fundamental dispositional properties: Russellian panpsychism and Russellian panprotopsychism are the only views that can avoid both the power-swapping objection to categoricalism, and the circularity argument against dispositionalism: while Russellian monism is a version of categoricalism, it is not subject to the former objection since it invokes fundamental properties with qualitative essential characteristics.136 By contrast, on pains of not collapsing into Russellian monism, dualism is committed to non-Russellianism in respect to the microrealm. Hence, the dualist can either adopt dispositionalism, categoricalism, or a mixed view about microphysical properties: if she opts for dispositionalism, then her view is subject to the circularity objection; if she adopts categoricalism, then it falls prey to the power-swapping objection; and if she chooses the mixed view, then her account cannot avoid power-swapping with regard to those properties possessing categorical natures. 8.1.2

The Pairing and the Fundamental Interaction Problems

When it comes to problems of mental causation, as we have seen in Section 7.4, emergent Russellian panpsychism can avoid the pairing problem due to the phenomenal architecture of Russellian panpsychism: unique external pairing relations can be provided between macroand microphenomenality rooted in the two-layered structure of the intrinsic dimensions for which this form of panpsychism allows. Moreover, the two-layered structure of Russellian panpsychism’s intrinsic dimensions allows for a genuine type of pluralistic downward causation rendering macrophenomenal properties capable of influencing myriads of microsubjects in their emergence bases simultaneously, thus avoiding the fundamental interaction problem. In Section 5.4, I argued that dualists have three different options for replying to the pairing problem: adopting causal singularism, allowing for individualized laws, or invoking Russellianism about macroqualia. Causal singularism entails antireductionism about causation, thereby rendering dualism incompatible with the majority of the most promising theories of causation. Individualized laws seem rather strange and, in addition, might come at the cost of an explosion of individualized dispositions of elementary particles. The prima facie most promising option, Russellianism in respect to macroqualia, renders dualism subject to the fun136 Note that this is also the case for the version of impure powers Russellian panpsychism which I defended in Section 6.14 as a solution to the structural exclusion problem: this position only involves dispositional essentialism about some micromental properties; it is therefore a version of the mixed view (invoking both primitive micromental dispositions and microphenomenal quiddities), thus avoiding the circularity objection which merely targets pure dispositionalism.

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damental interaction problem: that is, Russellian dualism can merely allow for the ‘wrong’ sort of downward causation, rendering macroqualia capable of causing local quantum-level effects, but incapable of influencing the global information structure of large neural patterns. The first two options thus come at considerable theoretical costs, while the third appears completely untenable. However, one might object that the particular version of emergent Russellian panpsychism which I defended in Chapter 7 might run into similar problems as dualism’s second strategy for avoiding the pairing problem. The reason is the following: I argued that the only tenable version of emergent panpsychism is a version of impure powers Russellianism invoking primitive micromental dispositions because only this version can avoid both the causal exclusion problem and the structural exclusion objection. Now, one might worry that the commitment to primitive microdispositions entails a primitivist theory of causation. For impure powers Russellianism is a version of the mixed view about fundamental dispositions, involving dispositional essentialism about some fundamental properties, and it is widely believed among powers theorists that dispositional essentialism entails a powers theory of causation. The idea is that if fundamental properties are essentially dispositional, then this entails a dispositionalist theory of causation, according to which causation is accounted for in terms of primitive dispositions, or powers. Furthermore, since ‘powers’ is itself a (partly) causal notion, powers theories of causation are nonreductive.137 But if so, impure powers Russellianism runs into similar problems as those encountered by dualists such as Audi (2011) who adopt causal singularism in order to avoid the pairing problem: both views are committed to some form of primitivism about causation, and are therefore incompatible with most of the leading accounts of causation. Against the thesis that dispositional essentialism entails a nonreductive powers theory of causation, Bird (2013) compellingly argues that there is no direct connection between one’s view about fundamental dispositional properties, and one’s analysis of causation: the debate between categoricalists, dispositionalists, and proponents of mixed views about the nature of the dispositions we encounter in fundamental physics is a debate in fundamental metaphysics: it concerns the question as to what the nature of (some of) the fundamental entities of the world might be. The debate over the correct analysis of causation, in contrast, is a debate in nonfundamental metaphysics: it concerns questions such as whether necessary and sufficient conditions can be provided for the presence of causal relations between certain entities, and if so, what these conditions might be. However, while it seems plausible to distinguish between projects in fundamental and nonfundamental metaphysics, it may seem strange in this particular case that there is no direct connection between both projects. For, as seen in Chapter 5, the various theories of fundamental dispositional properties come with distinct accounts of fundamental laws, yet laws play a crucial role in most accounts of causation. But, as Bird demonstrates using the examples of Lewis’ counterfactual analysis of causation, there is no principled incompatibility between a particular approach to laws and any theory of causation. Due to the clarity of Bird’s 137 See, in particular, Molnar (2003) and Mumford & Anjum (2011) for the view that dispositional essentialism entails a nonreductive powers account of causation.

