Thomas Aquinas: God and Explanations 9781474470742

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THOMAS AQUINAS

THOMAS AQUINAS God and Explanations

C. F. J. Martin

Edinburgh University Press

© C. F. ]. Martin, 1997

Edinburgh University Press 22 George Square, Edinburgh Typeset in Monotype Ehrhardt by Westkey Ltd, Falmouth, and printed and bound in Great Britain by CPI Antony Rowe, Eastbourne A CIP record for this book is available from the British Library

ISBN 10 0 7486 0901 6 ISBN 13 978 0 7486 0901 7 The right of C. F. ]. Martin to be identified as author of this work has been asserted in accordance with the Copyright, Designs and Patent Act (1988).

CONTENTS

Introductory Preface Acknowledgements Copyright Permissions

1. The Summa Theologiae as a Summary of a Divine Science

Vll XV111 XX

1

2. The Nature of Science in Medieval Thought

15

3. The Role of Questions in the Articulation of Science

32

4. The Signification of a Name

37

5. The Notion of Existence Used in Answering an est?

50

6. Demonstrating the Existence of a Cause from its Effect

80

7. The Existence of God as a Scientific Question

97

8. 'Does God Exist? Apparently Not'

110

9. The First Way

132

10. The Second Way

146

11. The Third Way

155

12. The Fourth Way

171

13. The Fifth Way

179

Select Bibliography

207

Index

209

INTRODUCTORY PREFACE 1

Like many other people, I have tended in the past to skip prefaces and introductions. I have always felt that if an author puts something he wishes to say to me outside the body of his book, then I am under no obligation to read it. This is ridiculous, of course, since I am under no obligation to read any of the book at all. But my experience suggests that this ridiculous attitude of mine is fairly common. Let me make a plea: do not skip this preface unless you are sure you want to. What I have to say now cannot properly form a part of what I have to say in the book, but I am sure that it needs saying. I only hope my readers will be sufficiently warned by this first paragraph that if they do skip the reading of it they may fail to understand the book. Worse, if they skip the preface they may find themselves reading something they do not like, or leaving aside something they would like. Since the days in which I was an undergraduate a change of nomenclature has been spreading over the teaching and the writing of philosophy in Britain. When I was young, all those who taught or learnt in philosophy departments were considered to be philosophers, in some sense, and to be doing philosophy. It was out offashion at the time to try to do philosophy entirely out of one's own head, and I approved and approve of this modest fashion. Since not everyone can manage to do everything, and since tastes differ, what philosophers principally read to support the efforts of their own minds varied. Some read principally Kant; others, principally the empiricists. Some, the kind I liked best, read principally the ancients, and a very few read the medievals, as I have done since those early days in philosophy. Others, meanwhile, were working in more restricted but more rapidly moving fields, and read principally their contemporaries. Each choice was respected by the others, at least to the extent that those who chose to do their philosophy one way recognised the right of others to choose to do philosophy another way. All were willing to concede to the others the right to claim that they were trying to do philosophy, even though they may have thought that those others were not going the best

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way about it. All were more or less aware of the restrictions and advantages of their own choice, and of those of others. (Usually, of course, they were more aware of the advantages of their own choice, and of the disadvantages of the choices of the others, but that is natural.) It was a fairly free and relaxed world, in my recollection of it, and no-one would refuse to cite a contemporary author in support of his or her view of an ancient text, or refuse to cite an ancient author in support of a step in a contemporary debate. We were all philosophers. But between ten and fifteen years ago I began to find that a new name was being given to the kind of studies I was interested in: searching for the wisdom with which to answer problems people have had all through the ages, problems apparently inseparable from the great problem ofbeing a human being, in the writings of those who had been dead for more than seven hundred years. My interests were now being called 'the history of philosophy'. I felt at the time that the name was inappropriate. It is a matter offact that in almost any schedule of examinations for undergraduates there will be some papers which are to be answered principally by reading material written by people still alive or not long dead, and some papers which are to be answered principally by reading material written by those long dead. It seems to me natural that the latter should be called 'historical' papers, though there might be another half-dozen labels at least as natural. But to call them studies in the 'history of philosophy' seemed, and seems, misleading to me. There is a discipline, or set of disciplines, called 'science'; and there is a separate discipline called the 'history of science'. There is 'art', and there is the 'history of art', quite separate; and there is 'music', and there is the 'history of music', also quite separate. While it is hard for people who know no music to study the history of music, it does not seem to me impossible. But I would claim that it is impossible for those who know no 'philosophy' to study the 'history of philosophy'. (I would also be inclined to make the stronger claim that those who study 'philosophy' and care little for the 'history of philosophy' will remain with a severely limited understanding of 'philosophy', but I do not intend to press this claim at once.) The label, which implies that 'history of philosophy' is not philosophy, seems to be at best misleading. Perhaps I should have said 'I would have made one or other of these claims' for as I found my own studies labelled the 'history of philosophy', inaccurately enough, I began to notice the growth of a subject which could also be called the 'history of philosophy' with a good deal more accuracy, a subject of considerably less interest to me. I found myself increasingly subjected, at conferences and in reading journals, to productions which seemed to me to be lacking in any philosophical

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interest, except incidentally. These productions showed a breadth and a depth of erudition that I could not aspire to: I do not have the necessary patience or eye for detail. But these admirable qualities seemed to be directed indiscriminately to any object, provided that it was within the scope of what people would now or would once have called 'philosophy'. A case in point was the loving care directed to the reading, recovery and elucidation of hitherto wholly neglected medieval texts which dealt with the medieval logic exercise of oppositiones. Listening to or reading these papers I noticed that either the medieval authors or their contemporary commentators were incapable of distinguishing between suggestions for winning strategies and proposals to improve the rules of the game. It seemed clear to me that no logical insight was to be derived from the studies of these texts, and so I neglected them. I was allowed to: I was lucky. A colleague of mine wrote a introductory book on medieval logic, in which he confined himself to those authors and texts which, in his (generous) view could afford valuable logical insights. A distinguished historian of logic said in print that this book should be consigned to the flames. This, besides being a highly offensive thing to say to a Jew, as my colleague is, implies to anyone familiar with the writings ofHume that the book contains nothing but 'deceit and sophistry'. Strong attitudes indeed. I, and those who thought like me, found ourselves in danger of falling between two stools, the only two stools currently permitted. On the one hand was the stool of'philosophy' which means developing some currently fashionable topic, in however detailed or trivial a way, basing oneself solely on material published within the last few years- or, since the advent of e-mail and the Internet, to be published within the next year or so. On the other hand was the 'history of philosophy', whose exponents seemed to be pure scholars, caring little or nothing for philosophical importance, or even logical importance, but only for the erudition of digging up the past- not, I fear, to learn from it anything that might be of value to anyone today who is exercised by that wonder which is traditionally said to be the origin of philosophy. The case of the history of logic is particularly interesting. It may be objected, perhaps fairly, that I seem to want to go back to a dilettante age, now fortunately superseded, of elegant gentlemen reading the classics for their own improvement. I have no objection to elegance, though I am not elegant, and no objection, other than political and economic, to gentlemen, though I am not a gentleman, and I certainly have no objection to people, of any class or level of elegance, reading anything with the desire, however far-fetched, of 'self-improvement', of making themselves better people. I certainly wish to improve myself, in many senses of the word, and I think

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that reading classic authors, in a broad acceptance of that word, may come to be a way of self-improvement. This criticism passes me by. If the alternatives suggested to me seemed of more value to myself, my friends or to society, then I might consider them. If another Ruskin came to ask me to help build a road to Hinksey village, I might join in. But I cannot see any reason to suppose that to devote myself to what is now called 'philosophy' or what is now called the 'history of philosophy' would contribute in any way to the improvement of myself, to the improvement of anyone else, to the well-being of Hinksey villagers, or even to the innocent gaiety of nations. A more serious criticism would be the following: these gentlemen you seem to admire lacked sufficient grasp of historical perspective. The problems dealt with in, say, the Middle Ages, were not the problems we face today, and the concepts they employed in their answers were not our concepts. We cannot learn from them, because we do not live in their world. One cannot learn to live well from Aristotle's theory of excellence, say, because that theory was developed in a wholly different social and political context from our own; and the same objections apply to Aristotle's medieval heirs. Their world is not our world, our faith is not theirs, and they are in any case as likely to have misunderstood Aristotle as much as your beloved elegant gentlemen did, or as the dons of the early twentieth century did when they insisted on translating Plato's polis as 'state'. Any differences between what Plato said of the polis and what they would be inclined to say about the state could be attributed to a mistake on Plato's part. Collingwood famously pointed out that this was about as sensible as translating Plato's word trieres, a trireme, as 'steamer', and then drawing attention to the odd ideas the Greeks had about steamers. I do not think this criticism is valid. First, I do at least claim to share, for example, a great deal of the faith of Aquinas, and thus I am convinced that it is not impossible for me to share a great many of his concepts, his problems and his answers to these problems. Moreover, I nevertheless live among my contemporaries, and though I strongly differ from them in all kinds of mental and moral attitudes, I have little difficulty in understanding them, and little more difficulty in making myself (at last) understood. This last claim, of an asymmetry between my understanding of my contemporaries and their understanding of me, is not, I think, arrogance: it is merely recognising my position as a member of a religious or conceptual minority. The average intelligent Jew or Muslim in Britain understands far more about Christianity than the average intelligent Christian understands about Judaism or Islam, and all three

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understand more about secular practical atheism that the average intelligent person in this country understands about monotheistic revealed religion. So in a case where the facts are little in dispute I think I can make good my claim that understanding of an alien way of thought, and learning from it, is not impossible. The case of the history oflogic comes in pat, strongly on the same side. There is no more possibility of denying that logic has made great strides over the last 120 years than there is of denying the similar progress made by aeronautical theory and engineering. (The remembrance of Wittgenstein leads me to put these two examples together.) No logician in the English-speaking world would deny it, and very few would even refuse to use the very expressions I have used. There does exist a set of undeniable logical principles and propositions, which are better known and better understood than they were in Kant's time, for example. No-one with sufficient knowledge would deny that this set was better known and better understood in, say, Aquinas's or Mair's day than they were in Descartes' day. Thus some writings of medieval philosophers and logicians do have a pure abstract logical interest (while other medieval writings, such as those on oppositiones, just like the logical writings of the period between Descartes and Boole, say, do not), and it would be sensible for a logician of the present day, were he or she skilled enough, to consult them. This is, I think, undeniable. And what is true oflogic, is true of other branches of philosophy, though the investigations in these other branches must be carried out with more caution. There really is a set of unchangeably true propositions about, for instance, the relationship between our language and our world. Any human performance of which these propositions did not hold we would not be able to recognise as a language at all. In the same way, there are propositions about our world and about ourselves whose truth we cannot deny, while continuing to live in the same linguistic world as our fellows. That we all must die, that we need to eat, be covered, enjoy ourselves, that we need company and some kind of friendship, that we are animals and have some compulsion to reproduce, none of these can be denied. That we are compelled to look for explanations, and go beyond the intellectual skills which suffice to adapt us to our environment, are also true. That we are puzzled by change and time, by the structure of our world, and that many people have an urge to look for an explanation, not of this or that phenomenon but of the world as a whole, all these are true. They were true in distant ages as well, and though it may seem possible to deny that the thoughts of people of distant ages may

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be of value to us, this denial is no more respectable than is the idea that foreigners are intrinsically funny. I am not arguing for the existence of'perennial problems' in the sense that our perhaps trivial and transient concerns and methods of investigation can be projected back on to the writers of the past. I have recently published a book in which I argue that such a performance is a mistake. But it is a mistake because it limits our chances of learning from those who have gone before us. If we make this mistake, like the dons satirised by Collingwood, we will look only for the answers to our current problems and have our eyes closed to the perhaps greater problems the ancients or the medievals might have shown us. We may even have our eyes closed to all but the sort of answer we might have been inclined to look for in the first place. At the very lowest level, to go to older writers to look for answers to current problems only will close our eyes to the fact that these writers had their silly and trivial current problems as well, and we will not be able to make the comparison and see many of our own problems as silly and trivial. To read former writers in such a spirit is not what I recommend. But I do protest against the abandonment of any attempt to go back to former writers to learn from them, an abandonment which is implied in the current opposition between 'philosophy' and 'the history of philosophy'. I know I am not alone in this protest and that many better writers have said what I am trying to say. Among the most popular are Martha Nussbaum and Alasdair Macintyre; I think it is not a coincidence that their works are read by people who would not dream of reading anything written in what is now called 'philosophy' or 'the history of philosophy'. But, apart from my lack of talent compared with these two authors, and with many others, I face further difficulties. I am writing on medieval philosophy, which was not accepted as serious or real philosophy when I was an undergraduate, as ancient philosophy was. If I were writing on Aristotle I should face a less difficult task: the task of bringing back something that existed and flourished in the English-speaking world as recently as twenty years ago and which is still practised by some. I have a far harder task. It is noticeable that the vogue for Macintyre has fallen off considerably since he started talking more about the Middle Ages than about the ancients or about the Enlightenment, and still worse, started talking about God. The task I am attempting in this work is that of 'analytical Thomism'. The recently published Oxford Companion to Philosophy tells us that this is a broad philosophical approach that brings into mutual relationship the styles and preoccupations of recent English-speaking philosophy

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and the concepts and concerns shared by Aquinas and his followers. This approach bears some relation to that of those post-war Oxford philosophers, e.g. Austin and Ryle, who sought to reintroduce certain concepts into the analysis of thought and action, such as those of capacities and dispositions, which are prominent within Aristotelian philosophy. In the case of analytical Thomists the primary areas of interest have been intentionality, action, virtue theory, philosophical anthropology, causation, and essentialism. The expression 'analytical Thomism' is rarely employed but it usefully identifies aspects of the writings of philosophers such as Anscom be, Donagan, Geach, Grisez, Kenny and Macintyre. There is pretty clearly no room for analytical Thomism either within 'philosophy' or 'history of philosophy'. It is noticeable that most of the writers mentioned above are of an older generation and achieved a position before this division became accepted or, in some cases, are people of immense and outstanding talent, or are even regarded by 'philosophers' and 'historians of philosophy' alike as marginal, as mere journalists or dilettantes. I have not achieved my position, I am not a person of immense talent, and so I must be content for my work to be marginalised, or to be regarded as a journalist or a dilettante. But having stated what this book is to be - analytical Thomism, neither 'philosophy' nor 'history of philosophy', but the best attempt I can make at what I consider to be philosophy - I can at least avoid those critics who will accuse me of blundering. It is not that I am trying to do both 'philosophy' and 'history of philosophy' in one book, foolishly and, of course, failing. I reject both notions - and I am trying to do something different. I am looking at how Aquinas discusses the question of whether there is an explanation for the world, distinct from itself, and the question of how the search for an explanation in general should proceed. I try to relate the two discussions and I hope that there will be material of interest and value for people who like to read Aquinas, or who like to speculate on the existence of God, or on the nature of the search for explanations. This is a modest aim, and I think I have in part achieved what I set out to do. It is for the critic to discuss how far I have succeeded, or how far what I sought to do is worth achieving. It is not for the critic to jump to the unreasoned conclusion that this work cannot be of any value because it is neither 'philosophy' nor the 'history of philosophy'. If a piece of work has value, it has it independently of current fashions of academic classification. This may sound an excessively arrogant claim, but I conceive that the tyranny of this division between 'philosophy' and 'history of philosophy', and the consequent persecution of those who do not choose to do either,

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has reached a point at which arrogant or harsh reactions are justified. I feel that in present circumstances I have some right to be harsh. It has happened that a tenured lecturer at a British university, an analytical Thomist, and thus neither a 'philosopher' nor a 'historian of philosophy', has found his freedom of association, his freedom of research and his freedom of teaching threatened or actually restricted, at least in part because he was neither a 'philosopher' nor a 'historian of philosophy'. He was driven into illness, depression and resigning his post, with long-term unemployment to look forward to. The matter is thus not of purely academic importance and thus justifies non-academic language in reacting to it. My proposal in writing this book, despite all my fears for the future in Britain of what I still think of as philosophy, is a modest one and a strictly scholarly or educative one: it is to communicate my understanding of St Thomas. This understanding, such as it is, is one which involves connexions and parallels. Perhaps this is true of any kind of understanding: we can only understand in relation to what is familiar to us. What is familiar to me is the English-speaking analytical style of philosophy. Thus the book is directed to those who share this familiarity and wish to extend their philosophical knowledge into other periods and ways of thought. I do not mean to claim that we are limited in our understanding to what, in the writings of another period, finds a direct echo in our own times. It is true that at times we will bump up against ideas which cannot be immediately understood in contemporary terms, or in anything obviously related to these terms. Thank God for that - otherwise we would be shut within an intellectual prison formed by temporal provincialism of outlook. I believe that it is, at least sometimes, possible to make the imaginative leap necessary to get some kind of understanding of what at first seems absolutely alien. But once the leap has been made, if understanding is achieved, this understanding can be, as it were, justified retrospectively. And this retrospective justification consists, to a great extent, in arguing through from the familiar to the imaginatively grasped unfamiliar, and so discovering that the apparently alien can indeed be understood in terms of some analogical extension of the concepts and even prejudices we began with. I offer this understanding, such as it is, in the first place to those who are likely to understand even less than I do: that is, to those who have been reading medieval philosophy for less time than I have. It would be, I think, something of an impertinence for me to offer it to my equals, and still more to offer it to my betters. If my equals or betters happen to find by some chance something in this book that helps their understanding, I shall

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be very pleased and rather surprised. It is meant to be of use to students with some grasp of the usual concepts of analytical philosophy and some slight understanding of medieval philosophy. The whole is supposed to be of value to those interested in the philosophy of St Thomas; the first half may also be of interest to those concerned with the philosophy of science, while the second half concerns what is called the philosophy of religion. (Perhaps I may be permitted to object to this label as well. There is clearly a philosophy of religion, as there is a philosophy of art, and as there ought to be a philosophy devoted to any important human activity. But a philosophical study of the existence and nature of God is not a study of religion or of any human activity. Religion and the philosophical study of God have little in common except their object, God.) The particular object of this study are the Five Ways in which St Thomas offers to prove the existence of God, considered in the context of his theory of science. I do not think that the Five Ways have been properly studied in this context before, but to try to do this is a very natural move. 'Does God exist?' is, for St Thomas, a scientific question; indeed, it is the first substantive question of the new divine science he is seeking to establish. This can be thought of as a science that is Augustinian in project and content, Aristotelian in structure and concept. 2 In the context of such a science, what kind of a question is 'does God exist?' How do we answer such questions? What kind of understanding of the word 'God' is required for us even to start? What notion of existence is involved in giving answers to this question, and how does this notion relate to other notions of existence? How does a question like 'Does God exist?', and the methods used in answering it, relate to other similar questions in other sciences? How do they relate to the sorts of scientific questions we ask and the methods we prefer to use in answering them? Do we in fact, in our scientific endeavour, ever ask such questions as 'Does X exist?' How do all these considerations apply in the special case of God? To what extent do the Five Ways follow the methods of science which I will claim to find outlined in St Thomas's works? What kind of arguments are the Five Ways? How are they structured? How well do they work? In essence, this book is what I have been teaching students in the part dedicated to Aquinas in the medieval philosophy optional course in Glasgow over recent years. Those students have professed themselves happy with what I offered them, but there is always the feeling at the back of one's mind that one's own students are a captive audience. I put this work before the wider public in the hope that others will find it useful and thus, as it were, retrospectively justify my classroom practices over recent years.

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Some readers may be annoyed by the rhetorical, frivolous, and wouldbe amusing nature of some parts of the book. 3 They may ask, is this rhetorical style worthy of philosophy? Well, the performance I actually achieve probably will not, as it stands, be worthy of St Thomas, but I should like to record my view that the idea that rhetoric and philosophy are mutually exclusive is an error. StThomas's own technical clarity and brevity is a mode of rhetoric, and they contribute admirably to his philosophy. His style, his rhetoric, is one of the features that makes him a greater man than either Scotus or Ockham. Many philosophers are great in spite of their style, but many others are great both in style and content. Wittgenstein springs to mind, but he is not the only one. It is probably in part the lucidity of Russell's style - i.e. his rhetoric - which helps us to appreciate him (justly) as a much greater philosopher than, say, Moore or Ayer. That may not be quite the point which critics may wish to make against the rhetoric I try to employ here. They will probably be irritated by the fact that I make fun of elements in the empiricist tradition and of important figures in the development of that tradition. The reason why I do this is that people in the empiricist tradition themselves make free use of the weapon of ridicule and it seems to me time that they got a dose of their own medicine. It is the commonest thing in the world for empiricist lecturers so to train their students that they giggle whenever they hear the word 'essence', or trot out the ancient joke about 'virtus dormitiva' 4 whenever they hear talk of powers. This, I fear, is either ignorance or dishonesty. The lecturers in question probably know that some of the greatest philosophical minds have based their thought about the world on the concepts of essence or of power, and if they pretend that anyone who does so is eo ipso a suitable target for ridicule, they are being dishonest. If they do not know that some of the greatest philosophical minds upheld the concepts of essence and power, then they are so ignorant that I wonder what they are doing in a university at all. To teach young people to laugh at things which you dislike and which you know they don't understand is to my mind not the noblest possible work of an educator. Empiricist lecturers, who may very well not understand the concepts of essence and power themselves, can be sure that their students don't, because they will have taken very good care never to explain them, but only to present a caricature. If my opponents can laugh at me, can I not laugh at my opponents? Particularly since, thank God, I am in a minority. I need not fear that I am teaching my students to laugh at something they do not understand, which has never been presented properly to them; I know that however

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little care I take to present empiricist attitudes to them, however caricatured the picture of empiricism I present, my esteemed colleagues will make sure that my students do not remain in ignorance of the best case that can be made for empiricism. I admit, indeed, that I hope to use the weapon of artificially provoked giggles, but my aim is that by so doing we may come to an agreement to end its use once and for all. While only one side uses such a weapon, it will continue to be used. When both sides use it, when some of my colleagues find half their classes breaking out in uncontrollable mocking laughter whenever they hear the words 'constant conjunction', we may be able to reach a truce. Clearly, artificially provoked giggles on both sides are valueless in a philosophical discussion, and once we have reached a state where both sides are suffering from their use we can then perhaps agree to drop them and concentrate on the real points of debate. But while they are used only on one side, the side which uses them will be more successful and will, moreover, be convinced that it is winning the debate. So, curiously enough, those colleagues who may feel that I am using unfair weapons are in fact the object of my dearest concern. I fear that they have become so accustomed to using unfair weapons that they do not recognise them as unfair and valueless. My use of unfair weapons may wake them up to this fact, and they will then be able to stop using them. All being well, everyone will benefit from the process. NOTES 1. I have never properly understood the difference between an introduction and a preface. As far as I can make out, an introduction attempts to explain the oddities of the book, while a preface attempts to explain the oddities of the author. If this is correct, then 'introductory preface' is a good title for this section, in which the oddities of both are exposed, if not explained, pell-mell. 2. A fully developed account of this view of St Thomas's thought can be found in A. Macintyre, Whose Justice? Which Rationality? (London: Duckworth, 1988) and Three Rival Versions ofMoral Enquiry (London: Duckworth, 1990). 3. If you dislike this sort of thing, take a look at the last chapter, where the tone is about as frivolous as I can manage. If you can't bear it, then invest your time and money elsewhere. 4. For this venerable joke, see Chapter 13, pp. 188-90.

ACKNOWLEDGEMENTS

The help I have had in this work from innumerable people, none of whom is in any way responsible for any errors of fact, of argument or of taste that the book may contain, would be impossible to catalogue. My philosophical debt to Professor Geach and Professor Anscombe is immense, as any reader will notice, and I have done my best to make this clear in my notes and citations; but there is much that I owe them which cannot be acknowledged in that kind of detail. The first chapter, obviously, also owes a lot to the work of Alasdair Macintyre. I should like to mention my colleague from Glasgow, Professor Alexander Broadie, and two colleagues from Pamplona, Professor Alejandro Llano (especially for his getting me started on the theme of esse ut verum, being in the sense of the true: see Chapter 5, p. 66 n. 37) and Dr Jaime Nubiola. I also owe a good deal to innumerable students in both places, as well as in Mexico and in Rome, for whose sake and with whom I have been working on this theme. Three of these students stand out as having helped me particularly to clarify my thoughts: Niall Taylor, Craig Russell and Dr Maria Alvarez. I also owe a good deal to the authorities of the University of Glasgow, particularly my Head of Department, Ephraim Borowski, for granting me one term's paid leave after six years' service in the university and a longer period of unpaid study leave thereafter. As is perhaps well known, no-one in Glasgow has any technical right to any study leave at all. Without these leaves the book would not have been written. I wrote this book during this period of leave, a time when I was ill, depressed and distressed. The work I have done would have been wholly impossible, and not just uncongenial and difficult, without the help and kindness of many people. It is beyond my ability to thank them adequately. In the first place are my father and mother, who both died between the completion of the first draft and the reading of the proofs. I owe too an incalculable amount to my very dear friend and colleague Alexander Broadie, already mentioned, to Scott Meikle, also of the Glasgow department, and to Dr John Divers of the University of Leeds. In addition I

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should like to thank, however inadequately, my friend, colleague and former student Eileen Reid, whose kindness and generosity to me in these difficult times was so great, and to which I never managed to respond in an appropriate way. I have to thank the people I have been living with over this period, for their forbearance: the residents of Dunreath Study Centre in Glasgow, the residents ofGrandpont House, Oxford, and the residents ofResidencia Universitaria Monreal in Pamplona. The help I have received from all the members of the sub-faculty of philosophy in the University ofN avarre has been immense. In Oxford I owe thanks to Corpus Christi College for offering me common-room rights during my stay. Among other people in Pamplona I wish to thank Andrew and Ruth Breeze for their kind hospitality, and I am especially grateful to Ruth for providing just the right degree of affectionate nagging to get me started and keep me moving on the bulk of the book. The material for this book was partly developed in and through classes and seminars I gave in the University of Navarre, as well as in the University of Glasgow, and the bulk of the book was written in Pamplona, where the University of Navarre is located. The book, if it has any merit, is thus yet another result of the magnificent relations which have been established between the philosophy departments in the two universities. These relations are mostly the fruit of the efforts of Professor Broadie. Perhaps no-one will expect this book to be very good, written as it is by a sick and perhaps embittered man. It is as good as I can make it and, as I have said, I have had many wise and good friends who have helped me make it better than it might have been. That the good is theirs and the bad is mine should be clearer even than it usually is in these cases.

COPYRIGHT PERMISSIONS

Some of the material published here, as part of a larger and more important project, has previously been published elsewhere, when I thought it had sufficient importance on its own to interest the learned public. Material used in Chapter 1, dealing with the argument from authority, has appeared in my Introduction to Medieval Philosophy (Edinburgh: Edinburgh University Press, 1996) and in A. J. Hegarty (ed.), The Past and the Present: Problems of Understanding (Grandpont Papers No. 1, Oxford, 1993). Material used in Chapters 2 and 3 has appeared in K. Jacobi (ed. ), 'Rules for demonstration and rules for answering questions in Aquinas', Argumentationstheorie: Scholastische Forschungen zu den logischen und semantischen Regeln korrekten Folgerns (Leiden: E. J. Brill, 1993). Material used in Chapter 4 has appeared in I. Angellelli and A. D'Ors (eds), 'Significatio nominis in Aquinas', Estudios de !a historia de !a L6gica (Pamplona: Ediciones Eunate, 1990). Material used in Chapter 13 has appeared in 'Libertad y revocabilidad', Anuario Filos6fico, 1994/5, and is about to appear in a collection of Thomistic Papers edited by J. Haldane, under the title 'Voluntary and non-voluntary causality'. I am grateful for permission to re-use this material here.

1 • THE SUMMA THEOLOGIAE AS A SUMMARY OF A DIVINE SCIENCE

The Summa Theologiae, Aquinas's uncompleted master-work, is, according to its title, a summary of the study of God. This study of God - theologia -Aquinas himself usually called 'sacra doctrina', sacred teaching, or 'sacra sci entia', sacred science. What these titles mean, and why such a study is necessary and opportune, is spelt out by Aquinas in the twelve articles of the first question of the Summa. The study of sacred teaching is necessary, he concludes, it is authentically a 'science', in the Aristotelian sense, it is a single science and it is a speculative science, though it has practical implications. It is superior to any other science, it is a kind of wisdom and it has God as its object. Like other sciences it proceeds by way of argumentation, and it depends on a correct interpretation of God's selfrevelation in Scripture. The first substantive question, which follows the methodological articles outlined above, is whether God exists, a question which is prefaced by a discussion of whether the existence of God is self-evident and whether it can be proved at all. Once these preliminary questions are settled, though, the first genuinely substantive discussion is, as I say, whether God exists. Is this a philosophical question at all? If so, why does it come here, at the beginning of a summary of theology, of the science of God, studied in and through God's own self-revelation? We need to answer these questions if we are to be confident that there is any interest of what we would call a philosophical kind in studying Aquinas on this point. To answer them we have to understand what Aquinas meant by a science. Aristotle defined 'episteme', the kind of knowledge that Latin Aristotelians called 'scientia', as 'definite knowledge through explanations'. 1 There is no doubt that St Thomas thought of this definition as correct, and that he used it out of respect for Aristotle's authority. 2 Both expressions just used are important here. Aquinas thought of this definition as correct, and he used it out of respect for Aristotle's authority.

2

God and Explanations

Before we begin to examine what the definition implies for the study of Aquinas's Summa, and for the philosophical nature of the examination of the existence of God, we need to see how authority and truth were related in StThomas's mind. For there can be little doubt that this feature of St Thomas's work is one which is extremely alien to the minds of present-day philosophers. Even though, as we shall see, St Thomas undoubtedly thought of the existence of God as what we would call a philosophical question- briefly, a question that can be answered correctly by the natural light of human reason alone, without recourse to the content of God's self-revelation he does not think it at all odd to appeal to the authority of the Bible putatively God's word -in answering it. 'Is there a God?' asks Aquinas and answers 'Apparently not'. He gives the two strongest arguments he can find for believing that there is no God, and then proceeds to explain why this appearance - that there is no God - is deceptive. The process is, as he calls it, argumentative. The arguments he gives against the position he is eventually to take up are the strongest he can find: this is his usual practice. In this case the arguments given continue to be the two most cogent arguments available. But he nevertheless appeals to authority: after giving the arguments against, the objections, as they are known, he at once begins his own response by quoting Scripture. There is a God, he says, because God's own name, as revealed by God, is 'I am who am'. 3 Aquinas was aware that someone who does not believe in God will scarcely be impressed by an alleged revelation. In his earlier summary, the Summa Contra Gentes, designed for the use of missionaries among Muslims, he draws attention to the hopelessness of trying to use against Muslims Scriptures that Muslims will not accept. 4 Muslims, to be sure, believed in God then as they do now; and while it is, I believe, a matter of some dispute among Muslim doctors about whether Christians really believe in the one true God or not, Christian doctors, like St Thomas, normally have no difficulty in concluding that Muslims believe in the Christian God, though they combine it with what a Christian regards as an over-simple view of God's internal life. (Christians, according to Muslims, hold what must be either nonsensical or blasphemous beliefs about a Trinity within God. To what extent these beliefs mean that the Christians are deceiving themselves when they claim to believe in the one God of Abraham and the Prophets is, I think, a disputed question among Muslim theologians.) Was it that StThomas, though acquainted with Muslims, did not know of the existence of atheists? Surely not. He knew enough history of ancient philosophy to refer to the Epicureans, and they held that there were no

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gods, or that if there were, they were only a part of the system of randomly generated worlds of which we also form a part.; He knew, surely, of the various philosophers and sophists labelled by their contemporaries as 'godless' (atheoi). He knew of the existence of the Emperor Frederick II Hohenstaufen- after all, he put to death at least one of Aquinas's family -who was alleged to be an atheist. 6 One who lived so much among the young would not have been more ignorant than was Adelard of Bath, whose young nephew, about a century before Aquinas's birth, told him that many of his contemporaries held that there was no God, or that God was identical with nature. 7 Above all, if I may myself use an argument from authority, Aquinas believed in what he read in the Bible, and in the Book of Psalms it twice says 'The fool has said in his heart, there is no God'- a text, incidentally, quoted by StThomas within the same question as the Five Ways. 8 Thus we can be sure that Aquinas knew that his use of an argument from authority would fail to convince in arguing against an atheist, and that there were such people as atheists. Why, then, does he use this argument? 9 The simplest answer is, perhaps, that he always uses such arguments: they are an indispensable part of his argumentative procedure, his way of handling a question. Medieval learning in the universities at this period proceeded by way of the quaestio, the 'question' in a technical sense, that is the discussion for and against a given thesis. This might appear as a real debate, which might or might not be recorded and published, with more or less editorial input; or it might just mean the use of the quaestio-form in a published work. The latter is what we have in the Summa. In either case the question was announced and arguments for and against either side were put. In a live debate, these would be suggested by the students, and the master's assistant (the bachelor) would marshal them into some kind of order- sometimes, for example, playing off one against anotherand present them to the master. In a composed work in quaestio form the master would do this, more briefly, for himself. The master would then give his 'determination' - his magisterial solution - and then deal with whatever objections to his answer had not already been resolved. The form of the live debate was followed in a streamlined way in works composed in this form. In such a work, like the Summa, the more streamlined questions are at some remove from this process, though not wholly detached from it. But in either case, in a live debate or in a question-based textbook, there was always an appeal to authority, an authoritative text given at the outset of the 'determination', to support the line the master had decided to take.

4

God and Explanations

Clearly this way of proceeding is very foreign to our way of doing philosophy. While even today a typical article in a philosophy journal will contain a high proportion of footnotes that give references, the texts are seldom, it is claimed, being used in an authoritative way. They are typically, or notionally, being used to show that a given author did indeed hold the view that is being ascribed to him, or because the author cited has expressed a point better than the author citing can hope to do. Or at least, this is what we hold. And there seems little doubt that the medievals did not use authorities in this way. It is clear that the medievals took the fact that Aristotle said so-and-so to be a good reason for believing that so-and-so is the case. We do not believe this, or profess that we do not. All contemporary philosophers would at least say that they refuse to accept such an 'argument from authority'. Indeed, one sometimes comes across cases of contemporary authors in philosophy who are inclined to reject a thesis simply because it was said by some older philosopher who has been highly regarded by others. This last attitude is perhaps abnormal and should be dealt with by psychological rather than philosophical or historical investigation, but the existence of such an attitude highlights the contrast between the modern and the medieval. Given that we at least believe that we do not appeal to authorities in the way that medieval thinkers did, how should we react to their texts? There are two obvious ways of reacting, which I should wish to reject. The first is that of people like Bertrand Russell, who held that the use of the argument from authority shows that the medievals were not doing philosophy at all- or, more modestly, that the medievals were not doing what we call philosophy. This kind of reaction is unfortunate, since one who reacts in this way is unlikely to bother to read the medieval philosophers and is thus unlikely to be able to learn anything from them. Another reaction is more intelligent, and less disastrous, but it still in the long run shows a failure of understanding. This is the reaction of those who are not put off by the use of the argument from authority and read on in the medieval philosophers. Those who do so soon discover that besides these, to us, unacceptable arguments from authority, there are other arguments which are, by our standards, very good indeed. This may lead them to read further, to become interested in medieval philosophy for the modern-style arguments that they can find in it; and they will thus become accustomed to skip the frequent arguments from authority, or to regard them as being of merely historical interest, as indicating the sources of the writer. In short, they will read the medieval writer as if he were a modern. This is a mistake. It is to fail to grasp what is distinctive in the medieval author. Read in this way, the medieval author will not be able to tell us

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anything very different from what a modern author would tell us, so we might as well read a modern author. We will not have our eyes opened by the shock of discovering a radically different way of thinking. Above all, we will not really have understood the authors we are studying. The modern who reacts in this way can find some justification even within medieval writings. It is often said that the most important parts of a conceptual framework are those that are never discussed, but taken for granted; but we are fortunate in that there were discussions among the medieval philosophers about the use of arguments from authority, despite the fact that arguments from authority formed an important part of their conceptual framework. The reason for these discussions is not that medieval thinkers had any doubts about the value of authority in general, it is rather that arguments from authority had different values when the authority they were based on was a human authority, and when the authority they were based on was divine. Hence we find these discussions, one of which, perhaps the best known and most accessible, is to be found early on in Aquinas's Summa Theologiae, in the methodological first • 10 questwn. Aquinas says that the argument from a divine authority is the strongest argument of all, while the argument from a human authority is the weakest of all. This conclusion would be supported by most other medieval thinkers. The reason for this distinction is that human minds, even when honestly applied, are quite often mistaken and sometimes may be applied dishonestly, while God cannot be mistaken, cannot be deceived and cannot deceive. Hence 'Aristotle says such-and-such' is obviously of much less weight than 'God says such-and-such'. There are complications, of course. There is the question of the interpretation of the authority: what exactly did Aristotle mean when he said that such-and-such was the case? Every statement needs to be interpreted in the correct way and this means, in practice, that it is rarely necessary to contradict an authority. Perhaps the text of Aristotle seems to say clearly that there are no centaurs, but even if you had seen a centaur, you need not say that Aristotle was wrong. You might argue that Aristotle meant something slightly different from the obvious sense of his words. No-one would be likely to worry about such a trivial case, of course, but the possibility always existed. This made it possible to blur in practice the important theoretical distinction which has been referred to, between the different strengths of divine and human authority. You could never straightforwardly contradict a thesis with divine authority behind it- that, the medievals considered, would have been unreasonable. (And given their premisses, they were surely right.) The argument from divine

6

God and Explanations

authority was stronger than any other. But what was the correct interpretation of the statements made with divine authority? The answer to that question would commonly rest on human authority: the usual or obvious interpretation of Scripture had been made by some human being at some time. It might typically derive from St Augustine. But the argument from Augustine's authority, that this interpretation is in fact the correct interpretation of Scripture, is an argument from human authority. Thus, for example, the Bible tells us that King Solomon made a large round vessel for the Temple, a vessel which measured ten cubits across and thirty cubits round.u The natural interpretation of this passage implies that 1t, the ratio between the diameter of a circle and its circumference, is three. Probably no figure respected as an authority by the medievals ever upheld this natural interpretation - certainly Augustine would not have done so. 12 But if any had upheld this interpretation, the human authority of that writer, which was an argument in favour of this interpretation, no matter how great his authority might be, would have been vulnerable to stronger arguments drawn from the science of geometry. The medievals knew that 1t is not three, and so would have claimed that the natural, literal interpretation of God's authoritative statement must in this case be rejected, despite any argument from human authority in favour of that interpretation. The interpretation of this passage in the Bible must be such that we take it to be giving only rough measurements. The argument from God's authority is the strongest of all: it is invulnerable to any other argument. But the argument from the human authority, which might be brought in favour of the literal interpretation, is the weakest of all arguments: it is vulnerable to any other argument, let alone one as strong as a proof of geometry. It is thus possible for the modern reader to justify his ignoring arguments from authority when he finds them in medieval writers on the grounds that the medievals did not take them very seriously either. The argument from human authority is, even to the medieval reader, the weakest of all; are modern philosophical readers of the medievals not justified in regarding this argument as being so weak as to be negligible? Moreover, modern philosophers probably do not believe in God, or even if they do, they may have very different ideas about what God may be supposed to have said, and how he said it, from the ideas the medievals had. Are modern philosophers not then entitled to believe that what the medievals thought of as the voice of God was in fact a merely human voice, the voice oflsaiah or St Paul? Are they not accordingly entitled to treat it as a human authority, the weakest argument, which modern philosophers regard as negligible?

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This is a fair point, but there is a feature of Aquinas's discussion that should cast doubt over this typically modern reaction. When discussing the thesis that the argument from human authority is the weakest of all arguments, Aquinas cites the human authority ofBoethius in its support. 13 This should make us think. The argument from human authority, for Aquinas, though weak, is not negligible, as he is willing to cite it even in support of the weakness of arguments from human authority. We can sum up the difference between the medieval and modern attitudes to authority as follows. For the moderns the voice of authority is no argument at all; for the medievals it was an argument. Admittedly it was the weakest argument of all, so that any other argument was stronger, but it was none the less an argument. You needed another argument to refute it, before you could ignore it. The moderns think they can just ignore it without any other argument. For the medievals, if Aristotle said that centaurs did not exist, and you had no stronger reason for believing that centaurs did exist- for example, the evidence of your own senses - then you had good reason for believing that centaurs did not exist. There was an authoritative statement, so the question 'Do centaurs exist?' was not purely an open one. Since an authority had spoken on the subject, the burden of proof and the form of the question were established. It is therefore a mistake for modern readers to understand the medieval position, that the argument from authority is the weakest of all, as a polite under-statement of their own position, that the argument from authority is no argument at all. This is not what the medievals meant: they meant what they said, that the argument from authority was an argument, even though any other form of argument was stronger. The medieval attitude to authority, then, was different from ours. Do we just have to accept this as a brute fact, or can we come to have some imaginative grasp of what it meant to have this different attitude? Can we even come to understand it, to see that it is at least not totally unreasonable or superstitious, as some modern philosophers might tend to regard it? The best way to go about this task of understanding, I think, is to try to see how our own attitude to authority is itself not self-evidently correct, but stands in need of an explanation, an explanation which is rather hard to find. I think that this self-examination - this instilling into the reader of the philosophy of the past a feeling of strangeness about his or her own unexamined beliefs - is of the greatest value in coming to understand the past, and also is one of the elements of greatest educational value in the study of past beliefs.

8

God and Explanations

It would perhaps be permissible to say that the main attempt of modern philosophy has been to give a firm foundation to knowledge. At the back of our minds all of us moderns have the idea that all our knowledge derives either from experience or from self-evidently true principles. 14 This notion derives from Descartes and his heirs, from the typically modern (i.e. post-Cartesian) project offounding all knowledge on true, certain and indubitable principles. Now, that which we believe because we have been told it- that which we believe on authority- though it may be true, is far from being certain or indubitable, at least by post-Cartesian standards. But we should try to clear our minds of this cant, and consider the matter calmly. If we do, we should be able to realise that most of what we believe we believe because we have been told it: we believe it on authority. Now we should be clear that on our own principles we have no right to believe this. As a result, it is our own attitude to authority that looks odd and in need of explanation, not that of the medievals. It is in fact entirely reasonable to believe what we are told. Most of what we are told is true, and when false, it is usually in itself unimportant, or false in unimportant ways. Moreover, when it is false, we can often correct it- usually, let me add, by being willing to learn from better authorities. To restrict our actions to what we can do on the basis of our own experience and on deduction from self-evident principles would be to restrict our action unreasonably. Also, it is clearly unreasonable to believe what we are told while also believing that we have no right to believe what we are told, which is, in fact, roughly what the modern position is. If we do believe what we are told, as we do - if we do trust in authority, as we do - then we should recognise the fact. Thus, it is reasonable to trust in authority. It is unreasonable to trust in authority and pretend that we don't. We can even go further: it is simply unreasonable not to trust in authority. How do we decide what is reasonable and unreasonable? In particular, how does a modern philosopher come to the conclusion that it is unreasonable to trust in authority? The answer must be, by applying his standards of reasonableness. The crucial question which follows on from this is, how do modern philosophers acquire their standards of reasonableness? I am sorry to say- or rather, I am really rather pleased and amused to say- that standards of reasonableness are acquired on authority. When we were children, we were brought up under authority. This teaching to a great extent made us what we are: it introduced us into our community, into our family, into our nation, into the human race (considered as a social phenomenon) as full and active members. There are two things to be

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noticed here. The first is that we needed to be introduced- we could not have attained this status on our own. We were made into full members of the club. We had, no doubt, a right to be made members of the club, in virtue of our birth into this species; but without our upbringing, and the use of authority in this upbringing, this right would never have been exercised. The other thing to notice is that this community is not just the community of those now living. My great-grandparents were dead before I was born, but part of what I am I owe to them, physically, psychologically and culturally. Despite all the generation gaps that exist or have existed, what we learn on the authority of our parents about who we are, about what to believe or do, is substantially the same as what they learnt from theirs. The differences which we know to exist between the attitudes of different generations are only noticeable because they stand out against a background of agreement. This is what it is for a culture to exist. It is passed on by authority, and it continues through time by tradition; what is passed on by the authority of a parent generation is mostly passed on by the authority of the child generation to its children. But nowadays we never speak of this. Tradition, like authority, is seen as very much a second-best: something to be superseded, something, perhaps, that is necessary in childhood, or in past centuries, but not at all to be welcomed by adults of today. Instead, we say, we should trust in reason. To see through the fallacy involved in this popular slogan we should notice the fact that if we are to trust in reason we need to know what the standards of reasonableness are. We do in fact have standards of reasonableness, as the little child does not. That is why we have to use tradition and authority in teaching children: there can be no dispute about this. But what is seldom noticed nowadays is that we have standards of reasonableness because we have been initiated into our culture by means of tradition and authority. Once we have the standards of reasonableness, we can challenge this or that part of traditional authoritative teaching in the name of these standards of reasonableness: that is, we can challenge doubtful parts of the tradition in the name of more basic parts - perhaps, in the name of the tradition as a whole. But we cannot use part of the tradition to challenge the tradition as a whole: we cannot claim that it is unreasonable to hold to any tradition, when the very standards of reasonableness which we are employing in this challenge only come to us from tradition. The unreasonableness of such a claim is like the unreasonableness of the following sentence: 'It is impossible for there to be an intelligible sentence written in the English language.'

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God and Explanations

It should be noticed that what I am myself doing here is precisely issuing a challenge to one part of our culture in the name of the standards of reasonableness that form another part of it. I am challenging our modern attitude to tradition, because it is not reasonable, and I make the challenge in the name of the standards of reasonableness that I hold as the fruit of tradition. This seems itself a reasonable challenge. What I could not do is challenge our modern culture as a whole for being unreasonable as a whole, because my standards of reasonableness derive from the tradition of this culture, with a little help from reflection on ancient and medieval culture. The modern opposition between tradition and reason is as unreasonable as a universal attack on the unreasonableness of modern culture as a whole would be. It would, indeed, be possible to maintain that it is not only unreasonable not to trust in authority: it is also impossible. There is a rabbinical story of a Gentile who came to Rabbi Hillel, asking to be taught the Law. But, he went on, he only wanted to be taught the written Law, not the oral Law; that is, he wanted to be able to read God's written word for himself, without the glosses put on it by the wisdom of the teachers of Israel. The story is of Rabbi Hillel, who was renowned for his kindness and courtesy, so the interview did not end at that point, as it might well have done if the Gentile had gone to another rabbi. Rabbi Hillel began by writing out the Hebrew alphabet on a sheet of paper and telling the Gentile to come back once he had mastered it. The Gentile, nonplussed, replied that he recognised the Hebrew alphabet, and admitted that he would have to master it before he could be taught the written Law, but he didn't know which letter was which. 'Ah,' replied the Rabbi, 'so you want me to tell you which letter is which?' 15 In the same way we need to be taught our very language, on authority, if we are to be able to systematise even our own experience sufficiently to make it into anything that could be a foundation of other knowledge, or to grasp even self-evident truths. Even if trust in authority is necessary, it is still hard for us, in our culture, to appreciate the fact. To help us, we can perhaps draw attention to a number of features of even our society and culture in which authority and tradition are paramount, even though they are not generally recognised. Religion is still mostly a traditional affair, even though many theologians do not seem to realise it, or even deny it. A couple of cases currently in point are the ordination of women and allowing priests to marry. The best argument against women's becoming priests is that this has never been done: that restricting the priesthood to men is something which the Christian Church has done in a traditional faithfulness to the

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inscrutable will of God, as first revealed in Christ's choice of the apostles. Theoretical arguments based on a supposed appropriateness of males for the priesthood certainly exist, but they seem weak. If the argument from authority and from tradition is not accepted, there seem few compelling reasons for continuing to do as has been done up to now; but if authority and tradition are recognised, the reason they give is entirely compelling. The same point is true of the marrying of priests. Journalists, commentators and even theologians nowadays fail to distinguish between the question of whether we should allow or even encourage married men to become priests, and the question of whether we should allow those who have become priests to get married afterwards. This failure to distinguish is based on a failure to recognise the importance of tradition. Different Christian communities, of undeniable apostolic tradition, have over the centuries had different opinions, for different reasons, of whether or not one should allow married men to become priests. No Christian community of unquestioned apostolic tradition has ever allowed priests to marry after becoming priests. The tradition is clear and strong, but we seem nowadays incapable of recognising it or regarding it as important. Once it is recognised, other arguments have to be evaluated in terms of whether they are strong enough to overthrow the argument from authority and tradition. The question is not an open one, which we are called upon to answer out of our own heads, as if for the first time. Religious tradition, however poorly understood by religious believers or commentators these days, provides a clear reflection of the attitudes of earlier ages. But there is another parallel: we can compare the pre-modern attitude to the tradition of learning to modern traditions of science. For Plato and Aristotle, to become a learned person, a philosopher, is a process that involves admitting the authority of the philosophical tradition, involves accepting the attitudes, beliefs, behaviour and standards of that community. These attitudes include attitudes to the history of that community and hence attitudes to the tradition itself. Like the traditional reasonableness of the human race, and like religious traditions, such a tradition has its own standards, which are also accepted on the authority of tradition. These can be used to judge individual parts of the tradition, or individual features of the present state of the tradition in this generation, which may be found to be defective in one way or another. But of course the tradition as a whole cannot be judged as not up to standard by the standards of that tradition. It could only be so judged by outside standards: and it is not at all surprising that those with different standards should judge it badly. But they are likely to misunderstand it, as much as we misunderstand the medievals. There are no neutral standards.

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God and Explanations

We can, if we wish, compare the tradition of learning as understood by Plato and Aristotle with the tradition of the scientific community in our own day. This is perhaps the nearest we come in our society to a community based on a genuine tradition. The truth about this is disguised from us by the rhetoric used by journalists, philosophers of science and even by scientists themselves about 'reason', but in fact the scientific community is a traditional one, based on authority. Those who wish to enter it have to give up whatever other beliefs, standards and attitudes they may have had, and adopt, on authority, the new standards of the scientific tradition. They cannot hope to justify the beliefs, attitudes and standards of science by means of beliefs, attitudes and standards which they bring from outside. Among these attitudes, it is important to notice, is an attitude towards the scientific tradition itself: an attitude to the history, or rather the story of science. The story of the scientific tradition which the newcomer must accept is not a detailed history of everything that any scientist has ever done in the name of science: it is a genuine tradition, a story which picks out only those things which are to be believed at the present day, or have in some way contributed to what is believed at the present day. This is very much the same as the way in which newcomers into a religious tradition are not told about all the heresies there have been: they are told the Faith. Once newcomers have established themselves in the scientific community, they may use the standards of science to correct this or that current or recently past view, but they cannot use the standards of science to overthrow science. It is indeed, no coincidence that while we do not find appeals being made to authority in articles in philosophy journals, we do find them in scientific journals. The average paper in Nature, as Geach has pointed out, contains far more references to past work than does the average article in the Summa Theologiae. 16 It will be said that the two cases are not on all fours: that the results cited in an article in Nature are, at least in principle, repeatable, while the authorities cited in the Summa are not. This would involve a confusion. Clearly, the authorities cited in the Summa do not refer to repeatable experiments, since theology is not an experimental science. But they do refer to repeatable reasonings. The experiments are unrepeatable because there are no experiments; but the reasoning is repeatable, which means that it is open to question and open to revision. Notice that there is no contradiction between the attitude of such post-modern contemporaries of ours as Quine and the attitude of St Thomas, while both attitudes are strongly at odds with the modernist, foundationalist conception of science and philosophy. Quine thinks we should regard any proposition which we

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hold as being in principle revisable. But this revisability in principle requires that we should hold the rest of our belief system steady while we revise the belief in question, and make whatever subsequent adjustments to the system that thus become necessary. The rest of the belief system can be used as lever and fulcrum to overthrow any given belief because we are able to treat the rest of the belief system as fixed. There is no bedrock truth, but at any time some beliefs must be treated as if they were fixed. Often they will be methodological beliefs: and for this reason St Thomas begins the Summa by setting out his methodology. In the same way some at least of our standards of reasonableness must be received from authority and held fixed if we are to overthrow others. In the same way, within science, our trust in older scientific authors and in the validity of their experimental methodology must be held fixed if we are to believe that their results are even in principle repeatable. To sum up, then, if St Thomas frequently cites Aristotle, or St Augustine, it is because, as I said at the beginning of this discussion, he both has respect for their authority and thinks that what they say is correct. St Thomas's trust in his authorities is not a blind trust, like that which the Pythagoreans are said to have had in the ipse dixit of their master: it is a rational trust. It is not just that St Thomas has this trust - he is able to expect his readers to have it too. His readers are to be students and masters in the schools, people who have a share in the tradition which he is developing. This seems alien to modern philosophy, and indeed it is, but it is not alien to the practice of modern science, and it should not be alien to the philosophy of those who, like Quine, are struggling to throw off the dogmas of modernism, in either its rationalistic or empiricist forms. I have often found, when leafing through university prospectuses, that philosophy is recommended to the prospective student by some phrase such as 'Philosophy teaches you to challenge accepted wisdom and question everything' .17 My only comment is, who says so? Is this phrase not a part of accepted wisdom? Should it not then be questioned? In fact, the student who questions everything (and you always get a couple each year) is no more likely to be successful in philosophy than he is in science, engineering or law. Philosophy teaches you to question the things that philosophers usually regard as questionable, no more and no less. There is no doubt that the exclusion of the student who wishes to raise the sceptical doubt in every single philosophy class is a necessary condition of progress in this as in every other form oflearning. That in StThomas's day the exclusions practised were different from ours should raise no difficulty. That these exclusions were more extensive than ours is a difference of degree and not of kind. Some may feel that any loss that was

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incurred through the breadth of medieval exclusions was more than made up for by the speed and intensity of the development that these exclusions made possible. NOTES I. 2. 3. 4. 5. 6. 7. 8. 9.

10. II. 12.

13. 14.

15.

16. 17.

See Aristotle's Posterior Analytics, I, 2, 72a!0--72b4. See Commentary on the Posterior Analytics, L.I, 1.4, n. 32. Summa Theologiae, I, q. 2, a. 3, sed contra; Exodus, 3.14. See Summa Contra Gentes, I, 2. The Epicureans were called atheists in the ancient world, and there seems little doubt that one of Aristotle's objections to Democritus was that he left no room for the divine in his system. He was also, I believe, alleged to be the son of Beelzebub, so one doesn't know how seriously this kind of accusation was meant or taken. Adelard of Bath, Questiones naturales, q. 76, edited by M. Miiller, in Beitriige zur Geschichte und Theologie des Mittelalters, vo!. 31, fasc. 2 (Miinster in Westfalen: Aschendorff, 1934), p. 69. Psalms, 14 [13]: I, and 53 [52]: I. StThomas quotes the latter in Summa Theologiae, I, q. 2 a. I. My discussion of the argument from authority, in this chapter, and of the figure of Augustine, derives in great part from A. Macintyre, Whose Justice? Which Rationality? (London: Duckworth, 1988) and Three Rival Versions of Moral Enquiry (London: Duckworth, 1990). The argument from authority is discussed in a more polemic context in my 'Arguments from authority', The Past and the Present: Problems of Understanding (Oxford: Grandpont Papers, 1993), pp. 25-35, and in a fuller historical context in my Introduction to Medieval Philosophy (Edinburgh: Edinburgh University Press, 1996) pp. 16--44. Summa Theologiae, I, q. I, a. 8. 1 Kings, 7:23. Augustine pointed out, in discussing to what extent the first two chapters of Genesis need be taken literally, that God's purpose in giving us this book was to make us Christians, not astronomers. His own interpretation of the seven days of Creation was so non-literal that it made no reference to any periods of time whatsoever. Summa Theologiae I, q. I, a. 8, second objection: 'Locus ab auctoritate est infirmissimus, secundum Boethium.' This thesis is dealt with excellently by P. T. Geach in 'Knowledge and belief in human testimony', in The Past and the Present: Problems of Understanding (Oxford: Grandpont Papers, 1993), pp. 15-24. The historical background is dealt with by Macintyre, in Three Rival Versions. To add another argument from authority, Pope John Paul II clearly takes a similar view in Crossing the Threshold of Hope (London: Collins, 1994). I believe I found this story in the notes to the Yale Judaica Series edition of The Sayings of the Fathers, with reference to a quotation attributed to Ben Bag-Bag, but I cannot now be sure. The editors conjectured that the Gentile protagonist of this story was so impressed by Hillel's answer that he eventually converted to Judaism and himself became a rabbi, taking the name written BGBG, because he was the man who had needed to be told the difference between Band G, beth and gimel. Geach, 'Knowledge and belief in human testimony', pp. 15-24. Compare, for example, the sections on philosophy in the Glasgow University undergraduate prospectuses for 1993--4 and 1994--5.

2 • THE NATURE OF SCIENCE IN MEDIEVAL THOUGHT

I have tried to make out what St Thomas thought he was doing in the Summa Theologiae, and to some extent I have tried to make out why he did it. Also I have tried to see why the attempt is not a wholly pointless one. My aim is to elucidate the first substantive question he asks in this study, and to do this it was necessary to examine what kind of a study it is. StThomas was trying to construct what he thought of as a science: that is, a systematic body of knowledge, a part of wisdom, as he says, out of all the materials available to him. Among the materials available to him are the authorities, and, as we have seen in the previous chapter, it came naturally to a medieval thinker to begin his scientific investigations with an examination of material derived from authority, as it comes natural to us in our ordinary occupations and thoughts. The two authorities whom Aquinas most respects and most uses are Aristotle and St Augustine. The choice of these two is not arbitrary. St Augustine in some sense provided the model, Aristotle the detailed method. The striking feature of the work of St Augustine is his attempt at harmonisation, at reconciliation. This is recognised by any encyclopedia, which will explain Augustine's achievement as that of bringing about a synthesis between Christian and pagan wisdom. But there is more to be said. The synthesis, the harmony, which Augustine first sought was a harmony between his thought and his life. This harmony was something he had been seeking over half a lifetime, but which he had only achieved through making the submission of humility required for his conversion. The well-known story of the moment of his conversion is extremely relevant here, as in the discussion of many other stages of Augustine's thought. The great scholar was only able to harmonise his life and his thought through taking the half-overheard inconsequential babblings of a child as a voice from Heaven. It was this that enabled his will to respond to his intellect and to achieve the harmony oflife that he had been seeking, the lack of which harmony had been torturing him for years.

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From this fact stems Augustine's belief that in some sense the understanding of faith precedes the understanding of reason: a paradoxical claim, since it seems rather obvious that while God gives reason to all, he gives faith only to some. But for Augustine reason on its own will wander blindly, incapable of understanding even its own truths, unless the reasoner submits to the radical conversion to the faith which Augustine himself had undergone, a conversion which threw new light on all his previous learning. At last, he thought, he had achieved an understanding in which his life and his thought could be united. This meant a wholesale re-appraisal of his previous thought. At last, he felt, he could understand Plato correctly, better even than Plato had done. He could at last see why and how Plato had been right (when he had been right) and why and how he had been wrong (when he had been wrong). All human learning could now be seen in the light of faith: it could either be pressed into service to illuminate the understanding of faith, or be definitively rejected as inconsistent with the faith. 1 This view of Augustine's developed into a tradition, which enlightened the succeeding centuries. Harmonisation, reconciliation and synthesis became the ideals pursued at the University of Paris, as they had been at the Augustinian-inspired schools which had preceded it. In Aquinas's time this ideal was facing its greatest challenge. The slow, argumentative discussion and development of this unified tradition of human and divine learning had been thrown into turmoil by the re-appearance in the West of the works of Aristotle. Aristotle was already, to the early medievals, a name to which respect was due, an auctor, one with authority. The neo-Platonic philosophy which Augustine had made the basis of the human part of his synthesis of wisdom had already, before Augustine's time, adopted Aristotle's logic to provide it with a structure. Moreover, some of Aristotle's fundamental metaphysical categories had become known in the West through the writings of Boethius, and had provided a framework for the development of theological speculation about the inner life of God and God's relation to the world. For this reason, the newly discovered writings of Aristotle could not merely be brushed off as unimportant, as trivial and erroneous philosophising. Moreover, the general philosophy of Aristotle fitted far better, unsurprisingly, with the logic of Aristotle which the medievals were used to working with, than it did with the general neo-Platonic philosophy adopted by Augustine. Above all, Aristotle's work presented a fully developed, coherent view of the world as a whole and of the human being's place in it, which was in important respects inconsistent with the view upheld by the Augustinian synthesis. It naturally presented itself as a rival to that view.