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presentation, I shall quote him at length (note that Bird uses ‘powers’ to denote primitive fundamental dispositions as invoked by dispositional essentialism): Lewis analyses causation in terms of the ancestral of the relationship of counterfactual dependence. We may then ask for an analysis of counterfactuals, and Lewis provides this in terms of possible worlds and their closeness. Laws of nature play a significant role in determining the closeness of possible worlds. So causation does depend on laws in Lewis’s scheme, but not in such a way that allows for an analysis of ‘A causes B’ in terms of any particular laws. […] There is a question of fundamental metaphysics and ontology: What features does the world possess that are responsible for the fact that there are causal relations? which powers can help answer, albeit in a very limited way. Powers are the principal elements of the world that are responsible for the existence of laws of nature and causation. This question and answer must be distinguished from a different question and its answer: Is there any true an informative substitute for Φ in ‘necessarily, Φ if and only if A causes B’? The latter is a project in non-fundamental metaphysics. It concerns not the fundamental level but a higher level of existence—causal relations are everyday, ‘macro’ phenomena. […] [W]e can pull apart [Lewis’] answer to the first, in terms of the existence of regularities in the Humean mosaic, from his answer to the second, in terms of counterfactuals. […] [O]ne can consistently accept his analysis of causation but reject his Humean ontology. (Bird 2013: 36–37) Given Bird’s important clarifications of the limits of the liabilities one takes on when accepting a certain view in the metaphysics of fundamental dispositions, the version of emergent panpsychism which I defended in Chapter 7 does not commit me to any particular view about causation. The situation is different for Audi (2011): his response to the pairing problem is based upon taking psychophysical causal relations to be primitive. But if those causal relations are primitive, then ex hypothesis any reductive analysis of causation fails. For if Audi is right, then sufficient and necessary conditions cannot possibly be provided for psychophysical causal relations in noncausal terms. Thus, rejecting the need of an external pairing relation, as Audi does, renders dualism incompatible with reductive accounts of causation. 8.1.3

The Causal Exclusion Problem

In Section 7.3, I argued that my version of impure powers Russellianism is not subject to the causal exclusion problem inasmuch as it can accept both of its premises and, nonetheless, allow for mental downward causation: the specific type of mental-to-mental downward causation for which this view allows manages to influence microphysical causal chains without violating either Completeness, or No Overdetermination. I believe that this gives emergent panpsychism considerable advantage over dualism, because it is not possible to formulate a version of the causal exclusion argument against emergent panpsychism which is not question-begging: all such arguments would have to resort to the strong principle of microphysical causal closure, which outright denies the possibility of mental downward causation.