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Moreover, the Augustinian position itself demanded that it should be able to give some account of this rival. The aim of the Augustinian project was a synthesis of all human wisdom. Any proposition put forward for inclusion in that synthesis, in principle, could be judged in the light of that wisdom. If true, it could be incorporated; if false, it could be shown to be false and rejected. It looked, at this time, as if the philosophy of Aristotle could neither be incorporated nor rejected. Medieval thinkers were all too prone to accuse their opponents of teaching that there could be two separate kinds of truth, a religious truth and a truth of reason. Any thinker who did so hold would have been guilty of abandoning the Augustinian project (as well as the Aristotelian logic which structured it), and it is in fact hard to pin down any medieval thinker as actually having made such a radical claim. But we do have, from the period, the notes of an anonymous student who was confused enough by the problems of the age to note, 'The above [Aristotelian] propositions are true in the Faculty of Arts, but not in the Faculty ofDivinity'. 2 It was into this world, facing this problem, that Aquinas came- and he did not shirk the problem. He attempted to establish the framework for, or to make the first step in, creating a new complete synthesis, a synthesis of the Augustinian tradition and the wisdom of Aristotle. The joint importance of these two authors to Aquinas can be brought out in a crude but effective way: in the index of a recent edition of the Summa theologiae, references to both run to over thirty columns, while references to their nearest rival, St Leo, run to only ten. We could say, putting it crudely, that the aim and spirit ofSt Thomas's project was Augustinian. Aquinas was seeking an understanding which a Christian could live by, and the holiness of his own life may be held by some to have confirmed that he achieved this aim. But in many ways the structure was Aristotelian. Thus in the case at issue, of the discussion of the nature of science: Aquinas is seeking for wisdom, wherever it may be found, and if the beginning of wisdom is the fear of the Lord, 3 a necessary preliminary is to establish that the Lord is God. But this wisdom is understood by Aquinas as being an Aristotelian science, a science of the kind for which Aristotle laid down principles in his Posterior Analytics and which he tried to develop in his Metaphysics. The Posterior Analytics is a curious work. It seems to present as the ideal science a system of deductive inferences from stated axioms. A body of knowledge on these lines was well known for centuries in Euclid's geometry. We may pause to marvel at Aristotle's perspicuity in laying down rules for what was not to be achieved until several generations after his death,

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but our principal reaction is usually one of impatience. Surely no other body of knowledge is, or could be, articulated in such a way. If no other body of knowledge can be an Aristotelian science, then the notion of an Aristotelian science is of very little interest to us. Moreover, there is a very apparent contradiction between Aristotle's account of science in the Posterior Analytics and his actual practice in the Metaphysics, the Physics, the Ethics or the De Anima, to say nothing of his practice in his magisterial works on natural history. We find nothing in these that is parallel to the structure of Euclid's geometry. Instead, Aristotle examines common experience, as found either in folk-wisdom or in the writings of the poets or of other philosophers; or, where common experience is lacking, he makes his own observations. He then brings arguments, his own or those of others, against the obvious or usual explanations of these experiences. If these objections can be rejected, as they often are, the common view is held to stand, perhaps suitably modified by criticism, or perhaps with a more developed explanation provided by Aristotle himself. And then on to the next topic. We can make of this what we will. One bizarre, but possible, reaction, might be to reject all of Aristotle's substantive work for not fitting in with his professed methodology. Another, less bizarre reaction, which actually occurred among later scholastics, would be to reduce all of Aristotle's work to the structure suggested in the Posterior Analytics. This, as I say, has actually been done; it is an operation which has in great part been responsible for the bad name that Aristotelian scholasticism still has in some quarters. Another reaction is to reject the Posterior Analytics, a course which has been taken by authors as recent, and as favourable to Aristotle, as G. E. M. Anscombe. 4 A sounder reaction is one which has more recently gained favour. 5 This is to observe that what Aristotle is recommending in the Posterior Analytics is not what he thinks he is doing in the rest ofhis works. In the Posterior Analytics Aristotle is laying down what he takes to be the correct articulation of a body ofknowledge once achieved: it has nothing to do with the way in which that body of knowledge is acquired. The model in the Posterior Analytics is just that, a model, an ideal. It bears the same relation to what Aristotle does in the rest of his works as a management consultant's flow-chart of the operations and relations aimed at in the operation of a work-space to the processes of designing and constructing an office layout, and hiring and training the staff who will carry out the operations and bear these relations. It is not, in fact, a theory of finding out truths, which, crudely speaking, is what we think a theory of science should be; it is a theory of the relations which should be seen to exist between truths once found out.

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Whether the theory in the Posterior Analytics is in fact a good account of the relations between the truths of a science once found out, is a disputable question, which will be examined shortly. What is important to notice here is that Aristotle should not be criticised for doing badly something he never set out to do - giving an an account of finding out and that therefore neither should St Thomas be criticised for imitating him. We might observe, though, that even if Aristotle's account of the structure of a completed science is correct, we may fault him for failing to draw our attention to the difference between this account and an account of the way in which we can find out. Certainly we can criticise him for not giving us a sufficient account of finding out. He gives us no theory of science in the modern sense, no theory of finding out, though he held such a theory, at least tacitly, as we can see by examining his actual practice. This criticism can also be made against StThomas, but with less force; in his Commentary on the Posterior Analytics St Thomas does give more explicit attention than his master to the process of finding out. Nevertheless, we can still criticise StThomas for a lack of explicitness in distinguishing between a theory of a completed science and a theory of finding out. And we also need to look at whether the theory of the ideal, completed, model science is accurate or not. If it is not accurate, then, we might think, just in so far as StThomas succeeds in making his new divine science like the model, he will be failing to produce a good science. In the same way, the management consultant's flow-charts may be perfectly well constructed, but they may not help us to achieve what we need to achieve. This reaction would be an exaggerated one. StThomas would not have thought that what he left at the end of the Summa Theologiae, even if that work had been completed, would have conformed to the model in any detail. The construction of a divine science is not work for one individual. Even in geometry, Euclid's achievement was to put together in a coherent structure the work of innumerable predecessors. Aristotle was proud of being the first to produce a science oflogic, but it was clearly not complete; he knew it was not complete, and StThomas, who himself provided some interesting developments and corrections of Aristotle's logic, did not take it to be complete. St Thomas would have held that no science, with the possible exception of geometry, was at his time complete: all required more development. The more developed a science was, the more one could hope to see in it the features of the model; and StThomas does often draw attention to the way in which Aristotle's work often does match the model in important respects. We can expect, then, to find St Thomas holding that in so far as his work is complete it will match the model, but

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the fact that the model is based on a misunderstanding, if it is a fact, need not mean that Aquinas's work, when valuable, is so only by mistake. Clearly, though, some examination of the model is in order. Crudely, the model is articulated in a top-down, deductive manner, though any science which has been built up to fit it will in fact have been developed in a bottom-up, inductive or dialectic manner. The process of finding out starts with individuals, and therefore with the contingent, but it eventually reaches the universal and the necessary. A completed science, therefore, has to do with the universal, and it consists of necessary truths. 6 The conception of 'necessity' involved here need not be a very strong one: often it seems to be equivalent to no more than 'universality' or 'everlastingness'. But, for an Aristotelian, there are, strictly speaking, no universal and everlasting contingent truths: there is nothing that just happens to be always the case. The necessity involved in a completed science is at least natural necessity. Though it need not be as strong as logical or mathematical necessity, it is never as weak as pure contingent universality or everlastingness, as what just happens to be always or everywhere the case. It is important to recognise, though, that for a theistic Aristotelian such as Aquinas, all the natural necessities in the world, though genuine necessities, are in a sense conditional necessities, and in that sense are infected with contingency. Aquinas thought, with Aristotle, that the uniform circular motions that had been observed in the heavenly bodies were necessary, both in the sense that they continue for ever, and in the sense that given that there are the heavens that there are, the movements could not have been otherwise. But it was a debatable point whether there could not have been more or fewer heavenly bodies and, for Aquinas, it was indisputably true that the world, with its heavenly bodies, might not have existed at all. What Aristotle would have thought on this question is again disputable, but the medieval thinkers who assimilated Aristotle were unequivocal on this question. The whole question of the necessity of the truths of a completed science is yet more complicated by an observation of Aquinas that the link from effect to cause is necessary, while the link from cause to effect is contingent.7 His point is that this individual effect could not have come to be without this cause- since had it come about any other way we would not count it as 'this individual effect', but as another, qualitatively indistinguishable, individual effect - while what in fact caused this effect, in a different overall context, could have had a different effect. Since in the realm of physics, for example, many of the explanatory links in a science

The Nature ofScience in Medieval Thought

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will consist of the efficient causality of which he is speaking here, 8 the distinction between the dialectical, inductive and contingent process of building up a science, and the necessary, deductive nature of the science once constructed, seems doubly threatened, in that the links of bottomup, effect-to-cause reasoning employed in the construction of a science, which should be contingent according to the theory, appear to be necessary; while the links of top-down, cause-to-effect reasoning that will be found in a completed science, which should be necessary, appear to be contingent. The problem is intractable. We can perhaps make a start by pointing out that there is no reason to suppose that every useful, interesting or important piece of knowledge which we acquire in building up a science will eventually find its place in the completed science. Certainly, not every necessary connection which we make use of in building up a science will have to form a part of the completed science. 9 While it is clear that St Thomas, following Aristotle, regards what he calls a 'science', a completed science, understood as we have said, as a paradigm of knowledge, it is also clear that there is plenty of important knowledge which fits this paradigm only very imperfectly. We need to take a step back, and try to understand, first, why their notion of'science' is important to Aristotle and to Aquinas, and how one science is related to another in the overall structure of speculative wisdom. Plato, before Aristotle, had drawn attention to the difference between knowledge and true belief, and the distinction may go further back than that, to Socrates. 10 Clearly, we are unwilling to grant that a person knows this or that fact simply because she or he very strongly believes it. We are all acquainted with strong, unfounded belief, and it may very well be false. Even when it happens to be true, that it is true is contingent. We expect someone who claims to know some fact to be able back the claim up with reasons, as Plato said in the Meno. We do not, in general, accept that people know that so-and-so is the case, even if so-and-so is the case, unless they have not only reasons, but the right reasons, for claiming that so-and-so is the case. The tag that Plato uses in the Meno to mark out the difference between true belief and knowledge - that knowledge is 'tied down by calculation of reasons'- comes close to Aristotle's own definition of episteme, science, already mentioned, that it is 'definite knowledge through reasons' or 'through explanations'. (The more classical translation, 'certain knowledge through causes', is ambiguous with regard to the 'certain', and too restrictive in modern philosophical English as regards 'causes'. 'Cause' in modern philosophical English tends to mean what Aristotle called the

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'efficient cause' or 'efficient mode of explanation', an explanation in terms of how a thing came about. Aristotle famously also recognises explanation in terms of matter- of what a thing is made of; in terms of form- of what makes what it's made of into what it is; and in terms of end- of what it's for). Aristotle and, following him, St Thomas, regard science as the fullest kind of knowledge because the reasons given in science are the right reasons. This appears to mean the following. Let us suppose, to take an example of Aristotle's own which St Thomas discusses, that there is an eclipse of the moon. 11 I can know this by observation. I may go further, and discover, building up a science, that there is an eclipse of the moon because the earth is obstructing the light of the sun. Is this all I need to know? Are my reasons for knowing that there is an eclipse of the moon, and that the Earth is obstructing the light of the sun, as good as they might be? Aristotle holds that they are not. In this case I know that p - that there is an eclipse of the moon - and I know that q- that the Earth is obstructing the light of the sun. I also know that p-because-q, that there is an eclipse of the moon because the earth is obstructing the light of the sun. Aristotle clearly thinks that until the order of reasons for my knowledge matches the order of reasons for reality, my knowledge is still imperfect. His ideal is that I should know that p because I know that q, that I should know that there is an eclipse of the moon because I know that the earth is obstructing the light of the sun. To know that the sun is obstructing the light of the sun because I know that there is an eclipse of the moon is an imperfect kind of knowledge, one that falls short of complete science. The example, though Aristotle's own, is in some ways badly chosen, and makes the whole idea of Aristotelian science look more absurd than it need. Aristotle's science is not concerned with individual occurrences: he does not, therefore, have to hold that scientific knowledge is a better way to know whether the moon is in fact at present eclipsed than is looking at the moon, though the way he sets up the example seems to suggest this. What he does have to hold is that ifl know that at times the sun's light is obstructed by the earth, and that therefore there are, at those times, eclipses of the moon, I have a better reason for holding that there are at times eclipses of the moon than I would have through having noticed the Moon eclipsed from time to time; and, a fortiori, it is to have a better and more complete kind of knowledge than if I only know that the earth sometimes obstructs the light of the sun because I know that the moon is sometimes eclipsed. This may still seem a little odd: surely, some would say, I could not have better warrant for believing that the moon is eclipsed than my having

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seen the moon eclipsed? I think this is a mistake. I have seen rainbows, and water on tarmac roads on hot days. But I do not believe that there is a physical object called a rainbow, and I do not believe that there is more water on tarmac roads on hot days than on cool rainy days. My having observed eclipses is far from being the best reason I could have for believing that there are physical processes called 'eclipses'. If I am to believe this, I need stronger warrant, which brings my belief in eclipses into an organised system of explanation of how the physical world works. It is because I have no such warrant for a belief in a physical object called the rainbow, or for the existence of water on the road on a hot day, that in the end I come to disbelieve in their existence. Put in this context, Aristotle's position does not look quite so absurd. Moreover, it draws attention to the fact that each piece of knowledge in a scientific system is only as good as the system of science as a whole that supports it. If the best reason I can have for holding that the moon is eclipsed is my knowledge that the earth is obstructing the light of the sun, then it matters a great deal what is the best reason I can have for holding that the earth is obstructing the light of the sun. And the best reason here would be to do with some optical thesis about the way light travels in straight lines, and some astronomical thesis about the relative movements and positions of earth, moon and sun. This explains why the notion of science is important to Aristotle and to Aquinas. A body of science, if achieved, would provide one with the best foundation or warrant for a knowledge-claim that one could have. In the same way, the best foundation or warrant for a claim to know some theorem in Euclid is to be able to demonstrate it from Euclid's axioms. This connects with the next point of explanation. Each 'science'- each articulated body of explanatory knowledge, within a given subject-matter - should, like Euclid's geometry, be traceable back to certain axioms. These will be truths which are taken as basic for the science in question. They will be few and of universal scope. Thus, certain definitions and statements about properties of bodies as such will form the axioms of physics, certain definitions and statements about properties of living beings will form the axioms of biology, and so on for each individual science. It is important to notice that these axioms are taken as fundamental for the purposes of the science concerned. It is not the task of a science to prove its own axioms; what a science has to do is to draw out the reasonings from them. The axioms can be, and usually are, the conclusions of a more fundamental science: indeed, it is the question of what conclusions are used as the basis for what science that settles the question of which science is more fundamental than which. Thus, strictly, no science

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is complete until all sciences are complete. It is hardly to be wondered at that the practice of Aristotle and St Thomas is so different from what they lay down in their model. If there were no reasonable process of constructing a science which differed markedly from the structure laid down for how a completed science should be, there would be no possibility of starting- nothing could be known until everything were known. Although the above remarks may have done something to make the notion of Aristotelian science less thoroughly alien to our conceptions, less absurd, and therefore to that extent more acceptable, little has been done in direct defence of the notion. In fact, little can be done. I shall continue by drawing attention to some other features of the articulation of science which have their effect in the theory of how a science is to be built up, in the hope of showing at least that the theory of a completed science, though perhaps in this day and age indefensible overall, is at least comprehensible, and is not likely to give rise to great distortions in the building up of a science in detail. Key elements in the structure of a completed science are definitions. Definitions, for Aristotle and St Thomas, are always real rather than nominal definitions: they are always definitions of what the thing is, not definitions of what the word is. I notice that the distinction between the two is well brought out by the difference between, say, the Oxford English Dictionary and the Spanish Diccionario de Ia Real Academia. The English dictionary seeks to tell you how the word is used, and thus tell you what it applies to. The Spanish dictionary tells you what the thing is that the word applies to, and thus tells you how the word should be used. Both kinds of dictionary are useful in different ways, and since the word often means what the thing is which the word is used to apply to, the definitions often coincide. But there is an important notional difference at stake. A definition, then, for St Thomas, 12 is a formula of words expressing what a thing is. This, too, is likely to be misunderstood. For Aquinas, as for Aristotle, what a thing is is its true essence - what explains why it is the way it is. Thus, to choose a geometrical example, a circle is a plain figure bounded by a line called the circumference, which is such that all straight lines drawn to the circumference from a single point within it are all of equal length one to another. 13 This definition explains why a circle has all the features that it has. Equally, a human being is a rational animal; this definition, if it is both true and complete, will explain why human beings have the features which they essentially have. Time is the measurement of movement, according to before and after. And so on. We will see later something of how these definitions are arrived at, in the stage of constructing a science. What is important here is to see what

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is their role in a complete science. They are the key steps in its structure. It is clear that very little about the real world of moving bodies follows from those first principles of physics, those axioms mentioned above, which define what it is to be a physical entity subject to change. For those first principles to give reasons for what bodies actually do in the world, we have to add information about what bodies there are in the world and what these bodies are. This information is given by the definitions. I have just said 'what bodies there are' and 'what these bodies are', as if distinguishing the question of existence from the question of essence. It is natural to make such a distinction, and indeed it is made by both Aristotle and St Thomas, but it is important to notice that in their minds they are linked. If there are no planets, for example, then there is no 'what' for the planets to be: there is no essence, and therefore no definition, of what does not exist. 14 Equally, to say that the planets have no essence is to say that the planets do not exist, perhaps in the sense that rainbows do not exist; or, if they do exist, that they are mere coincidental phenomena, as we might say the weather is, and not appropriate studies of science. Here we come up against the harder questions which I have been dodging. Do not the limits imposed on the notion of science by Aristotle and St Thomas make it too restricted to be interesting? Indeed, do they not make it too restricted to have any application at all outside the realms of Euclidean geometry and its offshoot, Ptolemaic astronomy? (And since it turns out that Ptolemaic astronomy is false in large and important respects, this is a limited field indeed.) It is true that for St Thomas and Aristotle it seems that there could be no such science as what we call the science of meteorology. For these two authors the phenomena which make up the weather are just that, phenomena, coincidental existents which obey no laws, which have no essence. This is not just ignorance on their part: the fact that we can point to regularities and laws in the weather would probably make no difference to them. The weather, and the entities that make it up, are not substances, things with their own nature or essence, and therefore there can be no unchanging truths about them. 15 For it is a well-known fact that Aristotelian science is about eternal, or at least everlasting and unchanging truths. 16 This follows from the 'necessity' of the truths of science, which again follows from the aim of science to provide as good a reason for one's beliefs as one could possibly have. We cannot have a better reason for our beliefthatp than that it could not possibly be that not-p. Hence science aims at necessary truths. And what is necessary is always the case, since what is sometimes not the case can be not the case. Hence science is of unchanging truths.

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Aristotle, indeed, may even have held that what is always the case is necessary, that there is nothing that just happens to go on for ever, though the attribution of this view of Aristotle is disputed. 17 But at this point we strike a difference with Aquinas. Part of the reason for holding that Aristotle believed that what is always the case is necessary, is the view that he believed in the principle of plenitude: that whatever can happen, at some time does happen. (There is an interesting parallel with the view of necessity and possibility which is nowadays called extreme modal realism, that whatever can happen does happen somewhere, in some real but non-actual 'possible world'.) Thus, whatever can stop happening, at some time does stop; thus, whatever always happens, happens of necessity. Aristotle was thus committed to a view, which we find him frequently mocked for, of the eternity of, for example, animal species. 18 Since it was clear that it is necessary for kittens to come from cats, in some sense of 'necessary', Aristotle seems to have thought that the series of cats producing kittens must have existed from eternity. But it is also arguable that all Aristotle meant by 'the eternity of species' was that a natural kind has no tendency to stop existing, as such, while the individuals of a given natural kind generally do have such a tendency. Be that as it may, this is where we begin to see important differences between Aristotle and StThomas. The latter's metaphysics is creationist; the former's is not. St Thomas believed that the world at some time came into existence and will at some time cease; Aristotle did not. Thus St Thomas cannot have held the principle of plenitude in the form that, it is alleged, Aristotle may have held it. That form of the principle depends on the existence of infinite time in which all real possibilities might be actualised. St Thomas did not believe in an infinite extent of time. St Thomas thus could not glibly identify the necessary, in any sense, with what always happens. Moreover, he had given some thought to the question of mules. Mules had been discussed by Aristotle, but he did not see the metaphysical implications. St Thomas did see the metaphysical implications, and accepted them. 19 A mule is born from a horse. and a donkey, but is neither a horse nor a donkey. It is recognisably a third equine species, another natural kind of the horse family :_ though an imperfect one, as one cannot breed mules from mules. Even if one grants that horses and donkeys might have existed for ever, as far back as the world exists breeding and giving birth to the next generation of horses or donkeys, this cannot be true of mules. It must be the case that species can come into existence; and it must have been obvious to St Thomas that if one took the trouble to keep horses and donkeys apart, that species would cease to exist as well.

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St Thomas, then, does not identify the necessary with what always happens. Nor, given his creationist metaphysics, could he hold that anything created could be in any very strong sense a necessary existent, that it could not have not existed. 20 Be that as it may, there seems to be room in StThomas's theory for a genuinely necessary science of the contingent. If this is so, he might be able to admit what we call the science of meteorology as a genuine science, in his sense- albeit one which is still in process of completion and not yet completed. The key text for this is the introduction to his Commentary on the Nicomachean Ethics of Aristotle. The subject-matter of ethics, in general, is human action. But human actions are individual, contingent, temporal and temporary. How then can they be the subject-matter of an Aristotelian science, which has to do with the necessary and everlasting? The answer given is to distinguish between a broader and a narrower sense of'subject-matter'. It is true that in general the subject-matter of ethics is human actions. Human actions form its 'material object', to use scholastic jargon. But clearly this is going to be in any case an insufficient account. Other studies, such as history, or, in our day, psychology and sociology, also study human actions. What is it that distinguishes ethics from these? The distinguishing mark of any science is its 'formal object': the precise aspect under which its material object is studied. Clearly the formal object of ethics will have to do with human actions in so far as they are good or bad. St Thomas prefers to say that the formal object of ethics is the ordering of human actions towards the end of human life, or, since one and the same science deals with contraries, 21 the extent to which human actions fail to be ordered to their end. There are clearly good reasons for holding that this ordering will be in the relevant sense necessary and unchanging. The end of human life is what human beings are for; and it is a plausible claim, as well as one which Aristotle and St Thomas would certainly endorse, that what human beings are for depends on the very nature which is expressed by the definition of the human being. It is arguable that this end, what human beings are for, does not, will not and cannot change so long as human beings exist. The manner in which human actions are directed towards or away from this end will also be radically unchangeable. Not, of course, that there may not be more or less wicked periods of history, but such a historical study falls outside the scope of ethics. All ethics has to tell us is, for example, that if there are periods in which such-and-such is done, they will be more wicked periods, to the extent that such actions are directed away from their proper end. This kind of thought is not wholly alien to us, though some people nowadays may find its application to the field of ethics troublesome.

28

God and Explanations

(Though in this context it is worth remarking that distinguished contemporary moral philosophers in the English-speaking world, at least until very recently, have been willing to take the alleged special 'universalisablity' of moral judgements as a mark of the special subject-matter of ethics.) But in other cases we can see the application. Science, we tend to think, in some sense prescinds from the here and the now and aims at timeless validity. Token-reflexive expressions such as 'here', 'now', 'I', 'you', 'yesterday', 'tomorrow', 'over there', have no place in what we would call a scientific discourse. This point is made clearly in Frege's essay, 'The Thought', 22 and Quine lays particular stress on it in, for example, Word and Object. 23 Even experimental results - which are of course achieved in a particular time, in a particular place, by a particular scientist or group of scientists- are supposed to be intrinsically repeatable, and in so far as they fall short of repeatability or are suspected of falling short of repeatability, are to that extent ruled out as being serious scientific discourse. Thus this kind of Aristotelian thought is far from being wholly alien to us. There can, then, be a true Aristotelian science of the apparently wholly contingent field of human actions, provided that the formal object of study is sufficiently clearly delimited to provide us with the necessity and unchangingness that we need. The same point can be made about physics. For Aristotle and St Thomas, most of the movements of terrestrial bodies are in themselves wholly contingent. But there is a necessary and unchanging ordering that they have, which we can make the object of scientific study. Aquinas will also allow us to express ourselves more loosely. We usually say that the subject-matter of natural philosophy is that which is subject to change, rather than speaking more strictly and saying it is 'the ordering of natural things'; and in the same way we can say that the subject-matter of moral philosophy is human performance in its ordering to its end, or human beings in so far as they act voluntarily for an end. 24 There are, indeed, more general considerations which help us to the same end. For Aquinas the per accidens, that which is composite or which exists coincidentally (see below, pp. 63-5), cannot properly be the object of scientific study. 25 But everything that is per accidens, that exists coincidentally, is made up of the per se, that which exists in its own right. 26 And the per se is a proper object of scientific study. Thus there is nothing in the world that falls outside the scope of scientific study, even though not every description which is true of this or that part of the world sufficiently determines it as a possible object of a scientific study. A passage early on in the Summa, later repeated, 27 gives a general epistemological and logical background to this point. The way we

The Nature ofScience in Medieval Thought

29

understand the world need not be the way the world is, in the following sense: our structures of thought need not exactly match the world's structures. To say that the cat is on the mat we need to use a number of words which cannot be all pronounced at once, though if the cat and the mat are not present all together, in the appropriate relation, the sentence will not be true. The relation between the cat and the mat is a spatial relation, while the relation between the words 'cat' and 'mat' is, in spoken English, a temporal one. In written English the relationship between the words is a spatial one, but not the same spatial relationship as that which exists between the cat and the mat. We do not need to perform typographical prodigies such as:

cat

mat Meanwhile, in Latin there is no particular spatial or temporal relationship that need exist between the words, and so on. This, as Aquinas says, does not mean that our thought is false. Our thought would be false if it represented the world as being otherwise than the way the world is. It does not become false merely by itself being otherwise than the way the world is. 28 This point, which is true of our thought in general, is true also of our scientific thought. It represents, in whatever way, necessary and unchanging aspects of a changing and contingent reality. According to Aquinas, the changeableness and contingency is made up of the coincidence of many strands of unchangeable and necessary causality or explanation. Our scientific thought does not misrepresent the world: it represents it to us in the only way that we can understand. That some descriptions that are true of the world are not descriptions relative to which we can understand the world adequately, or articulate our understanding, is not surprising. Understanding everything does not mean understanding everything about everything. When we read a book we do not need to know how many characters it contains, and when we examine the world of moving bodies we do not need to know how many moving bodies happen to have collided in the last half-hour between here and the end of the road. The conclusion we can perhaps draw is that the Aristotelian notion of science employed by St Thomas is neither so bizarre nor so restricted as at first sight appeared. We can understand the desire for achieving a science which will be in some sense universal, necessary, and unchanging, and we can see that this desire will not rule out the possibility of genuine scientific knowledge of the contingent and changing world. Neither Aristotle nor St Thomas are partisans of the kind of a priori science that

30

God and Explanations

made the young Kant think he could make an accurate guess at the physical and indeed moral characteristics of the presumed inhabitants of other planets. 29 NOTES 1. For a defence of this view of the Augustinian project, see A. Macintyre, Three Rival Versions of Moral Inquiry (London: Duckworth, 1990). 2. See Macintyre, Three Rival Versions, pp. 107-8. 3. 'Timor Domini initium sapientiae', Psalms, 111 [110]: 10. 4. See G. E. M. Anscombe, essay on 'Aristotle', in G. E. M. Anscombe and P. T. Geach, Three Philosophers (Oxford: Blackwell, 1981), p. 6. 5. See typically the view expounded by J. Barnes, in his translation of and commentary on Aristotle's Posterior Analytics (Oxford: Clarendon, 1975). 6. Commentary on the Metaphysics, L.II, 1.4, n. 323: 'Scientia non est de singularibus'. See also Summa Theologiae, II-II, q. 47, a. 5c. 7. See for example, Commentary on the Perihermeneias, L.I, 1.14, n. 186; cf. below, Chapter 6, note 45. 8. See Chapter 6 below, note 48. 9. For example, it is surely important to know, as Kripke as pointed out, and as Aquinas also believes, that who you are depends on who your parents are. Thus Socrates is necessarily the son of Sophroniscus and Phaenarete. But such a particular truth as 'Socrates is necessarily the son of Sophroniscus and Phaenarete', though it is both true and necessarily true, and though we might well use it as an example in building up a science of human identity, will have no place in the universal science of human identity once completed, which will ignore all such particular truths. 10. Cf. Plato, Meno, 98a4. 11. See Commentary on the Posterior Analytics, L.I, 1.1. 12. Commentary on the Metaphysics, L.VII, 1.11, 1528: 'Definitio vero significat quid est res'; and 1.12, n. 1537: 'Definitio enim ratio ratio significans quod quid est.' 13. Euclid, Elements, Book 1, section 1, defir.ition 15. 14. Commentary on the Posterior Analytics, L.I, lect. 2, n. 17. 'Non entium enim non sunt definitiones.' 15. See, for example, Commentary on the Metaphysics, L. VI, 1.2, 1172-6: 'scientia non speculat de ente per accidens' ('Science does not examine the coincidentally existent'). 16. See, for example, Commentary on the Posterior Analytics, L.I, 1.4, n. 32; L.I, 1.16, n. 136; L.I, 1.42, nn. 376-8. 17. See below, Chapter 11, p. 157, and the references there made to the work ofKnuuttila and Llano. 18. Though I cannot understand how there can be those who mock Aristotle and yet take seriously the extreme modal realism of, for example, D. Lewis, as an opponent which needs facing. Any difference between them seems to me to count in Aristotle's favour: for example, if he reduces necessity to what always happens, he has as restricted an ideology as Lewis and a far more restricted ontology. 19. See, for example, Summa Theologiae, I, q. 73, a. I, ad 3. 20. On this, a discussion in the first part of the Summa is relevant: on the power of God (Summa Theologiae, I, q. 25). In article five Aquinas asks whether God could have made things other than he did, and answers that he could; in article six he claims that at least in some sense God could have made things better than he did. The whole discussion takes place against the background of article three, which discusses the almighty power of God, in which StThomas claims that the only limits to the power of God are logical ones. But on this see the interesting discussion by P. T. Geach, in 'Omnipotence', in Providence and Evil (Cambridge: Cambridge University Press, 1977), pp. 3-28. 21. Commentary on the Physics, L.VIII, 1.2, n. 977: 'Scientia, licet sit una contrariorum .. .'. 22. In P. F. Strawson (ed.), Philosophical Logic (Oxford: Oxford University Press, 1967). 23. W. V. 0. Quine, Word and Object (Cambridge: M.I.T. Press, 1960); see, for example, p. 142. 24. Commenta~y on the Nicomachean Ethics, L.I, 1.1, n. 3. 25. See above, note 15. 26. Commentary on the Metaphysics, Book V, lectio 9; and cf. Chapter 5 below, pp. 63-5.

The Nature of Science in Medieval Thought

31

27. Summa Theologiae, I, q. 13, a. 12, ad 1 and I q. 85, a. 1, ad l. 28. SeeP. T. Geach, 'God's relation to the world,' in Logic Matters (Oxford: Blackwell, 1981). 29. In his Allgemeine Naturgeschichte und Theorie des Himmels (Universal Natural History and Theory of the Heavens), Third Part, in Kant's Werke (Berlin: Reimer, 1910), pp. 351--68. It is worth reading this just to see what Kant meant by 'dogmatic slumbers', and to realise that the influence of Hume was in at least one case highly positive.

3 • THE ROLE OF QUESTIONS IN THE ARTICULATION OF SCIENCE

The last chapter was an attempt to expound intelligibly, if not entirely to vindicate, the notion of scientific study which St Thomas derived from Aristotle, and to show that such a notion is not so foreign to our own conceptions of inquiry as we might at first sight think. If the ideal of science which they held is one we can, after all, with certain reservations subscribe to, we can also look to them for guidance in a task which is perhaps of more interest to us than it seems to have been to them: a search for an understanding of the processes of coming to acquire a structured body of knowledge, and of the rules that govern that process. If we grant that the Aristotelian/Thomistic scientific project is not so alien to us as it at first appeared, we need to look at the way in which this project is to be carried out. Here, as has been said, their explicit writings on science are not of much help, since these writings give us an account of the relationships between truths once grasped, an account of what is understood by one who has achieved perfect scientific knowledge. What we want is rather an account of how we can begin to build up such a science. Clearly, we can get some hints from the way in which our two authors in fact go to work. In Aristotle's case, this involves the gathering of common opinions, the dialectical challenging of them, and their acceptance, modification or rejection. St Thomas follows a similar dialectical pattern with the (to my mind rather slight) difference that he has a body of authoritative writings and opinions which he wishes to reconcile with one another and with his own thought, in so far as possible. But Aquinas at least occasionally gives us some kind of explicit account of the building up of a science, and, in any case, some of the considerations relevant to the structuring of a completed science once possessed are relevant also to the building up of a science. Chief among these is the role attributed to questions. Knowledge, for StThomas, and a fortiori the structured knowledge through explanations

The Role ofQuestions in the Articulation ofScience

33

in which science consists, is a series of answers to questions. To ask a question is to want to know, and to know is to be able to answer a question. 1 It is true that the very idea of a completed Aristotelian science means that StThomas is more interested in what is communicated by the knowledgeable teacher to the ignorant student, than he is in how the investigator finds out for himself. But even the perennial reference to the teacher, which appears to match the top-down, deductive nature of Aristotelian science, admits of some reference to the process of investigation. For while St Thomas holds that the top-down deductive structure of a completed science is in some sense more intelligible in its own right, the student can best come to understand it by going through a process which follows the process of the discoverer or investigator. 2 Even when it is a question of a student's learning rather than an investigator's discoveries, St Thomas has an interest in making the student find out, as if for himself, rather than allowing him to be told. Be that as it may, however we are to think of the way in which we come to understand the answers to questions, the first thing to grasp is what kinds of questions are scientific questions, and how they are related. St Thomas, following Aristotle very closely, uses two pairs of criteria to establish a four-fold division. The first pair of criteria consists in a distinction between what we could call questions of fact and questions of explanation. It is one thing to ask whether such-and-such is the case, another to ask why it is the case. The other pair is a distinction between questions about a thing and questions about a proposition. We thus have questions about the fact of a thing, and about the fact of a proposition; and questions about the explanation of a thing, and about the explanation of a proposition. The question about the fact of a thing is an est?, does it exist? The question about the fact of a proposition is quia? is it the case? The question about the explanation of a thing is quid est?, what is it? And the question about the explanation of a proposition is propter quid? why is it the case? 3 These four scientific questions can be set out conveniently in the following diagram:

Thing Proposition

Fact

Explanation

An est

Quid est

Quia

Propter quid

34

God and Explanations

Clearly there is an order of priority among these questions. We need to discover the answers to questions of fact before we can hope to discover the answers to questions of explanation. 4 This is indeed St Thomas's practice: we find him asking 'Does God exist?', as the first substantive question of the Summa, before looking at the question of what God is. (Though as a matter of fact he goes on to remark that in the case of God the best we can hope for is an answer to the question of what God is not. 5) But this, of course, is in the context of the construction of a science. St Thomas manages to give us the very strong impression that in a complete science, worked deductively from the top down, the answers to questions of explanation are given first and the answers to questions of fact are conclusions from the explanation. The picture he puts across is that the best possible reason we could have for believing that p is a good grasp of the reason why p is the case: the best reason we could have for believing that x exists is a good grasp of the real essence of x. This kind of science looks chimerical. To return to the example used in the last chapter, it looks as if the best reason we could have for believing that the moon is eclipsed is our belief that the earth is obstructing the light of the sun; indeed, it looks as if St Thomas wants us to hold that until we do know that the earth is obstructing the light of the sun, and that for this reason the moon is eclipsed, our knowledge that there is an eclipse does not count as scientific. Or to use an example that both St Thomas and Aristotle give for the answering of an an est? question, we do not know that thunder exists unless we know that fire is extinguished in clouds, on the (admittedly false, as St Thomas insists6) supposition that thunder is the quenching of fire in the clouds. Though we would be hesitant about admitting so much, we would surely agree that our knowledge that the moon is eclipsed does not form a part of a body of science unless it can be put in some intelligible relation with its explanation, and we might even agree that our knowledge that thunder exists requires tying down to some kind of explanation for us to be able to know what we really mean when we say thunder exists. Compare again the question, 'Does the rainbow exist?' Of course in one sense it does, and in another sense it doesn't: a scientific answer to this question will establish what the rainbow is in order to be able to tell us in what sense the rainbow exists and in what sense it doesn't. Even the picture of the completed science which StThomas gives us here, which seem to invert the natural order of the questions, is not so bizarre as at first sight it appears. In any case, there is explicit commentary in St Thomas about the order to be followed in answering the questions, when we are constructing a science. This order is the natural order

The Role ofQuestions in the Articulation of Science

35

suggested above: first, questions of fact, and only then questions of 7 exp1anat10n. We should remember that the answer to the question quid est? is supposed to be a definition, a real definition, a statement of the real essence of the thing in question. It is for this reason, above all, that this question has to follow on after the question an est? That which does not really exist will have no essence, and therefore no definition which really expresses that essence. In modern terms we might want to say that we need to have some grasp of what xis before we can have a chance of discovering whether or not x exists. StThomas sometimes talks in this way, 8 but he normally prefers to restrict the notion of 'what a thing is' in such a way that there is no answer to 'what is it?' when the thing in question does not exist. Clearly, though, he needs to give some account of the knowledge which we need to have previous to any attempt to answer a question an est? and in fact he gives us a very full and detailed account, in terms of his notion of significatio nominis. Before we can begin to ask whether X exists, we need to have some knowledge of what the word 'X' means. 0

NOTES I. On questions, see Chapter 6 below, pp. 80--93: Commentary on the Posterior Analytics, L.II, 1.1, n. 409. 2. On teaching and learning, see Summa Theologiael, q. 117, a. lc. 3. Perhaps the most important single passage for this doctrine is to be found in Commentary on the Posterior Analytics, L.II, 1.1 nn. 408-12: 408. There are four things which are asked about, i.e. that, why, whether it is, and what it is (quia, propter quid, si est, quid est). To these four everything that can be asked about or known can be reduced. (Though in Topics I he divides questions or problems into four another way, all of which kinds of question are included in one of the above kinds, namely the question that. But there he is talking only about the questions which are disputed dialectically.) 409. Then when he says 'For when we ask whether', etc., he makes clear what is meant by the aforementioned questions. First he deals with the composite questions. To make these clear we have to consider that it should be possible to know, and hence ask about, only a statement, since knowledge is only of the truth, and truth is signified only by a statement. But as it is said in De Interpretatione II, there are two ways of forming a statement. In one way it is formed from a noun and a verb without anything added, as when we say 'a man is', in the other way, when there is some third expression besides, as when we say 'a man is white'. A question can be formed which refers either to the first kind of statement, in which case it is a simple question; or to the second kind, in which case it will be a composite kind of question. This kind of question is also called a 'plural' question, because it asks about the composition of two things. About this kind of statement two kinds of question can be formed. One is, is this which is said true? Aristotle first sets this out by saying that we ask whether a certain thing is this or that. This is in some way plural: for we take two things, one of which is the subject and the other the predicate, as for example when we ask whether the sun is failing in an eclipse or not, or whether man is an animal or not. This is what is called asking that (quia). This is not because the word that is the mark or sign of asking a question, but because we are asking in order to know that it is so. The evidence for this is that when we find this out by means of a proof, we stop asking; and if we had known this at the beginning, we would not have asked whether it was so. For inquiry does not cease until the attainment of what was sought for. And so, since

36

God and Explanations the question we were asking, whether this is this, ceases when we attain the answer, it is so, it is clear what is sought by this kind of question. 410. Then when he says, 'For when we know', etc., he shows us the kind of question that follows from this, which is also plural. He says that when we know that it is so, we ask why (propter quid) it is so. For example, when we know that the sun is failing in an eclipse, or that the earth is moving in an earthquake, we ask why the sun is failing, or why the earth is moving. And we ask this with a plural question. 411. Then when he says, 'There is another way', etc., he shows us two other kinds of question, which are not plural but simple. He says that we ask some questions which are different from the two kinds mentioned, in that they are not plural- as when we ask whether there is a centaur or not. For here we simply ask about a centaur whether it is (an est), not whether it is this, for example, white or not. And just as, when we know that this is that, we ask why, so when we know about something whether it simply is, we ask what it is (quid est), for example, what is God? or what is man? These are all the things that we ask: and when we find out, we are said to know. 412. Then when he says 'For what we are asking when we ask', etc., he shows the relation between the above questions and the middle term .... On the first, we must notice that of the above four questions - two plural, two not - he links the first two of each kind together, i.e. the question that and the question whether it is. He says that when we ask about that this is this, or when we ask about something whether it is, we are just asking whether any middle term of what we are asking is to be found or not. This is not something which is said as such in the question. For when I ask whether the sun is eclipsed, or whether there is a man, I do not ask, as far as the form of the question is concerned, whether there is any middle term by which I can demonstrate that the sun is eclipsed or that there is a man. Nevertheless, if the sun is eclipsed, or there is a man, it follows that there is some middle term for me to find to demonstrate what I am asking about. For there are no questions asked about what is immediately known: even though they are true, they have no middle term. This is because such things are obvious, and do not fall under any question. So then, it follows that the person who asks whether this is this, or whether this is simply, is asking whether there is a middle term. For what is being asked in the question whether it is, or the question that, is whether there is something that is a middle term. This is because the middle term is the description of that about which we are asking whether it is this, or simply is, as we shall say below. But it is not being asked for qua middle term.

See Commentary on the Posterioranalytics L.I, 1.2, n. 17, and L.II, 1.1, n. 410. Summa Theo/ogiae, I, q. 3, preamble. Commentary on the Posterior Analytics, L.II, 1.7, n. 477. Commentary on the Posterior Ana/ytics, L.II, 1.7, n. 474. 8. De ente et essentia, 3.

4 5. 6. 7.

4 • THE SIGNIFICATION OF A NAME

The last chapter dealt with the crucial role of the asking and answering of questions in the medieval theory of the building up of a science. It also argued for the pre-eminence, among questions, of those of the form 'Does X exist?' or 'Do X's exist?'. Since, as we have remarked, the first substantial question in St Thomas's new science of God is 'Does God exist?', it is clear he is sticking very closely to what his theory prescribes here. But as St Thomas himself is very well aware, no answer to the question 'Do X's exist?' will be forthcoming, and no solid start can be made in attempting to answer a question, without a grasp of what the word 'X' means. St Thomas gives us a very full account of what it is for a word to mean something, and how we can come to find out what it means, and applies these reflections to the special case of the word 'God'. The notion of significatio nominis, the signification or meaning of a name, plays an important role in StThomas's account of answers to existential questions, what we have called questions about the fact of a thing; i.e. of how one can come to answer the question an est?, is there such a thing? The principal context in which he explains this notion is his discussion about the language we use about God, and how it signifies. 1 But he also uses it explicitly in his discussion of the logical preambles to the existence of God, 2 and in general discussions of how we can come to give answers to questions of the form 'Does X exist?'. It is worth our while to examine these doctrines closely, in order to see that while the doctrine seems to have been developed to deal with the rather special case of God, it is not a mere ad hoc: it has a clear rationale and a possibility of being applied far more widely. In order to see this more clearly I shall suggest parallels with wellknown doctrines and discussions of Frege and Kripke, which were developed well outside any theological context and are of very wide application.

38

God and Explanations

We read in the Commentary on the Posterior Analytics: Before one knows whether something exists, one cannot strictly speaking know what it is: for there are no definitions of what does not exist. Hence the question, does it exist, is prior to the question, what is it. But one cannot prove that something exists, unless one understands what its name signifies.' 3 Some of the notions involved here are clarified later: For there is no quiddity or essence of that which does not exist: so no-one can know what something that does not exist is. But one can know the signification of the name, or a description made up out of several names. In this way someone could know what the name 'tragelaphus' (or 'goatstag', which is the same) signifies: he could know that it signifies 'some kind of animal made up of goat and stag'. But it is impossible to know what the goatstag is, for nothing in reality is a goatstag.' 4 A 'name' here - and throughout this context - is not a proper name, but a 'name for a nature', nomen naturae, what Frege would call a Begriffiwort, concept-word, or what Geach would call a predicable expression. There are obvious similarities here with Frege's own doctrine, that concept-words have reference. It should be noticed that though St Thomas uses the word 'name' here, as Frege does not, the nature which is so 'named' is not considered to be in Fregean terms an object. A nature is not something complete, selbstiindig, any more than Frege's Begriffe are. St Thomas would say it is 'more something that belongs to an existent than an existent itself. 5 It is, however, something real, something actual, something in the realm of ens. The question of the genuine existence of non-actual or non-real entities, such as numbers, which was so important to the mathematician Frege, is of little interest to St Thomas. Given that for StThomas the field of interest is the real or actual, there is an even closer parallel between what St Thomas says and Kripke's doctrine on the reference of natural-kind terms. But there is an important difference here, too: Kripke is discussing the naming of natural kinds that we are acquainted with, while St Thomas is more interested in the question of how we can come to know or prove that a nomen naturae which we come across in fact refers to any nature. A nature is 'what a thing is': it is expressed by the definition of the thing. 6 The point being made here is that on the one hand one cannot know what a thing is until one has found and investigated it, while on the other one has to have some notion of it if the search for it- the answering

The Signification ofa Name

39

of the question an est?- is even to begin. This notion is supplied by what the word means, the significatio nominis. Borrowing slightly later jargon, we might say that we cannot have a real definition of a thing until we have found it, and thus know that it exists; but the search for it has to start from a nominal definition. This is made clear a little later on. On the first point, he supposes first that a definition is a description which signifies what a thing is. But if there could be no description of a thing other than its definition, it would be impossible for us to know that a thing exists without knowing what it is. This is because it is impossible for us to know that something exists except by means of some description of that thing. For we cannot know whether a thing that we are completely ignorant of exists or not. But there is such a thing as a description of a thing, apart from its definition. This is either a description which explains what the name signifies, or a description of the thing itself which has the name, which is different from the definition, in that it does not signify what the thing itself is, as the definition does, but perhaps some accident of it. 7 It seems possible to neglect the 'other descriptions' referred to here: St Thomas himself seems to do so, and even makes some theoretical difficulty about whether they can be really useful. 8 In any case, what does not exist will not have any accidents, any more than it has a nature or quiddity: so when we start from a position of complete ignorance about whether a thing exists only the significatio nominis will be available to us. When St Thomas really sets himself to prove the existence of something, there is no doubt that the description of the thing he uses is the significatio nominis. His first criticism of what he takes to be St Anselm's ontological argument, 9 is that perhaps a person who hears the name 'God' may not understand that it signifies 'something greater than which nothing can be thought of .10 His own Five Ways, on the other hand, are clearly intended to prove the existence of a God, by proving the existence of something which falls under a description which (he claims) anyone would recognise as expressing the signification of the word 'God'. Each of the Ways ends with a tag to the effect that everyone understands that an object which answers to the description of a first cause, etc., is understood by everyone to be God, or. is called God by everyone, or is said to be God by everyone. 11 The point is made particularly clearly a little after his discussion of the Anselmian argument:

The answer to the second objection is that when a cause is being proved by means of its effect, we have to use the effect in the place of the definition of the cause, in order to prove that the cause exists.

40

God and Explanations This is particularly the case with God, since in order to prove that something exists, we have to take as the middle term [sc. in the demonstration 12) what its name signifies, not what it is. This is because the question 'what is it?' follows on from the question 'does it exist?' 13

But immediately after this we have a complication within the notion of 'what a name signifies'. But the names of God are imposed in virtue of His effects, as will be shown later. Hence when we are proving that God exists by means of His effect, we can take as the middle term what this name 'God' . "fites. 14 stgm This is the first appearance in the Summa of a distinction which plays an important role in the discussion of the names of God in I, q. 13. The distinction is between 'id a quo imponitur nomen ad significandum' and 'illud quod nomen imponitur ad significandum' (or equivalent phrases)between that in virtue of which a name is imposed, and that which a name is imposed to signify. A good account of this distinction is given early on in the question. The answer to the second objection is that there is sometimes a difference, within what a name signifies, between that in virtue of which a name is imposed, and that which a name is imposed to signify. The name 'lapis', stone, for example, is imposed in virtue of its hurting the foot, 'laedit pedem'. But it is not imposed to signify what 'hurting the foot' signifies, but to signify some kind of body. If it were not so, then anything which hurts the foot would be a stone. 15 The inaccuracy of the etymology (which I believe derives from Isidore of Seville) is not relevant here. What is relevant is that we have a clear parallel here with Kripke's thesis about the difference between the fixing of reference and reference itself. The reference of the word 'helium', to use Geach's illuminating example 16 - which incidentally antedates Naming and Necessity by some time- was fixed in terms of the production of such-and-such lines in the solar spectrum: but the word refers not to a process of production but to an element. A later passage makes the parallel clearer. We have to say that that in virtue of which a name is imposed is not always the same as that which a name is imposed to signify. For just as we come to know a thing from its properties or operations, so we

The Signification ofa Name

41

sometimes name the substance of a thing in virtue of some property or operation that it has. So, for example, we name the substance stone in virtue of some action that it has, i.e. its hurting the foot. But this name is not imposed to signify this action, but to signify the substance stone. 17 This point has already been made, and is familiar to us. Less familiar is a point that follows immediately: But if there are things which are known to us in themselves, such as heat, cold, whiteness, and the like, these are not named in virtue of something else. Hence in such things there is no difference between what a name signifies and that in virtue of which a name is imposed. 18 There may be an attempt here to make something of the same point which Kripke wishes to make for the reference of the word 'pain' later in Naming and Necessity. Be that as it may, what is of interest to us in this passage, given that we are trying to tease out St Thomas's doctrine about signification and its relation to the answering of questions of existence, is that here we catch sight of a three-way distinction, as opposed to the two-way distinction we have seen so far. This is not a one-off slip of the pen: other passages seem to suggest that the three-way distinction appears to be genuinely part of StThomas's doctrine on signification as a whole. 19 The three-way distinction is as follows. First we have that in virtue of which a name is imposed, then that which a name is imposed to signifY, then that which a name does signifY. The first complication is that this last notion appears at first sight to be the very notion, that of the signification of a name, within which the distinctions are being made. But this does not of itself argue against St Thomas's claim to be making distinctions within the notion of what a name signifies: he is merely using one and the same expression both in a more generic and in a more specific use. The two uses seem to relate to a sort of a sense-reference distinction: we might say, crudely, that within 'what a word signifies' we can distinguish two other elements beside what the word actually in the end turns out to signify. The verbal complication is easily resolved, and in St Thomas's writing it does not seem to cause any confusion. Perhaps more perplexing is the fact that if we do introduce the notion of 'what a name signifies', in this more specific use, as in the last passage cited, the notion of'that which a name is imposed to signify' seems to have no recognisable role. We could compare and contrast Kripke, for example: he distinguishes between the fixing of the reference and the reference, which clearly correspond to 'illud a quo imponitur nomen' and 'id quod significat nomen' in this use. Where does the notion of'that which a name

42

God and Explanations

is imposed to signify' fit in? One might suspect mere confusion. St Thomas in fact sometimes even starts out by making the distinction between 'a quo imponitur nomen' and 'illud ad quod significandum imponitur nomen', but continues by contrasting it with 'illud quod nomen . 'fi1cat.' 20 s1gm On this point, McCabe suggests that when St Thomas distinguishes between 'id a quo nomen imponitur' and 'id ad quod significandum nomen imponitur', he is not simply pointing to the obvious fact that etymology is a poor guide to meaning. He is comparing the very odd difference between knowing how to use a word and knowing what it means when used of God to the difference between the etymology of a word and its • 21 meamng . This at first sight is not of much use for our problem: it tells us nothing about the difference between 'id ad quod significandum nomen imponitur' and 'id quod significat nomen'. What is more, this account lacks the generality which I claimed that this doctrine had: on this account, this is a problem which arises with language about God alone, while I am trying to see here a doctrine of general application. Fortunately there are two texts, which, while related to what McCabe says, bring out all three of the different notions: We must say something else, then: that names of this kind [e.g. 'good', 'wise', etc.] signify the divine substance. 22 The answer to the third objection is that these names, 'good', 'wise', and the like, are indeed imposed in virtue of perfections which proceed from God to creatures; but they are not imposed to signify the divine nature, but to signify those very perfections in themselves. 23 We see here that when such words as 'good' and 'wise' are used of God, what they in fact signify is God's own nature: but that is not what they are imposed to signify, and a fortiori not what they are imposed in virtue of. This, indeed, goes to make McCabe's point. But what McCabe has not noticed is that the point can be generalised. Though StThomas may have come to make the distinction in order to sort out the theological problem McCabe refers to, it is of wider philosophical interest than that. The theological point being made here is that a name that is imposed to signify a perfection which is usually distinct from the nature of the being which has that perfection, may, when applied to God, signify God's own simple nature. Q!.Iite generally, on the other hand, a name which is

The Signification of a Name

43

imposed to signify a certain nature may fail to do so, as the examples we first examined from the Commentary on the Posterior Analytics make clear. The name 'goatstag', though imposed to signify a certain nature, certainly does fail to signify any such nature, as we have seen: and, according to the opinion of for example the Biblical Fool, the name 'God' may so fail as well. 24 St Thomas thus has two notions which he opposes to 'id a quo imponitur nomen': that of 'id quod nomen imponitur ad significandum' and that of 'id quod nomen significat'. It is true that for the most part these double each other uselessly - usually a name is imposed to signify a nature or a perfection, and does so. Most of what we set out to say we succeed in saying, most of what we set out to talk about we succeed in talking about. Hence in most cases it is all one which notion we oppose to the notion of 'id a quo imponitur nomen' - we can start with one and continue with the other. We have seen that in fact Aquinas does this on occasion, without thereby leading the reader into any serious confusion. But sometimes it is not all one: sometimes we need to allow for the possibility of a nomen naturae failing to signify the nature it is imposed to signify, as when we are asking whether there is anything of that nature, or, of course, when we are discussing the application of that word to God. We seem to have here a parallel to Frege's doctrines on proper names -that they can fail to refer. But there is an important difference here, too. Frege does not hold that a concept-word can fail to refer; indeed, he would be very unhappy with the suggestion that such a word can fail to refer merely because there is nothing that falls under the concept. That there is something which falls under a concept is not a mark of a concept - it cannot affect what the concept, the reference of the concept-word, is. 25 'Goatstag' would be a concept-word for Frege, and would thus refer to a concept, even though we cannot truly predicate 'being a goatstag' of anything. So, even though if anything is a goatstag it is an animal of a certain nature, and even though there is no animal of that nature, the word 'goatstag' does not, for Frege, cease to have reference. St Thomas, of course, does not have the Fregean notion of concept. He would say, as we have seen, that the word 'goatstag' is imposed to signify a certain nature, but since there is nothing of that nature there just is no such nature that it in fact signifies. But he does have some grasp of the Fregean point: he holds that names signify realities only mediately, by means of a ratio or conceptio: 'The description which a name signifies is the intellectual conception of the thing signified by the name ... a name only signifies a reality by means of an intellectual conception'. 26 St Thomas would say, then, that in every case there is a ratio or description under which such a name signifies a nature, so that even if

44

God and Explanations

there is no nature that is in fact signified, the word which is imposed to signify a nature still signifies a certain ratio. StThomas, who is part of a philosophical tradition which ignores the modern problem of privacy, is naturally not bothered with the problem of how something mental, like the ratio, can be common to many thinking subjects. He would agree, moreover, with Frege that what a nomen naturae is true of makes no difference to what it signifies: The answer to the first objection is that there being many names is something that follows the signification of a name, not its predication. The name 'man', for example, is said in only one sense, no matter what it is said of, whether it be said truly or falsely. The name 'man' would have many senses only if we intended to signify different things by it: if, for example, someone intended the name 'man' to signify what really is a man, and another meant to signify by the same name a stone or something else. Hence it is clear that a Catholic who says that the idol is not God is contradicting the heathen who says it is. This is because both are using the name 'God' to signify the true God. For when the heathen says that the idol is God, he is not using the word in the sense in which it signifies 'that which is thought to be God'. If he were, he would be speaking the truth, as even Catholics occasionally use this name with such a signification, as when they say 'All the gods of the heathen are demons'. 27 Apparently, then, the intended signification of a nomen naturae is not in the least affected by what it happens to be predicated of, whether that predication be made truly or falsely. But if this is so, then the intended signification of the name 'goatstag' is still some nature, the nature of some kind of animal composed of goat and stag. But the signification of that name cannot be a certain nature, as there is no such nature. At this point StThomas seems to be badly in need of the Fregean notion of Begrijf, concept, but he can still make shift with his own notion of ratio. We could say in Fregean terms that the reference of the name 'goatstag' is to a concept- this reference succeeds. It is intended to refer to a concept that is a nature, but it does not in fact so refer - this more specialised intended reference fails. We have a case here not of failure of reference, but of error of reference. The parallel is not to a proper name such as 'Don Quixote', which is intended to refer to a human being, and has a sense, but no reference; the parallel is rather to the use of proper names by the victims of deception. Tom Castro, the Tichborne claimant, who had spent some time in Australia and in Chile, was called 'Orton' by his opponents and 'Tichborne' by his supporters. 'Orton' was certainly the name of a

The Signification ofa Name

45

criminal Australian butcher, and 'Tichborne' was certainly the name of an English aristocrat who had visited Chile. If the claimant was genuine, then the use of the name 'Orton' was mistaken in the following way: it was intended to refer to a human being, a human being who had spent time in Australia, and it did so refer; but it was also meant to refer to a criminal butcher, and it failed to refer to any criminal butcher. If the opponents of the claimant were right, then the name 'Tichborne' was mistaken in the following way: it was intended to refer to a human being, a human being who had spent time in Chile, and it did so refer; but it was also meant to refer to an English aristocrat, and it failed to refer to any English aristocrat. Likewise, 'goatstag' is intended to refer to a certain concept, and does so refer. But 'goatstag' is also intended to refer to a certain nature, and it fails to refer to any nature. Since there are no goatstags to possess that nature, there is no such nature either. St Thomas would have to say: 'goatstag' is intended to signify a certain ratio, and does so signify. But it is also intended to signify a certain nature, which it does not signify- since there are no goatstags to possess that nature, there is no such nature. The notion of 'illud ad quod significandum imponitur nomen', then, is used by St Thomas to double for 'id quod significat nomen' in making the distinction with 'illud a quo imponitur nomen' in order that the distinction can be used in cases where the name does not or may not signify any nature. This doubling or intentionalising of the notion makes this distinction a refinement on Kripke's distinction between the reference of a natural-kind term and that by which the reference is fixed. We have seen how the notion of a name's being imposed to signify a nature relates to Fregean notions of reference, and takes account of the problems which arise when we do not know whether there is anything that has the nature signified. What then of the other half of the distinction, the notion of'illud a quo imponitur nomen'? Apart from its value to make the Kripkean point about fixing of reference, is it, like the other notion, of any interest in itself? McCabe related this notion to its theological use, but the discussion of questions of existence, with which we are principally concerned, may seem to suggest that there is more to be made of it. We noticed that it was difficult to make sense of the idea of having any ratio (other than the significatio nominis) of the kind of thing whose existence we are proving; we also noticed that St Thomas actually does use the significatio of the name 'God' when proving His existence, and seems to suggest that this is what we should do to prove the existence of the goatstag. But what is this significatio nominis here? It cannot be the significatio nominis in the restricted sense, 'id quod nomen significat': whether the name actually signifies a real nature is just the point at issue when we are asking whether

46

God and Explanations

anything of that kind actually exists. The notion of 'id ad quod significandum imponitur nomen' looks more useful: we are certainly going to need to know what the name is imposed to signify. We are going to need to know that it is imposed to signify a nature rather than an individual: 28 and presumably part of knowing what the name is imposed to signify may be knowing that it is imposed to signify a nature rather than a (possibly accidental) perfection, or relation. 29 But beyond that, what notion can we have of something about whose existence we are not sure? We certainly need to have some notion of it, to have some description or ratio: if not, as we have seen, the search could never start. As St Thomas says: 'If there were someone who had no knowledge of God under any description whatsoever, he would not even name Him, except perhaps as we utter words whose meaning we are ignorant of?'. 30 In fact, StThomas gives considerable importance in this context to the notion of 'a quo imponitur nomen ad significandum', as giving us the ratio or rationes we need when we are seeking to prove something's existence. For example, as we have already seen, 31 StThomas considers that the fact that 'nomina Dei imponuntur ab effectibus', God's names are imposed in virtue of His effects, is relevant to establishing 'quid significet hoc nomen Deus', what the name 'God' signifies, with a view to proving that God exists. The same is true of the goatstag passage: the ratio of 'goatstag' that we could use when proving that the goats tag exists or not is one that is 'ex pluribus nominibus compositam', made up out of several names, and it is this that tells us that the name 'goatstag' signifies 'some animal made up out of goat and stag'. This is another case where the significatio nominis is told us by 'a quo imponitur nomen'. St Thomas elsewhere explains the relation between 'a quo imponitur nomen' and the significatio nominis. For example, we have already learnt from passages cited above 32 that the different names of God are imposed from His effects. This remark is refined when we discover that these different names are not synonymous because 'though they signify one thing, they signify it under various different rationes or descriptions'. 33 Different names, that is, have different descriptions under which they signify, and the different names answer to the different effects in virtue of which they are imposed. Hence the ratio or description under which a name signifies, which may be all that we know when we begin to enquire whether that which it signifies exists or not, is known by us from our knowledge of that in virtue of which it is imposed to signify. There is one last text, which helps to bring all these considerations together:

47

The Signification of a Name

So because God is not known to us in His own nature, but is glimpsed by us in virtue of His operations or effects, we can name Him from these, as has been said above. Hence this name 'God' is the name of an operation, in so far as that in virtue of which the name is imposed is concerned, since this name is imposed in virtue of His universal providential care for the world. For everyone who speaks of God understands that 'God' names that which has universal providential care for the world. 34 This passage clearly seems to relate to the tags with which each of the Viae concludes, which I referred to above. Those tags are to be thought of as filling out what the name 'God' signifies, and here StThomas relates those generally accepted notions of what 'God' signifies to that in virtue of which the name is imposed. We may find his unquestioning use of etymology, and especially oflsidorean etymologies, to help him establish that in virtue of which a name is imposed, and thus what it signifies, rather over-trusting. But this trait does not detract from the value of the account as a whole. It should be of general value to Kripkeans and other essentialists when they move on from referring to easily recognisable natural kinds and come to wonder about the problems involved when we are trying to establish the existence of a natural kind or of an individual of such a kind. In any case, it should be clear that when StThomas asks 'Does God exist?' his question is backed up by a fairly solid account of how we can understand such a word as 'God' in such a question. It remains to be seen whether he also has an equally full account of how we can understand the word 'exists'. NOTES I. Summa Theologiae, I, q. 13. 2. Summa Theologiae, I, q. 2, a. 2. 3. Commentary on the Posterior Ana/ytics, L.I, lect. 2, n. 17:

Antequam sciatur de aliquo an sit, non potest sciri proprie de eo quid est: non entium enim non sunt definitiones. Unde quaestio, an est, praecedit quaestionem, quid est. Sed non potest ostendi de aliquo an sit, nisi prius intelligatur quid significatur per nomen. 4. Commentary on the Posterior Analytics, L.II, lect. 6, n. 461:

Q!Iia enim non entis non est aliqua quidditas vel essentia, de eo quod non est nullus potest scire quod quid est; sed potest scire significationem nominis, vel rationem ex pluribus nominibus compositam: sicut potest aliquis scire quid significat hoc nomen tragelaphus, vel hircocervus, quod idem est, quia significat quoddam animal compositum ex hirco et cervo; sed impossibile est scire quod quid est hircocervi, quia nihil est tale in rerum natura. 5. 'Magis entis quam ens': Summa Theologiae, I, q. 45, a. 4; seeP. T. Geach, 'Form and existence', in God and the Soul (London: Routledge and Kegan Paul, 1969) For a discussion of the notion of'real existence', see Chapter 5 below, pp. 56,66-7. 6. Commentary on the Posterior Analytics, L.2, lect. 8, n. 484: '[D]efinitio [est] ratio significativa ipsius quod quid est.' 7. Commentary on the Posterior Ana/ytics, L.2, lect. 8, n. 484:

48

God and Explanations Circa primum, supponit primo quod definitio sit ratio significativa ipsius quod quid est. Si autem non posset haberi aliqua alia ratio rei quam definitio, impossibile esset quod sciremus ali quam rem esse, quin sciremus de ea quid est; quia impossibile est quod sciamus rem aliquam esse nisi per aliquam illius rei rationem. De eo enim quod est nobis penitus ignotum, non possumus scire si est aut non. lnvenitur autem aliqua ratio rei praeter definitionem; quae quidem vel est ratio expositiva significationis nominis, vel est ratio ipsius rei nominatae, altera tamen a definitione, quia non significat quid est, sicut definitio, sed forte aliquod accidens.