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8.2 The Prospects of Panpsychist Idealism Besides considerations about mental causation and phenomenal emergence, there is an ontological reason why emergent Russellian panpsychism might be an attractive option for antiphysicalists: in contrast to dualism, Russellian panpsychism seems to possess good prospects in qualifying as a monistic worldview. If so, then this variant of panpsychism represents a version of idealism, given that idealism is understood as the doctrine that all concrete facts are either fundamentally mental, or grounded in fundamentally mental facts. More precisely, panpsychist positions of this form are versions of realist idealism. The notion of idealism is often interpreted in a narrower sense as a form of anti-realism, according to which certain aspects of human mentality ground everything: a prime example of anti-realist idealism is Berkeleyan phenomenalism, which takes external reality to be grounded in subjective appearances of human (and/or divine) persons. In contrast to anti-realist idealism, realist idealism does not assume that it is appearances which ground all concrete facts, but rather the relations and structures of phenomenal states: this is prototypically the case in those forms of Russellian panpsychism on which phenomenal states realize all microphysical properties. Chalmers (2019) calls such views pure panpsychism. As we saw at the end of Section 5.3.1, not all versions of panpsychism are pure: in or der to qualify as panpsychism, a position is merely committed to the thesis that at least some fundamental physical properties are mentally realized. Accordingly, there are versions of Russellian panpsychism which hold that only the categorical underpinnings of some microphysical dispositions are microphenomenal, while those of others are not: for instance, a panpsychist might assume that the type of quiddity realizing charge is an experience, while the type realizing spin is not. However, only the sort of full-blown realist idealism for which pure panpsychism allows can rightfully claim to provide a monistic worldview comparable in parsimony to the physicalist worldview.138 By contrast, impure panpsychism is, to a certain extent, a dualistic doctrine allowing for both fundamentally mental and fundamentally physical entities: in contrast to standard versions of dualism, impure panpsychism is a form of dualism-all-the-way-down, invoking both fundamentally physical and fundamentally mental properties on the lowest ontological level. However, it is not obvious that panpsychism can, in fact, manage to comply with strict monistic requirements. While microphysical dispositional properties do indeed appear to be microphenomenally realizable, utilizing some version of the Russellian strategy, it is not clear whether this is also the case for other fundamental physical properties. In particular, spatiotemporal properties and relations might resist a Russellian treatment. Indeed, a crucial question presently only insufficiently addressed in the literature is as to whether and, if so, how the Russellian strategy might be applied to spatiotemporal properties. 138 Note that my usage of ‘monism’ in this chapter is different from its usage in ‘priority monism’: while monism in the latter sense concerns the number of basic token entities (and claims that there is only one fundamental token entity), monism in the sense I use in this chapter concerns the number of highest type of en tities: this is the usage which is common in the philosophy of mind, where dualism is the view that there are two highest types of entities (mentality and matter), and monism claims that there is just one highest type, which is then either matter (as physicalism and materialism assume), mentality (as pure panpsychism and other forms of idealism assume), or something which is neither mental nor material (as pure panprotopsychism assumes). See Schaffer (2018: section 1) on the different usages of ‘monism’.

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It can be argued that with regard to spatiotemporal properties, pure Russellian panpsychism is prima facie in a similar position to that of dispositionalism: if it can be demonstrated that spatiotemporal properties are dispositions, then both positions can account for them, albeit in differing ways; while the dispositionalist can rest content with such an analysis, the panpsychist can take it as a preliminary step for a straightforward Russellian analysis of spatiotemporality: if spatiotemporal properties are dispositions, then, analogously to the case of dispositions like charge and spin, the panpsychist can assume that they possess microphenomenal properties as categoricalist underpinnings. We saw in Section 5.3.1 that Bird (2007a: chapter 7) argues that General Relativity is compatible with a dispositional view of spatiotemporal properties: mass and spacetime are ‘causal partners’ which play the roles of stimulus and manifestation for each other. While Bird’s discussion remains preliminary, a dispositionalist interpretation of General Relativity along these lines might, indeed, be possible. If so, then the prospects of pure Russellian panpsychism appear to be good. Yet, to my knowledge, an elaborated dispositional theory of spatiotemporal properties and relations has not been provided as of yet. We thus currently do not know whether something akin to Bird’s idea is indeed tenable. However, even if the dispositionalist theory of spatiotemporal properties and relations is sound, another problem arises from the fact that there are spatiotemporal relations holding between distinct fundamental particles. According to Russellian panpsychism, microsubjects are the grounds of individual elementary particles; hence, these spatiotemporal relations do not hold within individual microsubjects, but rather between distinct microsubjects. But then, even if those relations have a dispositional nature, then it is hard to see how they can be grounded in microphenomenal properties borne by microsubjects: genuine relations between distinct microsubjects appear not to be reducible to monadic microqualia possessed by those microsubjects. In answer to his problem, the panpsychist might try to reductively explain spatiotemporal relations in terms of phenomenal relations between distinct microsubjects. But it seems hard to find appropriate experiential relations which can plausibly be taken to realize spatiotemporal relations. Chalmers (2019) discusses a number of potential candidates, none of which appears considerably promising: One familiar relation is the relationship of co-consciousness—but this holds between the experiences of a subject and it is not at all easy to see how it extends to a between-subjects relation. Others include the relationship of empathy, or of mental perception between subjects’ perceiving each others’ mental states, or of joint attention. (Chalmers 2019) Yet, as Chalmers points out, the named phenomenal relations seem to be reducible to monadic mental properties of individual subjects, and thus inappropriate to the task of grounding spatiotemporal relation between distinct subjects. Moreover, a general problem for this approach is that all fundamental phenomenal features appear to be monadic properties borne by single subjects. Experiential relations, by contrast, are derivative on such monadic phenomenal properties. Yet, in order to function as ultimate grounds for spatiotemporal rela-