B. As we shall see later, when the question of the existence of God comes up, StThomas uses the significatio of the name 'Deus', not some other description of God. The same is true of the goatstag mentioned above. On the theoretical difficulty, see Commentary on the Posterior Analytics, L. II, lect. 7, nn. 474--6. 9. StThomas, like Gaunilo, clearly understands this famous argument ofSt Anselm in a way which assimilates it to a great extent to Descartes' ontological argument. It is a matter of dispute whether this reading is faithful to the subtleties of St Anselm's thought. 10. Summa Theo/ogiae, I, q. 2, a. 1, ad 1: 'forte ille qui audit hoc nomen Deus non intelligit significari aliquid quo maius cogitari non possit'. 11. Summa Theologiae, I, q. 2, a. 3, c. 12. StThomas holds, in the Commentary on the Posterior Analytics, L. II, lect. 1, n. 412, that to ask 'is there such a thing?' is to ask 'is there a middle term which can be used in a demonstration of its existence?' 13. Summa Theologiae, I, q. 2, a. 2, ad 2: Ad secundum dicendum quod, cum demonstratur causa per effectum, necesse est uti effectu loco definitionis causae ad probandum causa esse: et hoc maxime contingit in Deo, quia ad probandum aliquid esse, necesse est accipere pro medio, quid significet nomen, non autem quod quid est, quia quaestio quid est sequitur ad quaestionem an est. 14. Summa Theologiae, I, q. 2, a. 2, ad 2: 'Nomina autem Dei imponuntur ab effectibus, ut postea ostendetur: unde demonstrando Deum esse per effectum, accipere possumus pro medio, quid significet hoc nomen Deus'. 15. Summa Theologiae, I, q. 13, a. 2, ad 2: Ad secundum dicendum quod in significatione nominis aliud est quandoque a quo imponitur nomen ad significandum et aliud ad quod significandum nomen imponitur; sicut hoc nomen, lapis, imponitur ab eo quod laedit pedem, non tamen imponitur ad hoc significandum quod significet Jaedens pedem, sed ad significandam quamdam speciem corporum, alioquin omne laedens pedem esset lapis. A parallel is to be found at De Potentia, q. 9, a. 3, ad I. 16. P. T. Geach, essay 'Aquinas', in Three Philosophers (Oxford: Blackwell, 1961), p. 109ff. 17. Summa Theologiae, I, q. 13, a. Be. Dicendum quod non est semper idem id a quo imponitur nomen ad significandum, et id ad quod significandum nomen imponitur. Sicut enim substantiam rei ex proprietatibus vel operationibus eius cognoscimus, ita substantiam rei denominamus quandoque ab aliqua eius operatione vel proprietate; sicut substantiam lapidis denominamus ab aliqua actione eius quia laedit pedem; non tamen hoc nomen impositum est ad significandum hanc actionem, sed substantiam lapidis. lB. Summa Theologiae, I, q. 13, a. Be: 'Si qua vero sunt quae secundum se sunt nota nobis, ut calor, frigus, albedo, et huiusmodi, non ab aliis denominantur. Unde in talibus idem est quod nomen significat, et id a quo imponitur nomen ad significandum.' 19. See, for example, Summa Theologiae, I, q. 13, a. 7, ad I. 20. For example, in Summa Theologiae, I, q. 13, a. Be and ad 2. 21. In his translation of Summa Theologiae, I, qq. 12-13, Blackfriars edn, vol. 3, Appendix 3, p. 105. 22. Summa Theologiae, I, q. 13, a. 2c: 'Et ideo aliter dicendum est quod huiusmodi quidem nomina [sc. bonus, sapiens et huiusmodi] significant substantiam divinam.' 23. Summa Theologiae, I, q. 13, a. 9, ad 3: Ad tertium dicendum quod haec nomina, bonu, sapiens, et similia, imposita quidem sunt a perfectionibus procedentibus a Deo in creaturas. Non tamen sunt imposita ad significandum divinam naturam, sed ad significandum ipsas perfectiones absolute.

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49

24. 'The fool has said in his heart, there is no God', Psalms, 14 [13]: I, and 53 [52]: I. 25. G. Frege, Grundlagen der Arithmetik (Oxford: Blackwell, 1959), §§ 46, 51, 52. 26. Summa Theologiae, I, q. 13, a. 5c and ad 1: 'Ratio enim quam significat nomen est conceptio intellectus de re significata per nomen .... nomen non significat rem nisi mediante conceptione intellectus'. 27. Summa Theologiae, I, q. 13, a. 10, ad 1: Ad primum dicendum quod nominum multiplicitas non attenditur secundum nominis praedicationem, sed secundum significationem. Hoc enim nomen, homo, de quocumque praedicetur, sive vere sive false, dicitur uno modo. Sed tunc multipliciter diceretur si per hoc nomen, homo, intenderemus significare diversa; puta, si unus intenderet significare per hoc nomen, homo, id quod vere est homo, et alius intenderet significare eodem nomine lapidem vel aliquid aliud. Unde patet quod catholicus dicens idolum non esse Deum, contradicit pagano hoc asserenti; quia uterque utitur hoc nomine, Deus, ad significandum verum Deum. Cum enim pagan us dicit idolurn esse Deum, non utitur hoc nomine secundum quod significat Deum opinabilem; sic enim verum diceret, cum etiam catholici interdum in tali significatione hoc nomine utantur, ut cum dicitur, Omnes dii gentium daemonia. 28. 'Impositum ad significandum aliquod singulare': Summa Theologiae, I, q. 13, a.9c. 29. See Summa Theologiae, I, q. 13, a. 9, ad 3: Ad tertium dicendum quod haec nomina, bonus, sapiens, et similia, imposita quidem sunt a perfectionibus procedentibus a Deo in creaturas. Non tamen sunt imposita ad significandum divinam naturam, sed ad significandum ipsas perfectiones absolute. Also Summa Theologiae, a. 7, ad I: Relativa quaedam sunt imposita ad significandum ipsas habitudines relativas, ut dominus et servus, pater et filius, et huiusmodi; et haec dicuntur relativa secundum esse. Qyaedam vero sunt imposita ad significandas res quas consequuntur quaedam habitudines, sicut movens et motum, caput et capitatum, et alia huiusmodi; quae dicuntur relativa secundum dici. 30. Summa Theologiae, I, q. 13, a. 10, ad 5: 'Si vero aliquis esset qui secundum nullam rationem Deum cognosceret, nee ipsum nominaret, nisi forte sicut proferimus nomina quorum significationem ignoramus'. This is clearly StThomas's way of explaining the question 'What is X?', as asked by a High Court judge. 31. Summa Theologiae, I, q. 2, a. 2, ad 2: seep. 40 above. 32. Summa Theologiae, I, q. 13, a. 2c, and I, q. 2, a. 2, ad 2. 33. Summa Theologiae, I, q. 13, a. 4c: 'Licet significant unam rem, significant earn sub rationibus multis et diversis.' 34. Summa Theologiae, I, q. 13, a. 8c: Qyia igitur Deus non est notus nobis in sui natura, sed innotescit ex operationibus vel effectibus, ex his possumus eum nominare, ut supra dictum est. Unde hoc nomen Deus est nomen operationis, quantum ad id a quo imponitur ad significandum. Imponitur enim hoc nomen ab universali rerum providentia. Omnes enim loquentes de Deo hoc intelligunt nominare Deum, quod habet providentiam universalem de rebus.

5 • THE NOTION OF EXISTENCE USED IN ANSWERING AN EST?

We are currently discussing questions of the form 'Do X's exist?', in the context of the Aristotelian-Thomistic theory that such questions have a key role in building up a science. In the last chapter we examined the grasp we need to have of the term 'X' in such a sentence if we are to hope to begin to answer it sensibly. Contemporary parallels were used, but if the reader finds them distracting or even incorrect they can be dispensed with. StThomas's doctrine, I claim, is as I have expounded it. In this chapter we will look at the other part of the key question, 'Does X exist?', the notion expressed by the verb 'exist'. Perhaps every philosopher has at the back of his or her mind the idea that Aquinas gives great importance to the notion of existence and has some rather odd doctrine about it. This view is, I think, not much more true than the idea that Aquinas discusses how many angels can dance on the point of a pin. Aquinas's doctrine on existence is solid, fully worked out, and, in the best of senses, really rather pedestrian. We can see this in his commentary on Book V, Chapter 7 of the Metaphysics of Aristotle. 1 Book V (or .::1, Delta) of the Metaphysics is Aristotle's philosophical lexicon, in which he gives an outline of the principal terms he is going to use. StThomas, as so often, follows Aristotle fairly exactly, but gives us a fuller and more systematic account. For St Thomas, Aristotle's notion of existence is a case of 'focal meaning' or 'analogy': there are several systematically related senses of expressions for existence, with certain family resemblances and connections, grouped more or less tightly around one sense which is central. The central or focal meaning of expressions of existence is regarded as central or focal, not because of any special logical, historical or semantic priority, but because what it expresses can be seen as the notion of existence which is in some sense metaphysically prior. Thus the senses of expressions of existence can be seen to form, as it were, a nest of increasingly central meanings, established by a series of distinctions. 2 The first distinction ( 1) is that between the potentially

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existent and the actually existent. The relevant passage begins: 'Then he makes a distinction between actuality and potentiality. He says that "the existent" and "exist" signify either that which is said or spoken potentially, or that which is said or spoken actually'. 3 The second distinction (2) is made within that which exists actually rather than potentially, between what Aquinas calls 'existence in the sense of the true' and what we might call 'real' existence. The passage begins: 'Then he gives us another sense of"the existent", according to which exist and exists mean the composition of a proposition, which is brought about by the intellect when it composes or divides. Hence he says that "existence" here means the truth of a thing: or rather, as another version has it, that existence means that some sentence is true'. 4 The third distinction (3), made within that which really exists, is between that which exists coincidentally (per accidens) and that which exists in its own right (per se); and the fourth distinction (4), within that which exists in its own right, is between accident and substance. These distinctions are introduced by Here the Philosopher distinguishes the different senses of 'the existent' [ens]. . . . First he distinguishes, within the existent, between the existent in its own right [ens per se] and the coincidentally existent [ens per accidens]. Then he distinguishes the different ways of being coincidentally existent, and thirdly, the different ways of being existent in one's own right. 5 The latter of each of the four pairs distinguished in this enumeration is thought of as more focal than the former: thus, substance is what is expressed by the most focal meaning of all. This fits with the epigram of Aristotle: 'The question that was asked long ago, is asked now, keeps on being asked and always baffles us - "What is being?" - is the question "What is substance?" ' 6 The order imposed in the enumeration above is not that followed by Aquinas in the passage under discussion, where instead of ( 1), (2), (3 ), (4), he gives us, following Aristotle, more or less (3), (4), (2), (1). However, the order I have given above seems more perspicuous, in that it is an ordering from less to more focal. The first distinction, then, to be made within the notion of existence is between that which exists potentially and that which exists actually. The full text of the relevant passage in the Commentary on the Metaphysics, V, 7, runs: Then he makes a distinction between actuality and potentiality. He says that 'the existent' and 'exist' signify either that which is said or

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God and Explanations spoken potentially, or that which is said or spoken actually. That is, in all the terms discussed above, the terms which signify the ten categories, something is said actually, and something said potentially. Hence it happens that each of the categories can be divided into actuality and potentiality. This is true of reality outside the mind: things are said actually and things are said potentially. It is also true within the activities of the mind, and for privations, whose existence is purely dependent on the mind. We say that people know, both because they could be using their knowledge, or because they are using it. It is the same with 'resting': one might either be actually in a state of rest, or able to be resting. This applies not only to accidents, but also to substances. For we say that the Mercury- i.e. the statue of Mercury- exists in the stone potentially, and that the half of a line exists in the line potentially. This is because any part of a continuum exists potentially within the whole. He gives a line as an example of a substance, using here the opinion of those who thought that mathematical entities were substances. He has not yet rejected that view. We say that there is corn even when it is not yet complete, and the corn is only sprouting: and this is there potentially. But when there is something potentially and when there is not yet anything potentially is a subject he leaves to be discussed elsewhere, in Book Nine. 7

The distinction being made is between potentiality and actuality, as he says. We should perhaps rather say: between that which can exist and that which does exist. One should notice that in fact he is appealing to a usage in philosophical Latin according to which that which can be is said to be; we might say, a usage in which the modal particle is omitted. It is not clear how common or how important this usage is in English, but the picture we are given, of our being able to consider that which actually is the case as being surrounded by a kind of penumbra of that which can be the case, is clear enough. The examples he gives are also clear, and several of them fit English usage well enough. We might well say that the statue is inside the stone, as Michaelangelo did, meaning that we can make the statue from the stone. In the same sense, of course, a heap of loose chip pings is also inside the stone, and though we would not normally say anything of the kind, it is a natural extension of what we would say. We say that this grain of corn is wheat, in the sense that it can grow into a fully developed plant of wheat. We also say that someone is resting when he or she is able to rest, i.e. is not currently performing any other task, although for all we know the unfortunate character may be wide awake, rigid and sweating in bed, and not actually resting at all.

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But, as I say, even if the usage of dropping the modal particle that expresses potentiality is not all that common, the picture is clear.lt is true that that which merely can be the case is not in fact the case. A potential trip to the Post Office is not a kind of trip to the Post Office, any more than a proposed trip is one. That is, it is not a kind of trip to the Post Office in the way that a recent trip to the Post Office, or a quick or an early or a troublesome trip to the Post Office are kinds of trips to the Post Office. 8 All the same, that which can be the case can be talked about sensibly in a way that we cannot talk about what cannot be the case. It is important for me to know the various things I can do this afternoon, in any sense of the expression 'I can do': can do sensibly, easily, without spending too much money, without making myself ill, and so on. But there is little point in my sitting down to make a list of all the things I can't do this afternoon: there are far too many of them. I can't calculate 1t to twenty decimal places, I can't calculate 1t to twenty-one decimal places ... and so on ad infinitum. Not to speak of all the calculations of other kinds that I can't perform, and all the other non-calculative operations I can't perform. While the picture of the 'penumbra' of possibility surrounding the actual world is surely to attribute too much reality to what is merely possible, it is equally a mistake to try to eliminate all talk of possibility altogether. StThomas, in fact, can give us some guidance about how to treat possibility. That which is existent in the sense of being possibly existent is less central and less focal than that which is actually existent. Potentiality rests on actuality in two ways. First, potential existence is always a potential existence in some way; a potentiality is always a potentiality to something. There are no pure potentialities. That which can be can be something or other. But, equally well, potentiality rests on actuality in another way as well. That which can be F is always something else, say G, actually. That which can be a statue is at present an unformed block of marble, and so on. These distinctions are closely related to the distinctions which Kenny makes between a power, its exercise, and its vehicle. 9 Every power- every active potentiality, to use a jargon closer to Aquinas's here- is defined in terms of its exercise, of what it is a power for. And equally every power rests on a vehicle, some actual state of the possessor of the power, in virtue of which the possessor has that power. Opium has a dormitive power, 10 a power to put people to sleep, and it is in terms of the actual exercise, sometimes carried out, of putting people to sleep, that the power is defined. It has that power even when it is not exercised. Equally, it has this power in virtue of the vehicle of that power, of some actual features

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of its chemical composition, which can, theoretically, be described independently of the exercise of the power. If no animal had ever taken opium, the power would exist, unknown to us, though it had never been exercised. If the brains and nervous systems of animals were different from what they are, the chemical reality which is in fact the vehicle of the power to put people to sleep would remain, but it would no longer be the vehicle of this power, since this power simply would not exist. There seems to be, as Kenny comments, n a variety of perennial temptations when we come to treat potentialities philosophically. We can try to reduce the power to its exercise, and say that the dormitive power of opium is no more than the fact that often when people take opium they go to sleep. We can try to reduce the power to its vehicle, and say that the dormitive power of opium just is its chemical structure. Or we can 'transcendentalise' the power and regard it as a kind of ghostly or shadowy actuality. There can be no doubt that in general St Thomas's ways of talking lead us closer to the 'transcendentalist' error, but it is arguable that he at least avoids the more serious errors that follow from it. For example, transcendentalism about the powers of the mind is Cartesian dualism; and it is notorious that St Thomas is a strong anti-dualist. In any case, since transcendentalism is a less common error nowadays than the other two, St Thomas can provide us with a good counter-balance to the errors to which we are ourselves more inclined. The next distinction Aquinas makes is that between what he calls 'the existent in the sense of the true' and what we could call 'the really existent'. Aquinas himself has no special label for this latter, more focal sense: he merely calls it 'existence' (esse) or 'the existent' (ens). 12 The 'existent in the sense of the true' is important. This notion corresponds closely to our contemporary notion of existence, which is roughly that existence is that which is expressed by the existential quantifier. Also, it is clearly stated by Aquinas to be the notion of existence used in answer to the question 'an est?', does it exist?. It is therefore the notion most relevant to our present investigation, which is aimed at elucidating Aquinas's answer to 'Does God exist?'. We will need, later in the chapter, to chase the notion through its numerous occurrences throughout Aquinas's work, but for the present we can confine ourselves to how it fits into the nest of increasingly focal meanings of expressions of existence, which Aquinas sketches for us in his Commentary on the Metaphysics V, 7.

Then he gives us another sense of'the existent', according to which exist and exists mean the composition of a proposition, which is brought about by the intellect when it composes or divides. Hence

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he says that 'existence' here means the truth of a thing: or rather, as another version has it, that existence means that some sentence is true. Hence the truth of a proposition can be called the truth of a thing through its being so caused. This is because an utterance is true or false depending on what the thing is or is not. For when we say that something exists, we mean that a proposition is true: and when we say it does not exist, we mean that a proposition is not true. This works whether we are making an affirmation or a denial. In making an affirmation, we say that Socrates is pale, meaning that this is true. In making a negation, we say that Socrates is not pale, meaning that this is true, i.e. his not being pale. In the same way we say that the diagonal is not commensurable with the side of a square, meaning that this is false, i.e. the diagonal's being commensurable. But you should know that this second sense is related to the first as effect to cause. This is because truth and falsehood in a proposition follow from what a thing is in reality. Truth and falsehood are signified by this word 'is', used as the copula. But there are things which are not existents, but which are dealt with by the intellect as if they were: such as negations and the like. Thus sometimes we speak of the existence of something in this second sense and not the first [i.e. in the sense of 'existence in the sense of the true', and not in the sense of 'real existence']. We say, that is, that blindness exists in the second sense, on the grounds that the proposition is true which says that something is blind. We are not saying that it is true in the first sense. For blindness has no existence in reality: rather it is being deprived of some existent. But it is merely coincidental that anything should have something truly said or thought of it: because reality does not depend on knowledge, but vice versa. The existence which each reality has by nature is substantial. So if, when we say 'Socrates exists', we take this 'exists' in the first sense, it is a substantial predication. The existent, after all, is a kind which is superior to all existents, as the kind 'animal' is a superior kind to 'human being'. But if we take it in the second sense, it is a coincidental predication. 13 The first thing which a contemporary linguist might say about this is that it displays something of a blurring between veridical and existential senses of the verb 'esse' in philosophical Latin. The 'veridical' usage is a usage which Latin philosophers seem to have taken over from Greek, in which it is common: a use of the verb 'to be' as roughly equivalent to our English 'to be the case that'. The use of the verb 'to be' on its own in a veridical sense is rare in English; a possible example might be 'He thinks Labour will win the next election, and it may well be'. 14

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It is fairly clear that in the first paragraph St Thomas is thinking primarily of this veridical use. His examples- 'Socrates is pale', 'Socrates is not pale', 'the diagonal is not commensurable with the side of a square' could equally well have been translated by 'It is the case that Socrates is pale', 'It is not the case that Socrates is pale', and 'It is not the case that the diagonal is commensurable with the side'. But it is surely equally clear that in the second paragraph St Thomas is thinking principally of some kind of existential sense. His examples here are 'Blindness exists', and two different existential senses of'Socrates exists'. What is going on here? The key is the distinction which he is making between the two senses of'Socrates exists' in the second paragraph. One of them is clearly a sense in which'- exists' can also be said ofblindness; the other is equally clearly a sense which cannot be said of blindness at all, because blindness is a privation. That is, blindness is not a reality, but the absence or lack of a reality, the power of sight in a given pair of eyes. There is a sense, then, of the predicate ' - exists' in which it is roughly equivalent to ' - is something real', and in this sense it cannot truly be said ofblindness. But there is equally a sense in which '-exists' means something else, and can be said truly of blindness. The sense in which'- exists' is true of Socrates, but not of blindness, is a sense which is, as it were, a generalisation of'- is alive', or, perhaps, so far as this passage would suggest, of ' - is a living being' or ' - is a human being'. A sentence of the form '-exists', taken in this sense, tells us something about the subject: the subject is not an abstraction, a mental entity, a privation or negation, but rather belongs to one of the following kinds: an animal, a plant, an inanimate object or collection of objects, a spiritual creature like an angel, or God. It is a sense of'- exists' in which it makes sense to say that something comes into existence, continues to exist, or ceases to exist; a sense in which it makes sense to say that one thing is dependent for its existence on another. That which exists in this sense, as Geach points out, is that which is capable of initiating or undergoing real change. The difference between 'real change' and any other kind ofchange-i.e. any change that fits the criterion that an object a has changed if and only if'a is F' is true at time t1 and is false at time t2 - is illustrated by the difference between 'The butter has gone down to the basement' and 'The butter has gone down in price'. 15 This is St Thomas's notion of'real existence', 16 which many authors profess to find mysterious. The fact that I don't find it mysterious at all is one of those worrying phenomena that make me worry whether I may not be really stupid after all. 17 What, then, does the predicable expression'- exists' mean in 'Blindness exists' or in the 'esse ut verum' sense of 'Socrates exists'? StThomas

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insists on relating it with the veridical sense he has been discussing in the previous paragraph, both by his use of the label 'existence in the sense of the true', and by the explanation he gives here. It means, he tells us, 'the composition of a proposition, which is brought about by the intellect when it composes or divides'. 'Compose' and 'divide' here are technical terms of medieval logic, roughly equivalent to 'predicate affirmatively or negatively'. This statement he thinks is made clearer by saying 'existence means that some sentence is true'. We can perhaps see what this means by looking at the first of his examples, 'Socrates is pale', 'Socrates albus est'. These sentences are indeed sentences, propositions, enuntiative utterances. They differ, from, for example, the mere complex expression (oratioi 8 'Socrates albus', 'pale Socrates', by the presence of a copulative use of the verb 'esse', to be. We can add this copula to a complex expression such as 'Socrates albus', and there seem to be three ways of describing the result. 1.

2.

3.

'Socrates est albus', 'Socrates is pale'. The addition of the copula is the mark of predication, 19 of what Frege called 'the advance to a truth-value'. 'Est Socrates albus', 20 'It is the case that Socrates is pale'. This is a veridical use of the same verb. It scarcely differs in sense from 1: it only stresses that there has been an advance to a truth-value. 'Socrates albus est', 'Pale Socrates is an existent'. This is an existential use of the same verb.

It would be wrong, then, to think of StThomas as having confused three senses of the verb 'to be' in philosophical Latin: rather he has observed that the three senses coincide in usage so closely that it is impossible to separate them. It is interesting to notice that Charles H. Kahn, in his magisterial work The Verb 'To Be' in Ancient Greek, 21 comes to a similar conclusion to that of St Thomas, when dealing with Greek, a language which had strongly influenced the philosophical Latin of the Middle Ages. According to Kahn, we should distinguish very clearly from all other uses what he calls the 'vital' use of the verb 'to be': a use in which '-is' is equivalent to ' - is alive', or to a generalisation of it, a use which is roughly equivalent to what I have called the notion of 'real existence'. All other uses, whether veridical or existential, are transforms of the copula, according to Kahn. 22 We cannot stop here. The sentences StThomas quotes in the second paragraph do not appear to be copulative uses of the verb 'to be', and not even veridical uses, but purely existential. We should surely consider them

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as secondary or derived uses. 'Caecitas est', 'Blindness exists', we are told, means that something is blind. This, when taken with the reference to veridical uses in the first paragraph, that 'existence means that some proposition is true', will give us a clue which we will be able to follow up later. Suffice it to say here that there is good reason to suppose that 'Blindness exists' is thought by StThomas to be equivalent to some such sentence as 'Some sentence of the form "a is blind" is true'. Equally, 'Socrates exists', in the relevant sense, is equivalent to some such sentence as 'Some sentence of the form "Socrates is F'' is true'. The sense just outlined, the sense of'existence in the sense of the true', is, as we shall see, the sense in which we use the word 'exist' when we ask 'Does God exist?'. But part of the point of saying this comes from contrasting this notion with other more focal notions. Within the notion of the really existent, as outlined above, Aquinas wishes to make a distinction between that which (really) exists in its own right and that which (really) exists coincidentally. 23 The relevant texts of Commentary on the Metaphysics, V, 9 are as follows: 885. Here the Philosopher distinguishes the different senses of'the existent' [ens]. First he distinguishes, within the existent, between the existent in its own right [ens per se] and the coincidentally existent [ens per accidens]. Then he distinguishes the [different] ways ofbeing coincidentally existent [section 886], and thirdly, the [different] ways of being existent in one's own right [section 889]. He says, then, that one sense of 'the existent' is the existent in its own right, and another is the coincidentally existent. But you should be aware that [despite the similarity between per accidens, coincidentally, and accidens, accident] this division within the existent is not the same as the division which is made between substance and accident. This is obvious from the fact that he himself later divides the existent in its own right into the ten categories, of which nine are accidents. The existent is divided into substance and accident by considering it without reference to anything else. In this way whiteness, considered by itself, is said to be an accident, and a human being is said to be a substance. But the coincidentally existent in the sense we are talking about here has to be grasped by making a relation between accident and substance. This making of a relation is signified by the word 'is', when we say e.g. 'a human being is pale'. Hence this whole, that a human being is pale, is an existent coincidentally. So it is clear that the division of the existent into the existent in its own right and the coincidentally existent comes to our notice in virtue of something's being predicated of another, either

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in its own right or coincidentally. The division of the existent into substance and accident, on the other hand, comes to our notice in virtue of something's being by its own nature a substance or an accident. 886. Then he shows us in how many ways the coincidentally existent is expressed. There are three ways, he says: the first is when an accident is predicated of an accident, as in the sentence, 'someone honest is musical'. The second is when an accident is predicated of a subject, as in the sentence, 'A human being is musical'. The third is when a subject is predicated of an accident, as in the sentence, 'Someone musical is a human being'. Since he has already distinguished [earlier in this book of the Metaphysics] between something's being a cause coincidentally and its being a cause in its own right, he uses here the notion of being a cause coincidentally to make clear the notion of being an existent coincidentally. 887. He says that we assign a cause coincidentally when we say that [e.g.] someone musical is building. This is because being someone musical coincides in a builder, or vice-versa. (It is clear that 'so-and-so is such-and-such', [e.g.] that a musical person is building, just means that such-and-such coincides in so-and-so.) It is just the same, too, with the different ways of being coincidentally existent, which we mentioned above. We say, then, that a human being is musical, predicating an accident of a subject; or that someone musical is a human being, predicating a subject of an accident; or that someone pale is musical, or vice versa, that someone musical is pale, predicating an accident of an accident. In all these sentences the word 'is' just means 'coincides in' This last - when an accident is predicated of an accident- means that both accidents coincide in the same subject. The former- when an accident is predicated of a subject - is said to exist because the accident coincides in an existent, that is in the subject. But we say that someone musical is human because the predicate is the person in whom being musical coincides, though being musical is put in subject-position. It is much the same kind of predication when a subject is predicated of an accident, and when an accident is predicated of another accident. [i.e. the grammatical structure of the sentence is no guide to the logical structure]. For a subject is predicated of an accident in the following way: the subject is said to be that in which the accident mentioned in subject-position coincides. In the same way an accident is predicated of an accident, because it is predicated of the

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God and Explanations subject of the accident. Hence, when we say that something musical is a human being, it is like saying that something musical is pale, since that in which being musical coincides - i.e. the subject - is pale. 888. It is clear, then, that the things that are said to be existent coincidentally are said to be so for three reasons. It may be that both the subject and the predicate belong to the same thing, as when an accident is predicated of an accident. Or it may be that the predicate - such as 'musical' - is in an existent, i.e. the subject which is said to be musical. This is the case when an accident is predicated of a subject. Or it may be that the subject, which is put in predicate position, is that in which the accident exists: that of which that accident, used as a subject-term, is said. This is the case when [what is really] a subject is [grammatically] predicated of an accident, as when we say, 'Someone musical is a human being'. 889. Then he makes distinctions within the [different] ways of being existent in one's own right. First he distinguishes the existent which is outside the mind into the ten categories or predicaments. This is what is completely existent. Then he puts forward another kind, the existent which is only in the mind [section 895-6]. Thirdly he divides the existent into the potentially existent and the actually existent [section 897]. The existent divided up in this way is more general than the completely existent, since the potentially existent is only relatively and incompletely existent. First, then, he says that the things which signify the figures of predication are said to be existents in their own right. You should be aware that the existent cannot be broken up in a determinate way in the way that a genus is broken up into its species, by specific differences. This is because a specific difference is not itself a member of the genus, and thus it does not fall within the essence of that genus. But there is nothing that can fail to fall within the essence of the existent, so as to be capable of specifying it. This is because that which does not fall within the existent is nothing, and so cannot make a specific difference. This is how the Philosopher proved in the third book of the present work that the existent cannot be a genus [998b21]. 890. Hence the existent should be specified according to different ways of predicating, which follow on from different ways of existing. As he says, "'Is" signifies in the same number of ways as there are ways of saying', i.e. there are as many ways of expressing the existence of something as there are ways of predicating something. That is why the first division of the existent is into what are called

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the categories or predicaments: because they are distinguished by different ways of predicating. This is because some of the things which are predicated signify what a thing is, others what it is like, others how big, and so on. So within each of the different ways of predicating, existence should signify the same thing. When we say 'A man is an animal', for example, the 'is' signifies [the existence of a] substance. But when we say 'A man is pale', it signifies [the existence of a] quality, and so on. 891. You should know that the predicate can be related to the subject in three ways. In one way, it is what the subject is, as when I say 'Socrates is an animal'. This is because Socrates is that which is an animal. This predicate is said to signify first substance, i.e. an individual substance, that of which everything [else] is predicated. 892. In the second way, the predicate is taken from something that is in the subject [i.e. an accident]. This predicate can be in the subject in its own right and without reference to anything else. This may be either as following from its matter, as it is in the case of quantity, or as following from the form, as it is in the case of quality. Or, on the other hand, it can be in the subject, not without reference to anything else, but with some reference to something else: this is the case of relation. In a third way, the predicate is taken from something outside the subject. This can be sub-divided: it may be completely outside the subject or not. If it is, then if it is not some measurement of the subject, then it is a predicate of having, e.g. Socrates has shoes on, or has clothes on. But if it is the measurement of the subject, then since extrinsic measurement is either time or place, the category is taken either from the side of time, i.e. when; or from the side of place, in which case it will be where, provided that the arrangement of its parts in the place is not considered. If it is considered, it will be posture. There is another kind of category if that from which the predicate is taken is in the subject of which it is predicated in some relative way. If it is in the subject as its origin, then it will be a predication of acting. This is because the origin of an acting is in the subject of the acting. But if it is in the subject as its terminus, then it will be a predication of being acted on. This is because being acted on has its terminus in the subject which is acted on. 893. But there are predications in which the word 'is' [which is the same as 'exists' in Latin] is clearly not used. You should not think, however, that such predications do not belong to the predication of existence. For example, take 'A man walks'. Aristotle dismisses this by saying that all predications of this kind signify that

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something exists. This is because any verb can be analysed into the verb 'is' [or 'exists'] and the participle. It makes no difference whether you say a man is walking, or walks; and similarly for the others. Hence it is clear that there are as many ways to express existence as there are ways of predicating. 24 What we can derive from this text is that the really existent (ens) can be in some sense divided into two: the really existent in its own right (ens per se) and the really existent coincidentally (ens per accidens). St Thomas insists that this is a division made on logical rather than metaphysical criteria: there are no metaphysical criteria on which to base a division of the existent, as the very notion of the existent is metaphysically prior to any criterion that could be used to make such a division. That is, any metaphysical criterion would have to be based, in some sense, on an existent, and this basis for the criterion would thus necessarily be part of what the criterion serves to divide. The criterion, then, is logical: that of Aristotle's 'Categories', manners of predication, which are outlined in the work of the same name. 25 Aristotle holds that of anything we care to mention there are several different things we may want to say: several different questions we may want to ask about it, we might say. The principal division among the things that we want to say about some subject is between what it really is in itself and what it happens to be. When this division is applied to the existent, the resulting two groupings of categories are those of substance and accident. Substance is what a thing is, rather than what it happens to be. When we make such a predication as 'a is F, within the category of substance, it is equivalent to' F is what a really is' .26 Since for both Aristotle and St Thomas the notions of 'the existent' and 'the one and the same' always go together, 27 we can think of a predication in the category of substance as providing the criteria of identity for the subject. Both these two would subscribe to Quine's dicta 'No entity without identity' and 'no identity without entity'. But when the predication 'a is F is made in one of the other categories, the accidental categories, as they are called, the sentence is equivalent to 'F is what a happens to be'. We can diversify the accidental categories, following StThomas's gloss on Aristotle here: we can explain 'Socrates is five foot six' as 'Five foot six happens to be Socrates's height'; 'Socrates is wise' as 'Wise is how Socrates happens to be'; 'Socrates is Crito's friend' as 'A friend is how Socrates happens to be to Crito', or perhaps 'A friend of Crito is how Socrates happens to be to others'; 'Socrates is wearing a coat' as 'Wearing a coat is how Socrates happens to be dressed'; 'Socrates is up early' as 'Early is when Socrates happens to be up'; 'Socrates is in

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prison' as 'Prison is where Socrates happens to be'; 'Socrates is sitting down' as 'Sitting down is how Socrates happens to be positioned'; 'Socrates is talking' as 'Talking is what Socrates happens to be doing'; and 'Socrates is having his pulse felt' as 'Having his pulse felt happens to be what Socrates is having done to him'. Clearly this list, if it is meant to be exhaustive, needs a good deal more work. St Thomas's justification of the criteria on which it is based, given in the text above, is ingenious but unconvincing. The category of time, of when, in particular seems to resist adequate phrasing and rationalisation. If we except time, we might want to give a rather more metaphysical account of the categories of being, and say that change can occur with respect to any one of the categories without occurring with respect to any other. 28 But even so more thought will be needed. The categories are important in this context because anything that is said entirely within one category expresses a per se existent, an existent in its own right, something that is also one and the same thing in its own right. For example, the sentence 'Socrates is a human being' talks about Socrates and Socrates alone; not Socrates plus something else, human nature. Equally 'This length [ ] is one inch' talks about a length, a quantity, and that alone, and thus expresses something wholly in the category of quantity; 'This shape [o] is a square' expresses something wholly in the category of quality. Both individual substances, such as Socrates, and individual accidents, such as this length [ ], this shape [o], are per se existents, existents in their own right. This doctrine does not affect the claim that Aristotle and Aquinas are about to make, that substance has, notwithstanding, a priority, a focality with regard to accidents. The claim that is being made here is that per se existents have a priority or focality with regard to per accidens existents, coincidental existents, things that are expressed by expressions which are made up of elements from more than one category. For example, 'Socrates is pale' tells us about two separate per se existents, the substance Socrates and the individual colour-accident, this paleness. It also tells us, therefore, of a complex existent, a coincidental existent, a complex unity, a per accidens unity or existent: the paleness of Socrates. The examples St Thomas gives of expressions which tell us about per accidens existents tend to be complete sentences, or at least complex expressions, such as 'Pale Socrates'. But there are of course innumerable single and apparently simple expressions which express per accidens existents: 'Postman', for example, means 'Person who delivers the mail', an extremely complex per accidens existent which combines the substance of the person, the action of delivering, the relation to letters,

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and possibly the whole complex of society in which people (more substances) write (another action) letters (themselves complex existents involving paper- another complex existent- and ink- yet another), and arrange for (another action) their (relation) letters to be carried (passion) to other people (more substances) who live elsewhere (place). 29 'Lunch' or 'party' are other words that express per accidens existents: I leave it to the reader to work out the per se existents involved in them. In general, any artefact and any complex is going to be a per accidens existent. How interesting is this? Is its value purely historical? I should say not. One may question to what extent St Thomas and Aristotle succeed in correctly identifying that which exists in its own right, as opposed to that which exists coincidentally. There is no doubt, for example, that they would both have thought that air was an existent in its own right, and there is equally no doubt that when we apply their criteria to what we now know about air, it turns out to be pretty highly coincidental. One may also wonder to what extent our ability to pick out the coincidental depends on the alleged fact that the expressions for the coincidental hop between categories. If this is so, does the whole enterprise not depend on the accuracy of the categories, which we have no special reason to believe in? But leaving aside these points, which seem to be minor, I do not think that we can do without some kind of a distinction between the coincidentally existent and that which exists in its own right, between the per accidens and the per se. Indeed, those who this century have tried hardest to overthrow the distinction have only ended up in suggesting alternative candidates for the per se and the per accidens. The young Russell claimed that persons and things are only logical constructions out of events. There is no doubt that with this he intended to undermine the distinction between the per se and the per accidens, according to which things and persons, being substances, are prior, while events are secondary. But all he succeeded in doing was claiming that we had got the same pair of candidates the wrong way round: if the young Russell were right, events would be existents in their own right and people and things would be highly coincidental complexes formed out of them. I take it that at this stage no-one is likely seriously to maintain that Russell might have been right: 30 if we are stuck with a distinction between the per se and the per accidens, we are stuck with the candidates we have had since Aristotle's time, and the order in which he placed them. Aristotle, after all, was only showing the way in which our common-sense metaphysics is reflected in our language; we cannot take Russell seriously until he has developed a whole new language and taught us to speak it. 31

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The distinction between the per se and the per accidens has some application in the specific case of the arguments for the existence of God, but so far as I can make out the distinction between substance and accident, and the arguments for the priority of substance, have not. 32 What is particularly important for the discussion of the existence of God is the notion of esse ut verum, which has already been sketched out with the help of texts from the Commentary on the Metaphysics. I intend to show that St Thomas thought that it was this notion, not that of real esse, which was used in answering questions of the form 'Does X exist?', and I hope to be able to suggest that he was able to anticipate, to a great extent, the points raised by Kant and Frege against the Ontological Argument of Descartes. For the first point, the texts are easily cited. Probably the best early text is from his Commentary on the Sentences of Peter Lombard: But 'being' in these two different senses is predicated in different ways. If it is taken in the first sense [real esse], it is a substantial predicate, and has to do with the question, what is it? But if it is taken in the second sense, it is an accidental predicate, as Averroes says in commenting on this point, and has to do with the question, does it exist.i' 3 Reference to the answers to two different questions is to be found also in two later texts, one from De Malo and one from the Summa Theologiae: The existent is said in two ways. In one way it signifies the nature of the ten categories, and in this sense, evil is not an existent or anything real, nor is any privation. But in another way it is used to reply to the question does it exist?, and in this sense evil does exist, just as blindness exists. Not that evil is a reality. Being a reality means not only the answer to the question does it exist?, but also to the question what is it.i4 Is there evil in reality? We approach this point in this way: apparently there is no evil in reality .... Moreover, the existent (ens) and reality are convertible terms. So if evil is an existent in reality, it should be a reality, which goes against what we have said .... The answer to the second objection is that (as it says in Book Five of the Metaphysics) the existent has two senses. In one sense, it means the existence of a reality: in this sense the existent is divided into the ten categories, and in this sense it is convertible with reality. In this

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I should like to suggest that the distinction St Thomas is making in these passages, between what is said in answer to the question 'does it exist?' and what is said in answer to the question 'what is it?' corresponds closely to the account given by Frege when he tells us that existence is analogous to number - 'affirmation of existence is in fact nothing but the denial of the number nought' 36 - and that number is not a mark (Merkmal) of a concept, but a property (Eigenschafi) of the concept itself. That is, the denial of the number nought is not something that is true or false of the individual things of a kind; it forms no part of the answer to the question what things of that kind must be like (quid est?). To put it briefly, to say that God exists, or that a unicorn doesn't exist, doesn't mean attributing existence to God, or non-existence to some unicorn, but attributing being God to something, attributing being a unicorn to nothing; or, for the matter of that, denying being a unicorn of anything. You name it, it isn't a umcorn. The assimilation of Aquinas's doctrine here to Frege's was first made, as far as I know, by Geach. 37 He draws attention to the fact that Frege himself is conscious of Aquinas's other notion of existence, real existence, as I have called it, 'actual existence', as Geach says, to assimilate the English expression to Frege's Wirklichkeit. The notion of existence which Frege regards as equivalent to the denial of the number nought, Aquinas's esse ut verum, Frege calls Esgibtexistenz. There are differences between the two doctrines, of course, as well as similarities. Both Aquinas and Frege regard esse ut verum or Esgibtexistenz as extending more widely than real esse or Esgibtexistenz. That for Frege the 'actual', the Wirklich, was only a part of the existent, is well known. Aquinas is equally explicit. Whatever is said to be an existent in the former way [i.e. really existent] is also an existent in the latter way [i.e. with esse ut verum] ... But not everything that is an existent in the second way is an existent in the first way .... Privations are said to be existents in the second way, but not in the first way. 38 Though there is a similarity here, it masks a difference. Frege's favoured examples of non-actual existents (non-real existents, in my jargon) are numbers; Aquinas's are privations. In fact there is little doubt that Aqui-

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nas would disagree with Frege's Platonism about numbers: although Aquinas has some luminous and suggestive remarks about numerical terms as applied to God, 39 his explicit doctrine about numbers in general is a rather poor Aristotelian account according to which numbers are human mental productions. 40 This is perhaps not important; we may, I think, agree with Geach that Frege and Aquinas would both accept that the dead are paradigmatically non-actual (or non-real) existents, things that exist with esse ut verum alone, not with real esse. It is clear that Frege would accept this; if we ask 'how many dead are there?' the correct answer is a denial of the number nought, while the dead are paradigmatically non-wirklich. Equally, for Aquinas we can form true affirmative propositions about the dead - for example 'Socrates was wise' or 'Socrates is famous', and it is thus clear that the answer to 'Do the dead exist?' is 'They do'. In the same way the answer to 'Does God exist?' is 'He does'. But the dead are par excellence those who no longer exist with real esse, since Aquinas holds, following Aristotle, that for living things, to exist is to be alive. 41 (It is worth recalling, by the way, that a dead person is not to be equated with a corpse. Clearly, since people die in explosions, and in any case corpses decay and disappear, there are far more dead people than there are corpses.) A much more serious difference between the two authors is that in this context Aquinas has nothing that answers to Frege's distinction of concept and object, to the distinction of levels of predication which forms the framework ofFrege's doctrine. We have already seen something of the account which StThomas gives of esse ut verum. Things exist with esse ut verum if a true affirmative proposition can be formed about them. Leaving aside for a moment the difficult question of what constitutes the 'affirmativeness' of a proposition, we already run into a disagreement with Frege. For Frege, things cannot exist with Esgibtexistenz at all, strictly speaking. Esgibtexistenz is something that can only be true of a concept, a kind, not of an object. For Frege, 'Julius Caesar exists' is equivalent to 'Julius Caesar is greater than zero', which ought to be as foolish an expression as 'Julius Caesar= 2'. However, forSt Thomas, we have already seen that a sentence such as 'Socrates exists', taken in the esse ut verum sense, makes perfectly good sense: indeed, it is even true, while the same sentence taken in the real esse sense has not been true since the hemlock took effect. Kenny suggests that Aquinas's account is actually limited to giving a sense to expressions of the form 'X est', i.e. 'X exists', in which 'X' is an abstract expression typically signifying a privation, but possibly some other kind of form. 42 This is a mistake. Aquinas applies his account to

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sentences such as 'Deus est', 'God exists', where the subject-term is not an abstract but a concrete term. It is a mere coincidence that in his favourite example, 'Caecitas est', 'blindness exists', the subject-term is an abstract one. ForSt Thomas, the difference between an abstract term such as 'caecitas', 'blindness', and a concrete term such as 'Caecum', 'blind' or 'something blind', is merely a difference of mode of signification (modus significandi), not a difference of thing signified (res significata ). 43 Aquinas makes this point with reference to positive and indeed substantive terms such as 'divinitas', Godhead, as opposed to 'Deus', God, or 'humanitas', human nature, as opposed to 'homo', 'human being'; 44 and it seems that it applies also to positive accidental determinations, such as the difference between 'albedo', 'paleness', and 'album', pale. 45 But there is no reason to suppose that it would not apply to the difference between 'vacuitas', 'emptiness', and 'vacuum', 'empty space'; and, as we shall see, Aquinas is willing to maintain the truth of the proposition 'Non est vacuum', empty space does not exist. 46 For this to be true, Aquinas has to maintain that we cannot form a true affirmative proposition about empty space, about 'vacuum'. Kenny wants to insist that what is said to exist or not exist must be considered as the subject of the sentence. But all Aquinas tells us is that the relevant affirmative proposition has to be formable 'about' (de) X. Surely a proposition can be formed about X in the relevant sense without 'X' being the grammatical subject of that proposition? 'Dominus so/us est Deus', 'The Lord alone is God', is clearly 'about' God as much as it is about the Lord. In any case, Aquinas's detailed account of the grammar of sentences which express esse ut verum tells us that the verb 'to be' as used in such sentences is a copulative use. Sentences such as 'Socrates est' and 'Malum est' ('Evil exists') are both sentences which express esse ut verum, and, ex hypothesi, the verb 'est' in either sentence is a copula. This leaves both sentences elliptical: 'Socrates est' has to be elliptical for 'Socrates est aliquid', or simply as equivalent to 'Socrates est-', where the gap is to be filled up by a predicable expression, a term taken to have what most medievals would have called 'simple suppositio'. 47 But then, by parity of reasoning, 'Malum est' cannot be taken as elliptical for 'Malum est aliquid', the more so as Aquinas has told us that 'Malum est aliquid' is in fact false. Even taking it as equivalent to 'Malum est-' must be wrong: the gap is in the wrong place. The paradigmatic use of 'malum' is not as a subject-term but as a predicate. 'Malum est' is thus elliptical for '-est malum'. We need not confine ourselves to reflection on general principles. Aquinas in fact gives us a text in which he definitely regards the 'X' in 'X

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est' as a predicate, and therefore regards the whole as elliptical for 'A liquid est X' or as equivalent to'- est X'. The text is in the Commentary on the Sentences ofPeter Lombard. Existence (esse) has two senses, that is as meaning the truth of a composition, and as meaning the act of an essence. So when we say: one thing is 'the Father exists', another is 'the Son exists'- in such a way that existence is the predicate of the sentence - it means the existence which is an accident of essence. Hence it is false, since all three have one essence, and one existence. But when we say: one thing is 'the Father exists', another is 'the Son exists'- in such a way that 'Father' is the predicate in the sentence- in 'exists' the truth of the composition is meant. 48 The theology here is clear: it is heretical to attribute to God more than a single real esse, act of existence. But obviously it is equally heretical to deny that there is a Father, there is a Son, and there is a Holy Spirit. These three existential propositions are of the esse ut verum form, and do not have anything to say about God's real esse. But no less clear is the grammar: for StThomas, the difference between 'Pater est' in the sense which expresses real esse, and 'Est Pater' in the sense in which it expresses esse ut verum, is that in the former sense the word 'Pater' is the subject-expression, while in the second sense the word 'Pater' is a predicable expression. The parallel with Frege is closer than it seemed at first, and certainly closer than it is on Kenny's account. Crucially, StThomas's account can be used, as Frege's was, to demolish the ontological argument of Descartes. A key text here is early in the Summa Theologiae: Is God's act of existence identical with his essence? We approach this point in this way: apparently God's act of existence (esse) is not identical with his essence .... Moreover, we can know of God that he exists, as has been said above. But we cannot know what he is. So God's existence (esse) is not identical with what he is, his essence or nature .... The answer to the second objection is that existence (esse) has two senses. In one sense it means the act of existence; in the other it means the composition of a proposition, which is made by the mind in joining a predicate to a subject. Taking existence in the first way, we cannot know the existence of God, just as we cannot know his essence: we can only know it in the second way. For we know that this proposition which we make about God, when we say God exists, is true: and we know this from his effects. 49

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Again, the theology is clear. God's essence is unknowable; but, according to Aquinas, God's essence is identical with God's existence. How then can we know the existence of God? Simply because what we know when we know the existence of God is God's esse ut verum. We are not claiming to know anything about God's real esse, which is indeed unknowable. Thus the existence which is identical with God's essence, the existence which is a perfection of God, which God necessarily possesses, which is inseparable from the very idea of God, as Descartes would say, is simply not what we are trying to show when we argue that there is a God, when we answer to the question 'An est Deus?' affirmatively. 50 Aquinas would say that when Descartes argues 'Necessarily, God has all perfections; existence is a perfection; therefore God exists', he is playing on the ambiguity of the two notions of existence which St Thomas is here distinguishing. In the premiss 'Existence is a perfection', the word 'existence' has to mean real esse, which is part of the answer to the question 'Quid est Deus?'. In the conclusion, 'God exists', the word 'exists' has to mean esse ut verum, the notion of existence which is used in giving an answer to the question 'An est Deus?'. We have already seen something of the rationale for the connection which St Thomas suggests between this notion of existence (esse ut verum) and the notion of truth, the connection which is enshrined in his very terminology. His full account of the connection- that X exists, in this sense, when an affirmative proposition can be formed about X- seems to take some time to develop. In some texts he speaks of an affirmative predication (compositio) being made about X. In some texts he omits to mention that the proposition has to be affirmative, and in others he omits to mention that the proposition has to be true. It seems impossible to establish any firm delineation between propositions or predicates which are affirmative and those which are negative. Is 'Socrates is bald' affirmative or negative? And what about 'Socrates is not bald'? As we shall see shortly, there may be a possibility of establishing a difference between those predicates that do and those predicates that do not presuppose the real existence (esse) of their subjects- what Prior called 'E!-predicables'. 51 But to justify calling predicates so distinguished 'affirmative' and 'negative' one would have to justify most of StThomas's account of the nature of truth, and also justify the relation of dependence which he alleges to exist between propositions which express esse ut verum and those which express real esse. Nevertheless, it is not difficult to see the intuitive distinction which St Thomas wishes to make, and the reasons for it. One can take as typical,

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perhaps, the sentences 'Deus est', God exists, which St Thomas regards as true, and 'Phoenix est', the phoenix exists, which St Thomas regards as false. 52 Either will be true if a true affirmative proposition can be formed about either God or the phoenix. St Thomas will want to claim that true affirmative propositions can be formed about God: for example, 'Dominus est Deus', the Lord is God; or 'Deus in principio creavit caelum et terram', in the beginning God created heaven and earth. There is no problem here. What is crucial is that St Thomas is committed to saying that no true affirmative proposition can be formed about the phoenix: any affirmative proposition which we can form about the phoenix will be false, and any true proposition which we can form about the phoenix will be non-affirmative. An affirmative proposition we might want to form about the phoenix could be 'Phoenix est avis', the phoenix is a bird, or, perhaps pointing to a sideshow at a fair, or to a picture 'Iste est phoenix', this is a phoenix. But both these will be false, according to St Thomas. The phoenix is not a bird because it is not real, is not anything at all. 53 And 'This is a phoenix' will not be true in either imagined situation: a picture of a phoenix is no more a phoenix than a picture of a human being is a picture of a human being, and if there are no phoenixes it will turn out that however cleverly the illusion is managed at the fair, it will be no more than the sort of trick we are used to at fairs. 54 Meanwhile, true sentences about the phoenix will be non-affirmative. We have established that 'The phoenix is a bird' and 'This is a phoenix' will both be false, and we may thus take it that 'The phoenix is not a bird' and 'This is not a phoenix' will both be true. True non-affirmative sentences such as these can be multiplied indefinitely: the phoenix is not a bird, and it is not a fish or a reptile, for that matter. And 'this is not a phoenix' is going to be true whatever it is that I point at. However, the very indefinite multiplicability of such sentences shows us partly what is meant by saying that such sentences are not affirmative: there is no end of saying what something is not. What about a less indefinite and less obviously negative proposition, such as 'Phoenix est avis fictus', the phoenix is a fictional bird? Here there is no negative particle to give us a clue, and 'The phoenix is a fictional bird' seems to have a certain contextual appropriateness which is not shared by 'The phoenix is a mythical fire-breathing reptile'. This contextual appropriateness makes 'the phoenix is a fictional bird' look true, while 'the phoenix is a mythical fire-breathing reptile' is false. There is in fact little problem here: the recourses of medieval logic are sufficient to establish that 'Phoenix est avis fictus', even if true, is no more affirmative than is 'Phoenix non est avis'. 'Fictus' is what the

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medieval logicians and grammarians called an adiectivum alienans, an alienating adjective. 55 This concept is best explained by way of examples, and a good example in modern English is 'forged'. A Scottish five-pound note is both a five-pound note and Scottish, but a forged five-pound note is not both a five-pound note and forged. Precisely because it is forged, it is not a five-pound note. The adjective 'forged' alienates or invalidates the true application of the other descriptions. The same is obviously true of 'fictional': Sherlock Holmes, in so far as he is a fictional detective, is not a detective at all, and thus the phoenix is not a bird. 'Phoenix est avis fictus' is thus clearly non-affirmative. There is a gap here. St Thomas should clearly have something to say about intentionality, and should discuss whether 'Phoenix dicitur esse avis', the phoenix is said to be a bird, counts as an affirmative proposition for the purposes of providing a basis for 'Phoenix est', the phoenix exists. But though clearly something could or should be said, it seems hard to bring intentional cases such as this under the heading of non-affirmative propositions. An attempt might be made, as mentioned above, to equate 'affirmative' propositions with those which affirm or presuppose some real existence in their subject. Clearly being said to be a bird does not imply any real existence in its subject, but at the most in those to whom the saying is attributed. But this cannot be used directly as a criterion for affirmativeness in the relative sense, since were we so to use it we would run up against the problem of negations and privations. By St Thomas's account, we ought not to be able to affirm truly of evil or blindness any predicate which would imply the real existence of evil or blindness. It is worth noting that we can, however, affirm being evil or being blind of a number of real existents, and, indeed, only of real existents. The dead are not evil or blind any more, though they once were. This looks like providing a more accurate criterion: some individual exists in the esse ut verum sense if we can affirm of it some predicate that implies its present or past real existence, and some concept is instantiated if we can affirm it of some present or past real existent. This criterion seems to give us what we want, but it has taken us far from StThomas's tag of 'forming an affirmative proposition'. However, it does not take us very far from a point which appears to be important in St Thomas's treatment of esse ut verum. St Thomas several times insists that the notion of esse ut verum is not only non-focal, but in some sense also derivative 56 from the notion of real esse. 57 Any sentence affirming esse ut verum can be traced back to, we might say, some sentence affirming real existence. A sentence affirming esse ut verum in some way

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depends for its truth on some sentence affirming real existence. The notion of esse ut verum is derivative. In some cases we can see what is meant. Often we simply affirm the esse ut verum of something that exists anyway with real existence, as in the case of God. When we affirm the esse ut verum of the dead we are implicitly affirming at least a past real existence. When we affirm the esse ut verum of privations such as evil or blindness we are implicitly affirming the real existence of the subject of the privation. At this point, however, St Thomas will have to part company very definitely with Frege. For Frege, numbers are genuinely non actual existents, (non-real existents, in my semi-Thomist terminology). It is hard (Frege would say impossible) to see their esse ut verum or Esgibtexistenz as derivative from some real existence. 58 St Thomas would probably answer quite shortly here that numbers are human constructions based on material realities, 59 and Frege would certainly answer even more shortly that StThomas didn't know what he was talking about. 60 It is indeed worth pointing out that St Thomas's claim about numbers is surely incompatible with his belief that there may have been very many angels before there were any material realities, and certainly before there were any human minds to reflect on them, and also with his belief that there were three divine persons before there was any created mind at all. 61 If numbers are a construction of any mind, they must be constructions of the divine mind. But it does seem a little implausible that numbers are part of God's creation; it would seem more appropriate to regard them as in some way part of God. This would appear to be the only way we can make the esse ut verum of numbers derivative from some real existence, and I admit it seems a pretty desperate recourse. Still, there seem to be reasons, independent of maintaining this thesis about the derivativeness of esse ut verum, for holding that numbers may be a part of God. The claim that numbers cannot be God's creation and therefore subject to God's will has its own intrinsic attractiveness, while Frege's Platonism about numbers- the claim that they are genuine non-real existents- was on occasion unattractive even to himself. 62 Enough has been said, perhaps, to show that StThomas's notion of esse ut verum, though in some ways strange to us, combines a great deal of logical and grammatical insight. Given that it is this notion which is used in answering questions of the form 'Does X exist?' (an est?), which is the form of the particular question which we are gradually approaching, 'Does God exist?' (an est Deus?), it remains for us to examine the account which St Thomas gives us of how in general such questions can be answered, particularly when it is a question, as it often is in science, of proving the existence of a cause from its effects.

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I. Commentary on the Metaphysics, L.V, lectio 9, nn. 885-97. 2. See G. E. L. Owen, 'Aristotle on the snares of ontology', in R. Bambrough (ed.), New Essays on Plato and Aristotle (London: Routledge and Kegan Paul, 1979). 3. Commentary on the Metaphysics, L.V, lectio 9, n. 897: 'Ponit distinctionem entis per actum et potentiam; dicens, quod ens et esse significant aliquid dicibile vel effabile in potentia, vel dicibile in actu.'

4. Commentary on the Metaphysics, L.V, lectio 9, n. 895: 'Ponit alium modum entis, secundum quod esse et est significant compositionem propositionis, quam facit intellectus componens et dividens. Unde dicit, quod esse significat veritatem rei. Vel sicut alia translatio melius habet, quod esse significat quia aliquod dictum est verum.' 5. Commentary on the Metaphysics, L.V, lectio 9, n. 885. 'Hie Philosophus distinguit quot modis dicitur ens .... Primo distinguit ens in ens per se et per accidens. Secundo distinguit modos en tis per accidens .... Tertio modo en tis per se.' 6. Metaphysics, book Z, 1028b 3-9. The translation is that of G. E. M. Anscombe, Three Philosophers, (Oxford: Blackwell, 1961), p. 19. 7. Commentary on the Metaphysics, L.V, lectio 9, n. 897: Ponit distinctionem entis per actum et potentiam; dicens, quod ens et esse significant aliquid dicibile vel effabile in potentia, vel dicibi1e in actu. In omnibus enim praedictis terminis, quae significant decem praedicamanta, aliquid dicitur in actu, et aliquid in potentia. Et ex hoc accidit, quod unumquodque praedicamentum per actum et potentiam dividitur. Et sicut in rebus, quae extra animam sunt, dicitur aliquid in actu et aliquid in potentia, ita in actibus animae et privationibus, quae sunt res rationis tantum. Dicitur enim aliquis scire, quia potest uti scientia, et quia utitur; similiter quiescens, quia iam inest ei quiescere, et quia potest quiescere. Et non solum hoc est in accidentibus, sed etiam in substantia. Etenim Mercurium, id est imaginem Mercurii, dicimus esse in lapide in potentia, et medium lineae dicitur esse in linea in potentia. Quaelibet enim pars continui est potentialiter in toto. Linea vero inter substantias ponitur secundum opinionem ponentium mathematica esse substantias, quam nondum reprobaverat. Frumentum etiam quando nondum est perfectum, sicut quando est in herba, dicitur esse in potentia. Quando vero aliquid sit in potentia, et quando nondum est in potentia, determinandum est in aliis, scilicet in nono huius. 8. The example is from Geach. 9. In The Metaphysics of Mind (Oxford: Oxford University Press, 1991), pp. 71-4 on vehicle, exercise and power, pp. 27-8, 83 on powers (capacities); and in Will, Freedom and Power, pp. 9-11. 10. This sentence 'opium has a dormitive power' is seldom uttered except in mockery. I assert it as plainly and simply true. The reader may find it interesting to consider what strange view of the world is involved in rejecting this statement as false, and how such a view of the world relates to the view of the world presupposed by, for example, the science of pharmacology and our common practice of buying aspirins. 11. In The Metaphysics ofMind, pp. 71-4, and in Will, Freedom and Power, pp. 10--11. 12. Though he does seem to suggest the label of 'ens perfectum' in Commentary on the Metaphysics, L.V, lectio 9, n. 889: see below, p. 80 and n. 24. 13. Commentary on the Metaphysics, L.V, lectio 9, nn. 895-6: Ponit alium modum en tis, secundum quod esse et est significant composition em propositionis, quam facit intellectus componens et dividens. Unde dicit, quod esse significat veritatem rei. Vel sicut alia translatio melius habet, quod esse significat quia ali quod dictum est verum. Unde veritas propositionis potest dici veritas rei per causam. Nam ex eo quod res est vel non est, oratio vera vel falsa est. Cum enim dicimus aliquid esse, significamus propositionem esse veram, et cum dicimus non esse, significamus non esse veram; et hoc sive in affirmando sive in negando. In affirmando quidem, sicut dicimus quod Socrates est albus, quia hoc verum est. In negando verum, ut Socrates non est albus, quia hoc est verum, scilicet ipsum esse non album. Et similiter dicimus quod non est diameter commensurabilis lateri quadrati, quia hoc est falsum, scilicet non esse ipsum non commensurabilem .... 896. Sciendum est autem quod iste secundus modus comparatur ad primum sicut effectus ad causam. Ex hoc enim quod aliquid in rerum natura est, sequitur veritas et falsitas in

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propositione, quam intellectus significat per hoc verbum 'est' prout est verbalis copula. Sed quia aliquid quod est in se non ens, intellectus considerat ut quoddam ens, sicut negationem et huiusmodi, ideo quandoque dicitur esse de ali quo hoc secundo modo et non primo. Dicitur enim quod caecitas est secundo modo, ex eo quod vera est propositio, qua dicitur aliquid esse caecum; non tamen dicitur quod sit primo modo vera. Nam caecitas non habet aliquod esse in rebus, sed magis est privatio alicuius esse. Accidit autem unicuique rei quod aliquid affirmetur intellectu vel voce. Nam res non refertur ad scientiam, sed e converso. Esse vero quod in sui natura unaquaeque res habet est substantiale. Et ideo cum dicitur 'Socrates est', si ille 'est' primo modo accipiatur, est de praedicato substantiali. Nam ens est superius ad unumquodque entium, sicut animal ad hominem. Si autem accipiatur secundo modo, est de praedicato accidentali. 14. See C.]. F. Williams, What is Existence? (Oxford: Clarendon, 1981), p. 305. It is perhaps worth noting that 'es que ... ' in modern Spanish is a clear example of a veridical sense of one of their two verbs 'to be', a usage which has become so common and worn-down that for many people it is no more than a verbal tic. 'No he pegadoni golpe' ='I haven't done a stroke of work'; compare 'Es que no he pegado ni golpe', which can perhaps best be translated, using a comparable verbal tic of some English-speakers, as 'I haven't done a stroke of work, actually'. 15. See Geach, 'What actually exists', in God and the Soul (London: Routledge and Kegan Paul, 1969), pp. 71-2. 16. The label is unfortunate, as if suggesting that the other notion of existence is in some way unreal. But etymologically, the label 'real' existence is appropriate, since it is the kind of existence that can truly be attributed to things (res) and their properties, determinations and combinations. Geach, who introduced the notion most clearly into contemporary English-speaking philosophical discourse, uses the label 'actual' existence. But this is a label that I have difficulty in using, since the label 'actual' is also needed for the distinction with 'potential' existence, and since it has made some think (e.g. Kenny) that the distinction between 'real existence' and 'existence in the sense of the true' can be juggled away by the use of a distinction between a classificatory sense and an actual, present-tense sense- see his The Five Ways (London: Routledge and Kegan Paul, 1969) pp. 89-91. The contrast established in the passage quoted, where tense is not relevant (since, to be accurate, Socrates does not exist any more) makes it clear that this is a mistake. 17. See C. F. J. Martin, The Philosophy of Thomas Aquinas: Introductory Readings (London: Routledge, 1988), pp. 49-55, 114-17, for a discussion of this perplexity. 18. For the difference between a complex expression (oratio) and a declarative sentence (enunciatio) or proposition (propositio) see Martin, The Philosophy of Thomas Aquinas, pp. 18-30, discussing passages such as L.I, 11.4-5 in StThomas's Commentary on the De lnterpretatione. 19. See, for example, Quodlibetales IX, q. 2, a. 3, notes 53 and 55 below. 20. Word order counts for little in Latin, but a medieval author might well have tried to fix the flexible usage of his language as something rather like what I suggest. 21. Charles H. Kahn, The Verb 'To Be' in Ancient Greek (Dordrecht: Reidel, 1973). 22. Op. cit. p. 224, pp. 407-14. Another passage relevant to the connection between copulative and veridical senses of the verb 'to be' in Latin, and StThomas's notion of esse ut verum, is to be found later on in the Commentary on the Metaphysics, at LVI, 1.4, n. 1223:

Here he is commenting on being (ens) in the sense of the truth of a proposition .... He says, then, that 'a sense of being means, as it were, true', that is, that it just means truth. For when we ask if man is an animal, the answer is, he is; which means that the previous proposition is true. And in the same way, non-being means, as it were, false .... This kind of being, which is called true, and non-being, which is called false, arise in composition and division. Simple utterances do not mean anything true or false; but complex utterances become true or false by affirmation and negation. Here affirmation is called composition, because it means that the predicate is in the subject, while negation is called division, because it means that the predicate is apart from the subject. Hie determinat de ente, quod significat veritatem propositionis .... Dicit ergo quod ens quoddam dicitur quasi verum, id est quod nihil aliud significat nisi veritatem. Cum enim interrogamus si homo est animal, respondetur quod est, per quod significatur propositionem praemissam esse veram. Et eodem modo non ens significat quasi falsum .... Hoc autem ens quod dicitur quasi verum et non ens quod dicitur quasi falsum, consistit circa compositionem et divisionem. Voces enim incomplexae neque verum neque falsum significant, sed voces

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God and Explanations complexae per affrrmationem aut negationem veritatem aut falsitatem habent. Dicitur enim hie compositio, quia significat praedicatum inesse subiecto. Negatio vero dicitur hie divisio, quia significat praedicatum a subiecto removeri.

23. 'Existent in its own right', and analogous phrases, translate ens per se. 'Existent coincidentally' and analogous phrases translate ens per accidens. This excellent rendering comes, I think, originally from C. Kirwan in his translation and commentary on books r, .1., E, of Aristode's Metaphysics (Oxford: Clarendon, 1971 ). 24. Commentary on the Metaphysics, L.V, lectio 9, nn. 885-93: Hie Philosophus distinguit quot modis dicitur ens. Et circa hoc tria facit. Primo distinguit ens in se et per accidens. Secundo distinguit modos entis per accidens. Tertio modos entis per se. Dicit ergo quod ens dicitur quoddam secundum se, et quoddam secundum accidens. Sciendum tamen est quod ilia divisio entis non est eadem cum ilia divisione qua dividitur ens in substantiam et accidens. Quod ex hoc patet, quia ipse postmodum ens secundum se dividit in decem praedicamenta, quorum novem sunt de genere accidentis. Ens igitur dividitur in substantiam et accidens, secundum absolutam entis considerationem, sicut ipsa albedo in se considerata dicitur accidens, et homo substantia. Sed ens secundum accidens prout hie sumitur, oportet accipi per comparationem accidentis ad substantiam. Quae quidem comparatio significatur hoc verbo 'est', cum dicitur 'homo est albus'. Unde hoc totum, homo est albus, est ens per accidens. Unde patet quod divisio entis secundum se et secundum accidens, attenditur secundum quod aliquid praedicatur de aliquo per se vel per accidens. Divisio vero entis in substantiam et accidens attenditur secundum hoc quod aliquid in natura sua est vel substantia vel accidens. 886. Deinde ostendit quot modis dicitur ens per accidens; et dicit quod tribus: quorum unus est, quando accidens praedicatur de accidente, ut cum dicitur, iustus est musicus. Secundus, cum accidens praedicatur de subiecto, ut cum dicitur, homo est musicus. Tertius, cum subiectum praedicatur de accidente, ut cum dicitur musicus est homo. Et quia superius iam manifestavit quomodo causa per accidens differt a causa per se ideo nunc consequenter per causam per accidens manifestat ens per accidens. 887. Et dicit quod sicut assignantes causam per accidens dicimus quod musicus aedificat, eo quod musicum accidit aedificatori, vel e contra, constat enim quod hoc esse hoc, idest musicurn aedificare, nihil aliud significat quam hoc accidere huic, ita est etiam in praedictis modis entis per accidens, quando dicimus hominem esse musicum, accidens praedicando de subiecto; vel musicum esse hominem, praedicando subiectum de accidente; vel album esse musicum, vel e converso, scilicet musicum esse album, praedicando accidens de accidente. In omnibus enim his esse nihil significat quam accidere. Hoc quidem, scilicet cum accidens de accidente praedicatur, significat quod ambo accidentia accidunt eidem subiecto; illud vero, scilicet cum accidens praedicatur de subiecto, dicitur esse quia enti (idest subiecto) accidit accidens. Sed musicum esse hominem dicimus quia huic - scilicet praedicato - accidit musicum, quod ponitur in subiecto. Et est quasi similis ratio praedicandi, cum subiectum praedicatur de accidente, et accidens de accidente. Sicut enim subiectum praedicatur de accidente ea ratione, quia praedicatur subiectum de eo, cui accidit accidens in subiecto positum; ita accidens praedicatur de accidente, quia praedicatur de subiecto accidentis. Et propter hoc, sicut dicitur musicum est homo, quia scilicet illud cui accidit esse musicum, scilicet subiectum, est album. 888. Patet igitur quod ea quae dicuntur esse secundum accidens, dicuntur triplici ratione: aut eo quod ambo - scilicet subiectum et praedicatum - insunt eidem, sicut cum accidens praedicatur de accidente, aut quia illud - scilicet praedicatum, ut musicum - inest enti, id est subiecto, quod dicitur esse musicum (et hoc est cum accidens praedicatur de subiecto ); aut quia illud - scilicet subiectum in praedicato positum - est illud cui inest accidens, de quo accidente illud (scilicet subiectum) praedicatur. Et hoc est scilicet cum subiectum praedicatur de accidente, ut cum dicimus, musicum est homo. 889. Deinde distinguit modum entis per se: et circa hoc tria facit. Primo distinguit ens quod est extra animam per decem praedicamenta, quod est ens perfectum. Secundo ponit alium modum entis, secundum quod est tantum in mente. Tertio dividit ens per potentiam et actum: et ens sic divisum est communius quam ens perfectum. Nam ens in potentia est ens secundum quid et imperfecturn. Dicit ergo primo quod ilia dicuntur esse secundum se quaecumque significant figuras praedicationis. Sciendum est enim quod ens non potest hoc modo contrahi ad aliquid determinatum sicut genus contrahitur ad species per differentias. Nam differentia, cum non

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participet genus, est extra essentiam generis. Nihil autem posset esse extra essentiam entis, quod per additionem ad ens aliquam speciem entis constituat: nam quod est extra ens, nihil est, et differentia esse non potest. 890. Unde oportet quod ens contrahatur ad diversa genera secundum diversum modum praedicandi, qui consequitur diversum modum essendi; quia quoties ens dicitur- id est quot modis aliquid praedicatur- toties esse significatur, id est tot modis significatur aliquid esse. Et propter hoc ea in quae dividitur ens primo dicuntur esse praedicamenta, quia distinguuntur secundum diversum modum praedicandi. Quia igitur eorum quae praedicantur, quaedam significant quid, id est substantiam, quaedam quale, quaedam quantum, et sic de aliis. Oportet quod unicuique modo praedicandi, esse significet idem: ut cum dicitur homo est animal, esse significat substantiam. Cum autem dicitur homo est albus, significat qualitatem, et sic de aliis. 891. Sciendum enim est quod praedicatum ad subiectum tripliciter se potest habere. Uno modo cum est id quod est subiectum, ut cum dico Socrates est animal. Nam Socrates est id quod est animal. Et hoc praedicatum dicitur significare substantiam primam, quae est substantia particularis, de qua omnia praedicantur. 892. Secundo modo ut praedicamentum sumatur secundum quod inest subiecto: quod quidem praedicatum vel inest ei per se et absolute, ut consequens materiam, et sic est quantitas; vel ut consequens formam, et sic est qualitas; vel inest ei non absolute, sed in respectu ad aliud, et sic est ad aliquid. Tertio modo ut praedicatum sumatur ab eo quod est extra subiectum: quod quidem si non sit mensura subiecti, praedicatur per modum habitus, ut cum dicitur, Socrates est calceatus vel vestitus. Si autem sit mensura eius, cum mensura extrinseca sit vel tempus vel locus, sumitur praedicamentum vel ex parte temporis, et sic erit quando; vel ex loco, et sic erit ubi, non considerato ordine partium in loco, quo considerato erit situs. Alio modo ut id a quo sumitur praedicamentum, secundum aliquid sit in subiecto, de quo praedicatur. Et si quidem secundum principium, sic praedicatur ut agere. Nam actionis principium in subiecto est. Si vero secundum terminum, sic praedicabitur ut in pati. Nam passio in subiecto patiens terminatur. 893. Quia vero quaedam praedicantur, in quibus manifeste non apponitur hoc verbum 'est', ne credatur quod illae praedicationes non pertineant at praedicationem entis- ut cum dicitur, homo ambulat- ideo consequenter hoc removet, dicens quod in omnibus significatur aliquid esse. Verbum enim quodlibet resolvitur in hoc verbum 'est' et participium. Unde patet quod quot modis praedicatio fit, tot modis ens dicitur. 25. Categories: see Aristotle's Categories and De lnterpretatione, translation and commentary by ]. Ackrill (Oxford: Clarendon, 1978), especially the first five chapters. 26. See Anscombe, 'Aristotle', in Three Philosophers, pp. 7-13. 27. See, for example, Commentary on Metaphysics L.IV, 1.2, n. 560. 28. See Anscombe, 'Aristotle', in Three Philosophers, pp. 14-18. 29. See G. T. Geach, section 'Form' in essay 'Aquinas', in Three Philosophers (Oxford: Blackwell, 1961), p. 87. 30. But see below, Chapter 13, pp. 187-8. 31. Compare the work of Kripke, who has taught us that the unconscious metaphysics which is enshrined in our ordinary use oflanguage is highly essentialist. Aristotle's metaphysics at times seems little more than a formalisation of this unconscious metaphysics. 32. For the application of the per se I per accidens distinction in the discussion of the existence of God, see Chapter 6 below, pp. 91-2, and Chapter 8, pp. 113-14. The distinction between substance and accident has no application to God: God has no accidents, and is not, properly speaking, a substance; God is beyond the categories. 33. Commentary on the Sentences ofPeter Lombard, L.II, d. 34, 1.1, sol: Ens autem secundum utrumque istorum modorum diversimode praedicatur: quia enim secundum primum modum acceptum, est praedicatum substantiale, et pertinet ad quaestionem quid est; sed quantum ad secundum modum, est praedicatum accidentale, ut Commentator ibidem dicit, et pertinet ad quaestionem an est. I may say that a careful reading of Averroes's Commentary on Metaphysics, V, 7 suggests that St Thomas is being over-modest: the distinction between the use of 'esse' as a substantial predicate and its use as an accidental predicate is indeed to be found in Averroes, but the connection with the answers to two different sorts of questions is Aquinas's own. The parallels with the passage on esse ut verum quoted from the much later Commentary on the Metaphysics, V, 9, especially para. 896 in fine - see note 13 above - are worth noticing.

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Ens dicitur dupliciter. Uno modo quod significat naturam decem generum, et sic neque malum neque aliqua privatio est ens neque aliquid. Alio modo secundum quod respondetur ad quaestionem an est, et sic malum est, sicut et caecitas est. Non tamen malum est aliquid; quia esse aliquid non solum significat quod respondetur ad quaestionem an est, sed etiam quod respondetur ad quaestionem quid est. 35. Summa Theologiae, I, q. 48, a. 2, ad 2. Utrum malum inveniatur in rebus. Ad secundum sic proceditur: videtur quod malum non inveniatur in rebus .... Ens et res convertuuntur. Si ergo malum est ens in rebus, sequitur quod malum sit res quaedam, quod est contra praedicta. Ad secundum dicendum quod sicut dicitur in V Metaphysicorum, ens dupliciter dicitur. Uno modo secundum quod significat entitatem rei, prout dividitur per decem praedicamenta, et sic convertitur cum re; et hoc modo nulla privatio est ens, unde nee malum. Alio modo dicitur ens quod significat veritatem propositionis, quae in compositione consistit, cuius nota est hoc verbum est: et hoc ens est quo respondetur ad questionem an est, et sic caecitatem dicimus esse in oculo. 36. Grundlagen der Arithmetik (Oxford: Blackwell, 1959), § 53. 37. In the section 'Esse' of the essay 'Aquinas', in Three Philosophers, and in 'Form and existence' and 'What actually exists?', in God and the Soul (London: Routledge and Kegan Paul, 1969). My debt to Professor Geach in my understanding of this topic is incalculable. Also I should like to pay tribute to Professor Alejandro Llano, of the University of Navarre, who first drew to my attention the importance of Geach's ideas here. Some of the development of Geach's ideas which I make here I owe to Professor Llano: cf. his Metafisica y Lenguaje (Pamplona: EUNSA, 1984). 38. In II Sententiarum, 34, 1.1, sol: Quaecumque ergo dicuntur entia quantum ad primum modum, sunt entia quantum ad secundum modum ... Non autem omnia quae sunt entia quantum ad secundum modum sunt entia quantum ad primum . . . [P]rivationes dicuntur esse entia quantum ad secundum modum, sed non quantum ad primum. 39. Summa Theologiae, I, q. 30, a. 3c: 'Termini numerales non ponunt aliquid in Deo, (roughly, 'the application of numerical terms to God does not signify any reality'. 40. See, for example, Commentary on the Metaphysics, L. XI, 1.1, n. 1262. 41. See Summa Theologiae, I, q. 18, a. 2c, referring to De Anima, L.II, 415b13: 'Vivere viventibus est esse.' 42. See A. Kenny, The Five Ways (London: Routledge and Kegan Paul, 1969), pp. 85-86. 43. Cf. Summa Theologiae, I, q. 13, a. 1, ad 2. 44. Ibid. 45. Quodlibetales, IX, q. 2, a 3: 'Whiteness is said to exist, not because it has self-existence in itself, but because by it something has being-white' ('Albedo dicitur esse, non quia ipsa in se subsistat, sed quia ea aliquid habet esse album'). 46. See Commentary on the Physics, L.IV, 11.9-14, where the non-existence of the vacuum is discussed; see also Chapter 6 below, p. 83. 47. Summa Theologiae, III, q. 16, a. 7, ad 4: 'Ad quartum dicendum quod terminus in subiecto positus tenetur materialiter, id est pro supposito; positus vero in praedicato, tenetur formaliter, id est pro natura significata.' ('The answer to the fourth objection is that a term in subject-position has material suppositio, that is, it stands for an individual; but when it is in predicate-position, it has formal suppositio, that is, it stands for the nature which it signifies'). It is clear from this that StThomas adopts the common logician's convention that in a sentence of the form 'A est B', 'A' stands for some object, and 'B' stands for some concept (to use Frege's terminology). A logician such as Burley would probably have made Aquinas's point by saying 'Terminus in subiecto positus supponit personaliter, terminus in praedicato positus supponit simpliciter'. See A. Broadie, An Introduction to Medieval Logic (Oxford: Oxford University Press, 2nd edn, 1993), where this doctrine of Burley's (and of Aquinas's) is given greater attention than in the first edition.

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Commentary on the Sentences, I, d. 28, in expositione textus:

Esse dicitur dupliciter: scilicet prout significat veritatem compositionis, et secundum quod significat actum essentiae. Quando ergo dicitur, Aliud est Patrem esse, aliud est Filium esse, ita quod ly esse sit praedicatum dicti: significatur esse quod est accidens essentiae; unde falsa est, quia sicut una est essentia trium, ita et unum esse. Cum autem dicitur, Aliud est esse Patrem, aliud esse Filium, ita quod ly Patrem praedicetur in dicto, in esse significatur veritas compositionis. The text of the last sentence as punctuated by Mandonnet gives no sense at all. Punctuated as above, one can get the sense given in my translation, though the use of 'in esse' to mean 'in the word"esse"' is an unusual one. But there is evidence in the manuscripts that this difficult sentence was corrupted and reconstructed very early: it is possible that what StThomas wrote was 'Cum autem dicitur, Aliud est esse Patrem, aliud esse Filium, ita quod ly Patrem praedicetur in dicto, ly esse significat veritatem compositionis', i.e. 'But when we say: "one thing is 'The Father exists', another is 'The Son exists"' in such a way that "Father" is the predicate in the sentence, the "exists" signifies the truth of a composition'. 49. Summa Theologiae, I, q. 3, a. 4, ad 2: Utrum in Deo sit idem essentia et esse. Ad quartum sic proceditur: videtur quod in Deo non sit idem essentia et esse .... Praeterea, de Deo scire possumus an sit, ut supra dictum est. Non autem possumus scire quid sit. Ergo non est idem esse Dei, et quod quid est eius, sive quidditas vel natura .... Ad secundum dicendum quod esse dupliciter dicitur. Uno modo significat actum essendi, alio modo significat compositionem propositionis quam anima adinvenit coniungens praedicatum subiecto. Primo igitur modo accipiendo esse, non possumus scire esse Dei, sicut nee eius essentiam, sed solum secundo modo. Scimus enim quod haec propositio quam formamus de Deo, cum dicimus Deus est, vera est: et hoc scimus ex eius effectibus. 50. SeeP. T. Geach, in the essay 'Aquinas', in Three Philosophers pp. 89-90. 51. See A. N. Prior, Past, Present and Future (Oxford: Clarendon, 1967). 52. I cannot for the life of me find any definite text where St Thomas professes disbelief in the phoenix. Nor, for that matter, in the centaur, which I would have sworn to. Let us, for the purposes of this discussion, take it that St Thomas doesn't believe in the phoenix. 53. For 'is not real' StThomas usually uses some such phrase as 'non est aliquid': see note 34 above. 54. Compare the stuffed mermaid which used to be on show in one of the hotels in Aden: it was, I gather, the stuffed upper half of a female chimpanzee rather clumsily sewn on to the stuffed lower half of a large cod. 55. Used by P. T. Geach, in 'Good and evil', in P. Foot, Theories ofEthics (Oxford: Oxford University Press, 1967), p. 64. 56. Commentary on the Metaphysics, L.V, lectio 9, n. 896: 'Sciendum est autem quod iste secundus modus comparatur ad primum sicut effectus ad causam.' See above, note 13. 57. Cf. also e.g. Quodlibetales, IX, q. 2, a. 3: 'Esse dupliciter dicitur: uno modo secundum quod est verbalis copula significans compositionem cuiuslibet enuntiationis quam anima facit: unde hoc esse non est aliquid in rerum naturae, sed tantum in actu animae componentis et dividentis.' 58. See e.g. Frege, Grundlagen der Arithmetik, § 61. 59. See e.g. Commentary on the Metaphysics L.VII, 1.10, nn. 1494-6. 60. See e.g. Frege, Grundlagen der Arithmetik, §§ 23-4. 61. Numbers of angels, see Summa Theologiae, I, q. 50, a. 3c; possible precedence of creation of angels over material creation, see Summa Theologiae, I, q. 61, a. 3c; precedence of creation of angels over creation of human beings, see Summa Theologiae, I, q. 90, a. 4c; on eternal existence of three divine persons, see Summa Theologiae, I, q. 30, a. lc. 62. Geach, in the preface to the essay 'Frege', in Three Philosophers p. 130, attributes the following anecdote to Wittgenstein: 'The last time I saw Frege, ... I said to him: "Don't you ever find any difficulty in your theory that numbers are objects?" He replied "Sometimes I seem to see a difficulty - but then again I don't see it".'

6 • DEMONSTRATING THE EXISTENCE OF A CAUSE FROM ITS EFFECT

The last chapter gave an account of the notion of existence which St Thomas believes to be used in the asking and answering of questions of the form 'Does X exist?', distinguishing it from other notions which he perhaps regards as more important. It has been argued that the notion St Thomas thinks he is using here is substantially identical with the notion which all post-Fregean philosophers have been familiar with, and thus need not cause us any particular hesitation. So much for the question; what about giving the answer? Once the question 'Does X exist?' has been analysed, distinguished from other related questions, and clarified, we can at least start to give an answer, but little that has been said so far gives us any clue to how to attempt an answer. To discover how to attempt an answer we have to turn again to the Aristotelian account of science. In recent years more attention than hitherto has been given to Aristotelian accounts of science. It is now widely accepted that Aristotle and his heirs are not, as was thought at one time, trying vainly to give what we would call a theory of science - a theory of how to find out, of how knowledge is acquired - but, as I claimed in Chapter 2, a theory of how knowledge once found out should ideally be structured. 1 This understanding has led to a new appreciation of Aristotelian work. Nevertheless, though we now understand what Aristotle and his heirs intended to do, and can thus see their work as valuable, we should not allow this to blind us to the fact that a theory of Aristotelian science is not enough; we also need a theory of science in the modern sense. That is, Aristotelians also need a theory of how to find out. This chapter aims at investigating whether a theory of the acquisition of knowledge, a theory of science in the modern sense, can be found in the writings of Aquinas. The text principally examined will be the Commentary on the Posterior Analytics, where Aquinas, following Aristotle, discusses both the notion of'demonstratio quia per effectum' 2 and that of

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answering the question 'an est?'. 3 These two notions are brought together memorably in the discussion of the possibility of demonstrating the existence of God from God's effects, which St Thomas gives us immediately before embarking on the Five Ways, a passage which is worth recalling. The answer to the second objection is that when a cause is being proved by means of its effect, we have to use the effect in the place of the definition of the cause, in order to prove that the cause exists. This is particularly the case with God, since in order to prove that something exists, we have to take as the middle term [sc. in the demonstration] what its name signifies, not what it is. This is because the question 'what is it?' follows on from the question 'does it exist?' But the names of God are imposed in virtue ofHis effects, as will be shown later. Hence when we are proving that God exists by means of His effect, we can take as the middle term what this name 'God' signifies. 4 The two notions can also be seen to be implicitly used together in discussions in the Commentary on the Physics, particularly that of the existence of place. 5 One obstacle in this investigation is that while Aquinas was clearly interested in finding out, in acquiring scientific knowledge, he seems to have little explicit interest in a theory that would give an account of the processes involved. Evidence for such a theory in his writings, then, has to be sought in asides, as it were, in digressions from what he sees as his main task of explaining Aristotle's theory of the articulation of a completed sctence. There is another obstacle to our understanding of what Aquinas has to say, which is at first sight more daunting. The circumstances in which Aquinas is attempting to build up some kind of natural science may be thought to be quite different from the circumstances we find ourselves in when we do science. We, it is often said, typically start from a phenomenon and look for its cause: this cause, until discovered, has no name in our language. This is not how things are with Aquinas: he has all the names he needs, perhaps too many. He has many words such as 'place', 'vacuum', 'self-mover' and the like- words which stand for concepts with an alleged explanatory role. His task is to find out whether the concepts that these words stand for are coherent, whether they in fact have any explanatory role, and whether there is anything in reality that these words stand for. Hence his typical starting point is a question such as 'an est locus?' or 'an est vacuum?' (is there such a thing as place or as the vacuum?).

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It might be alleged, against this, that though people often claim that modern science works in the way outlined, often it is not in fact true of present-day science. The contemporary scientist, it seems, very often does give names to causes whose very existence, let alone nature, is not understood. 'Quarks' and 'superstrings', I understand, would be cases in point. Be that as it may, it is clear that Aquinas's sort of enquiry is not totally alien to modern science. We can see this quite clearly if we leave aside the contentious present and look at the recent past: modern scientists have certainly had occasion to make the same sort of investigation as Aquinas typically makes. At the beginning of the nineteenth century, for example, modern scientists had to ask 'does phlogiston exist?', and at the beginning of the twentieth century, 'does ether exist?' (and I suppose scientists are probably asking even now 'do superstrings exist? or 'do quarks exist?'). Hence even modern science may fairly often have to ask questions of exactly the same form as Aquinas's. We shall see later that in any case the way in which Aquinas answers such questions uses techniques analogous to those that must be used to answer the question which is ideally seen as central to modern science, 'What is the explanation for this phenomenon?' There are still other obstacles to our seeking a theory of science, in the modern sense, in Aquinas, but they are more easily dealt with, at least initially. For example, Aquinas always speaks of the Aristotelian science which he is building up by answering questions as expressing 'necessary' truths. We, on the other hand, do not speak of the truths of science as necessary, but there can be no doubt that we treat them as if they were necessary, in Aquinas's sense- that is, as universally and everlastingly, or even timelessly, true. Again, we speak of our science as a technique of proving the cause from the effect, while Aquinas is clear that there can be no demonstratio propter quid per effectum. 6 It is not hard to get round this difficulty. The apparent conflict is resolved by noticing that our way of speaking is rather loose. What we prove is not the explanation, not the propter quid of the phenomenon, but the truth - the quia - of the hypothesis that we have formed to explain the phenomenon. We devise a hypothesis to explain a phenomenon, and what we seek to prove is that this hypothesis is the case. This is clearly a demonstratio quia, and quia can certainly be demonstrated from the effect. 7 With these difficulties out of the way, we can go on to Aquinas's treatment of the answering of questions. Scientific questions are to be answered by demonstration: 'Science is knowledge acquired by means of demonstration. We have to acquire knowledge by demonstration of what

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we were previously ignorant of; and we ask questions about what we are ignorant of.'8 How, then, according to Aquinas, can demonstration be used in the answering of questions? The difficulty we face here is that most of Aquinas's treatments of this relate to the answering of, say, a pupil's questions by one who is in possession of a complete science. The demonstrations usually discussed, therefore, are deductive demonstrations from higher principles, from the causes, from what is 'notius in se', more fully known in itself, if not always 'quoad nos', more fully known so far as we are concerned. The material thus needs careful handling if we are to show what can be demonstrated in the answering of a question by one who does not possess complete science, but is rather labouring to build it up. 9 The questions usually start with a word. We have drawn attention above to the claim that modern science is more likely to start with a phenomenon. We will see later how the two kinds of discussion can be connected. The aim, then is to start with a word that is in common use such as 'God', 'place', 'vacuum', or to be found in reputable authors, such as 'goatstag', 'Idea', 'phlogiston', and discover whether there is anything that the word picks out. 10 The discussion of 'place' is particularly interesting as it is the clearest case of St Thomas arguing for the existence rather than the non-existence of something, using the Aristotelian method he expounds, apart from the rather special case of the existence of God, on which we are aiming to throw light. The first thing we need is to understand the word, to have some idea of the 'significatio nominis', as discussed in Chapter 4.n If we do not have this, we cannot even ask 'Does it exist?'; we cannot ask anything about, it, except in so far as we can ask about the meaning of a word that is wholly unknown to us. 12 It is important to notice that a word may include being a cause in its very signification: this is certainly the case with 'God', according to Aquinas, 13 and would seem to be the case with 'Idea', 'phlogiston', and probably 'vacuum'. But there are many words which do not so obviously include the notion of being a cause in their very signification: 'goatstag' and 'place' are not immediately obvious to us as causal concepts. Some of the discussions of answers to an est questions seem to suggest that a good understanding of the signification of the word in question already gives us enough to be able to prove that there is nothing in reality to correspond to a given word: that the answer to 'an est X?' is 'non est'. It would seem, that is, that there are words whose signification is such that there can be nothing in reality that is signified: this would seem to be one of the approaches adopted in the discussion of 'an est vacuum?' . 14 Again, Aquinas has a word for 'squaring the circle', 'tetragonismus' .15 It seems

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fairly clear that 'An est tetragonismus?', 'Does tetragonism exist?', could be answered fairly simply by a consideration of the signification of this word alone. It is perhaps also of interest that Aquinas does not disagree in general with the view of Averroes, which he cites, that demonstrations by means of a reductio ad absurdum are often found among 'demonstrationes per signum vel per effectum', which again are often used in natural • 16 sctence. Consideration of the signification of the word in question, then, may lead one to be able to answer the an est question in the negative. On the other hand, such a consideration may lead one to seek to improve or clarify the usual understanding of the signification of the word. This seems to be what Aristotle does at the beginning of his discussion of the vacuum, and Aquinas seems to approve. 17 The usual signification of the word is accepted, but it is refined of obvious difficulties before the discussion is permitted to go any further. We might very well want to do the same thing with the signification of the word 'goatstag'. The obvious signification of'goatstag' is 'animal composed of goat and stag' . 18 This needs clarification. If we take it to mean an animal that really is composed of parts of two other animals, then the answer to 'an est hircocervus?', 'does the goatstag exist?', can probably be given very shortly, in the negative, from a consideration of the signification of the word alone. But while the ignorant who hear of the goatstag may take this to be the signification of the word, it is much more likely that those who first used it meant rather something like 'Animal that looks as though it is composed of goat and stag'. If we refine the signification of the word in this way, we have a far more interesting investigation on our hands, one that could be answered either affirmatively or negatively. How can we carry out this investigation? It is clear that while the signification of the name 'X' may justify us in answering 'an est X?' in the negative, it need not justify such an answer, and it must also be clear that it will not justify us in answering it affirmatively. Aquinas saw this point: one of his objections to the account he accepts of Anselm's argument for the existence of God (an account which assimilates it to the ontological argument of Descartes) is that even if we admit that the word 'God' is understood to signify 'that greater than which nothing can be thought of - which, as we have seen, he thinks would not be universally admitted it does not follow that we understand that what is signified by this name exists in reality. 19 Some investigations must be continued, then, by other means. Aquinas actually takes it on himself to demonstrate that God exists. How is this

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possible? To demonstrate one needs a medium demonstrationis. 20 In a complete science the medium demonstrationis that X exists would be the definition ofX, 21 but in building up science, a definition of X is precisely what we are trying to work towards. We should not forget that we do not even know yet whether X exists, and if it does not exist, it will have no nature, and thus no definition. 22 In the case of God, things are yet more difficult, for Aquinas knows that even if we were to prove that God exists, we can reach no definition of God. 23 How, then, can God's existence be demonstrated? The demonstration actually given of God is a demonstratio causae per effectum: the effect is used, in place of the definition, as the medium demonstrationis. 24 It is obvious to everyone, Aquinas thinks, that the word 'God' signifies 'cause of the world'. 25 Aquinas stresses, in the conclusion of each of his Five Ways, that everyone takes God to be that which has been proved to exist, 26 and what has been proved to exist is a cause or explanation of the world, in some causal mode or other. This insistence on the common understanding of the signification of the word 'God' gains point from his objection against Anselm, as we have seen, that not everyone- and least of all the Fool- will understand that the word 'God' signifies 'that greater than which nothing can be thought of. 27 But given that this is the common understanding of the signification of the word, we immediately grasp what is to be the medium in a demonstration of God's existence: it is to be the world, God's effect, considered under any aspect that may be found suitable. 28 But though the problem is so easily solved in the case of God, it may not be so simple if, as we said above, the word in question does not include being a cause in its signification. Aquinas gives us no lead here: but some kind of an answer can surely be found. An obvious course to take is to examine the signification of the word more carefully, and decide what the proper effect of the thing signified might be. The word 'goatstag', for example, includes in its signification being a kind of animal. We know what kind of effects we expect from animals - we know, in modern terms, what evidence to demand for the existence of an animal. It is such an effect, if it can be found, which will serve as the medium of the demonstration. If this suggestion is right- that a knowledge of what sort of evidence we can expect for the existence of a thing is eo ipso, in St Thomas's terms, a knowledge of what should be the effect of a supposed cause - then every case of trying to establish the existence will take the form of an argument from effect (once found) to cause. Every word that we may want to substitute for 'X' in 'Does X exist?' will be a word which signifies something with some kind of explanatory role. 29

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Thus, to take a case which Aquinas actually does discuss, we know that if place exists then it will be the terminus, and thus the final cause, of change of place. Thus change of place can be used, as Aquinas and Aristotle use it, as the medium of a demonstration of the existence of place. 30 We might point out here that at this point, too, we might be able to conclude directly to the non-existence of what the word in question signifies. When the existence of phlogiston was being disputed, Lavoisier pointed out that according to the theorists who defended it, phlogiston was supposed to have inconsistent effects - I believe, that the loss of phlogiston was supposed to have the effect of making a substance heavier on being released by rusting and tarnishing, and that of making it lighter on being released by combustion. Thus Lavoisier was able to argue that there was no such thing as phlogiston. The investigation must be carried on beyond this point by making use of Aristotle's notion of proving a cause from its effect. This is discussed by Aquinas in the Commentary on the Posterior Analytics. 31 It seems that the notion is used and discussed elsewhere: but, unfortunately, not always under exactly the same title. In the full discussion in the Commentary on the Posterior Analytics he speaks of a 'demonstratio quia per effectum', while in the Summa Theologiae he speaks of'demonstrare causam esse per effectum'. Elsewhere he speaks of 'demonstratio per signum vel per effectum' or 'demonstratio signi'. 32 How much importance should be attach to these different formulations? There seems no reason to suppose that 'demonstratio per signum' is anything other than equivalent to 'demonstratio per effectum', as Aquinas seems to imply. It is true that we can consider as a sign of X not only an effect of X but also its cause, as when we take the stars as signs in the forecasting of weather; 33 and also that we can take one thing as a sign of another when they both share the same cause, but are not otherwise directly related as cause and effect. 34 But it is clear that 'demonstratio per signum' is contrasted with 'demonstratio propter quid', and can thus surely be taken as equivalent to 'demonstratio quia per effectum'. 35 It is not so immediately obvious, though, that 'demonstratio quia per effectum' should be taken as equivalent to 'demonstrare causam esse per effectum'. After all, 'quia' and 'an est' are supposed to be two different questions. However, Aquinas tells us explicitly that the two kinds of question are very closely related. Neither can be answered by a demonstration without first finding out that a medium exists, 36 so every question quia at least involves a question an est. When we are asking' An est X?', then if the signification of 'X' includes being a cause then it will obviously be possible to demonstrate that X exists

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by means of its effect. Even if the signification of 'X' is not so clear, we can, it has been suggested, probably work out what kind of effect X might have. We need to examine whether there is any such phenomenon as what the effect of X would be; but the phenomenon that we pick on as our medium demonstrationis, as the effect of X, will presumably be one which either is obvious to the senses or might be if we came across it. The question an est? and the question quia? both involve the question 'an est medium?', is there a medium?, but if we choose our medium correctly the answer to this will be obvious. Hence, incidentally, the description of such a proof as 'demonstratio per signum'. If the effect is obvious when the cause is not, the effect is a sign of the cause, something that indicates the cause to us. 'There's no smoke without fire', we say, using even in our contemporary proverb what any medieval thinker would have given as a prime case of a 'natural sign'. 37 · A more rigorous answer can be given by insisting that cause and effect are correlative terms. Since what is demonstrated by demonstratio in the strict sense, scientific demonstratio per causam, is always an effect of that cause, we must expect that the only thing that can be demonstrated per effectum is a cause. 38 Moreover, any question about whether a cause exists -a question an est- can be re-expressed as a question about whether it is the case that A is the cause ofB- a question quia. It would seem necessary to grant, in fact, that every question 'an est?' can be answered by a demonstratio quia, and if we have no knowledge of the cause then the demonstration must be by means of the effect. Thus we can use demonstratio quia per effectum to demonstrate that a cause exists - demonstrare causam esse per effectum. 'Does A exist?', a question of the an est type, is answered adequately by 'A is the cause of B', which at first sight is the answer to a question of the quia type. A point that may be important here is the way in which Aquinas's typical questions of the 'an est X?' type differ from the questions which we might take as typical of modern science, where there is no name such as 'X' for the cause that we are trying to discover. We have said that Aquinas starts from a word, and wants to try to demonstrate that the word stands for something in reality. In order to do this, he first tries to establish the answer to the question 'What would be the effect of what the word stands for, if anything?', in order to be able to use this effect as a medium. We also pointed out that the answer to 'an est X?' where X is taken to be a cause, as here, can be expressed as an answer to a question of the type quia: whether it is the case that this effect is caused by X. This possibility is enough to entitle us to blur the distinction between the two types: Aquinas explicitly says that what the mind accepts as an answer to a

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question is the answer to that question, 39 and 'A is the cause ofB' would certainly be accepted as an answer to the question 'Does A exist?'. The difference between this kind of question and modern ones where there is no name for the cause can thus be seen to be unimportant. Aquinas usually starts with a word for a cause, whose existence he then proceeds to prove from its effect; we, perhaps, usually start with a phenomenon, about whose cause we form a hypothesis, and then proceed to prove the existence of the cause from the nature of the effect. The existence of the name is evidence that commonly a hypothesis has been formed. 40 Naturally, we could always invent a word for the cause of the phenomenon, which would bring our practice exactly into line with Aquinas's. Thus it is possible to make a rather trivial reduction of our account of finding out to Aquinas's. What is more important is the fact that in Aquinas's account the signification of the word that the investigation starts with plays the same role as a hypothesis about the nature of the cause does in ours. In neither case are we attempting what Aquinas regards as the impossible task of demonstrating 'propter quid per effectum': in both cases we have a quia to demonstrate. Thus the fact that Aquinas does not have an account of hypothesis, which one thinks of as a key notion in a theory of science, is perfectly explicable, and does not mean that his theory of finding out must be radically flawed. The question now is, how does demonstratio per effectum work? The exposition which Aquinas gives of Aristotle's account, in the Commentary on the Posterior Analytics, 41 adds little to what Aristotle himself says. Of more interest is what he actually does in his use of such demonstrations. The strategy he adopts in the Five Ways, for example, is to examine the characteristics of the alleged effect of God, that is, the characteristics of the world, the whole complex of things in process of change that we see about us. Since the world is a complex of things in process of change, it must be caused by something not in process of change, something, therefore, outside the world. He then points out that 'cause of the processes of change in the world, not itself in process of change' is generally accepted as being part of the signification of the word 'God'. 42 A similar strategy is used in the discussion of the existence of place. The phenomenon of change of place demands a terminus as final cause, and the signification of the word 'place' is certainly that of'terminus of change ofplace'. 43 It is not clear whether the conclusion reached by such a demonstration is scientific or not- that is, whether it must be necessary, universally and eternally true. 44 It has already been mentioned that for Aquinas the effect cannot exist without the cause, while the cause can exist without the

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effect;45 thus though, given the effect, the cause must exist, it does not follow that given the cause the effect must exist. Will the connection I have demonstrated count as scientific knowledge? It would seem not, as there need be no necessity about the connection between cause and effect: though we have been able to demonstrate the cause from the effect, it may not be possible to demonstrate the effect from the cause. Thus the knowledge which has been acquired need not be part of a system of scientific knowledge in the Aristotelian sense, though it would certainly count as scientific knowledge in the modern sense. 46 The problem appears particularly acute when we consider some of Aquinas's reflections on the peculiar characteristics of natural science. Aquinas insists that this kind of argumentation is especially frequent in natural science: demonstratio per e.ffectum is very frequent, 47 demonstration along the line of efficient and final causality is more common in natural science than in other sciences,48 and demonstration in natural science tends to demonstrate the existence of one thing from the existence of another which is really, not merely rationally, distinct from it. 49 But this seems to cast doubt on whether it is possible to produce an Aristotelian natural science at all. This perhaps does not threaten StThomas's project of proving the existence of God, but it does seem to threaten my aim of showing that the notions used by StThomas in his Five Ways are not ad hoc, but have a wide field of application in other parts of philosophy; and indeed, as I have hoped to suggest, that what StThomas has to say about the acquisition of science is in general of considerable value even to contemporary discussions. It may be that no general answer is possible here, but we can at least indicate certain lines of argument that may be useful. It seems that in some cases at least, once we have established the existence of a cause, it may be possible to go on to establish that the connection between cause and effect is necessary in the relevant sense. To show it as necessary in the relevant sense we have to establish that the effect follows necessarily, that is, by nature, from the cause. To do this we have to be able to establish what the nature of the cause is: we have to be able to find its real definition. So far we have been working with a more or less refined nominal definition, what Aquinas calls the 'significatio nominis'. It is important to remember that until it is demonstrated that the cause exists, we cannot have any better definition: there are no definitions, in the strict sense, of what does not exist. 50 Now that we have established the existence of the cause, are we any better off? The answer, in Aquinas's mind, seems to be that it all depends. We now know that this cause has these effects; we can use these to further

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refine the notion we have of the signification of the word that stands for the cause. Aquinas follows Aristotle in doing this for the notion of place, or rather, explains that this is what Aristotle is doing. 51 This refinement is carried out by answering counter-arguments based on the signification of the word 'place'. Aristotle has given an argument to prove that place exists, from the existence of change of place. In this section he puts forward objections to this argument, based on claims that the signification of the word 'place' is such that nothing in reality can be signified by it that the expression is in some way self-contradictory, and that thus place does not exist, and that the argument given for its existence must be fallacious. Aristotle is able to refute all these, and in the process learn some more about place - that it cannot be, for example, as some of the counter-arguments suggest, either a body or a non-bodily substance. But a clarification of our understanding of the signification of the word in question is not yet the production of a definition. However, Aquinas holds that if the effects are 'adaequati' or 'proportionati' to the cause then we can actually use the effects to discover the nature of the cause; and that even if they are not, as the world is not 'adaequatus' or 'proportionatus' to God, we can at least discover some 'conditiones', characteristics, of the cause. But there are some things which cannot be known by us by our considering them directly themselves, but only by considering their effects. If an effect is 'adequate' to its cause, then the nature of the effect is taken as a principle in demonstrating the existence of the cause and in tracing the nature of the cause. And from this, in turn, the properties of the cause are made clear. But if the effect is not 'adequate' to the cause, then the effect is made the principle of a demonstration that the cause exists, and also of some of its charac52 • • tensttcs. The exact meaning of 'adaequatus' and 'proportionatus' is not clear. In one place at least, consideration of a parallel passage seems to indicate that Aquinas holds that material effects are not sufficiently adaequati to spiritual causes for us to come to any real understanding of spiritual beings. 53 It is interesting, though, that Aquinas's most famous use of the word adaequatus, in his account of truth and knowledge, seems positively to demand an adaequatio between the material and the non-material. But we need not, perhaps, go into this question too deeply: it seems that it will be possible to acquire some knowledge of the nature of the cause, either directly or indirectly, from knowledge of any effects. 54 The step can be made if the effects from which the cause is being proved are, as Aristotle and Aquinas seem to think that ideally they should be, 55

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'convertibiles' with their cause. It seems obvious that effects which are 'convertibiles' with their cause must be 'adaequati' or 'proportionati'. Such effects, being 'convertibiles', are themselves properties of the cause. 56 From the properties of a thing we can come to know its nature: this is frequently stated. We should notice also that this acquisition of knowledge could be considered as yet another demonstration of cause from effect, since accidents can be considered as signa of essence, 57 though presumably the cause and the effect are to be found in the line of formal causality rather than of efficient causality. Thus when the effects are convertibiles we can infer directly, by one demonstration, what the nature of the cause is. But Aquinas tells us that if the effects are not convertibiles, nor even proportionati or adaequati, we can at least infer - by demonstration of cause from effect again, we must presume - some characteristics of the cause. 58 These characteristics may well be properties that are convertibiles with the cause, even if the effects themselves are not. From these properties, then, we can, as above, infer the nature of the thing whose properties they are, again by a demonstration of cause from effect in the line of formal causality. There is a difficulty here, though. The conditiones of the cause which some effect may give us knowledge may not be properties of it, but some non-proper accidents. It is to be supposed that Aquinas would answer that in that case the causality would not be per se- not necessary in the relevant sense- but merely per accidens. 59 But this is only to re-state the problem. What happens if we mistakenly take the non-proper accidents of the cause to be properties of it, as may very well happen, and develop, on that basis, an erroneous definition of the cause? We may observe that on Aquinas's own showing this may happen very easily: in the discussion of the existence of God Aquinas regards it as important that the word 'God' is imposed in virtue of God's effects. But a name may very easily be imposed in virtue of a per accidens effect. The word 'lapis', according to Aquinas and Isidore, as we have seen, is imposed in virtue of the per accidens effect of a stone in hurting the feet. The strategy successfully adopted in proving the existence of God might easily lead to disaster in proving the existence, and arguing for the nature, of stones. 60 The answer to this difficulty would seem to be that it is not the task of a theory of science to provide an infallible methodology: only to describe the way the method works when it does work correctly. It is surely not an objection to a theory of science that a science which is built up according to the method it prescribes may sometimes be mistaken. It is true, though, that we need an account of how such mistakes may come to light and be

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put right, and this, it seems, Aquinas does not provide. We can only appeal to the way in which chains of explanation converge and can be compared. We infer from the existence and characteristics of the effect the existence of a cause, and we attribute the efficacy to something in the cause. This may be a property, in which case we will be correct when we infer something about the nature of the cause from it, or it may be a non-proper accident. If we take a non-proper accident of a cause as a property, then we are eo ipso taking the effect to be a per se one when in fact it is only per accidens. A per accidens effect is the result of the convergence of more than one line of causality. 61 Thus our account will lead to some gap or some redundance in our account of some other line of causality, which may quite easily come to light. Moreover, we will take the nature of the cause to be other than it really is. These errors are surely likely to show themselves sooner or later. It may take a long time, and when they do show themselves prejudice may make it hard for us to accept the need to rethink that part of science - but that is actually what happened with the overthrow of the phlogiston theory. Aquinas's theory of science has not yet been shown to be inadequate as an account of the history of modern science. It is surely true, though, that even if we do rightly identify properties of the cause, and they are able to tell us something about the nature of the cause, this need not yet give us a suitable definition. Aquinas himself points out that some properties - shape, for example - are of more use than others in reaching a knowledge of the nature of a thing, in deciding on a definition. 62 If the effects only allow us to conclude the existence of some properties, there is no guarantee that these properties will be the ones from which the nature can be inferred. This is again an apparently serious objection, but surely all it means is that science is not easy, and that we may need to amass a great deal of information about effects before we have anything like complete knowledge of the cause. Science is not as easy as the sketchiness of the account extracted from Aquinas seems, at first sight, to suggest it is. But the account should be taken, not as a list of simple instructions, by following which we will infallibly build up a science, but rather as an account of how science works when, as a matter of fact, it is done successfully. Aquinas does not suggest that you can simply read off the definition of a thing from its properties - you will need to have, if not a full, at least an adequate list of the properties, and apply the methods of definition correctly. The methods of definition he gives are those of Aristotle: genus and difference, and 'like and unlike'. 63 It would be interesting to investigate

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how these are supposed to work: it may be that even in developing definitions we are to apply the notions outlined above. For example, genus is related to specific difference as matter is to form, 64 so perhaps part of arriving at a definition is the inference of a material cause from an effect, following the rules of demonstratio causae per effectum. But even if it proves that there is no application of the account developed here in the theory of definition, which is the heart of Aquinas's theory of scientia, at least the account developed here seems to give the skeleton without which that theory could not stand up. The claim, then, is that StThomas's discussion of the existence of God can be seen to be in line with his overall theory of the construction of a science, particularly in regard to the answering of questions of existence. Further, I claim that this theory has nothing mysterious about it, but is closely parallel to the familiar, pedestrian sort of scientific/philosophical discussion that takes place when the validity of an explanatory hypothesis is in question. There is nothing odd about the question of whether there is a God, and there is nothing odd in the way that St Thomas sets about answering it, any more than there is in the way he sets about answering any other question of the same type. NOTES 1. See the introduction to]. Barnes, translation and commentary of Aristotle's Posterior Ana/ytics, (Oxford: Clarendon, 1975). 2. Commentary on the Posterior Ana/ytics, L.l, 1.23, 196--200. 3. Commentary on the Posterior Analytics, L.II, especially 1.1, 407-17: see pp. 33-6 above. 4. Summa Theologiae, I, q. 2, a. 2, ad 2: Ad secundum dicendum quod, cum demonstratur causa per effectum, necesse est uti effectu loco definitionis causae ad probandum causa esse: et hoc maxime contingit in Deo, quia ad probandum aliquid esse, necesse est accipere pro medio, quid significet nomen, non autem quod quid est, quia quaestio quid est sequitur ad quaestionem an est. Nomina autem Dei imponuntur ab effectibus, ut postea ostendetur: unde demonstrando Deum esse per effectum, accipere possumus pro medio, quid significet hoc nomen Deus. See above, pp. 39-40. 5. Commentary on the Physics, L. IV, 11.1-2, 406--21 and 1.8, 487-93 (a passage too long and too dense to quote adequately here). 6. In the Commentary on the Posterior Analytics, L.l, 1.23, n. 195, it is stated that one way in which a demonstratio quia can differ from a demonstratio propter quid is that the former can be 'per effecta' while the latter cannot. 'In his quae probantur per effecta demonstratur quia, et non propter quid.' 7. Commentary on the Posterior Ana/ytics, L.I, 1.23: see note 6. 8. Commentary on the Posterior Analytics, L.II, 1.1, n. 408: 'Scientia est cognitio per demonstrationem acquisita. Eorum autem oportet per demonstrationem cognitionem acquirere, quae ante fuerint ignota: et de his quaestionem facimus, quia ignoramus.' 9. But see above, Chapter 2, p. 33. 10. Existence of God: Summa Theologiae, I, q. 2, a. 3; of place: Commentary on the Physics, L.II, 11.1-2; of vacuum: Commentary on the Physics, L.IV, 11.9-14; of goatstag: Commentary on the Posterior Analytics, L.II, 1.6, n. 461, Commentary on the Perihermeneias, L.l, 1.3, n. 35; ofldeas: Summa Theologiae, I, q. 15, a. I.

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94 11. Commentary on the Posterior Analytics, L.II, 1.6, n. 461.

12.

13. 14.

15. 16.

17.

18.

For there is no quiddity or essence of that which does not exist: so no-one can know what something that does not exist is. But one can know the signification of the name, or a description made up out of several names. In this way someone could know what the name 'tragelaphus' (or 'goatstag', which is the same) signifies: he could know that it signifies 'some kind of animal made up of goat and stag'. But it is impossible to know what the goatstag is, for nothing in reality is a goatstag. Quia enim non entis non est aliqua quidditas vel essentia, de eo quod non est nullus potest scire quod quid est; sed potest scire significationem nominis, vel rationem ex pluribus nominibus compositam: sicut potest aliquis scire quid significat hoc nomen tragelaphus, vel hircocervus, quod idem est, quia significat quoddam animal compositum ex hirco et cervo; sed impossibile est scire quod quid est hircocervi, quia nihil est tale in rerum natura. See above, Chapter 4, p. 38. Summa Theologiae, I, q. 13, a. 10, ad 5: 'If there were someone who had no knowledge of God under any description whatsoever, he would not even name Him, except perhaps as we utter words whose meaning we are ignorant of.' ('Si vero aliquis esset qui secundum nullam rationem Deum cognosceret, nee ipsum nominaret, nisi forte sicut proferimus nomina quorum significationem ignoramus.') See above, Chapter 4, p. 46. Summa Theologiae, I, q. 2, a. 2, ad 2- see above Chapter 4, pp. 39--40, 46. Commentary on the Physics, L.IV, 11.13, nn. 541-3. For example, n. 541: 'For the word "vacuum" sounds like something empty and non-existent; and it sounds empty and unreasonable and untrue that the vacuum should exist.' (Nam vacuum sonat aliquid inane et quod non est; et inaniter et absque ratione et veritate quod vacuum sit.') Commentary on the Physics, L.I, 1.2, n. 18: 'tetragonism, or the squaring of the circle' ('tetragonismum, id est quadraturam circuli'). Averroes is credited with the idea in Commentary on the Physics, LVII, 1.1, n. 889. Cf. also Commentary on the Posterior Analytics, L.I, 1.40, nn. 351ff.; Commentary on Boethius De Trinitate, 1.2, q. 2, a. 1, resp. ad q. 1.1: 'The demonstration by means of a sign or by means of an effect is of frequent use in natural science' ('demonstratio quae est per signum vel per effectum, magis usitatur in scientia naturali '). Commentary on the Physics, L.IV, 1.10, nn. 509-11, especially 509-10: 'In these three ways, then, the signification of this name can be taken ... Then [Aristotle] shows us what needs to be added to this signification' ('Sic igitur tribus modis potest accipi huius nominis significatio ... deinde ... ostendit quid addendum sit ad hanc significationem'). Commentary on the Posterior Analytics, L.II, 1.6, n. 461: 'Quoddam animal compositum ex hirco et cervo.'

19. Summa Theologiae, I, q. 2, a. 1, ad 2: 'Dato autem quod quilibet intelligat hoc nomine Deus significari hoc quod dicitur, scilicet id quo maius cogitari non potest, non tamen propter hoc sequitur quod intelligat id quod significatur per nomen esse in rerum naturae.' 20. Commentary on the Posterior Analytics, L.II, 1.1, n. 407: 'In demonstrationibus autem cognitio conclusionis accipitur per medium . . . medium in demonstrationibus assumitur ad aliquid innotescendum.' 21. Commentary on the Posterior Analytics, L.II, 1.1, n. 415: 'Non ergo demonstratio resolvet in primam causam, nisi accipiatur ut medium demonstrationis definitio subiecti.' 22. Commentary on the Posterior Analytics, L.II, 1.6, n. 461; Commentary on the Posterior Analytics, L.I, 1.2, n. 17: see above, Chapter 4, pp. 33--6, 38. 23. Summa Theologiae, I, q. 3, preamble: 'We cannot know what God is' ('De Deo non possumus scire quid sit'). 24. Summa Theologiae, I, q. 2, a. 2, ad 2: see above, p. 81. 25. 'The names of God are imposed in virtue of God's effects' ('Nomina Dei imponuntur ab effectibus'): Summa Theologiae, I, q. 2, a. 2, ad 2, quoted above, Chapter 4, pp. 39--40, and in this chapter, p. 81. See also texts from Summa Theologiae, I, q. 13 quoted above in Chapter 4, pp. 40-7. 26. Summa Theologiae, I, q. 2, a. 3: see above, Chapter 4, pp. 39, 47, and below, Chapter 7, pp. 104-5. 27. Summa Theologiae, I, q. 2, a. 1: see above, Chapter 4, p. 39 and note 9. 28. For example, as a system of efficient causality (perhaps the first and certainly the second way). See below, Chapters 9 and 10, pp. 132--44 and 146-53. 29. See above, this chapter, p. 81, where the expression 'explanatory role' is used, and below, this chapter, p. 88, on hypothesis.

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30. Commentary on the Physics, L.IV, 1.1, n. 411: 'It is local change that makes people recognise place ... place is something real, ... and is the terminus of local change' ('Transmutatio secundum locum induxit homines ad cognitionem loci ... locus est aliquid, et ... est terminus motus localis.'). 31. Commentary on the Posterior Analytics, L.I, 1.23, nn. 195-200. 32. Demonstrationes per signum and demonstrationes per effictum, and use in natural science, Commentary on Boethius De Trinitate, 1.2, q. 2, a. 1, resp. ad. q. 1.1: see above, Chapter 2, note 8, and below, note 48; demonstratio signi, Commentary on the Physics L.VII, 1.1, n. 889. 33. De Veritate q. 9, a. 4, ad. 5; Summa Theologiae, I, q. 70, a. 2, ad 2. 34. Ibid. 35. Commentary on the Physics, L.VII, 1.1, n. 889. 36. Commentary on the Posterior Analytics, L.ll, 1.1 n. 412: 'In a question "does it exist?", or in a question "Is it the case?", we are asking whether a medium exists' ('Qy.aeritur enim in quaestione si est, vel quia est, an sit id quod est medium'). 37. Cf. e.g. Summa Theologiae, 11-11, q. 95, a. 5c. 38. Commentary on the Posterior Ana/ytics, L.ll, 1.18, n. 570: a rather complex passage, but one whose clear moral is that the effect is demonstrated through the cause, and the cause is demonstrated through the effect. 39. See Commentary on the Posterior Analytics, L.ll, 1.1 n. 409. 40. See above Chapter 3, note 1 and note 29 in this chapter, on explanatory role. 41. Commentary on the Posterior Analytics, L.I, 1.23, nn. 195-200. 42. Summa Theologiae, I, q. 2, a. 3. See below, Chapter 9, pp. 141-2. 43. Commentary on the Physics L.IV, 1.1, n. 411: see above, this chapter, note 30. 44. Though we should notice that for Aquinas a truth may still be 'universal' and 'necessary' in the relevant sense, even if it has counter-examples, owing to the indeterminacy of matter. I am grateful to Professor S. Knuuttila, who made this point to me in discussion. See also the discussions above in chapter 2, pp. 20--1, 25-30. 45. See e.g. Commentary on the Periherrneneias, L.I, 1.14, n. 186; and see above, p. 20. 46. See above, p. 21. 47. Commentary on Boethius De Trinitate 1.2, q. 1, a. 1, ad. 9: 'Effectus sensibiles, ex quibus procedunt naturales demonstrationes . . .' ('Sensible effects, from which the demonstrations of natural science are drawn .. .'); and q. 2, a. 1, resp. ad q. 1.1: see above, this chapter, note 27. 48. Commentary on Boethius De Trinitate, 1.2, q. 2, a. 1, resp. ad q. 1.1: 'In natural science, in which we perform demonstration by extrinsic causes [i.e. not by the material or the formal cause, which are 'intrinsic' causes], we prove one thing from another which is wholly extrinsic to it' ('Sed in scientia naturali, in qua fit demonstratio per causas extrinsecas, probatur aliquid de una re per aliam omnino extrinsecam'). 49. Commentary on Boethius De Trinitate, 1.2, q. 2, a. 1, resp. ad q. 1.1: 'This is most obviously the case in natural science, where we pass from the knowledge of one thing to the knowledge of another- e.g. from the knowledge of the effect to the knowledge of the cause. And it is not that we pass from one thing to another that is distinct from it merely in reason, and not distinct in reality.' ('Hoc magis in scientia naturali servatur, ubi ex cognitione unius in cognitionem alterius devenitur, sicut ex cognitione effectus in cognitionem causae. Et non proceditur solum ab uno in aliud secundum ration em, quod non est aliud secundum rem.') See also note 48 of this chapter. 50. Commentary on the Posterior Analytics, L.II, 1.6, n. 461; Commentary on the Posterior Analytics, L.I, 1.2, n. 17: see above, Chapter 2, pp. 24-5, and Chapter 4, p. 38. 51. Commentary on the Physics, L. IV, 1.5, nn. 446ff. E.g. at 447: 'Then ... he shows what sort of definition should be given of "place" ' ('Deinde ... ostendit qualis debeat esse definitio danda de loco'). 52. Commentary on Boethius De Trinitate, 1.2, q. 2, a. 4, ad 2: Qy.aedam vero res sunt quae non sunt nobis cognoscibiles ex seipsis, sed per effectus suos. Et si quidem effectus sit adaequatus causae, ipsa quidditas effectus accipitur ut principium ad demonstrandum causam esse, et ad investigandum quidditatem eius, ex qua iterum proprietates eius ostendentur. Si autem sit effectus non adaequatus causae, tunc effectus efficitur principium ad demonstrandum causam esse, et aliquas conditiones eius. Cf. also Summa Theologiae, I, q. 2, a. 2, ad 3. 53. Parallel to Commentary on Boethius De Trinitate, 1.2, q. 2, a. 4, ad. 2: Summa Theologiae, I, q. 88, a. 2. 54. But see below, Chapter 8, pp. l15 and 125--{).