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tions, those experiential relations would need to be both fundamental, and to hold between distinct subjects. Of course, the panpsychist could just postulate relational quiddities custom-fitted to ground spatiotemporal relations. But then, the question arises how those relational quiddities might qualify as genuinely phenomenal given that they cannot be traced back to any familiar experiential relation. Moreover, since they do not hold within the phenomenal architecture of an individual subject, but rather between distinct subjects, there does not seem to be any plausible candidate subject which could function as the bearer of such relations; yet if those relational quiddities are not borne by a single subject, then they can hardy qualify as phenomenal relations, given that part of the core creed of panpsychism is that experiences require experiencers. Hence, such relational quiddities appear to smuggle in a nonphenomenal, noumenal element into panpsychism, depriving the position of its purity and, thus, its status as a form of idealism.139 Yet there is a more promising strategy for providing a Russellian analysis of spatiotemporal properties: if the panpsychist adopts cosmopsychism rather than micropsychism, she has at her disposal an overarching subject which encompasses the whole of spacetime such that spatiotemporal properties can be grounded in cosmophenomenal properties borne by the cosmic subject. This can be done in one of two ways: cosmopsychism can be combined with either a substantivalist or relationalist view of spacetime. On substantivalism, spacetime regions are prior to spatiotemporal relations which are grounded in the internal structure of those regions. Note that substantivalism as a general doctrine is neutral with regard to the question whether the whole of spacetime is prior to smaller regions, or the other way around. Substantivalism comes, therefore, in a priority monist version, as well as in priority pluralist variants.140 On substantivalist cosmopsychism, however, it is most plausible that the whole of spacetime is prior to its part, since cosmopsychism is a form of priority monism, and on the substantivalist version of cosmopsychism, the whole of spacetime is grounded in cosmic phenomenality. In Section 6.10, we saw that on the most plausible version of cosmopsychism, all properties of the universe are grounded by subsumption in an overarching distributional property borne by the cosmic subject. On the idealist form of this view, this distributional property is purely mental. In order to derive a Russellian account of spatiotemporal properties from this view, the cosmopsychist must demonstrate that spacetime is grounded in the internal structure of this distributional property. According to the relationalist view of spacetime, spatiotemporal relations are metaphysically prior to spacetime regions and the whole of spacetime. For the relationalist version of cosmopsychism, the challenge remains of finding appropriate phenomenal relations for grounding spatiotemporal relations. But as Chalmers explains, […] it is much easier to find experiential relations in the mind of a single subject than between subjects. For example, there are relations of co-consciousness, phenomenal feature binding, relative distribution in a sensory field, and so on. One 139 As discussed in Section 6.4, noumenal relational quiddities realizing spatiotemporal relations are also invoked by Goff’s (2016) phenomenal bonding solution to the subject combination problem, with the difference that on Goff’s account, they also play the role of partially grounding macrophenomenality. 140 See Schaffer (2009b) for an argument for the priority monist version of substantivalism.