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55. Commentary on the Posterior Analytics, L.l, 1.23, n. 195-200. 56. Commentary on the Posterior Analytics, L.l, 1.8, n. 73; 1.31, n. 267. 57. Commentary on the Posterior Analytics, L.II, 1.14, n. 533: 'We should ... consider their proper passions [e.g. quantity and quality, as explained in the previous sentence], since, as has been said, these are signs that make obvious the proper forms of species' ('Oportet ... considerare proprias passiones, quae, sicut dictum est, sunt signa manifestantia formas proprias specierum'). 58. Commentary on Boethius De Trinitate, 1.2, q. 2, a. 4, ad. 2. See above, this chapter, note 52. 59. Commentary on the Posterior Analytics, L.II, 1.19, nn. 576ff. This passage is too long and too dense to quote effectively here, but the whole discussion is one of whether a single cause implies a single effect, and vice-versa. 60. Summa Theologiae, I, q. 13, a. 2, ad 2: see above, Chapter 4, p. 40. 61. On the relationship between causality and the per accidens, see Chapter 8, pp. 113-14. 62. Commentary on the Physics, L. VII, 1.5, n. 917: 'Shapes correspond to the species of things most closely, and show them most clearly' ('Figurae maxime consequuntur et demonstrant speciem rerum'). It is presumably for this reason that non-zoologists regard black swans as black swans rather than rather large and odd-shaped aquatic crows. 63. Commentary on the Posterior Analytics, L.II, 1.14, nn. 537fT: 'First he puts forward the most appropriate way of tracing what belongs to a definition, i.e. the division of a genus' ('Primo proponit modum maxime convenientem ad investigandum ea quae sunt in definitione ponenda, scilicet per divisionem generis'). Also L.II, 1.16: 'Here he teaches us to trace the essence in another way ... If one is seeking the definition of a thing, one has to pay attention to the things that are like it, and also to the things that are unlike it' ('Hie docet investigare quod quid est alio modo ... si aliquis inquirit definitionem alicuius rei, oportet quod attendat ad ea quae sunt similia illi, et etiam ad ea quae sunt differentia ab ilia re'). 64. Genus as matter of species, Commentary on the Perihermeneias, L.l, 1.8, n. 97. 'The specific difference applies to the genus in its own right, not coincidentally; it delimits it, in the same way that form delimits matter' ('Differentia advenit generi non per accidens sed per se, tamquam determinativa ipsius, per modum quo materia determinatur per formam').

7 • THE EXISTENCE OF GOD AS A SCIENTIFIC QUESTION

I have claimed in the last chapter that the sketchy account of the building up of a science which Aquinas gives us, by way of answering questions of the form 'Does X exist?' by demonstrating the cause from the effect, is one that should satisfy us. It is coherent with the rest of the theory of science which St Thomas and Aristotle espouse, and it is consistent with the methods they actually employ in their development of sciences. It is consonant with common sense, and clearly matches a great deal of the experience of scientists in recent centuries. The present chapter is a central one. In it I aim to bring together the different doctrines of Aquinas which have been so far explained, and to show how they relate to the particular question of God's existence. That is, I have expounded what kind of inquiry St Thomas takes himself to be undertaking, and set out what he believes to be the rules and techniques to apply in such an inquiry, and what its order should be. It should be a scientific inquiry, carried out as a scientific inquiry should be, starting with questions of existence, which may require a preliminary examination of the meaning of the words used: the 'X' and the 'exist' used in 'Do X's exist?'. It should be an attempt to show the existence of a cause from its effect. All these features, I shall claim, can be found in St Thomas's approach to the question 'Does God exist?'. A key text here is Summa Theologiae, q. 2, articles 1 and 2, where St Thomas asks whether the existence of God is not so obvious to us that it does not need demonstration, and whether it is in any case possible to demonstrate it. These two articles discuss to what extent the existence of God is a question to be solved by reason, or by faith in authority; they suggest an answer to the question to what extent the existence of God is a scientific matter, and they hint at the relation between this kind of question (an est) and other questions. They make reference forward to Aquinas's later discussion of the signification of the word 'God', 1 and they make it clear that the existence of God is to be proved by showing reasons

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for regarding the world as an effect and by proving the existence of a cause. Later texts, some of them clearly referred to here, 2 develop the account of the signification of the word 'God' and establish a clear connection between the notion of 'cause of the world', under some description or other, and the signification of the word 'God'. First, the question of the existence of God is a question to be answered by reason rather than by authority; or, at least, a question which can be answered by reason, and does not need to be answered by authority. Naturally there is a curious problem involved in the notion of believing in God on the authority of God who reveals his existence, on which a number of things could be said. 3 But this problem need not be faced here. It is worthwhile making the point that in fact most people who believe in God believe it because they have been told that there is a God by people they respect, and despite the fact that they have probably been told that there is no God by people who they otherwise respect. 4 Equally, most people who believe there is no God believe it because they have been told that there is no God by people they respect, though they have probably also been told that there is a God by people they otherwise respect. The lessons of Chapter 1 of this book, on the respect due to the argument for authority, should make us slow to condemn either attitude as intellectually valueless. But Chapter 1 should also make us realise that different arguments from authority may have different values. Two crucial elements for determining the value of an argument from authority are the trustworthiness of those who transmit the authoritative teaching, and the intrinsic value of its source. It is often said that the trustworthiness of those who transmit the teaching that there is a God is vitiated by the fact that they very much want there to be a God - it is a question of wishful thinking. Clearly, for this remark to have any validity, the idea of God thus transmitted has to be the idea given by traditional religion, of a God who will bring the dead to life and reward those who have served him. But it is worth remembering that this same God of traditional religion has what we might call a dark side. Involved in the traditional religion ofWestern culture is the idea that God is the supreme end of human life, and that without possession of God human existence will be both endless and pointless. Traditional believers have to believe that both they and all those they care for stand in immediate danger of having to face an eternity of misery. No-one can possibly be a traditional believer through wishful thinking, though one might be a modernistic or liberal believer. But there is no sanction from tradition or authority for being a liberal or modernistic believer. A traditional believer may retort on the unbeliever with a tu quoque: a refusal to believe in God may equally

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be wishful thinking, a refusal to face up to unpleasant realities. As a genuine effort to help a friend who one suspects of wishful thinking, remarks of this kind may have their value, but they have no place in serious debate about the existence of God. As general remarks, they are simply unfounded rudenesses, which will get us no further. As regards the question of the intrinsic value of the origin of the authority and the tradition, the believer is in fact on slightly stronger ground than the unbeliever. Leaving aside the knotty question of whether we can believe in God on God's authority, the believer can appeal to, for example, the authority of Moses, who spoke to God face to face. Moses allegedly had experience of the existence of God, and a trust in the tradition that goes back to Moses is a trust in that experience. The unbeliever, on the other hand, cannot trace back his tradition to the authority of, say, Bradlaugh, who had an experience of God not existing. There is no such kind of experience. Of course the unbeliever can allege that the believer's tradition does not go back to Moses, or that Moses's experience was illusory, and these claims are quite plausible. There are such things as false and garbled traditions, on anyone's account, and there are such things as delusory experiences. But it is important to notice that some such claim must be made by the unbeliever to undermine the evidence presented by the believer. At this stage the unbeliever is on the defensive, the believer has the initiative, the believer is logically one jump ahead of the unbeliever. It is no doubt true that in the present age the unbeliever will claim to have arguments for not believing in God. But in our present age the respect which is due to the argument from authority and tradition is largely ignored. Very few people will admit to basing their beliefs on authority and tradition, despite the fact that most of our beliefs are so based. Anyone, believer or unbeliever, will claim to have arguments, other than those of authority and tradition, for what he or she believes. The question is, should we admit the claim? Without putting in question anyone's sincerity, the very badness of arguments which are often adduced either for or against the existence of God should make us doubt whether a belief in God or a belief in the non-existence of God can possibly be really based on the arguments alleged. This point cuts both ways; it affects both sides in the dispute. Many believers claim that they believe in God on the basis of arguments, and many of them are capable of enunciating the arguments which they consider to be the basis for their belief in God. It is a matter of extremely gross observation that many of these arguments are very bad indeed. Some people will say that they believe in God because of the obviously nonnatural character of moral norms. 5 This is a very poor argument indeed,

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since it is not obvious to most people that moral norms are non-natural. Still poorer is Descartes' Ontological Argument, which a number of people profess to be the basis of their belief in God. Yet others will give a muddled and indeed self-contradictory farrago based on one or other of StThomas's Five Ways: 'Everything has to have some cause, therefore there must be some thing that has no cause and causes all the rest.' A sincere belief that one has arguments for one's beliefs is no guarantee that one does in fact have them. If this is true of the one who believes, it may equally be true of the one who disbelieves. There is no a priori reason for supposing that atheists have any more non-traditional, non-authoritative rational grounds for their belief that God does not exist, than theists have for their belief that God does exist. What we have to do in either case is examine exactly what the rational grounds, the arguments, are. This is certainly the view of StThomas, who puts forward and answers a fideist objection: Apparently the existence of God is not something that can be demonstrated. For the existence of God is an article of faith. But the things that belong to faith are not things that can be demonstrated, since demonstration makes us know, and faith is of those things which are not obvious, as St Paul makes clear in Hebrews 11. So the existence of God is not something that can be demonstrated .... To the first objection we must reply that the existence of God, and other things that can be known of God by natural reason (see Romans 1), are not articles offaith, but approaches to the articles of faith. Faith presupposes natural knowledge, as grace presupposes nature, and any perfection presupposes something that is made perfect. There is no objection to something's being in its own right a thing that can be demonstrated and known, while by some individual who does not grasp the demonstration it is accepted as something believed. 6 Moreover, the existence of God is not merely something known by the natural light of human reason, rather than by faith: it is something that requires argument, a demonstrative process. It is not, as some believers have thought, something obvious to all human beings. It is an interesting fact of psychology that a number of believers seem to have thought that supposed unbelievers really know in their heart that there is a God and are only pretending to believe that there isn't. It is also an interesting fact of psychology that a number of unbelievers seem to have thought that supposed believers really know in their hearts that there is no God, and are only pretending to believe that there is one. I mention this merely to

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remind the reader that we are on delicate ground, where the most irrational beliefs- about the motives and attitudes of other people, at the very least - can apparently strike very deep roots. The rather cool rational attitude of StThomas in these questions is in fact rather uncommon, and we should not take for granted that we share it, though we should certainly accept it as a good model to follow. St Thomas discusses the question of whether or not the existence of God is known to all in the following passage: Apparently God's existence is known to us in its own right. Things are said to be known to us in their own right when a knowledge of them is fixed in us by nature, as is clear from the case of the first principles. But, as Damascene says, 'the knowledge that God exists is fixed in all by nature.' Therefore God's existence is known to us in its own right .... To the first objection, we should say that to know that God exists under some common description, and subject to some confusion, is indeed something that is fixed in our nature; i.e. in so far as God is human flourishing. For human beings by nature desire their own flourishing, and what human beings desire by nature they also have knowledge of by nature. But this is not to know that God exists without qualification. In the same way even though I know Peter, and Peter is approaching, this is not the same as knowing the person who is approaching. For many people judge the highest human good, human flourishing, to be riches; others pleasure, and others other things. 7 Though the question of the existence of God may be a question for reason to settle, rather than faith, and though the reason may have to proceed discursively in answering it, rather than finding the answer evident or 'known in itself, it is still not yet clear that the question is a scientific one. We can appeal, if we wish, to St Thomas's preamble to the second question of the Summa Theologiae, which sketches out the structure ofhis work. The divine science will deal with God, with human beings in so far as they are related to God, and with Christ, who is the way for human beings to reach God. When dealing with God, it will consider the divine essence, the divine persons, and the way in which creatures derive from God. When dealing with God's essence it will first ask whether God exists. 8 Nevertheless, though St Thomas regards this question as a scientific question, it cannot be dealt with in the top-down manner which belongs to a completed science. Clearly this science is just beginning, and is far

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from being completed; and, in any case, what stands in the place of the first general principles of a natural science, in the case of sacred science, are the principles of revealed faith. 'Just as the other sciences do not argue to prove their principles ... so this science does not argue to prove its principles, which are the articles of faith'. 9 Lastly, and perhaps most importantly, there can be no completed top-down science of God for human beings. A completed top-down science of God would require a grasp of God's essence or nature, which is impossible for us: But since we do not know what God is, the proposition 'God exists' is not known to us in its own right. Rather it needs to be demonstrated through things which are better known as far as we are concerned, and less known in their own nature: i.e. through God's effects. 10 The existence of God needs to be demonstrated, then, from God's effects, in a dialectical or bottom-up manner. My reply is that there are two kinds of demonstration. One kind is demonstration through the cause: the kind that is called 'demonstration why?', and which is carried out through things which are prior without qualification. The other kind is through the effect, and is called 'demonstration that', and it is done through the things which are prior so far as we are concerned. For since sometimes effects are more obvious to us than are their causes, we can proceed through the effect to knowledge of the cause. It is possible to demonstrate through any effect the existence of its proper cause, 11 provided that the effects are more known so far as we are concerned. This is because the effects depend on their causes, and so once we suppose the effect, it is necessary that the cause should exist before it. Hence God's existence, which is not known in its own right so far as we are concerned, can be demonstrated by effects which are known to us.' 12

It will be recalled from the last chapter that demonstrative answers to the question 'propter quid?', 'why?', can only be given from the top down, arguing from cause to effect. Here it is stated very clearly that the existence of God can only be reached arguing from the effect to the cause, dialectically, from the bottom up. Moreover, rather than attempting to prove the answer to 'an est Deus?', 'Does God exist?', we are attempting to prove the truth of the thesis that God exists, a demonstration quia, 'quia Deus est'. The existence of the word 'God', therefore, already provides us with an explanatory hypothesis: these effects exist, the world exists, because God exists. 13

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A similar point is made by StThomas in the reply to the third objection: To the third objection we have to say that we cannot come to a complete knowledge of a cause through effects that are not proportionate to that cause. But from any effect we can clearly demonstrate the existence of the cause, as we have said. Thus from the effects of God we can demonstrate God's existence, though we cannot, through these effects, come to a complete knowledge of God in the divine essence. 14 This passage relates to the problem we guessed at towards the end of the last chapter. It was argued there that for the full development of a science we will have to seek for effects that are 'proportionate' to their causes. 15 In the case of God, none of the effects that God brings about in the world are proportionate. Possibly, though, a point made in the previous passage is relevant. God's effects are not proportionate to God, in the sense that God might have willed not to bring about any created effects whatsoever and could have brought about many other kinds of effects. Moreover, we cannot directly conclude to a knowledge of God's nature from an examination of God's effects. Indeed, possibly we cannot conclude to a knowledge of God's nature at all; we certainly will never reach a full knowledge of what God is, 'quid est Deus' in the strict sense. 16 But nevertheless the existence of the created world may be a 'proper' effect of God in the relevant sense: the world is such that it could not have been made by anything but a God. The world as God's effect is not proportionate to God, but this does not mean that God is a 'common' cause of the world, and certainly it does not mean that the God is in some sense the 'per accidens' cause of the world. We saw that it is when a per accidens causality is taken to be a per se causality that there is danger of error in the science 17 • we are constructmg. Be that as it may, these passages make clear what sort of a question 'Does God exist?' is supposed to be, how it relates to questions of other kinds and how we can hope to set about answering it. Unsurprisingly, the notion of significatio nominis surfaces in this context, in passages we have already considered: The answer to the second objection is that when a cause is being proved by means of its effect, we have to use the effect in the place of the definition of the cause, in order to prove that the cause exists. This is particularly the case with God, since in order to prove that something exists, we have to take as the medium what its name signifies, not what it is. This is because the question 'what is it?' follows on from the question 'does it exist?' But the names of God

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The significatio nominis of 'God' is thus clearly stated to be that of being a cause of certain effects. It does, indeed, remain to see of what effects. There are attempts to prove the existence of God from some arbitrarily chosen object in the world; 19 more common are attempts to prove the existence of God from the existence and nature of some special object in the world, or some special part of the world, which is thought of as being in some way explanatorily privileged. Attempts to prove the existence of God from the current cosmological hypothesis of the Big Bang would be a clear instance of this: everything else in the world is explained in relation to the Big Bang, and then the Big Bang is held to require an explanation in terms of a relationship to something outside the world. It would seem that St Thomas would have no objection to this manner of proceeding, 20 but it is arguable that in the Five Ways he is seeking to prove the existence of God from the existence and certain features of the world as a whole21 the world as a whole, considered as a system of efficient causes, for example, as in the Second Way, or considered as a system of final causes, as in the Fifth Way. 22 In any case we can derive definite information about what St Thomas considers the significatio of the word 'God' to be, for the purposes of proving that God exists. Each of the Five Ways, as has been mentioned/ 2 ends with a tag which, it can be argued, gives us the significatio which is relevant to that Way. The First Way ends 'So we have to come to some first initiator of change which is not in a process of change initiated by something else, and everyone understands that this is God'. 24 The Second Way ends, 'Hence we must suppose some first efficient cause, and this is what all call "God" '. 25 The Third Way ends, 'We must suppose, then, something that is necessary in itself, which does not owe its necessity to some outside cause, but rather causes the necessity of the other things: and this is what all say is God'. 26 The Fourth Way ends, 'Therefore there is something that is the cause of the existence and the goodness and of all perfections in everything: and this, we say, is God'. 27 The Fifth Way ends, 'Therefore there is some being with understanding which directs all things to their end, and this, we say, is God'. 28 It would appear that in these tags St Thomas is making the claim not merely that these phrases express legitimate accounts of the significatio of the word 'God', but also that (at least most of them) are easily recognisable as doing so: 'everyone understands' that this is God. It will be remembered that Aquinas's first objection to the argument he derives from Anselm is

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that it may be that someone who hears the word 'God' may not understand that it signifies that greater than which nothing can be thought of. 29 1t is to be presumed that he regards his own arguments, and therefore the accounts he gives of the significatio of the word 'God', to be exempt from this criticism. This is a strong claim, but perhaps it is not too unrealistic. The accounts he gives of the significatio of the word 'God' are couched in clearly technical language, unlike that of Anselm. Aquinas may be permitted to explain what the technical language means, and may fairly plausibly claim that when this has been done these accounts of the significatio of the word 'God' will be accepted by all. They refer to familiar ideas, such as that God is the ultimate explanation of all change and of all efficient causality, an everlasting being whose everlastingness is not dependent on anything else, the most perfect being and the explanation of all perfection in the world, the point which the world exists for. These concepts are clearly familiar, though it is clearly still possible for the atheist to claim that nothing falls under them. But the account given by Anselm is different. It is given in non-technical language, in words that everyone can understand, but the idea is clearly unfamiliar, indeed original. Though one understands the words, one might very well want to spend time investigating exactly what concept it is that they delimit. We have seen that the notion of existence used in answering the question 'an est' is that of esse ut verum; and we have already seen a text in which this is explicitly stated of the answer to 'an est Deus?'. 30 We have also seen that for a proposition of the form 'X exists', in the esse ut verum sense, to be true, we need to be able to form some true affirmative proposition about X. The tags which conclude each one of the Five Ways, besides providing us with the significatio nominis of 'God', may also provide us with the relevant affirmative propositions on which the truth of 'God exists' is based. God is a first initiator of change which is not in a process of change initiated by something else; God is a first efficient cause; God is something that is necessary in itself, which does not owe its necessity to some outside cause, but rather causes the necessity of the other things; God is the cause of the existence and the goodness and of all perfections in everything; God is a being with understanding which directs all things to their end.

It is also clear that the existence of God is to be proved from God's effects, and that to that extent the significatio of 'God' must in some way include the notion of being a cause. The texts which support this claim for the word 'God' have already been cited. St Thomas holds that things have

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names imposed on them in virtue of what we know of them; and it is clear also that we have no direct knowledge of God, but only of God's operations in creation. Thus we name God in virtue of the relation that creatures bear to him. It is in so far as a thing can be known by our intellect, that we can put a name to it .... God cannot be the object of our vision in this life, in so far as his essence is concerned. Rather God is known to us from creatures, in so far as they have a disposition towards their originating principle.... In this way God can be given a name by us, drawn from creatures. 31

I submit, then, that we are fully justified in applying to the question of God's existence the logical and methodological considerations which have been expounded in the previous chapters. For some readers the previous methodological chapters may shed light on what follows; for others, what follows may shed light on what has gone before. All I can claim is that I believe that this (to me) obvious set of connections has never appeared in print before, and an understanding of the connections has helped me with both problems. NOTES I. In Summa Theologiae, I, q. 13: see Chapter 4 above. 2. E.g. a number of texts in Summa Theologiae, I, q. 13, some of which have already been quoted in Chapter 4 above; also e.g. I, q. 3, a. 4. 3. For interestingly different views, see G. E. M. Anscombe, 'Faith', in Collected Philosophical Papers ofG. E. M. Anscombe, Vol. 3 (Oxford: Blackwell, 1981), pp. 113-20, and P. T. Geach, The Virtues (Cambridge: Cambridge University Press, 1977), pp. 20-114. 4. Cf. Summa Contra Gentes, I, II:

The foregoing view [that the existence of God is known in its own right, and therefore cannot be demonstrated] comes in part from custom. People are used to hearing the name of God and invoking it from their infancy. But custom - and especially custom which goes back to infancy- acquires the force of nature. Thus is happens that the things our mind is filled with from childhood are held as firmly as if they were known by nature and in their own right. Praedicta autem opinio [sc. quod Deum esse sit per se notum, et ideo demonstrari non possit] provenit partim ex consuetudine, qua ex principio homines assueti sunt nomen Dei audire et invocare. Consuetudo autem, et praecipue quae est a principio, vim naturae obtinet; ex quo contingit ut ea quibus a pueritia animus imbuitur ita firmiter teneatur ac si essent naturaliter et per se nota. 5. This argument is used (among others) by C. S. Lewis, in Mere Christianity (London: Collins, 1955). 6. Summa Theologiae, q. 2, a. 2, obj. l and ad l: Videtur quod Deum esse non sit demonstrabile. Deum enim esse est articulus fidei. Sed ea quae sunt fidei non sunt demonstrabilia, quia demonstratio facit scire, fides autem de non apparentibus est, ut patet per Apostolum ad Hebraeos, XI. Ergo Deum esse non est demonstrabile .... Ad primum ergo dicendum quod Deum esse et alia huiusmodi quae per rationem natural em nota possunt esse de Deo, ut dicitur Rom. I, non sunt articuli fidei, sed praeambula ad

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articulos. Sic enim fides praesupponit cognitionem naturalem, sicut gratia naturam et ut perfectio perfectibile. Nihil tamen prohibet id quod per se demonstrabile est et scibile, ab aliquo accipi ut credibile, qui demonstrationem non capit. 7. Summa Theologiae, I, q. 2, a. I, obj. I and ad 1: Videtur quod Deum esse sit per se no tum. Ilia enim nobis dicuntur per se nota quorum cognitio nobis naturaliter inest, sicut patet de primis principiis. Sed sicut dicit Damascenus, 'omnibus cognitio existendi Deum naturaliter est inserta.' Ergo Deum esse est per se no tum .... Ad primum ergo dicendum, quod cognoscere Deum esse, in aliquo communi sub quadam confusione, est nobis naturaliter insertum, in quantum scilicet Deus est hominis beatitudo; homo enim naturaliter desiderat beatitudinem, et quod naturaliter desideratur ab homine naturaliter cognoscitur ab eodem. Sed hoc non est simpliciter cognoscere Deum esse, sicut cognoscere venientem non est cognoscere Petrum, quamvis sit Petrus veniens. Multi enim perfectum hominis bonum, quod est beatitudo, existimant divitias, quidam voluptates, quidam autem aliquid aliud. An alternative translation for 'known to us in its own right' might be 'self-evident' or 'evident'. 8. Summa Theologiae, I, q. 2, praeambula: 'Tractabimus de Deo; de motu rationalis creaturae in Deum; de Christo ... De Deo ... considerabimus ... essentiam divinam; ... distinctionem personarum; ... processum creaturarum ab ipso. Circa essentiam vero divinam considerandum est an Deus sit.' 9. Summa Theologiae, I, q. I, a. 8c: 'Sicut aliae scientiae non argumentantur ad sua principia probanda, ... ita haec doctrina non argumentatur ad sua principia probanda, quae sunt articuli fidei.' 10. Summa Theologiae, I, q. 2, a. lc: Sed quia nos non scimus de Deo quid est, non est nobis per se nota [sc. haec propositio, Deus est], sed indiget demonstrari per ea quae sunt magis nota quoad nos et minus nota secundum naturam, scilicet per effectus. II. A 'proper' cause, so far as I can make out, is a cause such that this cause could only have produced this effect, and, above all, an effect such as this could not have been produced by any other cause. A 'common' cause is a cause such that it could have produced many other different effects, and an effect such as this could have been produced by a number of other causes, e.g. by A or by B. We may be able to infer the existence of the proper cause- i.e. a cause such that without this cause an effect such as this could not have come about- even though the effect is not proportionate to the cause. But we cannot infer the existence of a particular common cause- i.e., the existence of cause A or of cause B, where either A or B is sufficient to have caused the effect - where the effect is not proportionate to the cause, i.e. proportionate either to A or to B. The cause of the world could only be God, which makes God the proper cause in one sense; but, of course, God could have produced many other worlds of different kinds, and thus is not the 'proper cause' of the world in the other sense. Equally well, the world is not a proportionate effect of God, in that we cannot infer from the nature of the effect to the nature of the cause. On the notion of 'proportionateness' or 'adequateness' of effects, see above, Chapter 6, p. 90, and below, this chapter p. 103. 12. Summa Theologiae, I, q. 2, a. 2c: Respondeo dicendum quod duplex est demonstratio. Una quae est per causam, et dicitur 'propter quid', et haec est per priora simpliciter. Alia est per effectum, et dicitur demonstratio 'quia', et haec est per ea quae sunt priora quoad nos. Cum enim effectus aliquis nobis est manifestior quam sua causa, per effectum procedimus ad cognitionem causae. Ex quolibet autem effectu potest demonstrari propriam causam eius esse, si tamen effectus sint magis noti quoad nos; quia cum effectus dependeant a causa, posito effectu, necesse est causam praeexistere. Unde Deum esse secundum quod non est per se notum quoad nos, demonstrabile est per effectus nobis notos. 13. See Chapter 4, note 11, Chapter 6, notes 10, 13,25 and 29, and Chapter 7, note 1: see also Chapter 4, p. 46, and Chapter 6, pp. 87-8. 14. Summa Theologiae, I, q. 2, a. 2, ad 3: Ad tertium dicendum quod per effectus non proportionatos causae non potest perfecta cognitio de causa haberi, sed tamen ex quocumque effectu potest manifeste nobis demonstrari causam esse, ut dictum est, et sic ex effectibus Dei potest demonstrari Deum esse, licet per eos non perfecte possimus eum cognoscere secundum suam essentiam.

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15. The word principally used for 'proportionate' in the texts cited in Chapter 6- see note 52- was 'adaequatus'. Here the word 'proportionatus' is used. I take it that the two words are being used to make the same point. 16. Summa Theologiae, I, q. 3, praeambula: When we know that something exists, we are left to seek out how it is, in order to know what it is. But we cannot known what God is, but rather what God is not; so we cannot give consideration to how God is, but rather to how God is not. Cognito de aliquo an sit, inquirendum restat quomodo sit, ut sciatur de eo quid sit. Sed quia de Deo scire non possumus quid sit sed quid non sit, non possumus considerare de Deo quomodo sit, sed potius quomodo non sit.

17. See Chapter 6, above, p. 91. 18. Summa Theologiae, I, q. 2, a. 2, ad 2: Ad secundum dicendum quod, cum demonstratur causa per effectum, necesse est uti effectu loco definitionis causae ad probandum causa esse: et hoc maxime contingit in Deo, quia ad probandum aliquid esse, necesse est accipere pro medio, quid significet nomen, non autem quod quid est, quia quaestio quid est sequitur ad quaestionem an est. Nomina autem Dei imponuntur ab effectibus, ut postea ostendetur: unde demonstrando Deum esse per effectum, accipere possumus pro medio, quid significet hoc nomen Deus.

19. I seem to recall Chesterton would offer to prove the existence of God from an umbrella, an elephant, a coal-scuttle or a pen-knife.

20. Cf. Summa Contra Gentes, I, 13, where there seems to be an attempt to show that everything else

21.

22. 23. 24. 25. 26. 27. 28. 29. 30.

in the world is to be explained in relation to the movement of the outermost sphere of the heavens, and that the movement of the outermost sphere of the heavens requires to be explained in relation to God. Comparison between the Summa Contra Gentes passage just referred to, and the First Way in Summa Theologiae, I, q. 2, a. 3 makes this clear, I think. Cf. the remarks in P. T. Geach, Three Philosophers (Oxford: Blackwell, 1961), pp. 111-13. See A. Kenny, The Five Ways (London: Routledge and Kegan Paul, 1969), pp. 35-{); and see below, Chapters 10 and 13, pp. 146 and 179. See above, Chapter 4, p. 39. 'Ergo necesse est devenire ad aliquod primum movens, quod in nullo movetur; et hoc omnes intelligunt Deum.' 'Ergo est necesse ponere aliquam causam efficientem primam, quam omnes Deum nominant.' 'Ergo necesse est ponere aliquid quod est per se necessarium, non habens causam necessitatis aliunde, sed quod est causa necessitatis aliis, quod omnes dicunt Deum.' 'Ergo est ali quid quod est causa esse et bonita tis et cuiuslibet perfectionis in rebus omnibus, et hoc dicimus Deum.' 'Ergo est aliquid intelligens, a quo omnes res naturales ordinantur in finem, et hoc dicimus Deum.' Summa Theologiae, I, q. 2, a. 1 ad 1: 'forte ille qui audit hoc nomen Deus non intelligit significari aliquid quo maius cogitari non possit.' See Chapter 4 above, p. 39. Summa Theologiae, I, q. 3, a. 4, ad 2: Is God's act of existence identical with his essence? We approach this point in this way: apparently God's act of existence (esse) is not identical with his essence .... 2. Moreover, we can know of God that he exists, as has been said above. But we cannot know what he is. So God's existence (esse) is not identical with his essence or nature .... The answer to the second objection is that existence (esse) has two senses. In one sense it means the act of existence; in the other it means the composition of a proposition, which is made by the mind in joining a predicate to a subject. Taking existence in the first way, we cannot know the existence of God, just as we cannot know his essence: we can only know it in the second way. For we know that this proposition which we make about God, when we say God exists, is true: and we know this from his effects. Ad quartum sic proceditur. Videtur quod in Deo non sit idem essentia et esse .... Praeterea, de Deo scire possumus an sit, ut supra dictum est. Non autem possumus scire quid sit. Ergo non est idem esse Dei, et quod quid est eius, sive quidditas vel natura .... Ad secundum dicendum quod esse dupliciter dicitur. Uno modo significat actum essendi, alio modo

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significat compositionem propositionis quam anima adinvenit coniungens praedicatum subiecto. Primo igitur modo accipiendo esse, non possumus scire esse Dei, sicut nee eius essentiam, sed solum secundo modo. Scimus enim quod haec propositio quam formamus de Deo, cum dicimus Deus est, vera est: et hoc scimus ex eius effectibus. See Chapter 5 above, p. 70, for a fuller discussion. 31. Summa Theologiae, I, q. 13, a. I, a. lc: Secundum igitur quod aliquid a nobis intellectu cognosci potest, sic a nobis potest nominari . . . . Deus in hac vita non potest a nobis videri per suam essentiam, sed cognoscitur a nobis ex creaturis secundum habitudinem principii .... Sic igitur potest nominari a nobis ex creaturis.

8 • 'DOES GOD EXIST? APPARENTLY NOT'

'Is there a God?' asks Aquinas, and answers, 'Apparently not' .1 This method is, of course, the one he follows throughout the Summa, a method derived from the intellectual practice of the quaestio, of which we saw a little in the first chapter. 2 In this, as in every case, StThomas first presents objections, the strongest arguments he can find against the thesis enshrined in the formulation of the quaestio, or against the answer which he is going to adopt. 3 Usually he presents us with three objections, but in this case he presents only two- two arguments which are still regarded as the most successful arguments against the existence of God. 4 They can be labelled 'the argument from evil', and 'the argument from partial explanation' or 'the argument from science'. Aquinas expounds the argument from evil as follows: Apparently there is no God. For if one of a pair of contraries were to be infinite, the other would be completely destroyed. But in the word 'God' is included the notion that God is an infinite good. If there were a God, then, there would be no evil to be found. But there is evil to be found in the world. Therefore there is no God. 5 It is worth noticing that, as St Thomas renders this argument, it is of a form that has already been discussed. It is an attempted demonstration of the non-existence of some supposed entity, on the basis of some features of the significatio which can be attributed to the name of that thing. 6 We have seen St Thomas using this technique himself to demonstrate the non-existence of vacuum, of empty space, and discussing (and eventually rejecting) its use to demonstrate the non-existence of place. Equally, it will be remembered that Lavoisier allegedly used the same technique to demonstrate the non-existence of phlogiston. It is clearly a valid method of reasoning. It is also clear that for this kind of argument to work, just as for Aquinas's own arguments in favour of the existence of God to work,

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there has to be a solid measure of agreement between the parties to the discussion on the signification of the word in question. In this case the one arguing against the existence of God has taken up a notion which is part of the signification of the word 'God' in what is called 'classical theism': 7 that God is infinitely good. The defender of the existence of God, in a context in which classical theism, or a religious tradition which includes classical theism, is the norm, is in fact not likely to deny this. There are many different versions of the argument from evil, but they all follow the pattern which is followed by the argument StThomas gives. This is roughly as follows: 1. 2. 3.

The existence of God and the existence of evil are incompatible. Evil exists. Therefore, God does not exist. 8

In so far as various forms of the argument from evil differ, it tends to be with regard to different kinds of evidence given for the first premiss. This is entirely appropriate. The argument is apparently of valid form; thus, if the premisses are true, the conclusion must be true. The defender of the existence of God has to attack the truth of one of the premisses. The second premiss is all too obviously true. There are, indeed, religious and philosophical groups both in East and West who hold that the existence of evil is only an illusion. 9 The claim appears to be confused. If they mean that if we could behold reality without confusion and without error, we would be free from evil, it is at least possible, though perhaps unlikely. If they hold that evil does not exist and there is only an erroneous (and therefore evil) appearance of evil, they stand self-contradicted. \Vhen we claim that evil exists, of course, we are not claiming that evil is an entity or a reality. The existence we attribute to evil is existence in the sense of the true, esse ut verum, the kind of existence which we can attribute to blindness and other similar privations. 10 All we need to maintain, to support the claim that evil exists, is that various people, things, actions or occurrences are bad: and this is obviously true. The second premiss is thus unchallengeable. Thus discussion has to centre on the first premiss, that the existence of God and the existence of evil are incompatible. This can be variously supported. Aquinas suggests a metaphysical justification for it; a more common line nowadays would argue on more moral grounds. We would not claim that some man we knew was good if he had power to stop certain evils which he knew about and did not do so. On the view of classical theism, God is supposed to be good, all-powerful and all-knowing. This appears inconsistent, since it appears that God does not stop evils which

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he knows about (being all-knowing) and which he has power to stop (being all-powerful). Therefore the existence of a good God such as classical theism supposes, and the existence of evil, are incompatible. 11 There are objections to this formulation of the argument from evil which query the notion of God's almighty power or universal knowledge. But these defences do not seem of much value. Sometimes they go so far as to abandon traditional elements of classical theism, which seems a desperate move. Moreover, as Geach has pointed out, the argument from evil still stands even if we leave aside questions of God's power and knowledge, and concentrate simply on the fact that God is the Creator of the world. 12 Since the Five Ways profess to demonstrate the existence of a Creator of the world, such a form of the argument from evil would certainly overthrow the Five Ways. The form which StThomas gives, in any case, does not depend on the notions of God's power and God's knowledge, but solely on that of God's infinite goodness, a notion of which he himself makes use in the context of the Five Ways, at least in the Fourth Way if not in the others. He cannot even defend himself, then, by claiming that God's power and knowledge are further claims which he has not yet made, and should not be supposed in advance of his proof that there is a God. It is sometimes suggested that the existence of evil and the existence of God are not incompatible, because evil proceeds not from God but from human free will. 13 This 'free-will defence', as it is called, appears ineffective as it stands. There seem to be innumerable kinds of evil which do not depend on human free will: an obvious example would be those sufferings of animals and of infants which are caused by natural phenomena. Moreover, the fact that an action proceeds from the free will of a creature does not mean that it does not also proceed from God. If human free actions did not proceed from God they would not be created. 14 Creation, as we shall see later, is not so much something God once did, as something that God is continually doing: it is more like a performance than a production. 15 There is nothing in the world, then, that is not God's action. For some forms of the free-will defence, human actions would have to exist independently of God's creation, and this is inconsistent with classical theism in general and with the thought of St Thomas in particular. Nevertheless, there is an argument, related to the free-will defence, which may be consistent with the thought of St Thomas. What is objectionable in the free-will defence is the doubt it seems to throw on the notion that God is the cause of the world as a whole and of everything that is in it. However, we may derive from StThomas's account of the way in which per accidens existents are caused, an argument which may suggest

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that God is not the cause of everything in the world in exactly the same way. This argument does not throw doubt on the notion that God is the cause of the world and of all that is in it, including the evil that exists: it only questions the mode in which we can attribute to God being the cause of evil. We have seen that we should not attribute reality, real esse, to evil. But if St Thomas is right in his suggestion of what I have called the 'derivativeness' of esse ut verum, there should be some reality on which the esse ut verum of evil is based. In general this is not difficult to see. Evil, like blindness or any other privation, needs to have some really existent subject. 16 But the presence of some defect or privation in some really existent subject is not a per se existent but a per accidens existent. 17 The real existent from which the existence of evil derives is thus a per accidens existent. This point may be of value. For St Thomas, as we have already seen hinted, 18 that which exists per accidens exists as the result of the coincidence of two different strands of explanation. The example he gives, following Aristotle, is that of a man digging in a field who finds a treasure. 19 There is no doubt a reason why the man is digging at that point in the field perhaps it seems to him the best place for a drainage ditch. No doubt there is also a reason why there is a treasure buried just there: perhaps the person who buried it thought that it would be easy for him to find there and difficult for anyone else to find. Once these two lines of explanation are given - a reason why our hero is digging at point X, and a reason why there is a treasure at point X- sufficient reason has already been given why this man should dig at point X and find a treasure. We do not need to seek a reason why this-man-should-dig-at-point-X-and-find-a-treasure, considered as a single phenomenon, as if it were a per se existent which requires a single explanation. 20 Similarly, though everything which happens happens by God's will, it is not necessarily true that every description under which an occurrence falls is a description under which that occurrence is willed by God. It is sufficient that there should be some description, even a per accidens one, under which it is willed by God. Obviously, if God knows everything, God knows every description which is true of every occurrence which he wills. But so do I know many descriptions which are true of the occurrences which I will. As Kenny points out, when I walk across the field to the river I do a certain amount of damage to the grass and wreak a certain amount of havoc among various micro-organisms which live in that habitat. 21 I am not so ignorant as to be unaware of this, but though I will to walk across the grass and I know I thus damage certain micro-habitats,

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is it therefore true that I will (in any interestingly strong sense) to damage the micro-habitats? To this it might be objected that my will is not, as God's is supposed to be, unlimited. I cannot be supposed to will everything which I do. The objection is unsound. God's will is unlimited because God's will extends to everything in the world, as mine does not. But this does not mean that God's will extends to everything under every description which is true of it. It is a common teaching among traditional believers in both Christianity and Judaism that the text of Scripture is inspired. Every word, and therefore every letter, is, as it were, written by God and willed by God: willed by God, indeed, in a very special and direct way in which other ordinary occurrences in the world, though willed by God, are not. Nevertheless, most Christians and many Jews have regarded as misguided and even superstitious those who have sought to use the dispositions of the letters in the Bible, taken according to some numerical pattern, as vehicles of special messages from God. The first letter of Scripture, say some of the Rabbis, is aleph, the first letter of the Hebrew alphabet; 22 the middle letter of Scripture is mem, the middle letter of the alphabet; the last letter is tau, the last letter of the alphabet. Surely this is no coincidence? And surely it is no coincidence that these three letters spell 'emeth, truth? Well, it seems to me that it is a coincidence, and it certainly forms no part of traditional belief, let alone of classical theism, that it is not. 23 Even if this argument against the truth of the first premiss- that the existence of God and the existence of evil are incompatible - is regarded by some as doubtful, there is at least one other argument. The first premiss relies on the accepted truth of the claim made by classical theists that God is supremely good. But it is also a claim of classical theism that God is transcendent and inscrutable. 24 The doctrine of God's transcendence is that God surpasses everything which we can say of him. All our language about God will contain at least some misleading elements. If we say that God is good we seem to imply that God's goodness is something distinguishable from God, as Socrates's goodness is something distinguishable from Socrates, and thus that God is in some way complex or composite. If, on the other hand, we say that God is goodness itself, we seem to imply that God is an abstraction, as the word 'goodness' in our ordinary language means something abstract rather than something concrete. 25 It is therefore highly dangerous to suppose that when we say that God is good we must be attributing to God the sort of thing we would be attributing to a human being when we say she or he is good. A good human being is brave and resistant to the temptations of pleasure, when in the pursuit of some good thing which is difficult of achievement. But God is

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not brave, as there is nothing that constitutes a threat or danger for God. God is not resistant to the temptations of pleasure: God has no temptations. God has no projects for pursuing some good difficult of achievement: nothing is difficult for God. A good man is kind to animals, but Geach has argued that there is no reason to suppose that a good God must be kind to animals. 26 This is just as well, as all the evidence seems to be that the world God has made is a system which is simply indifferent to the sufferings of animals. An appeal to the traditional belief in God's transcendence is thus of some value in taking away the force of the first premiss of the argument from evil. What reason do we have for supposing that God's transcendent goodness is incompatible with the existence of evil? We may indeed have a strong feeling that it ought to be, but strong feelings about what ought to be the case are notoriously a poor guide to what actually is the case, even as regards this world; a fortiori, they will be a yet poorer guide to what actually is the case as regards God. We can add to these considerations those drawn from God's inscrutability.27 'Inscrutable' is one of those curious words which outside a technical field- here, that of natural theology- is used only in a cliche, in this case a rather offensive one. Westerners traditionally regard Orientals, particularly Chinese and Japanese, as 'inscrutable'. I take it that this is because it is hard for a Westerner to guess what an Oriental is thinking from what he or she does or says, presumably because of the differences between Oriental and Western physiognomy, and those between culturally differing modes of expression in gesture and speech. If one is stupid and tactless enough one need not go to the ends of the earth, and spend one's time being rude about their inhabitants, in order to grasp the meaning of 'inscrutability' in human contexts. I am myself extremely stupid and tactless, and I find it practically impossible to make out what my own countrymen and women - perhaps especially womenare thinking, on the basis of what they do or say, unless it is painfully and embarrassingly plain and explicit. Thus most people are for me, in the relevant sense, inscrutable. However, I am not in other ways grossly stupid: I have managed to lead most of my life so far with a fair degree of what might be considered success, according to various criteria. Thus the difference between myself and my fellows is not really all that great. Nevertheless, it appears that the differences between me and my fellows is sufficient to have given rise to a high degree of inscrutability. The moral is fairly clear: the differences between God and any of God's creatures are infinitely greater than the differences between me and my fellows, and so we have to presume an infinite degree of inscrutability in God.

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If God is inscrutable, you cannot tell what God is thinking, or what God means, or even what God is like, directly from a contemplation of what God does or says. If I have often been mistaken about the goodness or badness of my fellow-creatures on the basis of my judgement about what they do or say, a fortiori any creature may be yet more grossly mistaken about the goodness of God, on the basis ofhis or her judgement about what God does or says. This conclusion is highly agnostic, of course, but I do not need here to offer more than an agnostic conclusion. I am trying to overthrow the confidence with which people feel they can assert that the existence of God is incompatible with the existence of evil. I am not here trying to prove that God is good, all I am trying to show is that there is no sufficient reason to believe that the goodness of God is incompatible with the existence of evil. Indeed, this is all that needs to be shown. As Davies points out, 28 on the basis of the argument from evil, as expounded above, we can form another argument which runs exactly on all fours with it.

1. 2. 3.

God exists. Evil exists. Therefore, the existence of God and the existence of evil are not incompatible.

This argument is a mere logical transposition of the argument from evil given above. If the argument from evil is of valid form- as it is- then this argument will be of valid form too; that is, if the premisses are true the conclusion will be true. The two arguments have the second premiss, 'Evil exists', in common. Thus the only difference between them lies in their first premisses, 'The existence of evil and the existence of God are incompatible' and 'God exists'. Which of these two premisses is true? Here there is no remedy but to investigate the two premisses, and the arguments for holding them. We have just taken a look at the first premiss of the argument from evil, and have seen that it depends on the truth of certain views of classical theism; and we have seen that the resources of classical theism are also sufficient to cast doubt on it. There is, I have claimed, no good reason for holding that the existence of evil is in com patible with the existence of God. Meanwhile, there may well be good reasons for holding that God exists - we are about to examine them in the Five Ways. Clearly, it is important that the arguments for the existence of God which we give should be independent arguments: that is, they should not be arguments which depend on the non-existence of evil or on the goodness of God, understood in some common, non-transcendent way.

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Someone who held that God exists because this is the best of all possible worlds would be vulnerable to the argument from evil, because the existence of evil would at the same time give him reason to question the truths of the premiss on which his argument for the existence of God is based. But the Five Ways are in this sense independent of the existence of evil. It is worth pointing out, in any case, with Davies, 29 that the argument from evil seems in practice to work less as an argument for not believing in God than as a reason for not bothering to consider what evidence there might be for believing in God. The possibility of turning the argument on its head, as Davies turns it, shows that this is intellectually dishonest. The arguments for the existence of God need at least to be considered, and compared with those for believing that the existence of God and the existence of evil are incompatible. I have suggested that the latter arguments are weak: it remains to be seen whether the arguments for the existence of God are any stronger. Aquinas, in his reply to the first objection, does not need to enter into the complications we have discussed. He couches the first premiss of the objection in strongly metaphysical terms, rather than in the quasi-moral or quasi-aesthetic terms which would probably be used nowadays, and in terms of which we sketched out the reasons for believing the first premiss. As a result the objection Aquinas gives is not vulnerable to the objections we have made: believing in it does not depend on ignoring the subtleties of God's mode of causation of the per accidens, or God's transcendence or inscrutability. It is, however, vulnerable to the reply which he makes. To the first objection, then, we have to say, as Augustine does in his Enchiridion, 'God is supremely good: so no evil would be allowed in God's works were God not so good and almighty as to be able to make even evil good'. It is proper, then, to the infinite goodness of God to allow evils to exist and to draw good from them. 30 This is clearly a denial of the first premiss, that the existence of God and the existence of evil are incompatible. The argument for this premiss, as sketched out in metaphysical form in Aquinas's objection, is that the very existence of something infinitely good is incompatible with the existence of anything which is evil. Aquinas simply denies this: God's bringing good out of evil is evidence of yet greater goodness than would be the non-existence of evil. There is no more reason to believe in the metaphysical version of the first premiss of the argument from evil than there is to believe in any other version.

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The next objection which St Thomas raises, the second argument for not believing in the existence of God, can be called the 'argument from partial explanation'. His version runs: Apparently there is no God .... The second argument is, that which can be achieved by a smaller number of originating principles is not brought about by a larger number. But, apparently, everything we see in the world can be achieved by some other originating principles even if there is no God. This is because natural things can be brought back to the originating principle of nature, while things which come about intentionally can be brought back to the originating principle of the human reason or will. So there is no need to suppose that there is a God. 31 As a matter of historical anecdote, it is perhaps worth noticing here the use of the principle which is (obviously incorrectly) called 'Ockham's razor': in Aquinas's formulation, that which can be brought about by a smaller number of principles is not brought about by a larger number. Aquinas's formulation appears to be a metaphysical profession of faith in a principle of explanatory economy, while the principle usually attributed to Ockham is rather a normative principle of methodology. The practical results are the same, though Aquinas's formulation appears in some ways more radically minimalist than Ockham's, strange as it may seem to the, alas, large number of contemporary English-speaking philosophers who accept the myth of Aquinas as a scholastic multiplier of unnecessary entities, and of Ockham as the forerunner of the glorious empiricist . . of our d ay. 32 re d uctwmsm But leaving aside anecdote and rhetoric, the objection is a serious one. The claim it makes is that the world does not in fact need an explanation. Since the Five Ways are an attempt to prove that the world requires an explanation in terms of a relationship to something other than itself, namely God, the argument, if valid, undermines precisely the kind of argument which Aquinas favours. The claim that the world needs no explanation, though, is one that needs disambiguating. Davies 33 tells of a famous debate on the wireless, about the existence of God, between Copleston and Russell. Russell, perhaps wisely, attempted a move similar to this objection: he tried to undermine Copleston's position by denying that there was any need to look for an explanation for the world. Copleston asked whether this meant that Russell regarded the world as 'gratuitous', like some existentialist philosophers; but Russell objected even to the word 'gratuitous', as it seems to suggest that the world

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might have been otherwise. He preferred to say 'The world is just there, that's all'. 'The world is just there, that's all' is not the claim being made in the objection which Aquinas offers. Aquinas's objection claims that the world has an explanation, or a number of explanations: nature and reason are those given. A similar kind of objection might claim that the world is such that it explains itself, or that in some other way needs no explanation; just as (on Aquinas's account) God is such that he explains himself, or needs no explanation. Russell, by contrast, claims that the world is 'just there'. I cannot see how Russell's claim differs from a stark refusal to bother to think whether the world needs an explanation or not. One thing is to look for an explanation and fail to find one; another is to show why the world requires no explanation; yet another is to show how the world explains itself; yet another, to show that it can be explained by for example nature or reason. Russell explicitly refuses to do any of these things, and I do not think that one would do him much of an injustice by characterising his attitude as 'sulks'. Copleston could equally have thrown a fit of the sulks and said 'God is just there, that's all', but I don't think it would have made for a very good debate, or for very good wireless. Moral: not all the reasonableness is always on the side of those who are called rationalists. As I say, the objection Aquinas brings is far more reasonable than Russell's sulks. It has a place in a serious debate, of which St Thomas's own arguments provide the other side. Like the argument from evil, it is common to this day - though, like the argument from evil, not exactly in the form which Aquinas gives us- and it is psychologically very forceful. The claim it makes amounts, roughly, to the claim that there is no need to look for God as the explanation of the world, because the world already has an explanation. The sum of the partial explanations which can be given for this or that part of the world - as Aquinas says, the sum of nature as an explanation for natural phenomena, and of human reason as an explanation for voluntary actions - provides a complete explanation of the world as a whole. Aquinas's own reply is perhaps, at this stage, not very enlightening. In it he refers us explicitly to his own Five Ways, as providing a reason for denying that the explanation offered for the world by the objection can be a complete one. To the second objection we have to say that since nature acts towards a determinate end in virtue of the direction of a superior agent, then we have to bring back the things that come about through nature to God, as well, as their first cause. In the same way, too, things that come about intentionally should be brought back to some higher

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cause: not the human reason and will, for these can change and fail, and everything that can change or fail must be brought back to some first unchanging originating principle which is necessary in its own right, as we have shown. 34 Since Aquinas himself refers us to his own developed arguments ('as we have shown'), we may perhaps omit for the present a careful examination of this reply. If Aquinas is right, going through the Five Ways will make it clear that the objection has no force. However, it will be useful to return to an examination of the apparent force of the original objection, perhaps couching it in terms which we would be more likely to use nowadays. This performance is of value not merely to help us to realise that the discussion StThomas is involved in is not so alien to us as might at first appear, but also because some considerations which arise from an examination of the objection may provide a clue to the strategy Aquinas is following in the Five Ways. Putting the matter crudely, the objection is as follows. If we have an explanation of the existence of each bit of the universe, can we not just lump all those partial explanations together? And if we do so, have we not then given an explanation of the whole universe? If such a complex of partial explanations existed, would not Aquinas's search for an explanation of the universe as a whole be at least redundant? If we had such an explanation of the whole universe (because we had an explanation of each and every bit of it) is it not a bizarre idea to then start looking for an explanation of the universe as a whole? Just what justification could there be for a distinction between 'the whole universe' and 'the universe as a whole' which seems to be necessary if Aquinas's project is not to be just ridiculous? We can go further. It is true that we do not have an explanation of each and every bit of the universe, nor do we feel confident that we are likely to get one in the very near future. We are not Victorians, after all: we do not believe that science provides all the answers- yet. But we do have an idea of what sort of thing science has to do to explain each and every bit of the universe. Some bits are well explained, some less well, some scarcely at all, but we are on our way. Providing an explanation of the existence of each and every bit of the world is an intelligible and theoretically feasible project. We have not got such an explanation yet, and we may never reach it, but we know what it would be to have such an explanation. Victorian optimism may have been misplaced, but do we not have grounds for holding that it is at least possible that there should be a scientific explanation of each and every bit of the universe? If this is so, then if it is not obvious that our search for God is wholly redundant and ridiculous, it is

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only our current state of relative scientific ignorance which conceals the · obviousness from us. This, in the eyes of any theist, is tantamount to a rejection of the existence of God. No classical theist can say, 'There must be a God now, but as science develops the need for God will diminish until maybe God becomes redundant'. (It is the fact that modern science is expected to come up with the explanations of this or that part of the world, incidentally, which has brought it about that this objection against the existence of God, which I have called 'the argument from partial explanation', a label which fits Aquinas's formulation well, is now often called 'the argument from science'.) This argument is already quite concrete and understandable, but it has become a commonplace in the philosophy of religion to bring it down to earth yet more by what is now called the example of the five Inuit, or argument of the five Inuit. 35 The argument goes as follows. If one were to meet a group of five Inuit standing on a street corner, the presence of this group is a surprising phenomenon, 36 one which requires an explanation. But suppose you had an explanation of the presence of each one of the group: would it then still be sensible to demand an explanation of the presence of the group as a whole? 37 Clearly not. It is worth pointing out that this kind of argument is one which Aquinas himself would accept. We have seen above that for Aquinas there need be no reason for coincidences, for the per accidens as such. That which is per accidens is the result of the convergence of two or more lines of explanation or causality, and once each of those lines of explanation has been given, the per accidens existent is already explained. To seek for an explanation of the per accidens as such is to demand that it should be, in the modern jargon, 'over-determined'. If I seek an explanation of why I should have bumped into a friend in the street, there need be no other explanation than the explanation of why I am proceeding along street S from east to west at time t, plus the explanation of why my friend is proceeding along street S from west to east at time t. I can lump the explanations for each bit of the meeting together, and I have an explanation of the meeting as a whole. What goes for the meeting of me and my friend goes for the group oflnuit, too: if there is a reason why lnuk A is at point X at time t, and a reason why lnuk B is at point X at time t, and a reason why lnuk C is at point X at time t, and a reason why lnuk D is at point X at time t, and a reason why lnuk E is at point X at time t, then there is eo ipso a reason why there is a group of five Inuit at point X at time t. More to the point, what goes for a group of Inuit goes for the world as a whole. In the example we have a complex and surprising phenomenon, the presence of a group of five Inuit; a phenomenon which excites our

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curiosity and makes us want to look for an explanation. The existence of the world, it is suggested, is in every way parallel: a complex and surprising phenomenon, a phenomenon which excites our curiosity and makes us want to look for an explanation. We ignore the siren call of Lord Russell to regard the world as 'just there', as we would probably ignore an appeal from one of our more boring friends to regard the Inuit as just there. (My grandmother used to say 'Don't stare' and 'mind your own business'. That Lord Russell should have so much in common with my grandmother is another of those trivial but interesting sidelights on the history of philosophy.) In the example, we are supposed to find an explanation of the presence of each and every one of the Inuit who compose the group; and once we have that, we will not need to look for an explanation of the presence of the group as a whole. In the case of the world, we are on our way to having provided for us by science an explanation of the existence of each and every thing in the world. Equally, then, it is claimed, we do not need to look for an explanation of the existence of the world as a whole. The case against arguing for the existence of God, in so far as arguing for the existence of God means arguing for an explanation for the existence of the world as a whole, rests. Clearly the time has come to tell a story. Once upon a time there were five Inuit standing on a street corner in Glasgow: Nanuk, Amoraq, Kadlu, Kotuko, and Angekok. 38 The claim being made is that when we have an explanation of the presence of each and every one of the group we then needn't ask for a reason for the presence of the group as a whole. Let us endeavour, then to find an explanation of the presence of each and every one of the group. Why is Nanuk there? Nanuk has a strong, if not necessarily a good reason for being there: he is deeply and madly in love with Amoraq, and where she goes, he goes. Why is Amoraq there? Amoraq is there because she is Kadlu's wife (I told you that Nanuk's reason for being there was strong but not necessarily good), and she is accompanying her husband. Why is Kadlu there? Kadlu is there because, not unnaturally, he does not wish to see his wife go off touring Europe without him, and particularly not in the company of Nanuk, of whom he has (justifiable) suspicions. Why is Kotuko there? Kotuko is there because he is the infant son of Amoraq and Kadlu, and is too young to be left at home on his own. Why is Angekok there? Angekok is there because (as, I understand, his name suggests) he is the village sorcerer or shaman, a person of some authority in the community, who is there to keep an eye on Kadlu and Nanuk, to make sure that they don't start quarrelling or even fighting, thus lowering the high reputation the Inuit people have hitherto deservedly enjoyed in Scotland.