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Re-Evaluating the Antiphysicalist Options could even imagine that spacetime as a whole is realized by complex spatiotemporal experiences of a single cosmic subject. There are still many questions to answer (for example, concerning how relativistic phenomena could be realized experientially), but the principled obstacle seems significantly smaller. (Chalmers 2019)

Moreover, if the dispositionalist account of spatiotemporal properties is tenable, then it seems especially natural to invoke microphenomenal categorical grounds for them. For if spatiotemporal properties and relations have dispositional profiles, then Russellian cosmopsychism qua categoricalism is required to equip them with quidditistic underpinnings of some sort, and those underpinnings might then very well be phenomenal. Furthermore, since on this view, spatiotemporal properties play causal roles, it can be avoided that those phenomenal quiddities have to be taken to be epiphenomenal; by contrast, if spatiotemporal properties do not possess dispositional profiles, then their categorical grounds must be epiphenomenal. It can therefore be argued that if dispositionalism about spatiotemporal properties and relations is tenable, then relationalist cosmopsychism is preferable to substantivalist cosmopsychist because only the former can fully avoid epiphenomenalism about the phenomenal grounds of spatiotemporal relations and properties. Both the substantivalist and the relationalist options for cashing out spatiotemporality within cosmopsychism appear promising prima facie, but further research is needed to determine whether one of these approaches is, indeed, tenable.141 Yet if so, then emergent Russellian panpsychism can be combined with a cosmopsychist account of fundamental physical properties as follows. All fundamental physical properties, both microphysical dispositions and spatiotemporal relations, are ultimately grounded in cosmophenomenality. Moreover, as we saw in Section 6.10, cosmopsychism entails the existence microphenomenality for principled reasons. But then, cosmopsychism can easily allow for microphenomenal emergence bases producing ontologically emergent macrophenomenal entities according to the model I provided in Chapter 7. Thus, the only difference to the micropsychist version of emergent panpsychism that was implicitly assumed so far is that microphenomenality is itself not strictly fundamental, but rather grounded in cosmophenomenality. Again, this move has the benefit that it might allow for a Russellian treatment of spatiotemporality, and thus allow emergent Russellian panpsychism to qualify as form of realist idealism. Of course, further research is needed to decide if this proposal is tenable. Let me conclude by emphasizing once again that providing a Russellian account of spatiotemporal properties is a core desideratum for proponents of all variants of panpsychism, be it constitutive or emergent panpsychism. Only in its pure form as variant of realist idealism can panpsychism fulfill its full potential, and provide a truly monistic view of the world; otherwise, panpsychism remains a variant of dualism-all-the-way-down, allowing for both fundamentally physical and fundamentally mental properties on the lowest ontological level. There is another reason why the question whether pure panpsychism is tenable is of considerable interest to the antiphysicalist project. We saw in Chapters 5 and 7 that there is cur rently no clear empirical evidence either for or against the thesis that the microphysical realm 141 Goff (2017: chapters 9 & 10) discusses (and tentatively endorses) the substantivalist version of cosmopsychism, but, while he puts forward some interesting ideas, he does not offer a detailed account of how spacetime is grounded in cosmic phenomenality.

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is causally closed. Yet future scientists might very well find irrefutable evidence for microphysical causal closure. If so, then interventionist variants of emergentist positions on the mind-body problem can be ruled out, since downward causation is impossible. In light of the considerations of Chapter 6 demonstrating that phenomenal constitution is untenable, the antiphysicalist is then forced to choose between epiphenomenal dualism and epiphenomenal emergent Russellian panpsychism. But then, with problems of mental causation becoming irrelevant, considerations regarding parsimony and elegance become even more crucial. Although emergent Russellian panpsychism’s advantage as a theory of dispositions might also play a role, I think that only if it can be demonstrated that this position qualifies as a version of idealism, might one convincingly argue that we should prefer epiphenomenal emergent panpsychism to epiphenomenal dualism.

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