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What is wrong with this story? As a novel, it's pretty thin on both characterisation and plot, as a pulpit anecdote its moral is rather unclear. But as a story to explain why each and every one of the group of five Inuit is standing on the street corner in Glasgow, there is nothing wrong with it. Ask 'Why is he there?' or 'Why is she there?' of any one of the group and the story provides a perfectly valid explanation. If the thesis which this example was developed to support is correct, we can now lump all these partial explanations together and we will have an explanation of the presence of the group as a whole. To look for any further explanation of the presence of the group as a whole should be redundant and ridiculous. One does feel, however, that not everything that needs to be said has been said. Yes, we might say, I can see a reason why each should be on a street corner in Glasgow, and these reasons, lumped together, do indeed give some sort of a reason why all should be there: what I cannot see is a reason why any should be there. Some explanation is surely still missing. Can I have found a sufficient reason for the presence of all when I have a crying need for a reason for the presence of any? What is wrong with the story, what makes it unsatisfactory for us to lump together the explanations of the presence of each and call the resulting story an explanation of the presence of the group as a whole, is the following feature: the explanation of the presence of each member of the group is given in terms of his or her relation to some other or others of the group. Naturally I composed the story, such as it is, to display this feature. When the explanation of the presence of each member of the group is given in terms of his or her relation to some other or others of the group, then we cannot lump together the explanations of the presence of each member of the group and call it an explanation of the presence of the group as a whole. It is therefore not redundant or ridiculous, in such a case, to seek for a further explanation of the presence of the group as a whole. This further explanation can take various forms. It could indeed be an explanation for the presence of each and every member of the group directly; in the imagined case, they might each be members of the North Manitoba Ethnic Dance Troupe which is about to perform at the Mayfest Arts Festival. Equally well, it could be an explanation primarily and directly for the presence of only one; maybe Kadlu is an exceptionally good footballer and is thinking of signing for Partick Thistle. 39 In the latter case, one might want to say that Kadlu has a reason for being there and that the others don't. This would be a mistake. The others have a reason for being there: they are there, directly or indirectly, because Kadlu is, and Kadlu is there to sign for Thistle. Thus the reason for the presence

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of the group is Kadlu's signing for Thistle. In this case Kadlu occupies an explanatorily privileged place relative to the rest of the group. If the story were told another way, another one, or several others, might occupy the explanatorily privileged place. Or, as has been said, it might be that none of them occupies an explanatorily privileged place; as in the dance troupe explanation, they might all have an equally strong and equally immediate explanation for their presence. The form of the explanation is at this point irrelevant: what is relevant is that the story as originally told cannot be the end of the matter, there must be an explanation of the presence of the group as a whole, over and above the various explanations of the presence of each member of the group. Equally unimportant, clearly, is the size of the group. What goes for five Inuit goes for ten, for twenty ... for as many as you have room for on the street corner. No matter how large the group, if the explanation of the presence of each is given in terms of that person's relation to another of the group, we need a further explanation of the presence of the group as a whole. This remains true, we may point out, even if the group is infinitely large. We may grant that there is something odd about the picture of an infinitely large group of Inuit, or of anybody, standing on any finite corner of any finite pair of streets in Glasgow, but the point remains. Easier to imagine, perhaps, is a group of infinite, or at least indefinite, temporal duration. For as long as you care to mention there are five Inuit standing on the street corner, since when one goes another comes. If the presence of each lnuk is explained in terms of his or her relation to another of the group- e.g. if each new arrival explains his or her presence by saying 'I'm here to take over from Whatsisname' - then even if the group is infinitely large, then we will still need an explanation of the presence of the group as a whole. Let us apply the parallel. Science, let us admit, does adequately explain the existence of each and every thing in the world; or, if in fact it doesn't, let us admit that it looks as if one day it might. If we ask for the explanation why this or that thing exists, science can give it to us, or at least can plausibly claim that one day it will be able to give it to us. In the same way our original story gave us a explanation of the presence of each and every Inuk. But the parallel continues. The explanation of each and every thing in the world is given in terms of that thing's relationship to something else in the world. Clearly this is so: science very carefully avoids telling us about anything outside the world; science is rightly agnostic about anything outside the world. So it was with the Inuit: the explanation of the presence of each was given in terms of his or her relationship to some other member of the group. For this reason we required a further explanation

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of the presence of the group of Inuit as a whole, and for the very same reason we not only may, but must, require an explanation of the existence of the world as a whole. The parallel continues yet further. This further explanation could relate each part of the world directly with some single explanation, as the dance-troupe explanation did to the Inuit; this, as we shall see, is the kind of explanation favoured by StThomas in the Five Ways. 40 Or the further explanation might relate in some more direct and privileged way to some individual part of the world, as the football explanation related directly to K.adlu and indirectly to the others; this would be similar to the way in which some people explain everything else in the world in terms of its relationship, direct or indirect, to the Big Bang, and then wonder about the explanation of the Big Bang. StThomas, I think, would not object to this kind of explanation, but, as we shall see, he does not (in the Five Ways, at least) think he has sufficient evidence to establish the explanatory priority of any particular part of the universe. 41 Lastly, the parallel applies also to the question of the infinite extent of the whole. ForSt Thomas, the world is limited in physical extent. He also believes, though, that while in fact the world had a beginning in time, it might have existed for ever. 42 He makes use in a number of the Five Ways of a step in the argument which claims 'We cannot go on to infinity in this line'. As we shall see, the sense in which he uses 'we cannot go on to infinity' is a curious one, one which is compatible with the hypothetical everlasting existence of the world; 43 he might have expressed himself more perspicuously by saying 'If we go on to infinity in this line, there is no explanation'. This is precisely the point made when the presence of the group of Inuit was imagined indefinitely protracted in time. This illustration- which the reader may feel has been over-labouredhas the additional justification that it can be used to illustrate what may be thought of as the overall pattern of the Five Ways. 44 StThomas's claim, in each of the Five Ways, is that the world as a whole requires some kind of explanation; and the conclusion of each of the Five Ways is that the explanation of the world of the kind which that Way demands is something which we call God. In a sense, 'God' is at this stage no more than a label for 'the explanation of the world'. St Thomas feels himself obliged to go on in later questions of the Summa to argue that, for example, there can be no more than one God, that God does not enter into any kind of composition with the world, that God is good and almighty, and so forth, through all the traditional attributes which classical theism attributes to God. The conclusions of the Five Ways are very agnostic, in a sense, though not tentative. It seems, for example, that the Third Way might be

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consistent with a multiplicity of physical or material Gods, such as the ancient Greeks traditionally believed in, and possibly that the Fourth Way is consistent with a multiplicity of formally distinct spiritual Gods, such as (perhaps) some of the Greek philosophers believed in. Though the Five Ways can be seen to follow something of a common pattern, they differ essentially in detail. They differ essentially, in that though in each case what is being argued for is the need that the world as a whole has for an explanation which is distinct from it, in each of the Five Ways the world as a whole is being considered under a different aspect, under a different description, as a systematic whole, representing various different manners of systematisation. This is clear from the first sentence of each of the Five Ways. StThomas begins by identifying a particular feature- call it feature X - a different feature for each of the Five Ways. This feature is displayed by this or that bit of the world: in each case St Thomas takes this claim as being obviously true, and does not argue for it. One of the distinguishing marks of feature X is that anything which displays feature X requires an explanation in terms of its relation to something else: the fact of displaying feature X means that whatever displays it requires an explanation, and does not explain itself. This is clearly a vulnerable point of each in the Five Ways: it is possible for the critic to argue that the feature which St Thomas identifies does not have this distinguishing mark. At various points we will see StThomas defending his identification of a feature X against obvious criticisms of this kind. A good example is the defence he offers for the principle 'omne movens ab alio movetur', everything which is in process of change has that change initiated in it by something else, in the First Way. 45 The next step in each of the Five Ways is likewise questionable. It is what Geach calls the 'lumping-together' move. 46 This consists in moving from the claim that this or that part of the world displays feature X to the claim that the world as a whole displays feature X. There is nothing particularly mysterious about this move: it can be made perfectly straightforwardly with regard to any number of features, and with regard to any number of systems which contain parts which display that feature. The pattern of argument is that any system which contains parts which display feature X is itself something which displays feature X. It is not disputable that this move works where feature X is, say, 'complexity'- any whole which contains complex parts is itself complex. Equally, it is not disputable that this move fails to work for 'smallness'- a system which contains small parts may itself be rather large, even, indeed, if all its parts are small. Here again there is room for the critic to raise a query: is the feature X which StThomas has identified one which permits of this move? We can

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see the point being argued fairly explicitly in the Third Way. 47 It is worth saying, however, that there is no obvious contradiction between this mark of feature X - that it permits us to make the lumping-together move and the previously identified mark, that whatever displays feature X requires an explanation in terms of a relation to something different to it. Any alleged inconsistency will need looking at on its merits. This brings us to the penultimate move in each of the Five Ways. It has been claimed that parts of the world display feature X, and that whatever displays feature X requires an explanation in terms of a relation to something else. If the lumping-together move is valid, we are obliged to admit that the world as a whole, which consists, at least in part, of things which display feature X, is itself something that displays feature X. On the supposition that an appropriate feature X has indeed been identified, we are forced to conclude that the world itself, as a whole, requires an explanation in terms of something else. It is worth pointing out that this move does not yet bring us directly to God. There might be something which explains the existence of the world as a system which displays feature X, which is in some way separate from or distinct from the rest of the world as a whole, which nevertheless itself displays feature X. If it does display feature X, then it too requires an explanation in terms of its relation to something else. We then must perform the lumping-together move over again, putting this new explanatory entity together with the rest of the world which displays feature X, and ask of this newly enlarged systematic whole, what is its explanation. We might, indeed, ask about that particular explanatory entity, itself displaying feature X, what is its explanation: this would be to attribute to it a position of explanatory privilege, such as we offered to Kadlu as footballing star in the story of the Inuit, such as some people nowadays would offer to the Big Bang, or such as StThomas in the Summa Contra Gentes seems to want to attribute to the outermost sphere of the heavens. 48 It is worth pointing out that in the Summa Theologiae StThomas abandons this strategy, and prefers that of performing the lumping-together move over again. Clearly this strategy is of greater generality and does not depend so much on shifting physical theories which would identify what is explanatorily privileged in different ways at different times. But now we come to the concluding moves of the Five Ways. No matter how many explanatorily privileged elements of the world we may identify at one time or another, we are entitled to perform the lumping-together move as often as we have reason to do so, and to recognise in the (now expanded) system of the world which we now behold, something which displays feature X. Now matter how big the world is, no matter how many

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extra elements, explanatorily privileged or not, we find ourselves obliged to build into it, the world does not cease to be something which displays feature X. And that which displays feature X requires an explanation in terms of a relation to something else. This remains true even if the world is of infinite extent: if the explanation of the presence of each member of the group of Inuit is his or her relationship to another member of the group, then the presence of the group requires an explanation, even if the group is of infinite size or of (at least) indefinitely long duration. The whole system - the group of Inuit, the world as a whole - will thus lack an explanation, until we posit the existence of something, in terms of a relationship to which the whole system which displays feature X can be explained. And this posited something, through the reasoning we have just expounded, cannot itself display feature X, or it would itself be just a part of the newly expanded system of things which display feature X. We therefore postulate the existence of some thing which does not display feature X, which therefore does not require an explanation in terms of its relationship to something else, in terms of a relationship to which the world as a whole is explained. And this, Aquinas tells us, we call God. Two glosses are worth making at this point. The way we have explained the Five Ways makes it clear why it is absurd to ask 'But who made God?'. The God whose existence we have been forced to postulate, by the very force of the argument, does not display feature X, and therefore the question 'Who made God?', or, more accurately, 'What is it in terms of a relationship to which the existence of God is explained?', does not arise. 49 The second point to be made is that this last line of each of the Five Ways provides yet another point at which the critic may object. The critic may very well protest that he does not see why the explanatory entity thus postulated needs to be called 'God': in more formal terms, that he cannot see why 'Entity lacking feature X, in terms of a relationship to which the world as a whole, in so far as it is itself something which displays feature X, is explained' enters into the signification of the word 'God'. The pattern I have suggested for all of the Five Ways thus admits three crucial points for the objector, while in each of the Five Ways there may also be particular points for objections to be made, which relate to the different ways in which the accounts of the different kinds of feature X are developed. Displaying the arguments in this way should make it easier to understand the arguments of St Thomas and to recognise them as valid, if they are valid; but it will also make it easier to find points of questionable validity. The structure alleged is not a kind of trick to make the arguments more acceptable: it seems to me to be a useful piece of common ground on which supporters and opponents of the Five Ways can carry out their debate. 5°

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If this position, that there is a discernible single structure to be found in all of the Five Ways, is acceptable, our next move has to be to examine the detailed development of each of them. NOTES 1. Summa Theologiae, I, q. 2, a. 3: 'Utrum Deus sit ... Videtur quod Deus non sit.' 2. See Chapter I, p. 3. 3. Usually; sometimes he regards neither the thesis enshrined in the quaestio nor the contrary which he expounds in the objections as being an adequate account of the problem. 4. See e.g. J. L. Mackie, The Miracle of Theism (Oxford: Clarendon, 1982), especially Chapter 5, pp. 81-101, and Chapter 9, pp. 150-176. 5. Summa Theologiae, I, q. 2, a. 3, 1st objection: Videtur quod Deus non sit. Quia si unum contrariorum fuerit infinitum, totaliter destrueret aliud. Sed hod intelligitur in hoc nomine 'Deus', quod sit quoddam bonum infinitum. Si ergo Deus esset, nullum malum inveniretur. lnvenitur autem malum in mundo. Ergo Deus non est. 6. See Chapter 6 above, pp. 83-4. 7. Usually taken as roughly equivalent to the belief defined in R. Swinburne, The Coherence of Theism (Oxford: Clarendon, 1977), p. 1. 8. This formulation, and much in my account of the argument from evil, I owe to B. Davies, An Introduction to the Philosophy of Religion (Oxford: Oxford University Press, 2nd edn, 1993), pp. 32-54. 9. In the East: various Hindu or Buddhist systems which hold that all existence is an illusion and the existence of evil is a fortiori an illusion. In the West: religious groups in the West such as the Christian Scientists; philosophers such as the Stoics and McTaggart. The Christian Scientists at least at times appear to hold the self-contradictory view expounded in this paragraph, while the others seem to have held the more reasonable claim. 10. Summa Theologiae, I, q. 48, a. 2, ad 2 and Quaestio Disputata de Malo, q. I, a. 1., ad 19. See Chapter 5 above, pp. 65-73. II. See Mackie, The Miracle of Theism, Chapter 9, pp. 150-76. 12. Cf. P. T. Geach, 'An irrelevance of omnipotence', in Providence and Evil (Cambridge: Cambridge University Press, 1977) pp. 29-39, and Truth, Love and Immortality (Berkeley and Los Angeles, University of California Press, 1979), pp. 164-5. 13. Expounded by A. Plantinga, God, Freedom and Evil (London: Routledge and Kegan Paul, 1975); discussed by Mackie, The Miracle of Theism, Chapter 9, e.g on pp. 155--6, 162-6, 172-6. 14. See Davies, An Introduction to the Philosophy ofReligion, especially pp. 42-3. Compare also I van's rejection of the free-will defence in The Brothers Karamazov, discussed in Davies, pp. 37-8. 15. See below, Chapter II, p. 168; also compare P. T. Geach, Three Philosophers (Oxford: Blackwell, 1961), p. 110. 16. See above, Chapter 5 note 35. 17. See Summa Theologiae, I, q. 11, a. I ad 1: 'Privation is a negation within a subject' (my stress), 'Privatio est negatio in subiecto'. 18. See Chapter 6 above, p. 92. 19. See the discussion of divination in Summa Theologiae, I, qq. 115, 116, where the indeterminateness of the cause of the per accidens is the principal reason given for the irrationality of this kind of superstition. 20. It is true that there can be such an explanation. A latter-day St Nicholas, wishing to do good by stealth, might have hidden the treasure at point X and then encouraged our hero to dig his ditch at point X. Anything which can be expressed by a proposition can be grasped by the mind and thus brought about by an intelligent agent. But the point is that there is no need to postulate a further explanation. 21. See A. Kenny, The Metaphysics ofMind (Oxford: Oxford University Press, 1991). 22. As a matter of fact to make this work you have to take what appears to be the third word of Genesis ( 'elohim, God) as being in some sense really the first word, either because it is the most important word in the sentence or because it is the subject of the sentence. But this kind of detail never stops the people who like this sort of thing.

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23. My thanks are due to Professor Geach, in conversation, for the idea expressed in this example, and to Professor Broadie for the elegant detail of this precise example.

24. On the relative inadequacy of any descriptions we may apply to God, see Summa Theologiae, I, q. 13, a. 2c. 25. Summa Theologiae, I, q. 13, a. I, second objection and reply. 26. See Geach, 'Animal pain', in Providence and Evil, pp. 67-83. 27. This point is made by Plantinga, God, Freedom and Evil. 28. See Davies, An Introduction to the Philosophy ofReligion, especially pp. 53-53. 29. See Davies, An Introduction to the Philosophy ofReligion, p. 54. 30. Summa Theologiae, I, q. 2, a. 3, ad 1: Ad primum dicendum quod sicut dicit Augustinus in Enchiridione, 'Deus cum summe bonus sit, ullo modo sineret mali aliquid esse in operibus suis, nisi esset adeo omnipotens, et bonus, ut bene faceret de malo.' Hoc ergo ad infinitam Dei bonitatem pertinet, ut esse permittat mala, et ex eis eliciat bona.

31. Summa Theologiae, I, q. 2, a. 3, second objection: Praeterea, quod potest compleri per pauciora principia non fit per plura. Sed videtur quod omnia quae apparent in mundo possunt compleri per alia principia, supposito quod Deus non sit; quia ea quae sunt naturaliter reducuntur in principium quod est natura, ea vero quae sunt a proposito reducuntur in principium quod est ratio humana vel voluntas. Nulla igitur necessitas est ponere Deum esse.

32. It is also worth pointing out that Aquinas, in his reply to this objection (see note 34 in this chapter) does not reject the principle used in the objection. Rather he insists that it is necessary to posit another originating principle, since the principles cited in the objection are not in fact sufficient to explain the relevant natural and voluntary phenomena. 33. Davies, An Introduction to the Philosophy of Religion, p. 87. 34. Summa Theologiae, I, q. 2, a. 3, ad 2: Ad secundum dicendum quod cum natura propter determinatam fin em operetur ex directione alicuius superioris agentis, necesse est ea quae a natura fiunt etiam in Deum reducere sicut in primam causam. Similiter etiam quae ex proposito fiunt oportet reducere in aliquam altiorem causam, quae non sit ratio et voluntas humana, quia haec mutabilia sunt et defectibilia. Oportet autem omnia mobilia et deficere possibilia reduci in aliquod primum principium immobile et per se necessarium, sicut ostensum est.

35. This argument used to be called 'the argument of the five Eskimos', but it appears that the North

36. 37. 38. 39. 40. 41. 42. 43. 44.

45.

American people who call themselves 'Inuit' (singular lnuk) very much dislike the more common name. Since I understand that the name they dislike comes from the Algonquian language of the Inuit's southern neighbours, and means something like 'stinking fish-eaters', one does not have to be a fanatic for political correctness to take the trouble to use the less familiar word. In Glasgow, at least, if not in Churchill, Manitoba. The example betrays its non-Canadian origin. The argument, I believe, was first used by P. Edwards, in 'The cosmological argument', in Rationalist Annual, 1959, pp. 63-77; also in D. R. Burrill, (ed.), The Cosmological Arguments: A Spectrum ofOpinion (New York, 1967), pp. 114-22. As far as I can make out, most of these are genuine Inuit names, and ifl'm wrong I submit that they're at least plausible. There is a rather ancient Glasgow joke which might suggest that Kadlu was given a trial for Rangers, but they dropped him because he ate fish on Friday. See e.g. above, Chapter 8, p. 104, and below, Chapter 13, pp. 196--201. See Chapters 9-13 below; but contrast Summa Contra Gentes, I, 13, where St. Thomas seems to attribute some kind of explanatory priority to the outermost heavenly sphere of Aristotle's cosmology. See Chapter 7, note 20. See Chapter II, p. 157, below, on the Third Way. See Summa Theologiae, I, q. 46, a. 2, ad 7, and Chapter II, p. 167, below on the Third Way. This pattern is in general that observed by Geach, 'Aquinas', in Three Philosophers, pp. 111-17. See Chapter 9 below, pp. 135-41. See also the parallel passage in Summa Contra Gentes, I, 13, where StThomas admits that this step in the argument is a 'questionable premiss'. See Geach, 'Aquinas', in Three Philosophers, p. 113. See below, Chapter 11, p. 160.

46. 47. 48. Summa Contra Gentes, I, 13.

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49. Cf. Geach, 'Aquinas', in Three Philosophers, p. 113. This point is worth stressing as the best-known contemporary anti-God propagandist in Britain, Richard Dawkins, seems to be unaware of it. 50. Cf. A. Kenny, The Five Ways (London: Routledge and Kegan Paul, 1969), pp. 1-5.

9 • THE FIRST WAY

The 'Feature X' identified in the First Way appears to me to be 'being in process of change', in Latin 'moveri'. There is some ambiguity in this Latin word: it can be used to mean 'moving', in the intransitive sense of the English word, i.e. precisely that of being in a certain process of change. Though the English word is usually limited to the notion of change of place, there seems no essential use of this specific sense (which the Latin word can also have) in the First Way. Moreover, the parallel passage in the Summa Contra Gente/ shows us St Thomas explicitly discussing a number of different kinds of change, so it would appear that the notion of change of place is not foremost in his mind. But the more serious ambiguity consists in this: the same word 'moveri' is also the passive form of'movere', to move in the transitive sense, to initiate change in something. It has been alleged by Kenny that Aquinas is thinking principally of the regular local movements of the Aristotelian heavens, on the one hand, and, on the other, is hopelessly confused by the ambiguity of 'moveri' as between 'being in process of change' and 'having a change initiated in oneself'. 2 Here we can perhaps see the first advantage of observing the structure we have outlined. Such an ambiguity, if it existed, would invalidate the identification of the relevant feature X as both being a feature which (at least) parts of the world uncontentiously display, and also being a feature in virtue of which that which displays that feature requires an explanation in terms of a relationship to something else. In the sense 'being in process of change', 'moving' in the intransitive sense, most of the world displays the feature of 'moveri'; and in the sense of 'having one's change initiated by something else', 'being moved by something' (using 'moveri' as the strict passive of 'moving' in the transitive sense), it is obvious that everything that displays the feature of'moveri' requires an explanation in terms of a relationship to something else. The fallacy would consist in holding, clearly mistakenly, that there is a single feature adequately expressed by 'moveri' in its two different senses.

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It should become clear, as we examine the First Way, that StThomas does not commit any such fallacy of equivocation. He spends a good deal of the First Way arguing that everything that is in process of change has that change initiated in it by something else: that is, he argues that whatever 'is moved' in one sense also 'is moved' in the other. It may be that his arguments fail to prove his point, and indeed they are slightly obscure, but it is clear that he has not been confused into a fallacy by the mere fact that one Latin verb has two senses. Someone who argues at length for the claim that whatever a particular verb applies to in one sense, that same verb applies to in the other sense, has not committed a simple fallacy of equivocation. Let us examine the text, then. The first and clearer way is one which is taken from the fact of process of change. It is certain - it is obvious to the senses - that in this world some things are in process of change. But everything that is in process of change has that change initiated in it by something else. For nothing is in process of change unless it can be that towards which it is in process of change. But a thing initiates change in so far as it actually is something. This is because to initiate a process of change just is to lead something from being able to be something to actually being it. But something cannot be led from being able to be something to actually being it except in virtue of some existent which actually is something. Thus, that which actually is hot, i.e. fire, makes the wood, which can be hot actually to be hot, and in virtue of this it initiates change in it and gives it a new quality. Now it is impossible for something to be able to be something and to actually be the same thing at one and the same time: only different things. For what actually is hot cannot be able to be hot at the same time, though it is, at the same time, able to be cold. It is impossible, then, that a thing should be an initiator of change and a thing in process of change, with respect to the same determination and in the same way. That is, nothing initiates change in itself. So everything which is in process of change must have that change initiated in it by something else. But if that which initiates the change is itself in process of change, then it too must have its change initiated by something else: and so on.

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We cannot go on to infinity in this line, for if we did there would be no first initiator of change, and thus no other initiator of change, since the later initiators of change initiate change only in virtue of their having change initiated in them by the first initiator of change. Thus a stick does not initiate change except in virtue of having change initiated in it by the hand. So we have to come to some first initiator of change which is not in a process of change initiated by something else, and everyone understands that this is God. 3 The curious indentation in this text is not merely a freak of the editor or the printer: it is aimed at clarifying the structure of the argument to some extent. The sections which begin at the left-hand margin are the main premisses of the argument and its conclusion. Those sections indented are subsidiary arguments introduced in support of what has gone immediately before. Beyond this, there are sections yet further indented which are yet more subsidiary arguments adduced in support of elements in the first-level subsidiary arguments. Running down the left-hand margin, then, we have a clear outline of the argument. The first and clearer way is one which is taken from the fact of process of change. 1. It is certain- it is obvious to the senses- that in this world some things are in process of change. 2. But everything that is in process of change has that change initiated in it by something else. 3. But if that which initiates the change is itself in process of change, then it too must have its change initiated by something else: and so on. 4. We cannot go on to infinity in this line, 5. So we have to come to some first initiator of change which is not in a process of change initiated by something else, and everyone understands that this is God. Premiss 1 identifies a feature X uncontentiously displayed by at least parts of the world. Premiss 2 asserts the claim that everything which displays this feature requires an explanation in terms of a relationship to something else. Premisses 3 and 4 perform and defend the lumping-together move, and lead us to the conclusion, 5. The argument appears to me to be of

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valid form, and thus if its premisses are true, its conclusion will also be true. Premiss 1 is, as I have said, uncontentious; premiss 3 is little more than a re-statement of one of the marks of the given feature X. It is premisses 2 and 4 which are contentious, and both are given detailed support here by Aquinas. It is worth noticing that in the slightly more articulated version of this argument which he gives in the Summa Contra Gentes, he identifies these two premisses as being 'doubtful' 'dubiosae', 4 or, as we might say, 'questionable'. He is quite clearly aware of the points at which his argument is vulnerable. The first questionable premiss, then, is premiss 2, everything that is in process of change has that change initiated in it by something else, and there is a long and difficult argument to support it. It stands in need of clarification, indeed, as much as support. At first sight, it looks like a straightforward denial that there are self-movers, things that initiate change in themselves. This claim appears ridiculously false: the dog which begins to bark would seem to be an obvious counter-example. St Thomas, who follows Aristotle in holding that one of the things that marks out animals is their capacity for self-movement - 'the originating principle is in themselves' 5 - does not in fact hold anything so false. His claim is rather that no material thing is a self-mover in a carefully defined sense: there is nothing which as a whole initiates change within itself as a whole. 6 In an animal, let us say, what happens is that one part initiates change in another part. This caveat is important if we are to make much of the argument which he adduces in support of his premiss 2. Skipping the indented subsidiary arguments, as before, the structure is as follows: For nothing is in process of change unless it can be that towards which it is in process of change. But a thing initiates change in so far as it actually is something. Now it is impossible for something to be able to be something and to actually be the same thing at one and the same time: only different things. For what actually is hot cannot be able to be hot at the same time, though it is, at the same time, able to be cold. It is impossible, then, that a thing should be an initiator of change and a thing in process of change, with respect to the same determination and in the same way. That is, nothing initiates change in itself. So everything which is in process of change must have that change initiated in it by something else. The argument, as it stands, looks rather dubious. It clearly rests on one general principle which is fairly acceptable, that that which becomes F is

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not-F and can be F. But it seems also to rest on a principle which is not only questionable, but in fact false: that only that which is F can make something else F. The example Aquinas gives in the subsidiary argument which we have just omitted makes it seem as if this principle is definitely being used. This is because to initiate a process of change just is to lead something from being able to be something to actually being it. But something cannot be led from being able to be something to actually being it except in virtue of some existent which actually is something. Thus, that which actually is hot, i.e. fire, makes the wood, which can be hot actually to be hot, and in virtue of this it initiates change in it and gives it a new quality. The example of heat itself is questionable, though there are obvious examples which do fit the point Aquinas seems to be making. As Kenny points out, you cannot dry yourself with a wet towel. But there are innumerable examples which do not fit the pattern that that which makes something F must itself be F. Again, with Kenny, we can say that the king-maker need not be a king, and indeed very few murders are committed by dead men. 7 And as Geach points out, Aquinas himself would have been aware of a strong counter-example even within the field of heat: Aquinas, like most Aristotelians, believed that while the sun was the cause of heat on earth, the sun was not itself hot. 8 It is true that if this second principle were true, Aquinas would have achieved his point, and made it clear that whatever is in process of change has that change initiated in it by something else, since nothing can both be F and not-Fat the same time, so if an initiator ofF-ness has to be F, and something that comes to be F has to benot-F, then nothing can initiate change in itself. But it is hard to believe that he can be meaning to offer us such an obviously defective argument. It is worth noticing, at least, that while the tone and the choice of example suggest that Aquinas may indeed wish to say that only what is F can make something F, the actual text of the argument does not say this. The conclusion which is indeed warranted by the premisses, and is explicitly drawn, is that only something that is actually something or other can make something else to be F. The reason for this might be as follows. The only requirements on that which is made to be F, so far as the process of 'being made to be F' is concerned, are that it should be not-F, and that it should be able to be F, that it should be F in potentiality. No doubt there are plenty of other determinations which it has, plenty of other descriptions which

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are true of it, but from the fact that it is a subject of a change to being F, all we are entitled to conclude about it is that it is non-F and can be F, is F in potentiality. Neither of these two descriptions suffice to give us a rationale or explanation for its coming to be F. Neither being non-F nor being capable of becoming F offer us any explanation of the fact which we have to explain, which is that it becomes F. If there is to be any explanation of its becoming F, it must be at the very least in virtue of some other aspect, given by some other true description: a description which is not purely negative, such as ' - is not-F', nor purely potential, such as'- can become F'. This does not get us any further than the claim which Aristotle and Aquinas would make for the obvious self-movers such as animals, that when the dog begins to bark, for example, it is a case of one part or aspect of the dog initiating a change in another part. 9 We seem to have some justification for the claim that nothing as a whole initiates change in itself as a whole. It remains to be seen whether this claim will serve us in the development of our account of the First Way, but before we examine that question, it may be worth while examining whether even the more modest claim just made can be justified. That it is justified on Thomistic grounds, and on the basis of the text of the First Way seems clear; and the parallel passage in the Summa Contra Gentes, which lists a variety of different kinds of change, seems to justify our taking the text of the First Way in this sense, and abandoning the obviously false suggestion that only what is F can make something else F .10 But there may also be considerations which we can draw from more contemporary views on the nature of change and explanation which may help us to provide a more convincing justification.11 We can begin by saying that every change is a beginning of existence. Not that the dog's starting barking is the beginning of existence of the dog, of course, but it is at least the beginning of the existence of the barking. And we can also insist, pace Hume, 12 that every beginning of existence has a cause. Anscombe, in the latter of the two articles cited, points out that the only way we can identify a beginning of existence as such, as being a genuine beginning of existence, is by attributing to it a cause. To claim that the dog's beginning to bark is indeed a beginning of existence of the dog's barking, and not, for example, the mysterious invisible and untraceable arrival to the dog's throat of a barking which may have existed for centuries elsewhere, is only possible through an identification of the cause, which we may take to be some kind of stimulation in the dog's brain.

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This seems to get us no further than the account we gave of what St Thomas actually said. We are, perhaps, forced to admit some cause or explanation of each change that is something different from the change itself. We can admit, too, that when the change is from not-F to F, from being able to be F to being F, it is not the being not-F as such, not even the being able to be F as such, which is the cause of the change. The cause, we may be willing to admit, must be something actual, some real existent, we might say, using the terminology we used earlier in discussing St Thomas's doctrine on existence. But this does not get us very far. We have to admit, perhaps, that there is something in the dog other than its barking which explains its beginning to bark; something in the dog which explains its beginning to bark, which is also other than its previous non-barking and other than its previous being able to bark. Neither of these two latter features are any kind of cause or explanation of the dog's beginning to bark; rather they are its logical presuppositions. But can we get from here to the general thesis St Thomas wishes to reach, that everything that is in process of change has that change initiated in it by something else? It may be possible to bridge the gap. If every change is, under a different description, a beginning of existence, and every beginning of existence requires a cause, it may be possible to argue that every change requires a cause, under some description. And it may be that possible answers to the question, 'under what particular description?', may be subject to certain limitations. A crucial feature in the philosophical analysis of any change is the identification of the subject of the change. This point has been known at least since the time of Heraclitus, who told us that upon those who go down into the same rivers, other and other waters ever flow. 13 An interesting feature of our shifting from the consideration of the dog's starting to bark in the night as being a change in the dog, to our consideration of the same phenomenon as the beginning of existence of the dog's barking, was that when we shifted our consideration, and thus the description we gave of the phenomenon, we found ourselves obliged to make a simultaneous shift from the dog as subject of the change to the barking as subject of the beginning of existence; or (in the possible alternative description envisaged) to the barking as the subject of a mysterious and invisible journey through what science-fiction writers like to call 'hyperspace'. What difference does this shift of subject make? Interestingly enough, it seems to make no difference to the argument. We know that the dog began barking because of some stimulation in its brain, and because we know this - because we can attribute a cause or

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explanation - we reject any possibility that the barking was really started some time earlier by some other dog and transferred to our Rover. If this is so, it seems that we can generalise from 'every beginning of existence must have a cause' to 'every initiation of a process of change must have a cause'. We can go one step beyond this, even. Every process of change (as opposed to an instantaneous change) is itself a continually repeated series of initiations of a process of change. To deny this would seem to take us into the territory of Zeno, in which we are to suppose a series of static instants at which no change takes place. We should rather say, with the medieval Aristotelians, that every instant is to be considered either as the last instant of the preceding state or as the first moment of the succeeding state. 14 If this is so, then every process of change requires a cause which is external to that process of change itself. We do not have to deny the existence of self-movers such as animals, but it seems that we do have to accept the Aristotelian account of them: that in the self-movement of animals it is strictly one part of the animal which moves another part, which initiates a process of change in another part. Clearly, too, 'one part' and 'another part' need not be understood in terms of spatially extended parts, though one of the arguments which Aristotle gives for this thesis seems most naturally taken in the sense of spatially extended parts. The mature Aristotelian doctrine actually suggests that in an animal it is the soul that moves the body, and here there is no idea of the spatial location of the soul. Leaving aside the soul and the body, we can instead at least admit that animals and other obvious self-movers, initiators of change in themselves, do not count as self-movers in the strong sense, as StThomas would say: it is not the whole animal which initiates a process of change in the whole animal. This still does not yet seem to have brought us clear reasons to accept the thesis that everything which is in process of change has that change initiated in it by something else. We seem to have been brought to the conclusion that every process of change has to be initiated by something other than the process of change itself, but we still seem far away from St Thomas's conclusion. St Thomas's conclusion seems to be that every process of change has to be initiated by something other than the subject of the process of change, and all we seem to be able to conclude is that every process of change must be initiated by something other than the process of change itself It seems that it will be necessary to bring forward the use of the lumping-together move, to which we would normally attribute a later place in the First Way as in the other Ways. Our premiss 3 says: 'But if that which initiates the change is itself in process of change, then it

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too must have its change initiated by something else: and so on.' This is a point which can surely be made, mutatis mutandis, for the conclusion we seem to have reached. If we admit the conclusion that every process of change has to be initiated by something other than the process of change itself, we can perform at this stage a low-level lumping-together move, and consider the process of change and that which initiates it as a whole. Is this whole itself in process of change, or not? There seems little reason to deny that every material thing acts on other material things - initiates changes in it - while being itself in process of change; indeed, in virtue of being itself in process of change. However many intermediate steps, aspects, and mechanisms there may be in the material subject of any process of change, we will eventually have to consider that material subject of a given process of change as itself the subject of a process of change, a process of change which can no longer be explained as being initiated by something else within that subject. 15 It begins to look as if for the material universe, at least, the principle 'Everything which is in process of change has that change initiated in it by something else' will hold good. I do not know whether Aquinas would regard this as sufficient: it may be that he thinks the principle holds good for the angels, for example, in which he had such a great interest. But I take it that since Aquinas's project is to prove the existence of the invisible God from the things we see/6 the principle need not apply more widely than the material universe for the First Way to work as he wishes it to work. Even if this account of Aquinas's defence of the principle 'Everything which is in process of change has that change initiated in it by something else' is sound, there is a difficulty with it. It seems to make the First Way indistinguishable from the Second Way, as we shall see in the next chapter. The Second Way works from considerations of efficient causality in general, and though the above discussion has been couched as far as possible in the terms of 'process of change' which are appropriate to a consideration of the First Way, it has made essential use of the principle 'Every beginning of existence has a cause': a principle which applies indifferently to all cases of efficient causality. But this can be considered later; in any case, StThomas clearly regards the First and Second Ways as closely linked, and perhaps to assimilate one to the other is not too . 17 1t of exegests. !". • a 1au senous Perhaps we need to take a step back at this stage and take a broader view. We began by alleging that the feature X identified by the First Way is 'being in process of change'. This seems fairly undeniable. For

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this feature to be an adequate feature X for the purposes of the argument, according to the structure which we claimed would be followed, it needs to be a feature such that whatever displays that feature requires an explanation in terms of a relation to something else. The subsidiary argument St Thomas gives, which we have been examining, is an argument aimed at proving that this is indeed the case. We can perhaps legitimately make two claims. One is that St Thomas's subsidiary argument does indeed seem to work provided that we are restricted enough in our identification of the subject of the change which again, of course, implies some kind of qualification (perhaps an unwelcome one) to the answers we might be entitled to offer to the question 'What counts as being a "something else" , in relation to which whatever displays feature X requires to be explained?'. The second claim is the one made in the last paragraph but one, that whatever we may think of the principle 'Everything that is in process of change has that change initiated in it by something else' as a universal metaphysical principle, there seem to be good reasons for accepting it as true of all bodies. And perhaps this is all we need to show. It is all we need to show at this stage in the argument, for it should by now be obvious that we are still very far short of proving the existence of God. One of the more curious features of the garbled versions of the Five Ways which can still sometimes be met with in books of apologetics is that they (mis-)represent, say, the first half of one of StThomas's arguments and then pretend to have proved the existence of God. The argument so far given would bring us to God only if the 'something else' which explains the possession of feature X by some parts of the world must necessarily be something which does not itself display feature X. This is because Aquinas takes it that 'God' means something that initiates change and is not itself in process of change. But a number of the considerations we have adduced about material things show that this direct jump to God is one which we have no right to make. It looks, indeed, as if the whole material universe is something which displays feature X as a whole; it looks as if the whole material universe is perpetually and in every part in process of change. I do not know whether this is a contingent fact or a necessary one, but it is probably the fact which makes St Thomas think that this 'way' is the clearest of all the five. But this fact is irrelevant to the argument. 'Being in process of change', besides having the mark proper to a well-chosen feature X, of requiring an explanation in terms of a relation to something else, also has the second mark proper to a well-chosen feature X, of being generalisable from a part to a whole. If a system has a part which is in process of change, then that

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system is in process of change. We do not need to claim that every part of the system is in process of change, though in fact this seems to be the case with the material universe. If there is change in any part, there is change in the whole, just as if there is (say) colour in any part there is colour in the whole: i.e. the whole is not monochrome, pure black and white, even if most of it is. Thus whether it is every part of the world or only some part of it which is in process of change, 'being in process of change' is something which can be said truly of the world. The world, as a lumped-together system, displays feature X. And, by the account given of feature X, anything which displays feature X requires an explanation in terms of a relation to something else - in this case, to something which initiates change. Here we can begin a very tedious set of suppositions, imagining, as it were, outside each limit of the world as we know it, some initiator of change. But we would then be able to ask of that initiator of change, whether or not it is in process of change. If not, then we have reached God already; but if it is in process of change then we have wearily to lump this new initiator of change in with the world as previously delimited, and ask about this (newly expanded) world, 'What is it that explains its possession of feature X?' and so on, and so on. This is where the next step which Aquinas makes may come as something of a relief: 'we cannot go on to infinity in this line.' As already commented, Aquinas in the Summa Contra Gentes calls this premiss 'doubtful' or 'questionable'. 18 Some of the points we have already made are relevant here, since this step is a part of the 'lumping-together' move, and to give an adequate account of the first questionable premiss we found ourselves having to begin to make the lumping-together move somewhat prematurely. The point at issue here is that if we grant that a system of things which display feature X itself displays feature X, and therefore requires an explanation in terms of a relation to something else, it does not matter how large the system is. If a system of things in process of change is itself in process of change, then that change must have been initiated in it by something else. The same is true for any initiator of change in the system which is itself in process of change, and it doesn't matter how many of them there are. To return to the homely example, it doesn't matter how many Inuit there are, if the only explanation of the presence of any is his or her relation to another: the presence of the group as a whole requires an explanation, even if the group is infinitely large. St Thomas is sometimes taken as saying here that the universe could not be infinitely large, or could not have existed for ever. This is a mistake. St Thomas certainly thought that the universe, though incalculably large

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-and I mean just that, incalculably: the medievals knew that the distance to the fixed stars was so great that the whole diameter of the Earth, which they knew quite accurately, was infinitesimally small by comparison- was finite in extension. He would also have had difficulties with the notion of an infinite spatial extension, difficulties which seem to me very reasonable. But though he also held that the earth had not existed for ever, he held that it might well have done. Only faith in God's revealed word is sufficient to inform us that 'In the beginning God created the heavens and the earth'. Our own reason is only sufficient to tell us that the world, even if it has existed as long as God has existed, i.e. for ever, has for ever been God's creation. 19 Thus St Thomas has no difficulty with the idea of the everlasting existence of the world, and thus no difficulty with the notion of an infinite series of initiators of change which are themselves in process of change. He gives the example later on in the Summa: if an eternal blacksmith had been making horseshoes for all eternity, he would have produced an infinite number of horseshoes and used, worn out and broken an infinite number of hammers and anvils. 20 There is nothing wrong with this kind of 'going on to infinity'. Thus Aquinas's point is not that the series of initiators of change, themselves in process of change, could not go on into infinity. He was sure, from his knowledge of the Bible, that in fact it didn't, but he is equally sure that it could have gone on for ever. His point is rather that even if such a series goes on for ever, it fails to explain the existence of feature X. In his own words: we cannot go on to infinity in this line, for if we did there would be no first initiator of change, and thus no other initiator of change, since the later initiators of change initiate change only in virtue of their having change initiated in them by the first initiator of change. Thus a stick does not initiate change except in virtue of having change initiated in it by the hand. The crucial sentence here is 'since the later initiators of change initiate change only in virtue of their having change initiated in them by the first initiator of change'. It is in virtue ofitself displaying feature X that this or that initiator of change explains the presence of feature X in other things: which gets us no further towards an explanation of the presence of feature X in the world as a whole, even though there should be an infinity of such initiators, a wilderness of such monkeys. 21 Hence the conclusion: 'So we have to come to some first initiator of change which is not in a process of change initiated by something else, and everyone understands that this is God.' If any reader dislikes the

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argument, I think that the plausible objections are as follows. The first is that one might say: 'I don't see that "being in process of change" is a suitable feature X, in that I don't see that it demands an explanation in terms of a relation to something other than what is in process of change.' This looks a difficult position to maintain, though Aquinas's argument in support of it is, as we saw, hard to follow in detail. The second is that one might say: 'I don't see that "thing that initiates change in other things, which is not itself in process of change" is included in the signification of the word God'- or, better: 'I don't see why this notion shouldn't apply to other things as well.' I don't know what answer StThomas would make to such an objection, but I suppose that it might have been the thought of objections such as this last one which made him develop five different ways to show that God exists. If the reader is doubtful about one of the suggested significations, perhaps another will be more plausible. NOTES I. Summa Contra Gentes, I, 13, n. 19. 2. A. Kenny, The Five Ways (London: Routledge and Kegan Paul, 1969), pp. 8-9, 19-23. 3. Summa Theologiae, I, q 2, a. 3: Prima et manifestior via est quae sumitur ex parte motus. Certum est enim, et sensu constat, aliqua moveri in hoc mundo. Omne autem quod movetur, ab alio movetur. Nihil enim movetur nisi secundum quod est in potentia ad illud quo movetur. Movet autem aliquid secundum quod est in actu, movere enim nihil aliud est quam educere aliquid de potentia in actum. De potentia autem non potest aliquid reduci in actum nisi per aliquod ens actu; sicut calidum in actu, ut ignis, facit lignum quod est calidum in potentia esse actu calidum, et per hoc movet et alterat ipsum. Non autem possibile est quod idem sit simul in actu et in potentia secundum idem, sed solum secundum diversa: quod enim est calidum in actu non potest simul esse calidum in potentia, sed est simul frigidum in potentia. lmpossibile est ergo quod idem et eodem motu aliquid sit movens et motum, vel quod moveat seipsum. Oportet ergo omne quod movetur ab alio moveri. Si ergo illud a quo movetur moveatur, oportet et ipsum ab alio moveri, et illud ab alio. Hie autem non est procedere in infinitum, quia sic non esset aliquod primum movens, et per consequens nee aliquod aliud movens, quia moventia secunda non movent nisi per hoc quod sunt mota a primo movente, sicut baculus non movet nisi per hoc quod est motus a manu. Ergo necesse est devenire ad aliquod primum movens, quod in nullo movetur, et hoc omnes intelligunt Deum. 4. Summa Contra Gentes, I, 13 n. 4. 5. 'Ev a\,.tcp ~ apxTt, Nicomachean Ethics, III, I, lllla, 22-7. 6. See e.g. Commentary on the Physics, L.VIII, 1.10. 7. Kenny, The Five Ways, p. 21. 8. SeeP. T. Geach, review of Kenny, The Five Ways, Mind, vol. 79, 1970, pp. 467-8. 9. Commentary on the Physics, L.VIII, 1.7, nn. 1023-4. 10. See Summa Contra Gentes, I, 13, n. 19. II. I am thinking especially of the accounts of causality developed by Professor Anscombe in 'Causality and determination' and 'Times, beginnings and causes', in Collected Philosophical Papers of G. E. M. Anscombe, Vol. 2 (Oxford: Blackwell, 1981), pp. 133-62. 12. Hume, Treatise on Human Nature, Bk I, Part 3, Section 3 (ed. L. A. Selby-Bigge, 2nd edn, Oxford: Clarendon, 1978), pp. 78-82. 13. Fragment 12. 14. Cf. Commentary on the Physics, L.VII, 1.8, n. 944, and L.VIII, 1.17, n. 1122. 15. This may be one of the points being made by StThomas in his listing of different kinds of change and modes of causality in his account in Summa Contra Gentes, I, 13, e.g. at n. 19.

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16. At Summa Theologiae, I, q. 2, a. 2, sed contra, StThomas quotes Romans I: 20: 'For the invisible things of him from the creation of this world are clearly seen, being understood by the things that are made'. 17. For the Second Way see Chapter 10. 18. See Summa Contra Gentes, I, 13, and also note 4 in this chapter. 19. On this point StThomas disagreed with many ofhis contemporaries, e.g. with his greatest British contemporary, Robert Grosseteste, and with his friend and colleague St Bonaventure. StThomas in fact went so far as to write what was for him a rather bad-tempered pamphlet to support his views, De Aeternitate Mundi Contra Murmurantes. 20. Summa Theologiae, I, q. 46, a. 2, ad 7:

Ad septimum dicendum, quod in causis efficientibus impossibile est procedere in infinitum per se; ut puta si causae quae per se requiruntur ad aliquem effectum multiplicarentur in infinitum, sicut si lapis moveretur a baculo, et baculus a manu, et hoc in infinitum. Sed per accidens in infinitum procedere in causis agentibus non reputatur impossibile; ut puta si omnes causae quae in infinitum multiplicantur non teneant ordinem nisi unius causae, sed earum multiplicatio sit per accidens; sicut artifex agit multis martellis per accidens, quia unus post unum frangitur. Accidit ergo huic martello quod agat post actionem alterius martelli. Et similiter accidit huic homini, inquantum generat, quod sit generatus ab alio. Generat enim inquantum homo, et non inquantum est filius alterius hominis. Omnes enim homines generantes habent gradum unum in causis efficientibus, scilicet gradum particularis generantis. Unde non est impossibile quod homo generetur ab homine in infinitum; esset autem impossibile si generatio huius hominis dependeret ab hoc homine et a corpore elementare et a sole, et sic in infinitum. Cf. P. T. Geach, 'Aquinas', in Three Philosophers (Oxford: Blackwell, 1961), pp. 111-12. 21. The point being made by the italicised phrase 'in virtue of is the point which StThomas develops more fully in the quotation from Summa Theologiae, I, q. 46, a. 2, ad 7 (see note 20 above), in terms of a distinction between a per se and a per accidens infinite series of causes: the former being impossible, the latter being perfectly possible.

10 • THE SECOND WAY

An obvious reaction one might have on passing from the First Way to the Second Way, is that the First Way is a particularly clear or paradigmatic case of the same phenomenon investigated in the Second Way; or, if you prefer, that the Second Way is a generalisation of the First. StThomas's own words show that he regards the First Way as especially clear and obvious, presumably because the phenomenon from which it starts, that of the processes of change in the world, is particularly clear and obvious. (This claim perhaps helps to cast some doubt on Kenny's reading of the First Way, 1 which makes it depend on a quite high level of training in Aristotelian physics, not to say Ptolemaic astronomy. Even among welleducated people in the thirteenth century it would surely have been stretching things a little to call an argument which depends on detailed knowledge of physics or astronomy one which is clearer and more obvious.) Be that as it may, there is a good case for making out that the Second Way is a generalisation of the First. The First Way has to do with process of change, the Second Way has to do with efficient causality in general. In St Thomas's book, not every example of efficient causality is an example of a process of change, or even of the initiation of a process of change. A beginning of existence, for example, which certainly requires an efficient cause, is not, strictly speaking, a change in that which begins to exist. As I commented in the last chapter, for the analysis of change one of the most important points to establish is the subject of change, and that which begins to exist is not strictly speaking a subject of change, a subject which undergoes some modification. Before it begins to exist, it isn't there to undergo any modification at all. A beginning of existence would thus fall under the Second Way, but not under the First Way. So far so good; but unfortunately one could make out just as good a case that the First Way is in some sense a generalisation of the Second Way. StThomas would hold that not every process of change is to be explained in terms of efficient causality, or, at least, he would claim that

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not every process of change is to be explained in terms of efficient causality alone. The most famous example in St Thomas's thought is one which is unlikely to appeal to us as scientifically serious. StThomas thought that the rotation of at least the outermost, and perhaps of others, of the heavenly spheres was to be explained in terms of final causality. These crystalline spheres of Aristotle's astronomy, which St Thomas seems to have taken perfectly seriously, are intelligent, or are at least guided by intelligences. They know what God is like and are moved by love of God to try to be like him. God is always active and never changing, hence the ceaseless and invariable circular movements of the heavens, which represent the nearest approach a material being can make to being both always active and never changing. The picture is a nice one, though to our way of thinking it is also bizarre, but what is important is that these spheres move as they do in order to be like God. Nothing pushes them along except desire, and that desire is based on knowledge of the good. That process in particular is initiated and continued by one particular type of final causality, and not by efficient causality at all. So there will be examples of changes which illustrate the First Way which do not illustrate the Second. 2 If the example just given is too alien to be of any help to the reader, then one can perhaps remember the dog that starts barking in the nighttime. The dog starts barking, perhaps, in order to scare away the intruder, or in order to warn the household, or in order to affirm its own territory, or in order to achieve a reward or avoid a punishment from its master. Any one of these explanations will do; which one you choose will depend on what you think is within the limits of canine intelligence. But all of the explanations are in terms of final causality. This would seem to be as good a point as any to outline the Aristotelian doctrine of the four modes of explanation or causality, to which reference has already been made. 3 Aristotle, and, following him, St Thomas, recognised four different modes of causality or explanation. 'Efficient causality', or explanation in the efficient mode, is the closest to what we nowadays generally mean by 'causality', an explanation in terms of how a thing came about. 'Material causality', or explanation in the material mode, is an explanation in terms of what a thing is made of. 'Formal causality', or explanation in the formal mode, is an explanation in terms of in virtue of what the stuff that a thing is made of is the thing that it is. Lastly, 'final causality', explanation in the final mode, is an explanation in terms of what a thing is for. We have already seen that for Aristotle and St Thomas 'science' is 'definite knowledge through explanations', and we have seen them using both efficient and

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final causality in proving the existence of a cause from the effect. 4 Science may be structured in terms of any of the four different modes of explanation. It is therefore worth being sure that we know what we mean by them. A good example, one given by Aristotle, is that of a faggot, a bundle of sticks tied together in order to be carried more easily. 5 The example is one of an artefact, and indeed most of the straightforward examples are of artefacts. This is because the question of the explanation of natural objects in the final mode is highly disputable nowadays. We will examine it when we come to look at the Fifth Way, but I do not wish to prejudge here the discussion which I will be carrying out there, about the possibility and legitimacy of looking for final modes of explanation of natural phenomena. If we are looking for an explanation of the faggot, then, the first thing we have to say is what it's made of, its matter - we have to give an explanation in the material mode. The answer is clear: sticks and string. If instead of sticks and string it consisted of flowers and ribbon, it would not be a faggot but a bouquet. 6 But the same matter, the same sticks and string could be scattered half-way across the forest, or put together in a different way to make a rudimentary birdcage. What makes the sticks and string to be a faggot and not, for example, a heap of sticks with a piece of string on top, or a rudimentary birdcage, is the way they are tied together. This is the form of the faggot, the explanation of what the faggot is in the formal mode, what distinguishes it from other things which could be made of the same matter. The explanation in the efficient mode is clear and simple: it is yonder peasant, gathering winter fuel. Yonder peasant is the one who effects or brings about the existence of the faggot. The explanation in the final mode is also clear: for ease of transportation. That is what faggots are for, the end of a faggot- if you live a good league hence, it's the devil's own job to carry a heap of sticks through the snow if you haven't tied them up in a faggot. Possibly the notion of explanation in the formal mode is the most obscure of the four. Aristotle gives other examples, in the same context. 7 The difference between a lintel and a threshold is not one of their matter, he would say - they are both beams of wood wide enough to stretch between the uprights of the doorway. One could be substituted for the other and no harm would be done: the former threshold would have become the lintel and the former lintel would have become the threshold. The difference is in their position; it is thus the position at the top of the doorway which is the form of the lintel, what makes this matter, this beam of wood to be a lintel, which constitutes the formal explanation of what it is to be a lintel. Equally, it is the position at the foot ofthe doorway

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which is the explanation in the formal mode of what a threshold is. Or, again, the difference between breakfast and dinner is not one of matter but of time: the form or formal explanation of breakfast, what makes breakfast breakfast as opposed to dinner, is the time of day, and likewise for dinner. We should be able to accept this even though as a matter of fact we don't normally have cornflakes for dinner or soup at breakfast. For us there may well be a culturally determined, but purely accidental, difference of matter between breakfast and dinner. The ancient Greeks, less dietetically fortunate than we, had a breakfast that consisted of a sort of porridge, and a dinner that consisted of a sort of porridge. If they were better off they might have had two courses at dinner, the first a sort of porridge and the second a sort of porridge. Plato went on record as saying that no-one could do philosophy in a place as rich as Sicily where people ate three times a day. 8 Leaving aside the gastronomical questions, though, the different modes of explanation should be fairly clear. Since a science progresses towards explanations in one or another of these modes, we could expect that the Five Ways could be classified according to this system. But it does not seem so easy. The Second Way is explicitly said to be based on efficient causality, and the word 'finis', end, that in terms of which explanation in the final mode is given, is also explicitly used in the Fifth Way. But the First Way, as we have just seen, may relate to any kind of explanation which may be given of processes of change, whether efficient or final. Kenny claims that the Third Way relates to explanation in the material mode, 9 and it is certainly true, as we shall see, that one of the 'derivatively everlasting' things which the Third Way speaks of is matter. But so are the forms of, for example, animal species: so the Third Way may relate as much to the formal mode of explanation as it does to the material mode. As for the Fourth Way, it is not the easiest task on earth to identify any conceivable or intelligible mode of explanation to which it relates. I have seen it claimed that the Fourth Way relates to 'transcendental causality', which I sometimes suspect to be an academically more respectable way of saying 'it is not the easiest task on earth to identify any conceivable or intelligible mode of explanation to which it relates' .10 Thus while one might wish to claim that the First Way relates to final causality at least as much as it does to efficient causality, there is no doubt that the explanation I gave of the First Way in the last chapter in fact related to efficient causality alone. This is partly because final causality is both a difficult and an unfamiliar notion, one which arouses fairly justifiable suspicions in the contemporary reader; and partly because to give an adequate account of final causality would have

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dragged out the chapter too much, and it seems better to leave that account until we come to deal with the Fifth Way, where it cannot be avoided. But also, in part, the reason was that I could not see how to give an adequate account of the initiation of processes of change in terms of explanation in the final mode. This had the perhaps unfortunate consequence that many of the considerations adduced in the account of the First Way have at least as much right to be given in the account of the Second Way. In order to justify Aquinas's principle, 'Everything that is in process of change has that change initiated in it by something else', I made use of the principle that every beginning of existence has a cause. This principle relates most obviously to efficient causality, and, indeed, to cases of efficient causality (beginnings of existence) which are not strictly speaking initiations of processes of change at all. It is not clear what should be said here. It may be that the understanding of the First Way we have been striving to achieve conflates it unduly with the Second Way, and the critic may suspect that the apparent effectiveness of either of the two ways rests on an unnoticed confusion of the distinct but related notion used in the other. There seems to be no a priori way of determining an answer to this; what one must do is await a definite challenge in this line and hope to find a way to refute it. I suspect that any such challenge would have to centre on an allegation that there has been a confusion in the way in which subjects of change in the First Way were identified rather loosely, and draw attention to the mis-match between the account given there and any likely identification that could be made of the efficient causes and effects mentioned in the Second Way. The actual text of the Second Way clearly follows a structure similar to that of the First Way, and equally clearly exemplifies the overall structure which was suggested for all of the Five Ways. The second way is from the notion of efficient cause. We find, in things around us that we sense, an order of efficient causes. But we do not find - nor could there be - anything that is the efficient cause of itself. For if anything were, it would have to be prior to itself, and this is impossible. Now, it is not possible that there should be an infinite series of efficient causes. This is because in any ordered series of efficient causes, the first cause is the cause of the intermediate causes, and the intermediate cause is the cause of the last cause.

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This is so whether there is just one intermediate cause or more than one. If a cause is eliminated, the effect is eliminated too: so if there were no first efficient cause, there would be no last or intermediate cause either. But if the series of causes is infinitely long, then there will be no first efficient cause, and hence no last effect and no intermediate causes. This is obviously not the case. Hence we must suppose some first efficient cause, and this is what all call 'God' .11 Again the indentation indicates the structure of the argument, to some extent. The main structure is clear and apparently valid: 1. We find, in things around us that we sense, an order of efficient causes. 2. But we do not find - nor could there be - anything that is the efficient cause of itself. 3. It is not possible that there should be an infinite series of efficient causes. 4. Hence we must suppose some first efficient cause, and this is what all call 'God'. What I have called 'feature X' here is, roughly speaking, being an effect; or, perhaps better, being a subject of efficient causality. That this feature is part of the world is obvious, as the first premiss tells us. That it is a feature which requires an explanation in terms of a relation to something else is the point of the second premiss. The argument given in support of the second premiss - 'for if anything were, it would have to be prior to itself, and this is impossible' - though possibly acceptable to the average contemporary reader, requires a little elucidation. Contemporary thought tends to regard causality - what Aristotelians call 'efficient causality', more or less - as a relation between two events, the cause and the effect. The medievals, however, regarded efficient causality as a relation between a thing, the agent or cause, and an event, the effect. This medieval account is perhaps more defensible than many people nowadays would think, but I shall leave the defence of it to the discussion of the relationship between efficient causality and final causality I shall make when we come to deal with the Fifth Way. Another important point of exegesis is to clarify the meaning of 'prior' in this argument. According to the contemporary account, the cause-event has to precede the effect-event temporally. This kind of thought is very alien to the medievals, who preferred to think of the existence and activity of the cause or agent as being simultaneous with the effect caused. 12 The word 'prior' in this argument, then, means

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'metaphysically prior'. We do not have a handy technical term in contemporary philosophy to express this notion. The word 'derivative' can be used (as it is by Anscombe 13 ) to express the correlative relation, and so we could express the point which St Thomas is making as, 'For if anything were [the efficient cause of itself], it would have to be derivative from itself, and this, we may well admit, is in fact impossible. The next step is taken tacitly: it is the lumping-together move. Anything which is a system of parts related by efficient causality, in which parts are effects, is itself an effect - something which cannot be the efficient cause of itself, and which requires an explanation in terms of a relation to something else. Put this way, the step looks dubious. One might want to hold that there might be parts of the world which are outside the system of efficient causality. One would want evidence for this, but it seems to me that in this case feature X does not generalise sufficiently. It is true that a whole which contains any parts which are in process of change is itself in process of change, as we saw in the First Way; but it does not seem so obvious that a whole which contains parts which are effects must itself be an effect. Perhaps, though, the lumping-together move need not be so widely generalisable. Whatever we may say of the world as a whole, it is clear that a great part of the world is a system of efficient causality, and, indeed, it is worth saying that so far as any of us can tell the whole world is a system of efficient causality. It is hard to see what could be meant by saying that there are parts of the world which fall outside the system of efficient causality which the rest of the world belongs to. In what sense would these causally ineffective and unaffected bits of the world form part of the same world at all? What, we might ask, is a world supposed to be except a unified system of efficient causality? A system of efficient causes, like the world, is eo ipso a system of effects, and here the lumping-together move appears valid: a system of effects is an effect. Feature X is sufficiently generalisable, in that it extends to a great part of the world at least, if not necessarily to the world as a whole, though in fact it seems to, and it also seems difficult to understand what it would be for this feature not to extend to the whole world. This system of effects, of efficient causality, which is at the very least a very great part of the world, cannot cause itself: it requires an explanation in terms of a relation to something different. St Thomas goes on to make, in his third premiss, 'It is not possible that there should be an infinite series of efficient causes', in slightly different terms, the point made in the First Way, that we cannot go on to infinity in this line; or, as I claimed above, more accurately, going on to infinity in this line fails to be an explanation.

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Now, it is not possible that there should be an infinite series of efficient causes. This is because in any ordered series of efficient causes, the first cause is the cau~e intermediate causes, and the intermediate cause is the cause of the last cause. This is so whether there is just one intermediate cause or more than one. If a cause is eliminated, the effect is eliminated too: so if there were no first efficient cause, there would be no last or intermediate cause either. But if the series of causes is infinitely long, then there will be no first efficient cause, and hence no last effect and no intermediate causes. This is obviously not the case. This, I think, given the formulation of Aquinas's claim which I have used, that going on to infinity in this line fails to be an explanation, and given the account I have provided of this claim in the last chapter, needs no detailed defence here, though Aquinas's detailed defence has some interesting features which might be worth investigating elsewhere. And thus Aquinas reaches his conclusion: 'Hence we must suppose some first efficient cause, and this is what all call "God" '. The account of the signification of the word 'God' contained in this conclusion seems to be unquestionable. Objections to this Way will have to rest on the notion of efficient causality being employed, or on the possible identifications of the subjects of efficient causality, and on the doubt about the extent to which 'being a subject of efficient causality' is appropriately generalisable in the lumping-together move. Otherwise the argument appears unassailable. NOTES l. 2. 3. 4. 5. 6.

7. 8. 9. 10. 11.

A. Kenny, The Five Ways (London: Routledge and Kegan Paul, 1969), pp. 27-33. See e.g. Commentary on the Metaphysics, L.XII, 1.7, nn. 2519-2535. See above, Chapter 2, p. 22. See above, Chapter 6, pp. 88--9. See Metaphysics, Book VII, 1042b, 15-22. To show that material causality can indeed have a role in explaining phenomena in the world, consider how in the explanation of a marital quarrel the following line of dialogue might feature: 'Happy St Valentine's Day, dearest, I've brought you a faggot.' Metaphysics, Book H, 1042b, 15-22. Plato, Seventh Letter, 326b. Kenny, The Five Ways pp. 35-36. See, e.g., A. L. Gonzalez, Teologia Natural (Pamplona: EUNSA, 1985), p. 152. Summa Theologiae, I, q. 2, a. 3: Secunda via est ex ratione causae efficientis. lnvenimus enim in istis sensibilibus esse ordinem causarum efficientium. Nee tamen invenitur, nee est possibile, quod aliquid sit causa efficiens sui ipsius, quia sic esset prius se ipso, quod est impossibile. Non autem est possibile quod in causis efficientibus procedatur in infinitum, quia in omnibus causis efficientibus ordinatis primum est causa medii, et medium est causa ultimi; sive media sint plura, sive unum tantum. Remota autem causa, removetur effectus. Ergo si non fuerit primum in causis efficientibus,

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12. See Kenny, The Five Ways (London: Routledge and Kegan Paul, 1969), p. 40. 13. In one of the papers already cited, 'Causality and determination', in Collected Philosophical Papers of G. E. M. Anscombe, Vol. 2, p. 136.

11 • THE THIRD WAY

The Third Way is subtle and complex, and has no obvious surface similarity to the previous two, as the Second had to the First. It is couched in terms of the possible and the necessary, and thus has at least a strong verbal resemblance to another argument given for the existence of God, most famously by Leibniz. There are several points at which the argument appears extremely weak, but at which it can be defended quite well. The jump from the world to God does not take place, surprisingly enough, at the step between the possible (or contingent) and the necessary, but at a step between the derivatively necessary and the underivatively necessary. This last pair of notions, of derivative and underivative necessity, is highly obscure, as is the feature X on which the Third Way is based. Let us look first at the text: The third way is drawn from the possible and the necessary, and is as follows. Some real things that we find have the possibility of being and not being. This is because we find some things that come into existence and cease to exist, and hence have the possibility of being and not being. But it is impossible that everything that exists should be such [or: it is impossible that all such things should always exise]: for that which has the possibility of not being at some time does not exist. If, then, everything had the possibility of not being, at some time there would be nothing real. But if this were the case, then there would be nothing now: since that which does not exist only begins to exist through something that does exist. Hence if nothing were in existence, it would be impossible for anything to begin existing, so nothing would now exist. This is clearly not the case.

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God and Explanations Therefore not all beings have this possibility: there must be something real which is necessary. But everything which is necessary either owes its necessity to some cause outside it, or not. There cannot be an infinite series of necessary beings whose necessity is caused, just as, we have seen, there could not be in efficient causes. We must suppose, then, something that is necessary in itself, which does not owe its necessity to some outside cause, but rather causes the necessity of the other things: and this is what all say is God. 2

The first thing which needs to be said here is that the notions of'possible' and 'necessary' are here being taken in a temporal sense: they mean, roughly speaking, 'having a tendency to stop existing' and 'having no tendency to stop existing'. This usage, curious enough to our ears, is common enough among Aristotelians. It is clear that what is necessary is always the case, is everlasting. Equally that which sometimes is and sometimes is not the case is contingent; it is 'possible' in the sense of 'maybe it is, maybe not'. This point would be accepted quite generally. More disputable is a claim which Aristotle may sometimes make, that that which is always the case, or is everlasting, is eo ipso necessary, while that which is possible to be thus and so at some time is thus and so. Aristotle, it will be remembered, held that the world had existed from all eternity, and it may be that he held that whatever is possible is at some time realised, and that that which is always the case is necessary. 3 What is certainly true is that Aristotle is strongly unwilling to believe that anything can just happen to be always the case: he will not recognise any contingent universal or everlasting truths. Whether or not it is correct to attribute a belief in the Principle of Plenitude to Aristotle, there is no doubt that he quite often uses the words 'possible' and 'necessary' in temporal senses: that which is sometimes the case is called 'possible' and that which is always the case is called 'necessary'. 4 This is perhaps not as bizarre as it might seem, or at least not quite so unfamiliar. There is a strong school of modal logicians, those who deal with necessity and possibility, who insist on taking literally the language of 'possible worlds' which is used to clarify certain aspects of modal discourse. That which is necessary is true in all possible worlds (or 'at all possible worlds'- the jargon varies), and that which is possible is true in some possible world. That is, they in some sense maintain that that which is necessary is everywhere the case, and that which is possible is somewhere the case. 5 The shift from expressions of time - always, sometimes - to expressions of space or

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quasi-space - in all possible worlds, everywhere, or in some possible world, somewhere- is not so great a change. Aristotle's most questionable and least plausible doctrine about modality, and the apparently bizarre language which expresses it, turn out to have very close parallels in a widely-held- or at least strongly defended- contemporary theory. It seems undeniable that St Thomas is using Aristotle's language here, and using modal terms in temporal senses. What is not so clear is the extent to which this implies an acceptance of any other modal views of Aristotle. Whatever we may say of Aristotle - and, as has been said, it is a disputed question - there is no doubt that St Thomas did not maintain the Principle of Plenitude. One can find it said in works on the history of modality that everyone from, say, Boethius through to Duns Scotus held the Principle of Plenitude, 6 but this is simply a mistake. St Thomas could not have held the Principle of Plenitude simply because he did not hold an eternity of time: since for him the world had a beginning some finite time ago and is to have an end some finite time in the future, there simply is not enough time for all real possibilities to be realised. Moreover, when StThomas speaks in propria persona about modalities, as opposed to when he is expounding Aristotle, his account is not temporal but logical. 7 But there is a complication which needs mentioning here. It is clear from the way the Third Way develops that StThomas is in fact arguing from the (false) hypothesis that the world has existed for ever. The rationale for this is given very clearly in the parallel passage in the Summa Contra Gentes. 8 Aquinas thinks that if it is admitted that the world had a beginning in time, the existence of God follows immediately. The beginning of the world in time is clearly a phenomenon which demands an explanation in terms of its relation to something outside the world, and here we might all admit that 'that which explains the beginning of the world' is something we all call 'God'. But Aquinas also believes that he has no philosophical evidence that the world did begin in time, and so he is going to grant to his atheist opponent that maybe the world has existed for ever. Even so the world is demonstrably God's creation, claims Aquinas; he is granting to his opponent the chance to make his strongest case, since he believes that even so it can be overthrown. I do not know quite what we should make of this. It is true that to me it seems obvious that if the world had a beginning in time, then it was made by something outside the world. Since earliest childhood, however, I have been subject to propaganda from atheist writers on cosmology who have been dinning it into me that the mere fact that, so far as we can make out, the world had its origin in a single moment a certain finite time ago,

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does not mean that we have to look for an explanation for that origin outside the world itself. There are several things that need to be said here. One, against the atheist, is that I am incapable of regarding a beginning of existence as anything but a phenomenon which requires an explanation. Another, against certain theists who lay great stress on the Big Bang, is that I see no especially strong reason to hold that the Big Bang is to be identified with the moment of which the Bible says 'In the beginning God created the heaven and the earth'. The Big Bang is the start of the present disposition of material reality; it is the point beyond which our investigations of material reality cannot reach. I can see no reason why material reality might not have had its origin at some earlier moment. If the whole of the matter of the universe was once very, very small, very, very dense and very very hot, and at a certain moment began the process of expansion and cooling in which it continues to this day, I don't see why it might not have existed in some incalculable way for some incalculable period in its hot, small and dense state before the initiation of its expansion, or Big Bang. That said, I notice that the same atheist writers on cosmology who tried so hard to convince me that the Big Bang did not need an explanation were tremendously excited by the alleged rival theory of the steady state of the universe: a theory for which there existed not the slightest evidence, but which was pursued with great enthusiasm and at great expense, merely because if you could believe in the steady state you didn't have to believe in the Big Bang. The steady state theory has, I believe, finally been given up by its supporters; but instead I find an equally enthusiastic search for justification for the theory of the concertina-like universe. 9 If the universe contained a good deal more matter than it does- something like ten times what it does, I believe- then we need not conclude that the Big Bang was a unique event, which seems to require an explanation, and which we might be tempted to identify with the Biblical moment of creation. Given the actual mass of the universe, as far as we know it, the universe is continually expanding and is getting gradually less and less dense and cooler and cooler. One day (though 'day' is the wrong word) all the differences of heat in the universe will have been equalised, and the whole universe will be very large, very cool, and entirely static. 10 But if there were ten times the mass in the universe that there is, there is a possibility that gravity would suffice to reverse this process at a certain point. The universe would begin to collapse in on itself again until at last it was again a very dense, very hot, very small lump, indistinguishable from the original lump from which the Big Bang started.

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Well, I am told that the theory of the concertina-like universes will not work particularly well either, because the swings of the concertina will continue to get wider and wider until in any case the mass of the universe is insufficient to bring about the re-collapse: so even if this epoch of the universe will end in a re-collapse, a new Big Bang, and thus a re-born universe, some epoch of the universe will have a definite end in the uniform coolness of 3° K. (Or maybe for that epoch, which is to come about on the last and widest swing of the concertina, the uniform temperature is supposed to be something else: I don't know. It would be funny if it were a temperature which was capable of sustaining human life in a paradisal state. If it were discovered that the concertina universe would leave us all at the end of time in a paradisal state we might find fewer physicists keen on the theory. It would be still worse if we found ourselves obliged to believe that the final state of the universe were one in which human life were possible, but acutely uncomfortable.) Be that as it may, what seems to me to be definitely significant is the apparently obsessive activity of some physicists in searching for what they persist in calling 'the missing mass', i.e. the quantity of matter which they think would be sufficient to make the universe collapse in on itself again. Every two years or so the newspapers announce with a fanfare that the missing mass (or at least quite a lot of it) has been found. Then a few months later some of the newspapers publish a far smaller article in which it is admitted that the mass which has been discovered was rather less than had been at first thought. What never appears in the papers is an admission that within a year it has always, so far, been proven definitively that the extra mass which has been detected has turned out to be incommensurably tiny compared with what would be required to make the concertina swing. There are perhaps more things to be said on this, but they can be left for a book on the socio-psychology of the scientific-philosophical community. I shall take it, then, that St Thomas is right, and that if the world had a beginning in time it is obvious that there is a God. I therefore also take it that he is right, in the Third Way, to presume that it had no beginning in time, and to attempt to prove that there is a God even on that hypothesis. With so much of a preamble, the structure of the Third Way is fairly clear: 1. Some real things that we find have the possibility of being and not being. 2. But it is impossible that everything that exists should be such [or: it is impossible that all such things should always exist]: for that which has the possibility of not being at some time does not exist.

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God and Explanations 3. Therefore not all beings have this possibility: there must be something real which is necessary. 4. But everything which is necessary either owes its necessity to some cause outside it, or not. 5. There cannot be an infinite series of necessary beings whose necessity is caused, just as, we have seen, there could not be in efficient causes. 6. We must suppose, then, something that is necessary in itself, which does not owe its necessity to some outside cause, but rather causes the necessity of the other things: and this is what all say is God.

Again the question arises of identifying feature X. It looks as if feature X, so far as this Way is concerned, will be 'possibility', or, as I glossed it, 'having a tendency to stop existing'. In fact, as the argument develops, it is clear that this does not get us to God: it does not get us past the third premiss. The notion then taken up is that of 'derivative necessity', or, following the temporal gloss, 'derivative everlastingness'. Thus feature X is a rather complex disjunctive feature: it is 'either having a tendency to stop existing, or having no tendency to stop existing, but only in some derivative way'. More elegantly, we might identify it as 'not having a tendency to go on for ever, except derivatively'. Expressed either way, the notion is pretty obscure. The first part of the notion, the idea of 'possibility' or of 'having a tendency to stop existing', is not too hard. It is something we observe in ourselves and in most of the things around us. The first premiss 'some real things that we find have the possibility ofbeing and not being' -is clearly true. It scarcely needs the supporting argument StThomas gives, that 'we find some things that come into existence and cease to exist, and hence have the possibility of being and not being'. The second premiss, though, is more doubtful. 'But it is impossible that everything that exists should be such [or: it is impossible that_all such things should always exist]: for that which has the possibility of not being at some time does not exist.' I think we should grant that that which has the possibility of not being, at some time does not exist, at least if we grant the supposition of unlimited time. But this truth does not seem to support the first part of the premiss, on either reading: 'it is impossible that everything that exists should be such'; or, 'it is impossible that all such things should always exist'. The supporting argument which St Thomas gives does not seem to help matters.

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If, then, everything had the possibility of not being, at some time there would be nothing real. But if this were the case, then there would be nothing now: since that which does not exist only begins to exist through something that does exist. Hence if nothing were in existence, it would be impossible for anything to begin existing, so nothing would now exist. This is clearly not the case.' The further claim being made here is that it cannot be that everything should be 'possible' in the relevant sense, should have a tendency to stop existing: for if everything did have a tendency to stop existing, then, given infinite time, it would already have stopped and nothing would exist now. It looks here very strongly as if St Thomas thinks he can pass from the premiss 'Everything has to stop some time' to the conclusion 'There is some time at which everything has to stop'. This is a thoroughly dodgy move, as it stands: it appears to be a clear instance of what is called technically the 'quantifier-shift fallacy', 11 or, less technically, the 'nice girls and the sailor fallacy'. The name is drawn from an obvious example. We may grant, if we like, that it is true that every nice girl loves a sailor. But we are not entitled to conclude from that premiss that there is some superlatively attractive and fortunate sailor such that every nice girl loves him. From the true premiss 'Every road leads somewhere' we cannot conclude 'There is somewhere -e.g. Rome- where every road leads' .12 The fallacy is technically called the 'quantifier-shift' fallacy because such words as 'every' and 'some' or 'a' are the natural-language expressions of the universal and particular quantifiers in logical notation: and between the premisses and the alleged (fallacious) conclusions we have inverted the order of the quantifiers, i.e. we have 'shifted the quantifiers'. This same inversion of the quantifiers occurs when we pass from 'everything stops existing at some time' to 'there is some time at which everything stops existing'. It is certainly true that Aquinas's argument here can be represented as embodying a fallacy, as being an instance of an invalid form. But, as Geach points out, if we wish to show that an argument is invalid, it is not sufficient to show that it can be represented as instantiating an invalid form. 13 It might instantiate an invalid form and at the same time instantiate a valid form: and for an argument to be valid it is sufficient that it should instantiate a valid form. The potentially vast numbers of invalid forms which it may instantiate are completely irrelevant. As Geach goes on to point out, we can represent any valid argument as instantiating at least one invalid form. For there is nothing to stop us linking the premisses of any argument together with 'ands' or other connectives, and representing the long sentence thus formed by the letter 'p'. Representing the

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conclusion of the argument by 'q', we are thus able to represent any argument as a whole as instantiating the form 'p, therefore q', which is about as invalid an argument form as one could wish to avoid, or to detect in the work of one's rivals. Clearly, though, some kind of burden of proof rests on the defender of St Thomas to show that there is some valid form which his argument instantiates; or, given that logic is far from being a complete science, to show that there is some form instantiated by this argument which can plausibly be regarded as valid. 14 We can begin by a clarification. Aquinas does not in fact say 'if everything stops existing at some time, then there is some time at which everything stops existing'. Rather he says 'if everything stops existing at some time, there is some time at which everything has stopped existing'. The use of tenses is essential to this argument, and makes the argument at least not a pure and direct example of the quantifier-shift fallacy. A pure and direct example of the quantifier-shift fallacy would lead us to conclude (fallaciously) that there is some moment at which everything ceases to exist, zap, like that, a universal power-cut, as it were. This is not what Aquinas wishes to suggest. Unfortunately the logic of tenses is little understood these days. It was brilliantly developed by Arthur Prior in the 1960s, but he was so far ahead of any of his contemporaries that no-one since seems to have got up to the level even of fully understanding Prior, let alone developing his work. My own understanding of tense-logic is slight, but I spent a full week once filling innumerable sheets of paper with probably ill-formed logical formulas in an attempt to work out this argument as valid. I failed, but some of the points I noticed in the process of wrestling with the logic, with the different ways of representing the present and the perfect tenses in the two versions, accurate and inaccurate, of the argument in question, made me suspect that there is a way of demonstrating the validity of Aquinas's real conclusion here. 15 Another possible way out is to attend not to the form but to the content of the argument. The passage from 'All the nice girls love a sailor' to 'There is some sailor that all the nice girls love' is certainly fallacious, but in a suitable context - among a population containing only one sailor, for example, such as the population of the rather curious neighbourhood in which Popeye is represented as living - when the premiss is true, the conclusion will be true as well. 16 Equally well, there may be features of the content of the argument, or of the context in which it is being made, which will enable us to pass from the premiss to the conclusion. It is arguable that if everything has a tendency to stop existing, then there is a real possibility of everything's stopping existing.

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Certainly, if one claims that everything has a tendency to stop existing, one is eo ipso debarred from saying that it will never be the case that everything has stopped existing. We have seen that it is possible to attribute to Aristotle the belief that in infinite time all real possibilities will be realised; and while we cannot attribute the Principle of Plenitude to Aquinas in propria persona, it may be that he held that on the supposition of infinite time all real possibilities will be realised. This would explain Aquinas's argument and acquit him of the charge of having committed a gross fallacy; and the additional premisses we have provided may even be true. But in fact we need not worry about to what extent the Principle of Plenitude is true, or may be true on the supposition of infinite time, or may have been held by Aquinas to be true on the supposition of infinite time. We can simply say the following: given that the world now exists, then if it never had a beginning, but has existed for ever, it must be capable of existing for ever. 'X is F' entails 'X can be F'; therefore, 'the world has existed for ever' entails 'the world is capable of having existed for ever'. As the medievals would have put it, 'Ab esse ad posse valet consequentia', 'The inference from 'is' to 'can be' is a sound one'. Or, in more modern terms, 'P, ergo possibly P' is a theorem of any system of modal logic that aims at capturing our notions of real or logical necessity and possibility. Therefore, at least the world as a whole, and maybe also some part of it, must have a capability of existing for ever. If the world has a capability of existing for ever then it is not like, for example, human beings who have a tendency to stop existing. Thus we have to accept the conclusion of the sub-argument, what we listed above as premiss 3: not all beings have this possibility (of ceasing to exist); there must be something real which is necessary [i.e. everlasting, having no tendency to cease existing]. We might say, more carefully: there must be at least one real thing, viz. the world itself, which has no tendency to cease existing and is thus everlasting or 'necessary' in the relevant sense. I suppose that most people think that there will always be, in each of the Five Ways, some flaw, falsehood, or fallacy, and that such readers may get nervous when an apparent fallacy has been disposed of. They should not get nervous at this stage: we are very far from God. All we have arrived at is the everlastingness of the world, the fact that the world itself (and, for all I know, some parts of it) has no tendency to stop existing- given, that is, that it has in fact existed since for ever. In fact Aquinas would hold that not only the world, but also certain elements of the world are 'everlasting' in this sense, the sense of not having a tendency to stop existing.

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One of the elements or parts of the world which will be in this sense 'everlasting' will be matter: using the word this time not in the sense given it by modern physics, but in the Aristotelian sense of the stuff of which things are made. 17 Things cease to exist, though the matter of which they are made does not cease to exist, but becomes something else. The stuff which at one moment is a hedgehog jogging gently across the road is the next moment, after my car has passed, a flat parcel of spiky meat. The stuff which at 8.00 a.m. is nicely arranged and separate toast, butter and marmalade, by 8.30 a.m. has become a nasty mess in my stomach, and well before lunchtime has become (for the most part) part of me. The part of it which fails to become part of me within a couple of days will be part of the reason why one is foolish to go swimming off the beach at Troon. The stuff which is me, as I wander carelessly out into the desert, within a few days will be parts of vultures, hyenas and a large number of beetles. Thus, hedgehogs cease to exist, but their matter persists. Toast, butter and marmalade cease to exist, but their matter persists. I will cease to exist, but my matter will persist: if not transformed into vultures, hyenas, and beetles, since I hope for an easier and more homely death, at least dissolved and changed into flowers and fruits with Adam and all mankind. Matter, then, is in the relevant sense everlasting - it has no tendency to stop existing. It is for this reason that Kenny alleges that the Third Way has to do principally with material causality, explanation in the material mode, in terms of what things are made of. 18 It is certainly true that matter is one of the everlasting things which Aquinas thinks exist, and indeed is one of the everlasting things which, if the argument he has given above is sound, he has proved to exist. But as I commented, the argument certainly proves the everlastingness of the world as a whole. That matter should turn out to be everlasting as well is no more than an extra. There seems no reason to associate the Third Way with matter in any special way. This becomes yet clearer when we realise that for Aquinas, as for Aristotle, forms have as much right to be considered everlasting in the relevant sense as does matter. By 'forms' here I mean, for example, the species of living things. Aristotle apparently thought that such species were eternal. He is usually taken to mean that as far back as you go in the everlasting history of the world you find cats having kittens, people having children, etc. It is often also alleged that he thought that it was impossible for any species to die out, but there does not seem to be sufficient evidence that he held this belief. All we can bring home to him is the belief that biological species do not have the tendency to stop existing that individuals of that species have. This is what reproduction means, and it is

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undeniable. Whether he thought that it was impossible for any species to come into existence is not so clear, but StThomas definitely thought that at least one (imperfect) species had come into existence: I refer you yet again to his discussion of the question of mules. 19 When people say, as they do, that Aristotelian conceptions of animal species are in frank contradiction to Darwinian views they are to be absolved of the charge oflying only by incurring the lesser charge of parroting falsehoods they have never bothered to check. What is important to both Aristotle and Aquinas, and important to us in our following the Third Way, is that, for example, animal species are everlasting in the relevant sense. That is, they do not have the obvious tendency to cease existing which individuals of those species have. That, indeed, is the whole point of an animal species: it can replace itself, if not infinitely, at least indefinitely. This does not mean that it cannot be extinguished, and it does not mean that it cannot have had a beginning; what it means is that once started it might as well go on for ever, so far as we know. It may be that nowadays with our knowledge of the second law of thermodynamics we can be sure that nothing in the world will in fact go on for ever. This would naturally weaken this argument, as any proof that the world is not everlasting would weaken any argument based on the hypothesis that it is everlasting. But since it is the second law of thermodynamics which leads us to conclude not only that the world will have an end but also had a beginning, so far as we are concerned, this whole consideration returns us to the question of St Thomas's strategy here. If the only answer to StThomas's arguments that even an everlasting world must be God's creation, is that the world is not everlasting, St Thomas would take it that he has won the debate. If the world had a beginning, then it is God's creation and there's an end on it. As I commented, people have tried hard to convince themselves and others that the fact of the world's having had a beginning in time does not mean that it must be God's creation, but the effort they put into proving by whatever dubious means there are at their disposal that in fact the world did not have a beginning in time makes their affirmations less convincing than they might like them to be. Be that as it may, if we grant the hypothesis of the everlasting world, then we should also grant the hypothesis of the everlastingness of the species of living things, i.e. the fact that they lack the tendency to stop existing which is shown by the individuals which go to make them up. Thus the Third Way relates just as much to form and to formal causality -explanation in terms of form- as it does to material causality, explanation in terms of matter.

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We now come to the step which is aimed at getting us from the world to God, premiss four: 'But everything which is necessary either owes its necessity to some cause outside it, or not.' We are supposed to ask whether the everlastingness displayed by the everlasting things in the world - i.e. the world itself, matter, the species of living things, and whatever other everlasting things there may be which I have failed to notice - is an everlastingness which they possess in their own right or derivatively. This at first sight appears to be a curious question. How should we know? And what are these everlastingnesses supposed to be derivative from? To answer 'derivative from God' would seem fairly obvious, but until we understand what derivativeness consists in this would be to repeat words without much sense for us. Moreover, since Aquinas is about to re-use the 'we cannot go on to infinity in this line' step, which in the previous two ways related to a series of causal derivativeness within the world, it seems as if to give the answer 'God' at this stage would be premature and therefore unwarranted. I wonder whether it is, possibly, too good to be true, or at least too appropriate to be a pure coincidence, but the three examples of everlasting things which I have been able tv find all allow of a fairly straightforward interpretation of the notion of 'derivativeness'. I assure the reader that I did not consciously choose these three examples with this in mind: the example of matter was given me by Geach and Kenny; the example of species I developed in thinking about possible objections to Kenny's association of the Third Way with material causality; and the example of the world as a whole came to me in a flash as I was wrestling with the problem of showing clearly and briefly in a lecture that Aquinas's earlier argument was valid, despite his apparent use of the quantifier-shift fallacy. The everlastingness of the world as a whole is clearly derivative from the succession of its parts, in the way that the existence of any whole is derivative from the existence of its parts. The world is everlasting (ex hypothesi) not because any individual thing in the world has lasted for as long as the world has, but because it has always been the case that at least one thing has started before all the others have finished. In a similar way a royal dynasty lasts for as long as it lasts because the heir has been born or at least begotten before the king has died. Matter is likewise derivative. Matter does not exist except in some form or other: the same matter is first living human flesh, then dead human flesh, then part of a vulture, but is always matter subject to some form. If the very existence of matter is derivative from the existence of the formed things which the matter goes to make up, a fortiori the everlasting existence of matter is equally derivative. The existence of species is likewise derivative from the

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existence of the individuals of that species: no rats, no Rattus rattus. Hence, again, a fortiori, if the existence of the species is derivative then the everlasting existence of the species is derivative. Here it looks as if Aquinas should be objecting not to a vicious infinite regress (premiss 5, 'there cannot be an infinite series of necessary beings whose necessity is caused, just as, we have seen, there could not be in efficient causes') but rather to a vicious circle. It looks as if we are saying that this or that individual can cease to exist, but this doesn't mean that everything has to cease to exist. This is just as well, since by the earlier argument we are committed to holding that everything did have to cease to exist, nothing would exist now, which conclusion is palpably false. No, the mere fact that individual bits of the world, or individual material entities, or individual members of species, have to cease to exist, doesn't mean that the world as a whole, or matter in general, or the species of living things have, to cease to exist: these last three are everlasting. But when we ask why they are everlasting, we find out that they exist everlastingly- indeed, that they only exist at all- because of the existence of this or that perishable individual bit of the world, or this or that perishable individual material entity, or this or that perishable living individual of a . . gtven spectes. Intuitions vary - to me this circle looks yet more vicious than any of the infinite regresses StThomas has offered us so far. That is, it looks like even less of an explanation. It is as if I asked why a group of five Inuit is still standing on the corner after so many years, since I know that even Inuit get tired, get cold, get hungry, get bored, grow old and die. I am then told that this is not a problem: of course individuals get tired and cold and go away, etc., but the group doesn't get tired or bored or go away or die. When I ask how this is, I am told that it is because as one individual goes away another joins the group. This, as I say, looks like a vicious circle. Moreover, it will remain a vicious circle no matter how big the circle is. Maybe the everlasting existence of the species Rattus rattus depends on the ever renewed generation of an infinite number of perishable rats. But the infinite number of the group of perishable individuals on which the everlastingness of the species depends still leaves me without an explanation: we cannot, in fact, go on to infinity in this line. As I see the argument, the vicious circle is rather tight, but St Thomas is quite right to point out that a vicious circle is still a vicious circle even when it is of infinite size. Perhaps, indeed, this is what a vicious infinite regress consists in: it is a series which, were it less than infinite, would be a vicious circle. I think that we can safely conclude, then, that even if the world is everlasting, 'we must suppose something that is necessary in itself, which

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does not owe its necessity to some outside cause, but rather causes the necessity of the other things: and this is what all say is God'. If the world is not everlasting, as apparently it isn't, then I leave the reader to her or his intuitions. Though leaving aside that particularly vexed question, the fact that Aquinas undertakes to prove to us the existence of a God who created the world even if the world has existed for ever, makes one point which is of crucial importance in understanding the relationship between God and the world. The thesis that the world was made by God does not require that the world was made by God in time - that for some number n, God created the world IOn seconds ago. Contemporaries ofSt Thomas (such as Grosseteste) often cited an ancient example: if an eternal foot had been pressing eternally in the dust, there would be an eternal footprint beneath it. But though foot and footprint were equally eternal, there would be no doubt that the footprint was the effect of the foot. Equally, an eternal world, though eternal, would be the creation of, and dependent on, an eternal God. 20 We can go further than that. The world is not something which God once made: the world is something which God is still making: indeed, 'which God is still doing' would be more accurate, as creation is more like a performance than it is like a production. The world is made by God from nothing, i.e. not out of anything. It thus has no consistency of matter to keep it in existence. As Aquinas says, 'God made the world' is more like 'The musician made music' than it is like 'The blacksmith made a horseshoe'. 21 The horseshoe is made out of iron, and once the making is finished the iron remains. But the world is made not made out of anything, so if God stops making the world the world stops, just as when the musician stops making the music, the music stops. Despite Aquinas's use of tags such as 'we cannot go on to infinity in this line' there is no question in any of the Five Ways of our having to trace the universe back through time to its origin. Whether we continue to believe in the Big Bang or not, St Thomas's arguments stand. Though if we turn out to be capable of convincing ourselves that there was a Big Bang but that it does not require an explanation, my own view is that no arguments, whether those of St Thomas or those of anyone else, will be able to help us very much. To what extent the Lord helps those who help themselves I am not sure; but I am sure that when those who could help themselves by thinking intelligently and resolutely refuse to do so, they have no right to expect the Lord to help them- or anyone else, for that matter.

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I. It appears impossible to settle the correct reading of the text at this point - see the Latin alternatives given in the next note. However, it makes no difference to the effectiveness of the account I shall be giving of the Third Way, which reading we take. 2. Summa Theologiae, I, q. 2, a. 3: Tertia via sumpta est ex possibili et necessaria, quae talis est. Invenimus enim in rebus quaedam quae sunt possibilia esse et non esse, cum quaedam inveniantur generari et corrumpi, et per consequens possibilia esse et non esse. Impossibile est autem omnia quae sunt talia esse [vel omnia talia semper esse], quia quod possibile est non esse, quandoque non est. Si igitur omnia sunt possibilia non esse, aliquando nihil fuit in rebus. Sed si hoc est verum, etiam nunc nihil esset: quia quod non est non incipit esse nisi per aliquid quod est. Si ergo nihil fuit ens, impossibile fuit quod aliquid inciperet esse, et sic modo nihil esset, quod patet esse falsum. Non ergo omnia entia sunt possibilia, sed oportet aliquid esse necessarium in rebus. Omne autem necessarium vel habet causam suae necessitatis aliunde, vel non habet. Non est autem possibile quod procedatur in infinitum in necessariis quae habent causam suae necessitatis, sicut nee in causis efficientibus, ut probatum est. Ergo necesse est ponere aliquid quod est per se necessarium, non habens causam necessitatis aliunde, sed quod est causa necessitatis aliis, quod omnes dicunt Deum. 3. This double claim is called 'The Principle of Plenitude', and is frequently attributed to Aristotle: e.g. by J. Hintikka, in Time and Necessity (Oxford: Clarendon, 1973), p. 109. However, other authors have disputed this attribution: see A. Llano, 'The Principle of Plenitude', in D. M. Gallagher (ed.), Thomas Aquinas and his Legacy (Washington: Catholic University of America Press, 1994), pp. 131-48, especially pp. 136--7. 4. See, for example, Chapter 9 of Book I of the De Interpretatione. 5. The leading exponent of this view is David Lewis: see his books Counterfactuals (Oxford: Blackwell, 1973) and On the Plurality of Worlds (Oxford: Blackwell, 1986). 6. Ifl have not misunderstood him, this is the thesis of Simo Knuuttila, probably the greatest expert on medieval accounts of modality. See, for example, 'Time and modality in scholasticism', in S. Knuttila (ed.), Reforging the Great Chain of Being: Studies in the History of Modal Theories (Dordrecht and Boston: Reidel, 1980), and 'Varieties of natural necessity in medieval thought', in I. Angelelli and A. d'Ors (eds), £studios de Ia Historia de Ia L6gica (Pamplona: Eunate, 1990). For a solid refutation of the view that StThomas held the Principle of Plenitude, see Llano, 'The Principle of Plenitude', in Thomas Aquinas and his Legacy, pp. 131-48. 7. Compare the passage about God's power already referred to in Chapter 2 above, p. 27 (Summa Theologiae, I, q. 25). 8. Summa Contra Gentes, I, 13, 30. 9. On these murky questions in psycho-cosmology (or cosmo-psychology), see S. L. Jaki, 'Oscillating worlds and wavering minds', Chapter 14 in Science and Creation (Edinburgh: Scottish Academic Press, 1974), pp. 336--60. 10. I admit that my way of expressing these physical truths may not be particularly accurate or elegant. Most of my knowledge of the Second Law ofThermodynamics depends on the Flanders and Swann song called, I believe, 'First and second law'. I have been unable to find full publication details for this reference, much to my regret. 11. See A. Kenny, The Five Ways(London: Routledge and Kegan Paul, 1969), pp. 63-9, who accuses Aquinas of committing this fallacy. 12. For something of the history of this fallacy, and a number of interesting examples, see P. T. Geach, 'History of a fallacy', in Logic Matters, pp. 1-12; also Kenny, The Five Ways, provides some examples. 13. SeeP. T. Geach, review of Kenny, The Five Ways, in Mind, vol. 79, 1970, pp. 467-8. 14. Ibid. The Five Ways. 15. I had the encouragement in this particular task of Dr Maria Alvarez, then an M. Phil. student at Glasgow, whose name I should like to mention here with the gratitude and admiration that I owe her for this and for much other help and intellectual stimulation over the years. 16. Mention of Popeye reminds me that we are indebted to his inventors for what has been called 'the redundancy theory of personal identity': 'I am what I am and that's all that I am.' 17. SeeP. T. Geach, Three Philosophers (Oxford: Blackwell, 1961), p. 115. 18. See A. Kenny, The Five Ways pp. 36, 46--69.

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19. See Chapter 2, p. 26 above. 20. Used by e.g. Grosseteste in the First Particula of his Hexaemeron. 21. Summa Theologiae, I, q. 46, a. 2, ad 7: see Geach, Three Philosophers, pp. 111-12; see also Chapter 9, p. 143 above.

12 • THEFOURTHWAY

It is a sound rule of academic prudence to admit one's ignorance promptly when one's chances of disguising it are slight. Thus I had better begin this chapter by saying that I don't think I understand the Fourth Way, and have even less confidence in my ability to make it out as an argument that proves the existence of God. I console myself by the consideration that I am in good company: both Kenny and Geach seem to give up on the Fourth Way. 1 But since a book with a title or sub-title like Four out ofthe Five Ways in the Context of St Thomas's Theory of Science would have attracted yet fewer readers than one sub-titled (as I intended) The Five Ways ofSt Thomas in the Context ofhis Theory ofScience I shall make bold to offer the reader some considerations about the Fourth Way, in the hope that the Advertising Standards Authority will thus be encouraged to treat my publishers leniently. We might as well begin with the text: no previous explanation, I think, will make it any easier. The fourth way is taken from the degrees which are found in things. In things we find that some things are more or less good, or true, or noble, and other such things. But 'more' and 'less' so-and-so are said of various things in so far as they approach, in their different ways, that which is most so-and-so, as that which is hotter is that which is closest to that which is hottest. There is, then, something which is most true, and best, and most noble, and which therefore most exists: for those things which are most true are most existent, as it says in the second book of the Metaphysics. That which is said to be greatest in any kind causes everything of that kind, as for example fire, which is the hottest thing, is the cause of all hot things, as it says in the same book.

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Therefore there is something that is the cause of the existence and the goodness and of all perfections in everything: and this, we say, is God. 2 As usual, the indentation is supposed to indicate something of the structure of the argument, but I offer this with even less confidence than on other occasions. If the indentation is correct, we have the following structure to the argument: 1. In things we find that some things are more or less good, or true, or noble, and other such things. 2. There is, then, something which is most true, and best, and most noble, and which therefore most exists: for those things which are most true are most existent. 3. That which is said to be greatest in any kind causes everything of that kind. 4. Therefore there is something that is the cause of the existence and the goodness and of all perfections in everything: and this, we say, is God. This not only does not look like a valid argument, it does not look much like an argument at all. We can begin by pointing out that the qualities Aquinas uses in this Way are what the medievals called 'transcendentals': good, true, noble, and the like. The label means that these notions apply indifferently to anything in any of the categories of the existent. This concept is not altogether unfamiliar to us: we are accustomed to regard certain notions, for example, the central concepts of philosophical logic, such as identity, existence, reference, truth, etc., as having some application in all fields of discourse without exception. The crucial difference, though, is that St Thomas's transcendental notions are not logical but metaphysical notions: they apply not within the realm of syntactically structured expressions but within the realm of reality. This we should not perhaps be surprised at, since we have seen how St Thomas sees a close relation between the realm of truth and the realm of existence, and sees the former as in some way derivative from the latter. 3 To stop to argue around the validity of the notion of the metaphysical transcendentals would perhaps require another couple of books, books which I am sure I am incapable of writing; so perhaps we can just take this notion on trust tentatively for the time being, and see whether it helps us make progress with the Fourth Way. An important part of the doctrine of the transcendentals is that of their 'convertibility' with existence. ('For those things which are most true are most existent, as it says in the second book of the Metaphysics.') That is,

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that which is, for example, good, also exists; and that which exists is also good; it is good to the extent and in the way that it exists, and it exists to the extent and in the way that it is good. Hence, for example, something that exists per accidens will only be good per accidens. A clearer and perhaps more obviously acceptable example might be that that which exists per accidens (an ens per accidens) will also be one and the same thing per accidens (unum per accidens). This brings us close to the Quinean principle of 'No entity without identity', and makes the whole doctrine of the transcendentals a little less bizarre. 4 However, the next point of the argument does look bizarre: the claim that there are degrees of existence which correspond to the degrees of the other transcendentals. One might wish to admit degrees of goodness or nobility; but the notion of the truth of a thing is one which we would immediately reject, and we would also reject any connection between degrees of this or that quality and degrees of existence. But again the doctrine can be, if not defended, at least sketched out in a way which makes it less obviously unacceptable. Take for example the question of the truth of things. To the average contemporary English-speaking philosopher, there can no more be a truth of a thing than there can be a meaning oflife. But the fact that the average first-year student of philosophy feels that his or her lecturers are missing something when they insist in their rather literal-minded way that life does not have a semantic structure and therefore cannot have a meaning, may encourage us to look for an understanding of the notion of the truth of a thing. The medievals defined truth in a number of ways, but the most favoured was 'adaequatio rei et intellectus', the match of mind and reality. 5 A match is a match, and if A matches B, then B matches A; but there is always a question of onus of match. Generally, when we look out on the world and talk about it, the onus is on our mind to match up to reality. But this is not always so. When we act or speak or make some production, we can condemn the action or utterance or production as being in some way false if it does not match our mind, our intention. The onus of match here is reversed. (It is worth noticing, by the way, that there is no doubt that it was this sense of'true' and 'false' which was uppermost in the minds of the Greek philosophers, and they had a struggle to develop the more abstract sense in which sentences on their own are true independently of the mind of their utterer. That is why when Aristotle and Plato want to talk about truth and falsity in an abstract sense they very often talk of 'is and is not'. 6} So much for the different ways in which the human mind and reality have to match: the onus is on the human mind to match the reality it

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observes, and the onus is on the reality we produce to match the human mind. But the human mind, forSt Thomas, is not the only, nor the most important mind. What of God's mind? The whole world is God's production, and so the relationship of the whole world to God's mind is analogous to the relationship which exists between our own mind and our productions or performances. That is, the onus of match is on the world: it is up to the world to match up to God's mind, and in so far as it does so, it will be true, in this sense. But how can the world fail to match up to God's mind? Presumably only in virtue of some defect, and a defect, as we learned earlier, 7 is an absence of some real existent or existence. The doctrine is beginning to look a little less odd. But what of degrees of existence? Geach has pointed out that we can find at least one good and clear example in which something may exist to different degrees without any substantial, substantive or qualitative change: that of sound. 8 A note may be sung or performed at a greater or lesser volume; it may, indeed, swell or diminish or die away entirely. The ceasing to exist of the note is no more than the diminution to zero of the intensive magnitude of the note; and since there is ex hypothesi no qualitative change in the note thus performed, what are we to say except that the note, when louder, exists to a greater degree, and when softer, exists to a lesser degree, until perhaps it ceases to exist at all? Kenny has pointed out that this example is a pretty isolated one: 9 Geach has retorted that it doesn't matter how isolated it is, it shows that the doctrine makes sense. 10 If we are to get any further forward with the Fourth Way we will have to accept Geach's point, at least tentatively, and admit that there seems to be some sense in what is said here. Unfortunately it seems to me that at this point we begin to run out of possibilities of understanding. It looks as if feature X in this Way is 'having a perfection to a limited degree', or perhaps, if we bring forward the account of the convertibility of the transcendentals with existence, 'existing to a limited degree'. As a feature X in use in the alleged structure of one of the Five Ways, whatever displays this feature will require an explanation in terms of its relation to something different, and I cannot for the life of me see why this should be. Indeed, the use of this feature X presents an extremely curious contrast with the Third Way. In the Third Way it appeared that the feature X which required an explanation was, more or less, 'possessing existence to a (temporally) unlimited extent'; while here it is 'possessing existence to an (intensively) limited degree' which apparently requires explanation, according to the mind of St Thomas.

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Nor does this feature X inspire confidence as one which has the other mark which a feature X must have for the purposes of this type of argument. This other mark is that of generalisability. A whole which contains parts in process of change is itself something which is in process of change, as we saw in the First Way. A similar point could be made with regard to the Third Way: a whole which contains parts which are either perishable or derivatively everlasting is itself something which is either perishable or derivatively everlasting. But is it the case that a whole which contains parts oflimited perfection or limited existence is itself something of limited perfection or limited existence? Taking the word 'perfection' in its more familiar English sense of 'complete goodness' the point might be made out, provided that we accept a very sound medieval principle, frequently cited by St Thomas, which appears to have originated with the distinguished scholar who is now known by the rather splendid name of Pseudo-Dionysius the Areopagite. 11 The principle is 'Bonum ex integra causa, malum ex quocumque defectu': a thing is good if everything about it is good, and bad if anything about it is bad. 12 This thesis about the asymmetry of good and evil is clearly true. For my dinner-party to be a good one, I have to provide good materials and prepare them well. No matter how careful the cooking, the dinner will be a failure if I have stocked my larder with what I have found in the bins at the back of Pricerite; and no matter how expensive or carefully chosen the provisions, my guests will feel somewhat cheated if I have just thrown the whole lot into the oven at gas mark 7 for a couple of hours. I remember hearing Mrs Foot appealing to the asymmetry of good and evil, and quoting this ancient principle, in an ethical context in the not too distant past, so it may well have some contemporary appeal. Taking 'perfection' in this familiar way, then, there is some justification for holding that 'limited perfection' is generalisable; and if we have some faith in the doctrine of the transcendentals and their convertibility with existence, we may hold that this applies to the more general sense of perfection which St Thomas is employing here. What is not at all clear is, as has been said, that whatever displays this feature X requires an explanation in terms of a relation to something else, let alone that it requires an explanation in terms of a relation to something of unlimited perfection. St Thomas seems to allege that the existence of a more and a less requires an explanation in terms of a relation to a most. But 'more' and 'less' so-and-so are said of various things in so far as they approach, in their different ways, that which is most so-and-so,

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God and Explanations as that which is hotter is that which is closest to that which is hottest. There is, then, something which is most true, and best, and most noble, and which therefore most exists: for those things which are most true are most existent, as it says in the second book of the Metaphysics. That which is said to be greatest in any kind causes everything of that kind, as for example fire, which is the hottest thing, is the cause of all hot things, as it says in the same book.

There are some things which can be said. The existence of a more and a less does indeed require the existence of a de facto most: if all of the male lecturers of Glasgow University are more or less good-looking, then there will be one (allegedly the former Dean of Arts) who is the most good-looking. But this does not help us much: the Dean of Arts, though a fine figure of a man, has no chance next to Daniel Day-Lewis. His de facto relative highest beauty falls very far short even of a more widely extended relative beauty, let alone absolute beauty. In any case, the same point can be made with regard to defects as well as perfections. Lecturers in Glasgow are relatively ugly, and while it would be invidious to name names, there is no doubt that there is one who is the ugliest of the lot. 13 This existence of a de facto most, which is required by the existence of a more and a less, will not get us where we want to go: particularly as I can see no reason whatsoever why the existence of the de facto most should cause or explain the existence of the more and the less. One might try to claim that the existence of a more and a less requires a notion of the most, but I find this doubtful. And again, it is hard to see how the existence of an idea of the most can explain the real existence of the more and the less. Indeed, it is hard to see how the existence of any kind of idea can explain the real existence of anything at all. In any case, an argument like this is going to bring us only to the existence of an idea of God, which may be very interesting but was hardly in doubt from the beginning. I am inclined to leave this argument as a mystery. But there is some slight illumination which I think may be cast on the problem by the original example of the group of Inuit. The phenomenon which needed to be explained in the case of the group of Inuit was their presence on a street corner in Glasgow. The presence of the group of Inuit, or of each member of the group, was the parallel to the existence of the world or of any part of it. One might query whether presence admits of degrees, and whether the existence oflimited presence requires an explanation in terms of absolute presence. Put like that, the story of the Inuit looks even more bizarre than the

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Fourth Way itself, but we can perhaps smooth off some of the rough edges. Presence may not admit of degrees, but presence on a street corner certainly does. If you have ever waited leaning against the wall on the street corner for someone who was meanwhile leaning on the wall just round the corner waiting for you, you will know what I mean. For a group of as many as five Inuit, the concept of standing on the street corner admits of degrees: unless the corner is of a very odd shape, 14 or unless they are standing in a human tower on one another's shoulders, one will be nearer the corner than another. Does this require explanation? Not really, since it is something that is so obvious. But it does require the existence of a street corner, for them to be nearer to or farther away from. The street corner is, I suppose, in some unlimited and perfect degree present at the street corner, since everything is in an unlimited and perfect degree present where it is. And in a sense it is the perfect and unlimited presence at the street corner of the street corner itself, which does something to explain the presence, to a greater or lesser extent, of the Inuit at the street corner. If there is no perfect and unlimited presence of the street corner, there will be no limited and varying degree of presence of the Inuit. If this parallel represents in any way the argument StThomas is trying to give us in the Fourth Way, then the Fourth Way is very different from the others. I do not know how to classify the kind of explanation of the world that it offers. But this fits fairly well with the text of the Fourth Way: 'Therefore there is something that is the cause of the existence and the goodness and of all perfections in everything: and this, we say, is God.' What kind of cause is being spoken of here is obscure. It is not a question of efficient, final, material, or even, so far as I can make out, formal cause. Equally well the presence of the street corner explains the presence of the Inuit in a quite different way from the story that they are a dance troupe due to perform at Mayfest, or that Kadlu is signing for Thistle, that they are waiting for a bus or even that they have been transported there by a whirlwind, as in The Wizard of Oz. It is a strange argument, and the stranger the notion of explanation we claim is being used in it, the better chance we have of being right. Or perhaps I should say, the slightly less chance we have of being wrong. Good luck to the next person to approach the Fourth Way. NOTES 1. See, e.g. P. T. Geach, Three Philosophers (Oxford: Blackwell, 1961), pp. 116--17, A. Kenny, The Five Ways (London: Routledge and Kegan Paul, 1969), p. 95. 2. Summa Theologiae, I, q. 2, a. 3:

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God and Explanations Quarta via sumitur ex gradibus qui in rebus inveniuntur. Invenitur enim in rebus aliquid magis et minus bonum, et verum, et nobile, et sic de aliis huiusmodi. Sed magis et minus dicuntur de diversis secundum quod appropinquant diversimode ad aliquid quod maxime est, sicut magis calidum est quod magis appropinquat maxime calido. Est igitur aliquid quod est verissimum et optimum et nobilissimum, et per consequens maxime ens. Nam quae sunt maxime vera sunt maxime entia, ut dicitur II Metaphysicorum. Quae autem dicitur rnaxime tale in aliquo genere est causa omnium quae sunt illius generis; sicut ignis, qui est maxime calidus, est causa omnium calidorum, ut in eodem libro dicitur. Ergo est aliquid quod est causa esse et bonitatis et cuiuslibet perfectionis in rebus omnibus, et hoc dicimus Deum.

3. See above, Chapter 5, p. 73. 4. See e.g. Commentary on Metaphysics, L.IV, 1.2, n. 560. 5. Used by Aquinas in e.g. Summa Theologiae, I, q. 16, a. lc.: attributed to Isaac Israeli, De definitionibus. 6. On this, see C. F. J. Martin, 'Virtues, motivation and the end oflife, in L. Gormally (ed.), Moral Truth and Moral Tradition, Dublin: Four Courts Press, 1994), p. 125, note 36. 7. See Chapter 5 above, p. 56, and chapter 8 above, p. 113. 8. SeeP. T. Geach, in the section 'Esse' in the essay 'Aquinas', in Three Philosophers (Oxford: Blackwell, 1961), pp. 93-4. 9. A. Kenny, 'Form, existence and essence in Aquinas', in H. A. Lewis (ed.), Philosophical Encounters (Dordrecht: Kluwer, 1991), pp. 71-2. 10. P. T. Geach, 'A philosophical autobiography', Philosophical Encounters, pp. 1-25. 11. This author appears to have been an early sixth-century monk from Syria, a remarkable neo-Platonic theologian, who wrote pseudonymously under the name ofDionysius, the Athenian disciple of St Paul (Acts 17: 34), who was a member of the Athenian religious council of the Areopagus. In StThomas's time the author was actually identified with the original bearer of his pseudonym, and his writings were considered of near-apostolic authority for this reason. In the sixteenth century it became clear that a mistake had been made: hence Pseudo-Dionysius. But though he was not a disciple of St Paul his works are worthy of great attention. 12. See e.g. Summa Theologiae, I-11, q. 18, a. 4, ad 3. 13. I shall name no names, but Glasgow folklore and tribal loyalty demand that I should claim that he supports Rangers. 14. Glasgow folklore regards the ultimate in romantic humiliation as being 'left standing on Boots's corner': the corner on which Boots's largest shop in the centre of town used to stand was covered by a canopy, and was an excellent place for a young man to arrange to meet his girlfriend. If she didn't turn up, he was left standing. Fortunately the corner was designed with a re-entrant angle, protected by the canopy: thus it had a relevantly odd shape. No doubt it was partly this feature which made it popular as a trysting-place. It was nearly impossible for the young man to be round one side of the corner while the young woman was round the other.

13 • THE FIFTH WAY

The Fifth Way, as often remarked, depends on final causality, explanation in terms of an end, of what is the point of things. The aim is to show that the world, like its parts, requires an explanation in terms of what it's for, and what the world is for is set by God. It is a mistake to say that this argument is based on the world's being for a purpose: it is rather based on the world's having a point, which is at first sight quite another thing. The circulation of my blood has a point, but it does not have a purpose; nor do I even have a purpose in circulating my blood, since circulating my blood is not something in the strict sense which I do. I can't help it. It is true that in order to reach God Aquinas has to argue that the point of the world has to be a purpose set for it by God, but that is a further step in the argument. We can see this clearly from the text: The fifth way is taken from things' being directed. We see that there are things that have no knowledge, like physical bodies, but which act for the sake of an end. This is clear in that they always, or for the most part, act in the same way, and achieve what is best. This shows that they reach their end not by chance but in virtue of some tendency. But things which have no knowledge do not have a tendency to an end unless they are directed by something that does have knowledge and understanding. An example is an arrow directed by an archer. Therefore there is some being with understanding which directs all things to their end, and this, we say, is God. 1 This is the briefest of all the Five Ways, and its structure is apparently clear.

1. We see that there are things that have no knowledge, like physical bodies, but which act for the sake of an end.

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2. But things which have no knowledge do not have a tendency to an end unless they are directed by something that does have knowledge and understanding. 3. Therefore there is some being with understanding which directs all things to their end, and this, we say, is God. But this simplicity is deceptive, and the history of natural theology and apologetics has made it yet more difficult for us to read this argument as we should. Most people would want nowadays to object to the first premiss, and to deny that we see that physical bodies act for the sake of an end. But they would grant that if we saw physical bodies acting for the sake of an end, we should conclude immediately to the existence of God. Aquinas does not agree, I think. He thinks that it is almost unquestionable that, for example, physical bodies act for the sake of an end; what is tricky is the step from the unconscious end-directedness which we see all around us to the conscious end-directedness which he needs to assert if he is to prove the existence of God. One of the things that has happened between Aquinas and ourselves has been the growth of a general disbelief in explanation in terms of what things are for. This is partly the result of a failure to understand what it is to explain something in terms of what it's for, and partly the result of the rather curious psychological phenomenon of the near-universal acceptance of what is really a rather poor argument for the existence of God, the argument from design. The argument from design had its heyday between the time of Newton and the time ofDarwin, say, a time in which most people apparently came to see the world as a minutely designed piece of craftsmanship, like a clock. It is no coincidence that the most famous presentation of the argument from design actually compares the world to a clock: it is known by the name ofPaley's watch. 2 It is also worth noticing that according to the great computerised Index Thomisticus, in the 8,000,000 words Thomas Aquinas definitely wrote, and the 3,000,000 he may have written besides, the universe is never compared to a clock. 3 The argument from design takes as its basis the perceived mis-match between the detailed dovetailing of the different parts of the mechanism of the world and any story we could tell about how this comes to be as the result ofblind chance. A favourite example ofPaley's is the eye: how could the eye be so perfectly adapted to its function if it came about merely by chance? It must have been designed. It is worth noticing that this is not so much an argument about final causality, an argument in terms of what things are for, as an argument about efficient causality, an argument in terms of how things have come

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to be the way they are. This is because the notion of teleology, of things' being for a point, which is used in the argument from design is indeed a notion of purpose, of conscious teleology. Unconscious teleology or final causality, as we shall see, does not conflict with efficient causality; indeed, a decent explanation of what things are for actually demands a decent explanation of how they come to do what they do. Conscious teleology, or purpose, or design, is different. Conscious teleology supplants any alternative explanation in terms of efficient causality and supplies its own. An account in terms of conscious teleology, purpose or design says 'Some mind conceived the idea of the end, and set about to arrange things so as to bring it about'. When there is a designing mind involved, end or point becomes purpose, and as it were gets in behind the chain of efficient causality and sets it going. There is no doubt that this argument is or was immensely attractive. Reid regards the human tendency to infer from detailed arrangement some designing mind as one of the principles of commonsense; 4 and even Hume regards the argument from design as the chief reason for believing in God. 5 But the argument from design has two enormous drawbacks. The first is that it is, roughly speaking, an argument from ignorance, and is thus immensely susceptible to advances in science. Paley could not see how the eye could have come to be without a Designer; Darwin comes along and does no more than sketch a sort of answer of how things like eyes might more or less have come to be, and no-one finds it possible to take Paley seriously any more. This is not good philosophy, but it is a pretty clear picture of the fate of eighteenth-century natural theology in the early part of the nineteenth century. 6 The second objection to the argument from design is that it does not get us to God, but only to a Designer, a Demiurge, as Plato would say; or, as the eighteenth century loved to say, the Great Architect. The Being whose existence is revealed to us by the argument from design is not God but the Great Architect of the Deists and Freemasons, an impostor disguised as God, a stern, kindly and immensely clever old English gentleman, equipped with apron, trowel, square and compasses. Blake has a famous picture of this figure to be seen on the walls of a thousand student bedrooms during the 1970s: the strong wind which is apparently blowing in the picture has blown away the apron, trowel and set-square but left him his beard and compasses. Ironies of history have meant that this picture of Blake's is often taken to be a picture of God the Creator, while in fact Blake drew it as a picture of Urizen, a being who shares some of the attributes of the Great Architect and some of those of Satan. 7 The Great Architect is not God because he is just someone like us but

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a lot older, cleverer and more skilful. 8 He decides what he wants to do and therefore sets about doing the things he needs to do to achieve it. God is not like that. As Hobbes memorably said, 'God hath no ends': there is nothing that God is up to, nothing he needs to get done, nothing he needs to do to get things done. 9 In no less lapidary Latin, Aquinas said, 'Vult ergo Deus hoc esse propter hoc; sed non propter hoc vult hoc' .10 In definitely unlapidary English we could say: the set-up, A-for-the-sake-of-B is something that God wants; but it is not that God wants B and for that reason wants A. We know that the set-up A-for-the-sake-of-B is something that God wants, because it is something that exists, and everything that exists exists because of God's will. But it is simply profane to think that you can infer from that the unfathomable secrets of the inside of God's mind and will. Acorns for the sake of oak trees, to repeat an example ofGeach's, are definitely something that God wants, since that is the way things are. But it is not that God has any special desire for oak trees (as the Great Architect might), and for that reason finds himself obliged to fiddle about with acorns. If God wants oak trees, he can have them, zap! You want oak trees, you got 'em. 'Let there be oak trees', by inference, is one of the things said on the third day of creation, and oak trees are made. There is no suggestion that acorns have to come first - indeed, the suggestion is quite the other way around. To 'which came first, the acorn or the oak?' it looks as if the answer is quite definitely 'the oak' .11 In any case, what's so special about oak trees that God should have to fiddle around with acorns to make them? God is mysterious; the whole objection to the great architect is that we know him all too well, since he is one of us. 12 Whatever God is, God is not one of us- a sobering thought for those who use 'one of us' as their highest term of approbation. The argument from design fails, then, because it is an argument from ignorance, because it confuses the final and efficient modes of explanation, and because even if it succeeded it would not prove the existence of God but of some Masonic impostor. But like other bad arguments, its defeat and death has left it to wander the world like a ghost, oppressing the spirits of those who are looking for other and better arguments. 13 The haunting we suffer from when we attempt to take a proper look at the Fifth Way means that people think that as soon as we admit any kind of teleology into the world, any kind of explanation in terms of what things are for, we are at once committed to God. I have a heavy burden of prejudice to overcome here. Let me just say that as far as I can make out by far the hardest move in the Fifth Way is the move from unconscious to conscious teleology, and, for my part, I am not sure that StThomas gives us conclusive reasons for making that move.

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I regard them as strong, but not conclusive, and the impression I have is that others regard them as not very strong at all. So bear with me. The case I am going to make for explanation in terms of what things are for is worth examining in its own right, and I give you my word that there is no booby-trap: you will not find yourself suddenly committed to believing in God merely because you have come to accept that at least some things in the world need to be explained in terms of what they're for. 14 'Having a point' or 'being for something' or 'displaying a tendency', or, as Aquinas would probably say, 'directedness', is the feature X in this Way. I think that it is, as Aquinas says, perfectly obvious that some things in the world display this feature X, and it is clearly a feature X that requires an explanation in terms of a relation to something else: viz, their point, what they are for, what they have a tendency towards or what they are directed to. We see that there are things that have no knowledge, like physical bodies, but which act for the sake of an end. This is clear in that they always, or for the most part, act in the same way, and achieve what is best. This shows that they reach their end not by chance but in virtue of some tendency. Aquinas clearly thinks that this feature X is generalisable: that if any part of the world displays this feature X, the world as a whole displays it. This step I find more doubtful, though I do find it plausible to infer that if any part of the world apparently displays this feature X, has a point, then it at least makes sense to ask whether the world as a whole displays feature X. I shall not in fact stop with the obvious facts to which Aquinas alludes, but shall go on to argue that in fact every bit of the world displays feature X, at least to the same extent as that to which every bit of the world displays the feature X we looked at in the Second Way, that of being a subject of efficient causality. This move I shall make principally for its own sake, because it is philosophically important and deeply unfashionable. But this move also helps the Fifth Way a little: if every bit of the world displays this feature X it becomes a good deal more urgent and at least apparently a good deal more sensible to ask whether the world as a whole displays it; and, by parity of reasoning with the lumping-together move we performed in the Second Way, it even begins to look likely that the world as a whole does display feature X. But we still will not have reached God. There will be a further step, which Aquinas scarcely even sketches for us, which will say that if the world as a whole does display feature X, the way in which it displays this feature cannot be an unconscious way. In this respect the world as a whole is unlike most of the bits

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of the world which display feature X, since they do display feature X in an unconscious way. The point in terms of a relation to which the world is to be explained is thus going to be revealed as being indeed a purpose, a point conceived by a mind to which the world is directed by that mind. But it is this last step that brings us to God, and it is the most contentious step of all. To an unprejudiced mind there are innumerable features of the world which display the relevant feature X, that have a point. All the different parts of an organic whole- a human body, for example- have a point in relation to the life of the whole body. Acorns we have already mentioned; and indeed all the paraphernalia of animal and plant reproduction actually resist definition except in terms of what they are for. Imagine, for example, the task of identifying the sexual organs of some animals that were very different from us, animals found on Mars, for example. 15 You cannot hope to identify the sexual organs in terms of three-dimensional geometry, of what bits stick out and what bits stick in - you have to identify the function. People who study the ecology tend more and more to describe it in teleological terms: what else is meant by the metaphor of calling the whole ecosystem of the earth by a proper name, 'Gaia', as if it were itself an organism? These biological examples are particularly useful in that they show us that we are not here depending on ignorance. The way the sexual organs work is well understood. We even known quite a lot about how the ecosystem works, and it is significant that we have come to speak of the ecosystem in more and more organic terms - that is, more and more in terms of what things are for- the better we have come to understand how it actually works. Thus teleological explanations, explanations in terms of what things are for, are not in the least rivals to efficient explanations, explanations in terms of what things do or of how they do it. 16 The idea that final causality and efficient causality are in some sense at loggerheads derives from arguments like the argument from design, where efficient explanations were lacking. Because efficient explanations were lacking, the obvious final explanation was postulated as pre-existing as an idea in someone's mind, which would then provide the required efficient explanation. The mind of the Great Architect is a cover for ignorance of efficient causality: the existence of final schemes of explanation may have suggested that cover, but the reason why it suggested the cover is that a decent teleological explanation, far from usurping the place of a decent efficient explanation, actually demands one. Unlike Paley's watch, Geach's watch is worthy of a place in contemporary and non-historical works of philosophy. 17 A good old-fashioned

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mechanical watch, like many other artefacts, is a paradigm of something that can and must be explained in terms of efficient causality. The minute hand rotates twenty-four times in each period of the earth's rotation, because it is moved by cog A; the hour hand rotates twice in every period of the earth's rotation, because it is moved by cog B; cog A and cog B move at such-and such a rate because they are moved by cog C via gearing D; ... because it is moved by the escapement, which moves because it is moved by the hairspring, which moves because it is moved by the mainspring. So far so good. If I had had a story like that to tell about the world my version of the Second Way would have been far more elegant. But the same watch, like many other artefacts, is also a paradigm of something that can and must be explained in terms of final causality. The mainspring moves in order that the hairspring may move which moves in order that the escapement may move which moves ... in order that cog C via gearing D may move cog A and cog B, and cog A moves in order that the minute hand may rotate twenty-four times in each period of the earth's rotation, and cog B moves in order that the hour hand may rotate twice in every period of the earth's rotation. This story, in terms of final causality, of what is the point of what, of what things are for, is just as good as the last story, which was in terms of efficient causality, of how things come about. Indeed, it does not take much philosophical acumen to realise that the one story has to be as good as the other, since they are the same story read in opposite directions with suitable adjustments to the connectives. Neither is prior, neither makes the other redundant. Sometimes, as in the case of the sexual organs, we start by telling the final story and get round to developing the efficient story, and sometimes, as in the case of, I believe, the pineal gland, we first tell the efficient story and then get round to telling the final story- working out what it's for. 18 So, prejudices aside, we can ask what this or that bit of the world is for; and we can, in some cases, get an answer. We get it, at least sometimes, by considering efficient causality: what this or that bit of the world actually does. There is, thus, no conflict between final explanations and efficient explanations, and it might be possible to maintain, as in the cases we have considered, that the one requires the other and vice-versa. They require each other, they even live off each other, given that the final explanation is just the efficient explanation read in the opposite direction, with the 'becauses' substituted by 'in order tos', while the efficient explanation is just the final explanation read off in the other direction, with the 'in order tos' substituted by 'becauses'. This is certainly Aquinas's doctrine: as he puts it, rather more elegantly, 'causae sunt ad invicem causae' (one kind of explanation explains the other). 19

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Aquinas thinks that the world as a whole is a system of efficient causes, as we saw when considering the Second Way. This is not the sort of claim that many people, except possibly neo-Pythagoreans, would bother to question. But a corollary of this belief, combined with this account of the relationship between efficient and final modes of explanation, is that the world as a whole is a system of final causality; and this claim is unlikely to be even considered by the majority of our contemporaries. It implies, for example, that of almost anything- certainly of anything that forms a part of a system of efficient causality- we can sensibly ask 'What's it for? What is the point of it?', and can hope one day to be able to give an answer which is more or less correct. Pick up any book of the history of the philosophy of science and you will find this sort of view guyed unmercifully. Aristotle - and, by implication, St Thomas, though few of those who work on the history of the philosophy of science even bother to look at StThomas, confining themselves to remarks about angels on the points of pins- is represented as a sort of primitive animist. Stones fall to the ground, Aristotle says, because they have a tendency to return to their proper place, which is the centre of the earth. Add to this the fact that the word he uses for 'tendency' is 'orexis', 'appetitus' in Latin, which can equally well be translated as appetite, desire, or even lust, and you have a rather charming but deeply ridiculous picture. Things like stones can be represented as having a little and rather simple soul within them, a soul which only knows where its rightful place is and only wants to return there. Remove constraints from the stone and this passionate desire takes over, and it flies to the bosom of the earth panting with lust. Why this picture, which I find rather exciting, should be considered as ridiculous in the century of Freud, I am not quite sure. I would have thought that a picture of the universe as brimming with quasi-sexual desire would be rather attractive to our contemporaries. Perhaps this tells us something about the way in which philosophy has become detached from the concerns and interests of ordinary people in the last couple of hundred years. The picture just drawn of Aristotle's world-view, though worthy of serious poetical consideration, is in fact no more than a parody, aimed at making the notion of final causality ridiculous. But the reality of the doctrines of Aristotle and St Thomas, someone might want to say, is already ridiculous enough. The idea that we can seriously ask of almost any bit of the universe, at least in so far as it forms a part of a system of efficient causality, 'What's the point of it?', is an idea which has been seriously out of fashion for about the last three hundred years.

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Well, many ideas which have been out of fashion for the last three hundred years are quite good ones. About three hundred years ago it became unfashionable for preachers to tell their flocks that the goods they happened to have in their power over and above what they needed for their own support and that of their families, and for the discharge of any civic duties they might have, did not belong to them at all, but belonged to the poor, to those who needed it, and was owed to them as a debt of justice. Someone who had more than he needed and did not give to the poor was not guilty of a lack of charity or philanthropy but was simply a thief. 20 That idea became unfashionable three hundred years ago, but it seem to me a pretty good one. The same might well be true of the notion of final causality. 21 Unsurprisingly, I should like to approach this question of final causality through the question of efficient causality. We have already mentioned that the standard modern account of causality regards it as a relation between two events. This is entirely false to the practice of science, which deals with relations not between events but between things. As was perhaps mentioned when discussing the notion of the per accidens, and the young Russell's pretence that people and things were logical constructions out of events, making events prior to things is not so much to put the cart before the horse as to put the mule before the horse and the donkey. Events cannot be identified except as in terms of their relations to things. The Battle of Waterloo, an event which we quite frequently refer to, at least if we live to the south-west of London, can only be identified in terms of Napoleon and a lot of his chaps meeting Wellington and (rather later) Blucher and a lot of their chaps on the slope of a hill about twenty miles south of Brussels and spending most of the day beating all hell out of each other. There is no chance of identifying Wellington dependently in terms of his being the victor of Waterloo. The death of Socrates is the death that it is because it is Socrates' death: Socrates is not who he is because he is the person who died that death. Which death? we ask, and the only answer that we can give which makes no reference to Socrates is that it was the death that occurred early in the morning of (say) the fourth day of the month Boedromion, in the prison of the Eleven, in the archon year of (say) Agathocles. But this identification of the event depends on the prior identification of all kinds of things and persons: the sun, to give us the hour, the moon, to give us the day of the month, Athens, whose officers the Eleven were, and where the prison was situated, and Agathocles. '399 BC' is even less help, since it contains a reference to the birth of Jesus 22 of Nazareth 23 in Bethlehem, 24 a reference which we know was

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established by one Dionysius Exiguus 25 in terms of a reference to Rome 26 and its foundation 27 by Romulus, 28 which Dionysius derived from the histories of Livy, 29 a reference which we know (by reference to the account given by Josephus 30 of the life and death 31 of Herod the Greae 2) must have been mistaken. In brief, things are prior to events, and the world, as a system of efficient causality, is a system of things. The world is the totality of things, not of facts. I believe that this claim is already likely to be unpopular enough, but having started I might as well continue. These things which are related by efficient causality are things with powers, and it is in virtue of their powers that they exercise causality. This thesis is usually subject to as much ridicule as is the picture of Aristotle's highly sexed physical universe. As soon as the word 'power' appears on the page, someone will already be penciling in the margin a witticism about 'virtus dormitiva'. This joke derives from Moliere and is probably the poorest joke ever used in any philosophical context -certainly the poorest joke to be used more than once. I have a certain right to speak here, as many of the jokes I make in philosophical contexts are very poor indeed. Some of them have no point, others have a very slight and unimportant point. But at least my jokes don't miss the point altogether, and don't get used to make exactly the opposite point to the one they really represent. And the really poor ones I feel embarrassed about, and don't use more than once. Moliere represents for us an examination of a medical doctor, and the joke is that when the doctors can't answer difficult questions they disguise their ignorance with high-sounding Latin phrases. Thus, when asked why opium puts people to sleep, the candidate replies that it is because opium has a 'virtus dormitiva', that is, a power to put people to sleep. It seems a little hard to pull such a joke to pieces, but since contemporary authors continue to misunderstand the point of the joke, I am going to have to. This joke is funny for the following reason 33 - in his answer the doctor merely repeats what everyone knows in technical-sounding language. Doing so is supposed to inspire confidence in the patient. This is a trick which doctors often play: in the First World War, what the troops called 'trench fever' the doctors called 'P. U. 0.', pyrexia of unknown origin. The nature of this pyrexia is still unknown. The technique sometimes makes the patient feel more confident, which often helps towards a cure. Sometimes the mere giving of a label - for example, RSI, or repetitive strain injury, which means no more than that you are suffering discomfort or pain because you have strained your nerves, tendons and muscles, in some obscure way, through repeatedly performing slight movements such as typing - can be of immense

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benefit to the patient because he or she is thus enabled to sue the pants off his or her employer. But when the doctor uses some high-sounding phrase to repeat what we already know, and we are sharp enough to spot this, and have no hope of a recovery or of compensation based on jargon alone, we laugh. So (let us hope) did Moliere's audience. I feel deeply embarrassed flogging this joke to death, but it has to be done. The joke is funny because the answer is true but profoundly uninformative. Uninformativeness is a relative notion: an expression can be informative to one person, uninformative to another. When I point out that Glasgow is in Scotland, not England, this is uninformative to most of my readers, but when I visit Spain I have occasion to make this remark quite often, and it is informative. In the Moliere case, we are supposed to be an intelligent and well-educated seventeenth-century audience who can work out that the dog-Latin sentence in question means that opium puts people to sleep because it has a power to put people to sleep. This is profoundly uninformative (and therefore, let me insist, mildly funny) because we knew it already. The answer is true, but tells us nothing we didn't know. We pay doctors to tell us things we didn't know, so when a doctor is represented as earning his money by telling us things we already knew well, covering his minor dishonesty in high-sounding language, we find it amusing. Contrast, if you can bear to, the account given of this same joke by those who use it most, people of an empiricist cast of mind. Rather than regard 'opium puts people to sleep because it has a dormitive power' as true but uninformative, they see it as tautological. What else, they ask, could 'opium has a dormitive power' mean other than 'opium puts people to sleep'? They think that the doctor in the play is to be laughed at because he repeats a tautology as if it were informative. This will not do. Informativeness and uninformativeness are, as I said, relative notions: relative to the degree of ignorance or education of the reader or listener. If Moliere had wanted to give us a tautological answer, his own dog-Latin and that of his audience would surely have been up to it. 'Why does opium put people to sleep?' 'Cl!.10niam dulce sugus papaveri inquantum sumitur omne animal dormitare facessit'. That Latin is pretty doggy, but the worse the Latin, the easier to understand: 'because the gentle juice of the poppy sends to sleep any animal that takes it'. That is a tautology. In contrast, 'opium sends people to sleep because it has a dormitive power' is a perfectly sensible, if not very informative, scientific statement. It is not a tautology, and we can prove this in a nicely ironic way. A tautology is not significantly deniable: the negation of a tautology is a self-contradiction, which no-one can believe or even sensibly affirm. It is

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ironic that those very people of empiricist casts of mind who claim that 'opium sends people to sleep because it has a dormitive power' is a tautology are just the people who deny this alleged tautology, who claim that it is false that opium sends people to sleep because it has a dormitive power. They deny, in fact, that opium has a dormitive power, because they deny that there are any such things as powers. They should not be allowed to have it both ways: they must not claim both that the famous sentence is a tautology and that it is false. Someone like Locke would say that we have no way ofknowing whether opium has, in its real essence, a dormitive power or not. We should limit ourselves to commenting on the fact that the (possibly quite disparate) kinds of thing which we group together roughly under the nominal essence of opium in fact send people to sleep. Though, for Locke, we shouldn't be surprised when they don't: a man who was not surprised at the story of the rational parrot, or the offspring of bulls with mares, or of apes with women, has no real right to be surprised at anything. 34 Or let us consider Hume. If you ask Hume whether it is the case that opium puts people to sleep because it has a dormitive power, he will answer no (at least if you catch him in the library rather than at the backgammon-board). There is no possible evidence on which we can base such an affirmation as 'opium puts people to sleep because it has a dormitive power'; all we find is a constant conjunction between people taking opium and people going to sleep. To what extent we find this, and how constant the conjunction is, we had better not ask. In the interests of science and of annoying Humeans I am perfectly capable of taking a powerful emetic just before taking my opium, and thus showing that the conjunction between taking opium and going to sleep is by no means as constant as one might have thought. Of course it will be alleged that a constant conjunction which can be so easily falsified is not what Hume or the Humeans meant, and I am well able to believe it; but I have yet to find anyone capable of telling me just what the devil they do mean. Putting the rhetoric on the back burner for a little bit, the thesis I am trying to suggest is that the system of physical science with which we are all familiar, a system which most would be happy to see described as a system of efficient causality, is a system of things, principally bodies, and their powers, and the effects of these powers. It is true that science is more than this. I have claimed that the answer 'opium puts people to sleep because it has a dormitive power' is perfectly true, and, indeed, if the account of science I have just offered is in any way accurate, it is in some ways a model answer. But 'model' answer is exactly right; or perhaps I should rather call it a blueprint for an answer, or the framework for an

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answer. It is, after all, wholly uninformative, it tells us nothing which we did not know already; and it can scarcely be claimed that science tells us nothing which we did not know already. I am not a particular fan of uninformative answers, but I see nothing wrong with them when they prepare the ground for an informative one. And this answer is a case in point. Against the beliefs of any empiricists, or any believers in magic, it tells us that opium has a dormitive power and thus prepares us for an investigation into what that power consists in. Kenny would say it prepares us for an investigation of the vehicle of that power, 35 and the account he gives of the relationship between powers and their vehicles is a good one. What was wrong with the doctor's answer in Moliere is that we expect the doctor to know more than we do, to be capable of going one step beyond the uninformative answer we already know, and to tell us what the vehicle of this dormitive power is- some feature of the chemical structure of opium which enables it to send us to sleep through some action within the chemical content of the brain (I expect). When the doctor fails to say something like this we feel cheated because we are paying him a lot for the years of study which are supposed to take him further in the investigation of the powers of natural things than we will ever get, and if he cannot tell us a suitable story about the vehicle we expect him to admit it and not fob us off with a lot of Latin. In my bedside table I have a packet of tranquillisers, and in the instructions that came with the pills I find the superb phrase: 'Alapryl, a preparation of halazepam, is a tranquilliser derived from benzodiazepine. As with other benzodiazepines, the exact mechanism by which it achieves its therapeutic effects is not clearly established.' 35 That's the way to talk: no comic dramatist in the world could take the mickey out of that kind of remark. Nor could any empiricist have any objection. But oddly enough the real scientists regard this kind of admission rather shamefacedly. I take this as evidence that my account of science, as an investigation of powers and their vehicles, though crude, is at least more accurate than that of the empiricists. But if the world, considered as a system of efficient causality, necessarily involves the notion of powers, then it also necessarily reveals itself as a system of final causality. For powers are defined and identified in terms of their ends- their 'exercises', as Kenny would say. 37 We can thus perhaps see reason for identifying, (not merely this or that bit of the world), but the world as a whole as a system which requires explanation in terms of what it's for. We can go further. Leaving behind the question of powers, it is possible to claim that the notion of efficient causality requires the notion of a

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tendency, and the notion of tendency, still more clearly than that of a power, needs to be defined and identified in terms of what it's a tendency towards. 38 I shall attempt to show this by outlining a framework for understanding reasoning in causal contexts- contexts of efficient causality - which works by assimilating causal reasoning to practical reasoning. Following a suggestion of Geach, I shall argue that systems of causal reasoning display the logical feature of 'defeasibility', a feature which is often held to be distinctive of practical reasoning. I shall suggest that the reason for this logical isomorphism between causal and practical reasoning is that just as practical reasoning starts from goals, which are conscious ends, so all causal reasoning involves the notion of tendencies, which are specified in terms of ends. Causal set-ups, then, are to be described as stating tendencies. These tendencies are specified in terms of their end, of that to which they are tendencies. For example: substances A and B, when mixed, have a tendency to produce an explosion. Given the additional premiss that substances A and B have been mixed, we very happily conclude that there will be (or has been) an explosion. But suppose that we add in extra premisses, as for example that substances A and B have been mixed in a medium of substance C: and that substance C has a tendency to interfere with the operations of these tendencies of substances A and B. We conclude that there will be no explosion. This reasoning is as defeasible as practical reasoning is. 39 If causal premisses are taken to express tendencies, which can be interfered with, and if this interference may invalidate any conclusion that may be drawn from the premisses, the parallels between causal reasoning and practical reasoning seem to be clear. That which may defeat the conclusion of the causal reasoning is interference, that is, the action of other causal tendencies not mentioned in the original premisses. Meanwhile, that which may defeat the conclusion of practical reasoning is the addition of other goal-expressing premisses. This parallel can be developed. The relevant premisses in practical reasoning are premisses which express goals: in causal reasoning, the relevant premisses are premisses which express or describe tendencies. The premisses in both cases involve an unavoidable reference to an end. This is clear in the case of practical reasoning: but it should be no less clear in the case of causal reasoning. A tendency is specified in terms of what it is a tendency towards: the notion of an end is thus unavoidably involved. 40 It is true that an explosion is not produced, in the imagined case, and to that extent the tendencies of substances A and B to produce an

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explosion are not fulfilled. But though these tendencies, under that description, are not fulfilled, there are surely other descriptions of the same causal tendencies of substances A and B under which the tendencies are fulfilled. We have to to tell some such story as that while substance A has a tendency to combine with substance B in such a way as to produce an explosion it also has a tendency to combine with substance C to produce some compound which does not have a tendency to produce an explosion when combined with substance B. Both these tendencies could perhaps be redescribed in general terms of, for example, valency, in such a way that both tendencies can be seen as species of one and the same generic tendency, just as both effects - the combination with B to produce an explosion, and the combination with C to prevent an explosion - can be seen as different fulfilments of the same tendency. We are not to think of tendencies becoming wholly inoperative when interfered with. A mixture of A and B in a medium of C is something with causal tendencies quite different from those of the same quantity of C alone: the tendencies of A and B continue to exist and to have some fulfilment. The same tendencies, we want to say, under certain descriptions may be fulfilled, and under other descriptions may not be fulfilled. A question may arise of what right I have to speak of 'the same tendencies under different descriptions'. If a tendency is specified by its end, as it surely must be, then a tendency with a different end is a different tendency. I believe this problem can be circumvented. Every tendency has an end, but this end will be variously describable. Quite a lot of what one is first taught in science classes, I would say, consists in establishing alternative (and more general) descriptions of given tendencies. For example, in basic dynamics, attaching such-and-such a weight to this rope, running over a pulley, has a tendency to lift such-and-such other weight attached to the other end. An alternative description of this tendency, in terms of force, and alternative descriptions of the weights in terms of mass, are made available. It is clearly the same tendencies which are differently described here. This may give the clue to an answer. We should not say that a tendency that is 'frustrated' by interference is not fulfilled, we should rather say something like 'this tendency is fulfilled in a non-paradigmatic way'. Each tendency will be specified in terms of an end, the end will be an event, and hence the tendency will be specified by a description of an event. For example, we may describe a tendency as a tendency to produce an explosion, say. The paradigmatic fulfilment of the tendency will be the occurrence of an event that meets the description that was used in specifying the tendency - in this case, an explosion. There may well be

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no such occurrence, no explosion, in which case there will be no paradigmatic fulfilment of the tendency. But there will be some fulfilment of the tendency - a non-paradigmatic one. We will have to redescribe the tendency to produce an explosion in such a way that the failure of the mixture to explode is also a fulfilment of the tendency: for example, by redescribing it as a tendency to combine with other substances in suchand-such ways. But a fulfilment of a tendency will be paradigmatic or non-paradigmatic relative to a certain description of the tendency: for every fulfilment of a tendency that is non-paradigmatic under a certain description, there will be another description of the tendency such that the fulfilment is paradigmatic under that description. Both the combination of substance A with substance B to produce an explosion, and the combination of substance A with substance C, and the consequent failure of substance A to produce an explosion despite the presence of substance B, will both be paradigmatic fulfilments of the same tendency of A under different descriptions. Moreover, as our understanding develops, we can offer a description of the tendency in A to the paradigmatic effect of producing an explosion in the presence ofB such that is also a description of a tendency to the paradigmatic effect of failing to explode in the presence of B and C. This will need tightening up. A first objection to this would seem to be that since any event can be described as 'something happening', any tendency can be described as a tendency for something to happen. This would empty this doctrine of all content. 'If there is a tendency for something to happen, something will happen' does not look helpful. (We may notice, though, that even this example is not wholly vacuous: it has enough content to be false. If the conflicting or interfering tendencies are equally balanced, then nothing will happen.) But the point is well made. We will need some kind of stipulations about levels of generality of descriptions of ends to be used in specifying tendencies. A first shot would be to stipulate something like the following: when we are dealing with conflicting or interfering tendencies, we are to seek for alternative, more general descriptions of these tendencies such that both tendencies are fulfilled paradigmatically. That is, the tendencies are to be specified in such a way that both are fulfilled paradigmatically. If we then stipulate that the least general such description is to be taken, we shall avoid at least the uninformativeness of attributing to agents 'tendencies to bring it about that something happens'. That is, we don't want to have laws of chemistry that say something like 'When the substances A and Bare put together, something happens'. But nor do we want laws that say 'When substances A and B are put

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together, an explosion occurs', which, given that there may be interference, would be false. We want a description of the tendencies of A and B such that the event described by 'an explosion occurred' and the event described by 'an explosion did not occur' are equally paradigmatic fulfilments of the tendencies. We may want to add here a suggestion that the scientific project is one of determining appropriate levels of generality of description. The least general level is the place to start, but this, in our example, may get us no further than saying that A has a tendency to combine with B to produce an explosion and to combine with C to avoid an explosion. This is not yet a scientific explanation: but it seems to be the place at which to start a scientific investigation, to see what further more general and more explanatory, and hence more appropriate, descriptions of this tendency in A we can produce. Appropriateness here is a difficult notion to specify, but it is one which it is necessary to use. What we want is a level general enough for us to be able to say that the tendencies are fulfilled paradigmatically, but not so general as to be uninformative- and not so particular, meanwhile, as to be useless for explanation of other causal efficacy of the subjects. The mysterious notion of explanatoriness seems to be making an entrance here. Explanatoriness is indeed a mysterious concept, but there are features which it is known to have which can be seen to be relevant here. The giving of an explanation appears to create a non-extensional context: to use Professor Anscombe's example, to say 'There was an international crisis because the President of the French Republic made a speech' is explanatory, while 'There was an international crisis because the man with the biggest nose in France made a speech' is not, even if the President of the French Republic is the man with the biggest nose in France. 41 That is, explanation is in some sense relative to a description. It should occasion no surprise, then, that causal reasoning in terms of tendencies, which is supposed to be explanatory, should turn out to have description-relativity built in to it. This is yet another parallel to practical reasoning: actions are said to be intentional only under certain descriptions, and here we have it that effects are attributable to a tendency only under certain descriptions. I am not able to enter into a full discussion of this. This account clarifies a number of difficulties about non-voluntary causality, and allows us to make clear the difference between voluntary and non-voluntary causality. Non-voluntary causality needs to be described in terms of tendencies, tendencies to some paradigmatic effect. These tendencies may often be fulfilled non-paradigmatically, because of

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interference. That is, there may well be no possible description of the effect which is also a description of the paradigmatic fulfilment of the tendency. However, the tendencies will always be fulfilled, if only nonparadigmatically: there will always be some description of the tendency, in terms of some paradigmatic fulfilment, such that the tendency, so described, is fulfilled paradigmatically. The apparent vacuousness of this is limited by the fact that if the paradigmatic fulfilment does not occur, there will always be some interference; and the actual outcome will also be a non-paradigmatic fulfilment of the interfering tendency. Once we are committed to taking the least general descriptions of the two tendencies under which the fulfilments are paradigmatic, the account we give will be the starting place, at least, for the search for an appropriate explanation it will describe the outcome as the paradigmatic fulfilment of the conflicting tendencies. There will always be such a description available, barring the case of miracles. The case which has here been made, then, is that a description of the world in terms of its being a system of efficient causality is necessarily a system which involves tendencies, and therefore also a system which involves finality: indeed, that a description of the physical world which ignores finality is as absurd as a description of human action which ignores human goals. Of course both kinds of description, which I here categorise as absurd, are possible, in the sense that they can be written out or talked about. What is more difficult to know, as Aristotle remarked about Heraclitus, is to what extent it is possible to believe in them. 42 If what has been said is accepted, or even half-accepted, it makes sense to see the world as a system of final causality, as displaying a tendency. This, it will be remembered, was the feature X for the Fifth Way. That 'displaying a tendency' has the mark of a suitable feature X of requiring an explanation in terms of a relation to something else is clear. It is not so clear to what extent it is generalisable, to what extent we can infer from 'part of this whole displays feature X' that 'the whole displays feature X'. It is pretty clear that StThomas believes that the feature is generalisable since he does not take the trouble, as I have done, to claim that each and every part of the world displays a tendency. It is perhaps simple enough to understand why he thinks this. lfl put my file on the floor, and then a book on top of it, and then my word-processor on top of the book, and then a flower-vase on top of the word-processor, and then put a stick in the flower vase, and then carefully wrap a small scrap of ribbon around the stick, a question arises of what the devil I'm up to; more scientifically, what is the point of all that?

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I answer: 43 I put the file on the floor in order to put the book on top of it, and I put the book on the file in order to put my word-processor on top of the book, and I put my word-processor on top of the book in order to put the flower-vase on top of the word-processor, and I put the flowervase on top of the word-processor in order to put a stick in it, and I put the stick in the flower-vase in order to tie a piece of ribbon around the end of the stick. I have given something of a sketch of a system of final causality. Each part of the system of final causality, until the last, has a perfectly good explanation. (We might have given this example in terms of our stock group oflnuit, of course, and the same point could have been made: lngekok is here to prevent quarrels between Kadlu and Kotuko, and so on. I have avoided using the example here because the point of any of the group's presence will be in terms of conscious teleology, their purpose. When dealing with teleological relations within the world, we are interested principally in unconscious teleology.) Something remains to be said. If the last step of tying the ribbon, or the system as a whole, fails to have a point, one is surely entitled to say that the apparent point of each previous stage is wholly illusory. Again, as in the case of the Inuit, there can be a variety of forms of final explanation which will suffice. Maybe the point of each part other than the tying of the ribbon derives from the point of the ribbon in itself, as in the case where the ribbon is yellow, and lacking an old oak tree I wish to build some structure tall enough for my sweetheart to be able to catch sight of the ribbon from the window of the bus. Or it may be that the point of each part does not relate directly or indirectly to the point of the explanatorily privileged ribbon- I am merely seized by the aesthetic passion of making piles of incongruous objects. Or something between the two: the upper part of the structure is a booby-trap, and the lower part is to make sure that it stays put until my victim gets here. As in the case of the Inuit, no-one knows and no-one cares, but it is a plausible claim that unless the whole has a point no part of it has a point, all appearances of final structure notwithstanding. Thus St Thomas thinks that if the world as a whole does not have a point, then the things in the world that seem to have a point don't have a point either. There is room here for a subordinate argument such as he gives us in the first three Ways, that we cannot go on to infinity in this line, but perhaps there is no need for him to give it. The point had already been made for him by Aristotle in the Nicomachean Ethics44 - if everything is for the sake of something else, there is no point in anything. A parallel example which I have sometimes given is the 'Lottery in Babylon' of

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Borges's short story of the same name. 45 The story contains a number of deliberate inconsistencies, but one of the things that is said or suggested is that the lottery, which has come to embrace all aspects of Babylonian life, and doles out both good and bad fortune, has become infinite. Nothing ever happens as a result of any drawing of the lottery except some further drawing of the lottery. The governors of Babylon, or the gods of Babylon, have introduced and extended this lottery with the aim of keeping their subjects in a useful and agreeable state of apprehension and hope. The reader, though, wonders how long it will be before someone recognises that the lottery determines nothing but further drawings of the lottery, and announces, as it were, that the emperor has no clothes on at all. And what will happen to the useful and agreeable state of hope and apprehension then? St Thomas seems to put before us a stark choice: either the world requires an explanation in terms of what it's for, or nothing in the world in fact has any point, though it may seem to. The problem with this choice is that people may very well take the alternative St Thomas rejects. It is not uncommon for people to say that they regard the world as having no point, and regard any appearance that anything in the world has a point as purely delusive. Some theists, reacting to this answer, might make the kind of remark that Aristotle makes about Heraclitus: they say it, but they can't mean it. Having myself suffered in my time from clinical depression (that is what working in the Philosophy Department of Glasgow University can do for you), I think that this theistic retort is both cheap and inaccurate. One can perfectly well believe that neither one's own life nor the life of the world as a whole has any point that one is capable of understanding, and still jog on without feeling logically, morally or psychologically compelled to go for the overdose of sleeping pills. But this is where my stronger claim, that the world as a whole has to be seen as a system of final causality, makes it harder to refuse to take St Thomas's preferred alternative: that the world as a whole is something that requires explanation in terms of some point that it has, in terms of being for something. For if my account of science is anything like right, then the whole of science is entirely fallacious if the world is not the sort of thing that has a point. This is an option which will seem perfectly plausible to depressives, but will seem less so to others. It is not merely a question of failing to see much point in life, but one of suddenly being unable to see any intelligible structure to life at all. This would take us well beyond anything which we can find parallels for in depressive symptoms, and brings us into the country of people who mistake their wives for hats. And here Aristotle's point against Heraclitus does seem to

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have a certain validity. We know that there was at least one man who mistook his wife for a hat, but if someone tells us that it is a mistake he is prone to make we find it pretty hard to believe:- at least when he is playing backgammon rather than elucubrating in the philosophy section of the l1.brary. 46 It begins to look, then, as if the lumping-together move with this feature X has some validity. Even if we are willing to be hard-nosed about St Thomas's claim that the bits of the world which apparently have a point will fail to have one if the world as a whole has no point, we may feel a bit more doubtful about being hard-nosed if we find out that if we refuse to ask what the point of the world is, we are left with a world whose structure as a system of final causality, and therefore as a system of efficient causality, turns out to be wholly illusory. Or perhaps not: perhaps this is the reason why people have been trying to drum into us for centuries that the world can be a comprehensible structure of (quasi-) efficient causality without implying any beliefs about tendencies, and therefore without implying any vision of the world as a structure of final causality. The question which remains, though, is not that of whether we are capable of seeing the world as a structure of quasi-efficient causality while ignoring the tendencies which are thus presupposed, thus enabling us to ignore the final structure of the world. Of course we can do it - we've done it for centuries. The question is whether we should. Likewise, it is clear that we are capable of considering all the money and goods that come into our power by means which our legal system sanctions as being our own, to do what we like with. The question is whether we should: whether we would not be behaving with some kind of minimal honesty if we returned to the unfashionable old idea that what we have above and beyond what we need for our own support, that of our families, and the fulfilment of our civic duties, is not actually owed as a debt of justice to those who are in need of it. Be that as it may, once we start wondering about what the point of the world is, about what the world is for, or even once we start wondering whether it might not after all make sense to ask such a question, we run into a curious little problem which takes us on to the last step in the Fifth Way: 'But things which have no knowledge do not have a tendency to an end unless they are directed by something that does have knowledge and understanding. An example is an arrow directed by an archer.' This is the crucial claim of the Fifth Way, the step that takes us to God - and it is a little curious. It can be paraphrased as: every unconscious teleology, every case of something being for something without awareness of what it's for, is dependent on some conscious teleology, on some mind

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which is aware what that thing is for. It seems obvious to me that just in so far as one is disposed to admit the existence of unconscious teleology, one will be disposed to deny this claim, and just in so far as one is disposed to admit this claim one will be disposed to admit the existence of unconscious teleology. Here I find myself isolated. Both Reid and Hume were inclined to admit the claim, and neither is much of a friend to unconscious teleology. Most of my contemporaries, I think, would agree with the two Scots here. St Thomas admits the existence of unconscious teleology and actually makes the claim. I feel rather friendless when I admit that to me the evidence for the existence of unconscious teleology seems overwhelming, but I cannot at first sight see any reason for holding the claim that it must in general depend on conscious teleology. 'In general', I say. In the case of the world as a whole, there is, as I have mentioned, a problem with the lumping-together move which may in this case, if in no other, justify the dependence of unconscious teleology on conscious teleology. We have agreed, at least for the sake of argument, to regard the world as a system of things which are for something, which have a point, which display unconscious teleology. And, at least for the sake of following StThomas's argument, we have to agree to perform the lumping-together move and ask what is the point of the world as a whole. This leads to a problem. Unconscious teleology seems always to be system-relative, if that is not too much of a neologism. A typical relation of unconscious teleology, of one thing being for the sake of another without consciousness of what it's for, will be the relationship of a part to a whole, as in the case of a bodily organ; or the relationship of one part of an interconnected teleological system to another part of the same system, as in the case of the acorn. The examples are the most obvious ones, but clearly if we agree to count anything which manifests a tendency as having a point, and any part of the system of efficient causes which we call the world as manifesting a tendency, this will be quite generally true. The bit of the world which displays unconscious teleology, which has a point, which is for the sake of something, is, in the end, for the sake of the world as a whole. What then can we say of the world as a whole? If the world has a point, if it is for anything, this cannot be a case of unconscious teleology, since unconscious teleology is always relative to a system, is always a case of a part being for the sake of the whole. There is, by definition, no greater whole of which the world forms a part. Even if there were, we could just perform the 'we cannot go on to infinity in this line' move, and quickly come to the limit. There is therefore going to be something, viz. the world, which has to have a point if anything within the world is to have a point.

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Apparently there are things within the world that have a point; indeed, apparently the whole structure of the world depends on things displaying tendencies and thus having points, being for something. Therefore the world as a whole does have a point, does display teleology. But this teleology cannot be unconscious, since there is no greater whole for the world to have as its unconscious point. Therefore the teleology of the world must be conscious: the point of the world must be conferred on it by some mind. 'Therefore there is some being with understanding which directs all things to their end, and this, we say, is God.' I can never quite make up my mind as to whether or not I find this argument convincing. A parallel discussion in ethical arguments strikes me as equally perplexing, and perplexing in an interestingly similar way. The kind of moral philosophy I favour is broadly speaking Aristotelian, and has as its most fundamental concept that of human well-being, flourishing. I can argue to some effect about the content of this notion of well-being, about how it is related to human dispositions and actions, and what sort of things we can or should do to achieve it. That is, grant me that human well-being is a good thing and I can deduce for you a whole ethical system, offering on the way at least specious refutations of any rival system. But if you ask me to prove to you that human well-being or flourishing is itself good, I find myself at a loss. I don't even know how I could begin such a proof. The only way to start which occurs to me is to go all ecological and relate the life of human beings to the life of Gaia, or whatever. This has several difficulties. First, I don't believe in the existence of Gaia. Secondly, it's pretty obvious that there are at least important aspects of the life of Gaia which we human beings are not very good for. Thirdly, we cannot go on to infinity in this line: were I able to prove that human well-being is good for the life of Gaia you would be perfectly entitled to ask me what the life of Gaia is good for. No answer is obviously forthcoming. At this stage the temptation is to throw up one's hands and appeal to an intuition that human well-being is a good thing, or that the life of Gaia is a good thing. Intuitions are in any case suspect, and in this context, that of ultimate goods, I find so many different candidates for the post of being the ultimate good, offered to me on the basis of so many different people's different intuitions; and so many of these candidates I find absurd or disgusting. So the appeal to intuitions is doubly or trebly suspect. 47 Though I am a philosopher, and regard with the gravest suspicion any attempt to bring in theological considerations into my strictly philosophical work, I begin to wonder whether the only point of human well-being is that it seems to be something God wants. Perhaps here we are still in

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the realm of philosophical theology, natural theology. I spoke earlier of the truth which things have through their matching God's mind. A closely related doctrine to this is that God's knowledge of the world is causative: 'Scientia Dei, causa rerum' ,48 (God's knowledge causes things to be). God does not have to observe the world to see how things turn out- this would make him passive to the world, and that contradicts the notion of God as Creator. God's knowledge of the world is like our knowledge of our own actions: we know what we are doing without observation. 40 The truth of things in the world depends on God's knowledge, not vice-versa; it is not, that is to say, that the truth of God's knowledge depends on things in the world. A parallel point can be made for God's will, and sometimes is. Things are the objects of our desire and goodwill because we find them good. But to transfer this kind of love to God would involve us in the same kind of mistake as would to think of God as having to learn from the world. Things are the object of God's desire and goodwill and this makes them good. (I do not wish to enter into the famous voluntarist/ anti-voluntarist controversy of the late Middle Ages here, and give serious consideration to the question of whether we might not wake up tomorrow to find that adultery was perfectly legitimate after all. 50 The thesis I have maintained does not entail this kind of voluntarism. There might be aspects of God's nature which set limits to what God can desire, and adultery might well fall outside these limits.) If human flourishing is a good thing, I want to suggest, in any ultimate sense, it can only be because God wants human beings to flourish. Likewise, if the world has a point, if it is for anything, it is because God has given it a point, has made it for something. As I have said, I don't know whether or not the Fifth Way is a good proof. The alternative is pretty dreadful- that there's no point to anything -but just because a thing is pretty dreadful doesn't have to make it false. Here the atheist cannot sensibly be accused of wishful thinking. But, as I have already commented, the theist need not be guilty of wishful thinking either, particularly if he or she subscribes to one or other of the traditional religions in our culture which embody classical theism. The atheist's conclusion, that there's no point to anything, may be a pretty dreadful one; but a more dreadful one, surely, is the theist's conclusion that there is a very definite point to everything and that I and you and everyone you care for and countless others may well miss it. If the worse comes to the worst, and you feel you have gained nothing either way from this book, draw this moral: don't make facile accusations of wishful thinking against people who disagree with you, and try to be

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consistent enough in your thought to make sure that any accusation of wishful thinking made against you is false. So much for the irrelevant moral tacked on at the end of the tale- what has the real point of the tale been? The real point of writing this book has been to show that what I used to think of as philosophy can still be done. With modest attention to our own limitations, we still can gather remarkable new insights into important problems - the existence of God, the nature of scientific inquiry, the notions of meaning and existence - from a study of the wisdom of older authors. We are not confined to studying them as if they were members of an alien species, pegged out on a card maybe, or even going about their unfathomable business, whose thoughts can have no impact on our own. If we want to know about the existence of God, or about the nature of science, we should read Aquinas, not merely the writers of this century. If we want to study Aquinas we should pay him the compliment of treating as important what he thought of as important. To study Aquinas as Aquinas is a poor piece of flattery, since Aquinas cared very little for Aquinas, while he did care for God and for science. Not that he cared for God and science in equal degrees, but he clearly thought that caring for God, for him, entailed developing a science of God. This meant he had to develop a theory of science. The first steps - perhaps the most important step - in his developed science is the question of the existence of God, and he answers it strictly according to his own rules for answering such questions. The Five Ways are not a brilliant jewel that can easily be wrenched out of its setting; to understand them we have to understand what kind of a question St Thomas thinks he is asking, why he asks it, how he thinks it is possible to set about answering it, and how the answers he gives meet up to his own standards- yes, and to our standards too. Unless, of course, the careful reading of StThomas has sometimes given us reason to abandon our own standards, which we have acquired in a severely limited environment, and take on his standards. The great benefit to be derived from reading pre-modern authors is to come to realise that after all we might have been mistaken up to now. This realisation is perhaps the chief and most general service I hope to have done to my readers. There is a lesser, more modest and more specific aim that I have had: to make it clear that it is wise to attempt some understanding of St Thomas's theory of science before trying to understand his arguments for the existence of God. I also hope to have contributed something to the understanding of both. Equally well, I think it would be foolish to try to

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understand StThomas's theory of science and explanation without relating it to his most famous scientific arguments in the context of explanation, which are the five ways. Lastly, I hope that some may have been able to develop new ideas of their own on the problems of the theory of science, on explanation, and of the existence of God, by being exposed to St Thomas's thought in a new way. That is the sort of thing I mean by 'philosophy'. NOTES I. Summa Theologiae, I, q. 2, a. 3: Quinta via sumitur ex gubernatione rerum. Videmus enim quod aliqua quae cognitione carent, scilicet corpora naturalia, operantur propter finem; quod apparet ex hoc, quod semper aut frequentius eodem modo operantur, et consequuntur id quod est optimum. Unde patet quod non a casu sed ex intentione perveniunt ad finem. Ea autem quae non habent cognitionem non tendunt in fin em nisi directa ab ali quo cognoscente et intelligente, sicut sagitta a sagittante. Ergo est aliquid intelligens a quo omnes res naturales ordinantur in finem, et hoc dicimus Deum. 2. See W. Paley, Natural Theology (London: Charles Knight, 1836), pp. 1-6. Paley's watch is clearly to be included among the exhibits of any Museum of the History of Philosophy, along with Aristotle's black swan, Ockham's razor, Buridan's Ass, Zeno's Arrow and Aquinas's point of a pin. 3. To those who object that he may have been unfamiliar with mechanical clocks, it is worth commenting that he compares to clockwork the way animals sometimes operate, in Summa Theologiae, 1-11, q. 13, a. 2, ad 3. 4. 'The last metaphysical principle ... is, That design, and intelligence in the cause, may be inferred with certainty, from marks or signs of it in the effect': T. Reid, Essay VI, 'Of judgement', Chapter V, 'First principles of necessary truths', in Essays on the Intellectual Powers of Man (Cambridge, Mass.: MIT Press, 1969), p. 660. In the same place he refers to Hume's attitude to this principle. 5. See the discussion of the argument from design, and Hume's reaction to it, in]. L. Mackie, The Miracle of Theism (Oxford: Clarendon, 1982), Chapter 8, pp. 133-49. 6. The enormous attraction of the argument from design is shown by the fact that Professor Dawkins, the best-known scientific atheist in Britain today, devotes most of his anti-God arguments to showing that the argument from design fails to prove the existence of God. I agree, as will be seen. However, he seems also to think that the failure of one argument for the existence of God proves that God does not exist. Perhaps this is merely because he has heard of no other, or has failed to notice that other arguments are significantly different. 7. It is no coincidence that according to Blake the Fall of Man occurred when Newton ate the apple. 8. Being 'one of us', of course, the question arises for him, as it does for us, 'and how did he get there?' or 'and who made him?'. This question cannot arise for the true God who we argue to as one who precisely lacks the features which we have, which make the question 'who made us?' inescapable. 9. This point is excellently made by P. T. Geach, 'An irrelevance of omnipotence', in Providence and Evil (Cambridge: Cambridge University Press, 1977), p. 36. My knowledge of Hobbes is not up to identifying the source. 10. Summa Theologiae, I, q. 19, a. Sc. II. 'Let the earth bring forth the green herb, and such as may seed' (my italics). 12. E.g. it's pretty obvious that his other name is Sarastro and he has the most marvellous bass voice. This fact makes me worry less about the obvious identification of the Qjleen of the Night, the villainess in The Magic Flute, with the Catholic Church: those who think the Great Architect is the goodie pay the Catholic Church a compliment by considering her the baddie, since such a conception admits that she upholds a belief in God the Creator by virtue of her opposition to the Great Architect.

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13. A similar bad argument was the one that contraception is bad because it's like anal intercourse, traditionally regarded as unquestionably bad. Since the invention of the Pill contraception may have no physical similarity whatsoever to anal intercourse, but the mind of the Catholic church has continued to regard it as bad. The ghost of the bad old argument makes some people think that contraception isn't bad because it isn't like anal intercourse, and makes others think that anal intercourse can't be bad after all because contraception isn't. Readers unfamiliar with liberal Catholic moral theology will find it hard to believe that people can be guilty of such confusion, but they had better take my word for it: anything would be better than having to read through liberal Catholic moral theology. On this question, see G. E. M. Anscombe, 'You can have sex without children; Christianity and the new offer', in Collected Philosophical Papers of G. E. M. Anscombe, vol. 3, pp. 82-96. 14. Many readers will have noticed the debt I owe in this passage, as elsewhere, to Geach, 'An irrelevance of omnipotence', in Providence and Evil, pp. 35-6, and the section 'Operations and tendencies' of the essay 'Aquinas' in Three Philosophers (Oxford: Blackwell, 1961), pp. 101-9. 15. Anscombe, 'You can have sex without children', in Collected Philosophical Papers, p. 85. 16. See P. T. Geach, in 'Why men need the virtues', in The Virtues (Cambridge: Cambridge University Press, 1977), pp. 9-12. 17. Ibid,p.11. 18. Ibid. 19. Commentary on the Physics, II, 1.5, n. 182: 'Quaedam sibi invicem sunt causae, secundum diversam speciem.' For a justification of this, see Commentary on the Metaphysics, L.V, 1. 2, n. 775. 20. See Summa Theologiae, II-II, q. 66, a. 2. 21. The parallel between the unfashionableness, in the modern enlightened age, of certain ancient and medieval views on explanation and certain ancient and medieval views on economics and ethics is not a freak of my own. A nice sidelight on the history of ideas is the fact that one of the last few books condemned by the Spanish Inquisition before it was forced to shut up shop in the early nineteenth century was Adam Smith's The Wealth ofNations. Fray Antonio de Ia Santisima Trinidad, the assessor appointed to examine the book, objected both to the moral doctrines, which implied that economic activity was wholly outside the scope of ethical considerations, and to the metaphysical presuppositions, which, among other things, rejected the idea of final causality. He also identified Smith as 'no mere Protestant, but a man of no religion, good or bad', and draws attention to Smith's use of Deistic or Masonic catch-phrases such as 'the religion of all sensible men'. The Great Architect was confused with God pretty generally in that period, but Fray Antonio was not deceived. Take note that the Inquisition did some good in its time. For further details, seeS. Meikle, 'Adam Smith and the Spanish Inquisition', in New Blackfriars Review, vol. 76, no. 890, February 1995, pp. 70--80. 22. A person. 23 A place. 24. Another place. 25. Another person. 26. A place. 27. An event! but one which is identified by reference to a place, Rome, and a person, Romulus. 28. Another person. 29. Another person. 30. Another person. 31. Another event! but one which is identified by reference to a person. 32. Another person. 33. It is painful to me (and no doubt to the reader) that here I have to pose as a joke German professor, but I can see no other way of making what I think of as an immensely important point. 34. I have often wondered why John Locke is considered the prime exponent of common sense. It has only slowly occurred to me that 'common sense' here means 'the system of beliefs which it is in the interest of the post-1688 British ruling class to propagate among its subjects', and in this sense I can see John Locke as a highly distinguished exponent. 35. In The Metaphysics of Mind (Oxford: Oxford University Press, 1991), pp. 71-4 on vehicle, exercise and power, pp. 27-8, 83 on powers (capacities); and in Will, Freedom and Power (Oxford: Blackwell, 1975), pp. 9-11. 36. Translation of Notes of Alapryl, trade name ofHalazepam, produced by Laboratorios Menarini SA, Barcelona, under licence from Schering-Plough.

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37. In The Metaphysics ofMind, pp. 71-4 on vehicle, exercise and power. 38. This sketch of an account of efficient causality follows ideas derived from a paper given by P. T. Geach, 'Teleology and laws of nature', at the conference Finality and intentionality, at the Universite Catholique de Louvain, 1990. I have been unable to establish whether this paper has been subsequently published. He was developing ideas he had used in G. E. M. Anscombe, and P. T. Geach, Three Philosophers (Oxford: Blackwell, 1961), pp. 101-9. 39. This paragraph exhausts my recollection and notes of Geach's paper - what follows is my reflection on it. It may be that this reflection has been guided by unconscious memories of other points Geach made. For the 'defeasibility' of practical reasoning, see Kenny, Will, Freedom and Power, pp. 71-96, and The Metaphysics of Mind, p. 145, although he would probably disagree with the claim which I make, following Geach, that causal tendencies are also defeasible. For a fuller discussion of the issues involved here, see my paper 'Libertad y revocabilidad', Anuario Filosrifico, vol. 23/3, 1994, pp. 991-1006. 40. This point is clearly made by Geach in the 'Operations and tendencies' section of the essay 'Aquinas', in Three Philosophers, p. 104. 41. An example drawn from 'Causality and extensionality', in Collected Philosophical Papers, p. 175. 42. Aristotle, Metaphysics, r, IOOSb, 24-7. Compare also Wittgenstein, 'Wass wir nicht denken ki.innen, dass ki.innen wir nicht denken', from Tractatus Logico-Philosophicus (London: Routledge and Kegan Paul, 1922). 43. 'Respondeo dicendum quod': Summa Theologiae, passim. 44. Nicomachean Ethics, Book I, 2, 1094a, 20--2. 'Nor do we choose everything for the sake of something else: this would drag on into infinity, and so the tendency would be vain and pointless.' 45. ]. L. Borges, 'Una loteria en Babilonia', in Ficciones, Obras Completas, Vol. 1 (Barcelona: Emece, 1989), pp. 456--60. 46. See 0. Sacks, The Man who Mistook his Wife for a Hat (New York: Harper Perennial, 1990); D. Hume, A Treatise on Human Nature, Book I, Part 4, Section 7. 47. In some ways the best apparent candidate for an ultimate good is money, which can measure and be exchanged for any good thing you care to mention, and which, in our society, seems to be generally sought as if it were the ultimate good. I'm sick oflove; I'm still more sick of rhyme: But money gives me pleasure all the time. Despite the elegance of the epigram, and despite the tendencies in our society to see money as the ultimate good, tendencies which our masters are apparently doing their best to encourage, money as a candidate for ultimate goodness has the unusual distinction of being both absurd and disgusting. 48. Summa Theologiae, I, q. 14, a. 8c. 49 Cf. G. E. M. Anscombe, Intention (Oxford: Blackwelll9 57). 'On sensations of position', Collected Philosophical Papers, pp. 71-4; P. T. Geach, 'Omniscience and the future', in Providence and Evil (Cambridge: Cambridge University Press, 1977), pp. 57-8. 50. There was a Bible published in England in the seventeenth century which contained an unfortunate printing error in what is variously known as the Seventh or the Sixth Commandment: the 'not' had been omitted in 'Thou shalt not commit adultery'. Whether this was a simple mistake, a hopeful gesture on the part of the proofreader or a contribution to the voluntarist/ antivoluntarist debate is not clear.

SELECT BIBLIOGRAPHY

Angellelli, I. and D'Ors, A. (eds), Estudios de !a historia de !a !Ogica (Pamplona: Eunate, 1990) Anscom be, G. E. M., Collected Philosophical Papers of G. E. M. Anscombe, 3 vols (Oxford: Blackwell, 1981) Anscombe, G. E. M., Intention (Oxford: Blackwell, 1957) Anscombe, G. E. M. and Geach, P. T., Three Philosophers (Oxford: Blackwell, 1961) Aquinas, Commentary on Boethius De Trinitate (In Boethium de Trinitate Expositio), in Opuscula Theologica Vol. 2, ed. R. Spiazzi (Turin: Marietti, 1954) Aquinas, Commentary on the De Interpretatione (In librum Perihermeneias Expositio ), ed. Spiazzi (Turin: Marietti, 19 55) Aquinas, Commentary on the Metaphysics (In XII libros Metaphysicorum Aristotelis Expositio), ed. M. R. Cathala and R. Spiazzi (Turin: Marietti, 1964) Aquinas, Commentary on the Nicomachean Ethics (In XII libros Ethicorum ad Nicomachum expositio), ed. Spiazzi (Turin: Marietti, 1964) Aquinas, Commentary on the Physics (In VIII Libros Physicorum Expositio), ed. P. M. Maggiolo (Turin: Marietti, 1954) Aquinas, Commentary on the Posterior Analytics (In II libros Posteriorum Ana(yticorum Expositio), ed. Spiazzi (Turin: Marietti, 1955) Aquinas, Commentary on the Sentences of Peter Lombard (In IV libros Sententiarum Petri Lombardi), ed. P. Mandonnet (Paris: Lethellieux, 1929) Aquinas, Disputed Question on Evil (Quaestio disputata de malo), ed. P.M. Pession (Turin: Marietti, 1949) Aquinas, Disputed Question on Truth (Quaestio Disputata de Veritate), ed. Spiazzi (Turin: Marietti, 1944) Aquinas, On Being and Essence (De ente et essentia), in Opuscula Philosophica, ed. Spiazzi (Turin: Marietti, 1947) Aquinas, On the Truth of the Catholic Faith (Summa Contra Gentes), ed. P. Marc (Turin: Marietti, 1967) Aquinas, Quodlibetal Questions (Quaestiones quodibetales), ed. Spiazzi (Turin: Marietti, 1949) Aquinas, Summa Theologiae, ed. T. Gilby (London: Blackfriars with Eyre and Spottiswoode, 1963) Aristotle, Categories: see Aristotle's Categories and De Interpretatione, translation and commentary by J. Ackrill (Oxford: Clarendon, 1978) Aristotle, Metaphysics, ed. W. Jaeger (Oxford: Clarendon, 1957) Aristotle, Metaphysics Books r, .1., E, translation and commentary by C. Kirwan (Oxford: Clarendon, 1971) Aristotle, Nicomachean Ethics, ed. J. Bywater (Oxford: Clarendon, 1894) Aristotle, Posterior A nary tics, translation and commentary by J. Barnes (Oxford: Clarendon, 1994) Bambrough, R. (ed.), New Essays on Plato and Aristotle (London: Routledge and Kegan Paul, 1979) Davies, B., An Introduction to the Philosophy ofReligion (Oxford: Oxford University Press, 2nd edn, 1993) Frege, G., Grundlagen der Arithmetik (Oxford: Blackwell, 1959) Gallagher, D. M. (ed.), Thomas Aquinas and his Legacy (Washington: Catholic University of America Press, 1994) Geach, P. T., God and the Soul (London: Routledge and Kegan Paul, 1969) Geach, P. T., Logic Matters (Oxford: Blackwell, 1981) Geach, P. T., Providence and Evil (Cambridge: Cambridge University Press, 1977). Geach, P. T., Truth, Love and Immortality (Berkeley and Los Angeles: University of California Press, 1979) Geach, P. T., The Virtues (Cambridge: Cambridge University Press, 1977) Geach, P. T. and Anscombe, G. E. M., Three Philosophers (Oxford: Blackwell, 1961) Gormally, L. (ed.), Moral Truth and Moral Tradition (Dublin: Four Courts Press, 1994)

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John Paul II, Crossing the Threshold of Hope (London: Collins, 1994) Kahn, Charles H., The Verb 'To Be' in Ancient Greek (Dordrecht: Reidel, 1973) Kenny, A., The Five Ways (London: Routledge and Kegan Paul, 1969) Kenny, A., The Metaphysics ofMind (Oxford: Oxford University Press, 1991) Kenny, A., Will, Freedom and Power (Oxford: Blackwell, 1975) Lewis, H. A. (ed.), Philosophical Encounters (Dordrecht: Kluwer, 1991) Macintyre, A., Three Rival Versions ofMoral Inquiry (London: Duckworth, 1990) Macintyre, A., Whose Justice? Which Rationality? (London: Duckworth, 1988) Mackie,]. L., The Miracle of Theism (Oxford: Clarendon, 1982) Martin, C. F.]., The Philosophy of Thomas Aquinas; Introductory Readings (London: Routledge, 1988) Swinburne, R., The Coherence of Theism (Oxford: Clarendon, 1977) Williams, C.]. F., What is Existence? (Oxford: Clarendon, 1981)

INDEX

a priori science, 29 adaequatus, 90-1 Adelard of Bath, 3 affirmative propositions, 70-2, 105 alien ideas, understanding of, x-xi, xiv alienating adjectives, 72 an est? questions, 33-9 passim, 54, 70, 73, 81-7 passim, 97, 102, 105 analytical philosophy, xiv-xv analytical Thomism, xii-xiv animal species, 26, 164-7 animals, sufferings of, 112, 115 animism, 186 Anscombe, G. E. M., xiii, xix, 18, 137, 152, 195 Anselm, St, 39, 84-5, 104-5 apologetics, 180 argument from authority, 2-7, 11-15,98-9 argument from design, 180-4 argument from evil, 110-17, 119 argument from partial explanation or from science, 118, 121 Aristotle and Aristotelian thought, x-xv passim, 1, 4-7, 11-29 passim, 32-3, 50-1, 61-4,67, 80-92 passim, 97, 113, 132-9 passim, 147-8, 156-7, 163-5, 173, 186, 196-8, 201 StThomas's differences with, 26 astronomy, 25, 146-7 atheism, 2-3, 105, 157--8, 202 Augustine and Augustinian thought, xv, 6, 13-17, 117 Austin, J. L., xiii authority human and divine, 5-7 modern attitiude to, 7-12 see also argument from authority Averroes, 65, 84 axioms, scientific, 23, 25 Ayer, A. J., xvi barking of dogs, 135, 137-9, 147 Begriffswort see nomen naturae Big Bang, 104, 125, 127, 158-9, 168 Blake, William, 181 Boethius, 7, 16, 157

'bottom-up' reasoning, 102 Bradlaugh, Charles, 99 Broadie, Alexander, xviii, xix causal reasoning, 192, 19 5 causality modes of see explanation voluntary and non-voluntary, 195--6 see also efficient causality; final causality; formal causality; material causality; per accidens; 'transcendental causality' cause and effect, links between, 20-1, 81-2, 85-93, 97--8, 102-5; see also efficient causality change, process and initiation of, 133-46, 150 children, upbringing of, 8-9 classical theism, 111-16 passim, 121, 125, 202 coincidental existence see per accidens Collingwood, R. G., x, xii concept-words see nomen naturae concertina-like universe, 158-9 conditiones, 91 contingency, 20-1, 28-9, 156 convertibles, 91 Copleston, F. C., 118--19 cosmology, 157--8 creation see God's creation creationism, 26-7 Darwin, Charles, and Darwinism, 165, 180-1 Davies, B., 116-18 deductive nature of science, 33-4 defeasibility, 192 definitions of things, 24-5, 38-9, 92-3 demonstration, 82-4, 87-91, 100, 110 'demonstration why' and demonstration that', 102 derivative necessity, 155, 160, 165-7 Descartes, Rene, 8, 65, 69-70, 84, 100 design, argument from see argument from design 'determinations', 3 dialectics, 32 divine science, xv, I, 19, 101-2 doctors' jargon, 188-91

210 Duns Scotus, Johannes, xvi, 157 'E!-predicables', 70 eclipses, 22-3, 34 ecology, 184, 201 efficient causality, 21-2,91, 104---5, 140, 146-53,177, 180-92passim, 196,199 elliptical language, 68-9 empiricism, xvi-xvii, 13, 118, 189-91 end-directedness, 180, 183; see also teleology ens see existence Epicureans, 2-3 episteme, 1, 21 Esgibtexistenz, 66-7 esse ut verum, xix, 56, 65-73 passim, 105, 111, 113 essence, concept of, xvi, 24---5, 69, 91 essentialism, 47 ethics, 27 everlastingness of the world, 163-8 passim evil, argument from see argument from evil existence actuality and potentiality of, 51---4, 60 degrees of, 173---4 questions of, 37---46 passim, 50-7, 61-2, 80-5, 93, 105 see also esse ut verum; God; per accidens; 'real existence' existentialism, 56-7, 118 experimental science, 28 explanation, modes of, 147-9, 182 explanation of the world, xiii, 85, 119-26, 197-200 one bit at a time, 120---4 explanations, knowledge through, 1, 21-2, 32, 147-8 explanatoriness, 19 5 extreme modal realism, 26 faggots, 148 faith, 16, 100-1 articles of, 100, 102 'fictus', 71 fideism, 100 Fifth VVay,the, 104,148,150-1,179-204 final causality, 147-51, 177, 181-7 passim, 191, 196-9 passim finis, 149 first principles see axioms First VVay, the, 126, 132-52passim, 155, 175 five Inuit, the, argument of see Inuit on a Glasgow street corner Five VVays to prove God's existence, xv, 39, 81, 85, 88-9, 100, 104, 112, 116-20, 125-9, 149, 163, 168, 203---4; see also First VVay; Second VVay; Third VVay; Fourth VVay; Fifth VVay flourishing, human, 201-2 folk-wisdom, 18

God and Explanations formal causality, 147-8., 165, 177 'formal object' of scientific study, 27-8 foundationalism, 12 Fourth VVay, the, 112, 126, 149, 171-7 Frederick II Hohenstaufen, Emperor, 3 'free-will defence', 112 Frege, G., 28, 37, 43-5, 65-7, 73 fundamental science, 23 Gaia, 184, 201 Geach, P. T., xiii, xix, 12, 38, 40, 56, 66-7, 69, 112,115,126,136,161,166,171,174, 182, 184, 192 geometry, Euclidean, 17-19,23,25 'goatstag', the, 38, 43-6 passim, 83-5 God existence of, xv, 1-2, 34, 37, 40, 45, 47, 54, 58,65-70,73,81-5,89-93,97-101, 106, 110-22, 128, 140-1, 157, 168, 181-2, 203---4 existence of an idea of, 176 names of, 46-7, 103-6 philosophical study of, xv, 20 I signification of the word, 97-8, 104---5, Ill, 128, 153 God's creation, 112, 143, 158, 165, 168 God's goodness, 114---16 God's mind, 174, 182, 202 God's transcendence, 114---15, 117 Gods, multiplicity of, 126 Great Architect, the, 181---4 Grosseteste, Robert, 168 harmonisation oflife and thought, 15-16 Heraclitus, 138, 196, 198 Hillel, Rabbi, 10 history of philosophy, viii-xiv history of philosophy of science, 186 Hobbes, Thomas, 182 Hume, David, 137, 181, 190,200 hypotheses, 88, 93 indentation of text, 134, 151, 172 Index Thomisticus, 180 inscrutability, 115-17 instantiation by argument, 161-2 interpretation of authorities, 5-6 intuition, appeal to, 20 I Inuit on a Glasgow street corner, 121-5, 127-8, 142, 167, 176-7, 197 Isidore of Seville, 40, 47, 91 jokes in philosophy, 188-9 journals, philosophical and scientific, 12 Kahn, Charles H., 57 Kant, Immanuel, 30, 65 Kenny, A., xiii, 53---4, 67, 69, 113, 132, 136, 146, 149, 164, 166, 171, 174, 191

211

Index knowledge as distinct from true belief, 21 theory of acquisition of see science: modern theory of Kripke, S. A., 37-8,40--1,45, 47 Lavoisier, A. L., 86, llO Leibniz, G. W. F. von, !55 Leo, St, 17 lintels and thresholds, 148-9 Llano, Alejandro, xix Locke, John, 190 logic, science of, ix, xi, 19 'Lottery in Babylon', 197-8 'lumping-together' move, 126-7, 135, 139-42, 152-3, 183, 199-200 McCabe,]. M., 42, 45 Macintyre, Alasdair, xii-xiii, xix, 30 marriage of priests, I 0--11 material causality, 147-8, 164-6, 177 matter, 164, 166 medieval philosophy and logic, ix-xii, xv, 3-5, 17,71-2, 151 medium demonstrationis, 85, 87 Meikle, Scott, xix Meno, the, 21 metaphysics, 117-18 meteorology, 25 Michelangelo, 52 'missing mass', the, !59 modal logic, 156-7, 163 modernism, 12-13 Moliere, 188-9, 191 Moore, G. E., xvi moral norms, 99-100 moral philosophy, 28, 201 Moses, 99 'moveri', meaning of, 132-3 mules, 26, 165 Muslim belief, 2 names, signification of, 35-46 passim, 83-90, 103-4, 110; see also God; nomen naturae natural science, 89 natural theology, 180--1, 202 Nature (journal), 12 necessary truths, 20, 25, 27, 29, 82, 89, 156 neo-Pythagoreans, 186 Newton, Isaac, 180 'nice girls and the sailor' fallacy, 161-2; see also quantifier-shift fallacy Nicomachean Ethics, 197 nomen naturae, 38-9, 44 nought (number), 66-7 numbers, doctrine of, 66-7, 73 Nussbaum, Martha, xii Ockham, William of, xvi

Ockham's razor, 118 opium, 53-4, 188-91 oppositiones, ix, xi ordination of women, 10

Oxford Companion to Philosophy, xii Oxford English Dictionary, 24 Paley's watch, 180--1, 184 parents, learning from, 9 partial explanation see argument from partial explanation Paul, St, 100 per accidens and per se, 28, 51, 58, 62-5, 91-2, 103,112-13, 117-121,173,187 philosophy different approaches to, vii-xiv, 4, 203-4 of science and of religion, xv see also analytical philosophy; history of philosophy; medieval philosophy; moral philosophy phlogiston, 82-3, 86, 92, llO 1t, value of, 6 place, concept of, 83, 86, 88, 90, 110 Plato and Platonism, x, 11-12, 16, 21, 67, 73, 149, 173, 191 Plenitude, Principle of, 26, 156-7, 163 'possiblity', concept of, 160--3 Posterior Analytics, 17-19 Posterior Analytics, Commentary on, 19, 38, 43, 80, 86, 88 powers, notion of, 190-1 practical reasoning, 192, 19 5 predication, 44, 58-62, 70 Prior, A. N., 70, 162 'proportionate' effects, 90-1, 103 propter quid? questions, 33, 102 Pseudo-Dionysius the Areopagite, 175 Pythagoreans, 13, 186

quaestio-form, 3, llO quantifier-shift fallacy, 161-2, 166 quarks, 82 questions asking and answering of, 32-3, 37, 82-3, 87-8 informative and uninformative answers to, 188-91 of fact and of explanation, 33 types of, 33-4 quia? questions, 33, 86-8, 102 quid est? questions, 33, 35, 103 Quine, W. V. 0., 12-13,28,62, 173 rainbows, existence of, 23, 34 rationalism, 13, ll9 rationes, 43-6 'real existence', 56, 58, 66 reasonableness, standards of, 8-13 reductio ad absurdum, 84

212 reductionism, 118 Reid, Thomas, 181,200 religion, traditional nature of, I 0-11 repetitive strain injury, 188 rhetoric, xvi, 190 ridicule of philosophical ideas, xvi-xvii, 26, 186--8 Russell, Bertrand, xvi, 4, 64, 118--19, 122, 187 'sulks' of, 119 Ryle, G., xiii sacred science see divine science science argument from see argument from partial explanation Aristotelian and Thomistic concepts of, 1-2, 15-29 passim, 32-3, 89, 147--8, 203--4 modern theory of, 80-3,88,91-3,97, 203--4 see also a priori science; deductive nature of science; divine science; experimental science; fundamental science; natural science Scotus see Duns Scotus Scripture, inspiration of, 114 second law of thermodynamics, 165 Second Way, the, 104, 140, 146--53, !55, 183, 185--6 self-imrovement, ix-x self-movers, 135, 137, 139 Sicily, 149 significatio nominis see names, signification of Socrates, 21, 187 soul and body, 139 sound, variable existence of, 174 steady state theory, 158 Summa Contra Gentes, 2, 127, 132, 135, 137, 142-3, 157 Summa Theologiae, 1-2, 5, 12-13, 15, 17, 19, 28, 34, 40, 65, 69, 86, 97, 101, 110, 125, 127 superstrings, 82 synthesis of all human wisdom, 15-17

God and Explanations tautology, 189-90 teleology, conscious and unconscious, 180--4, 197-201 tendency, 192-9 passim paradigmatic and non-paradigmatic fulfilment of, 193--6 tenses, logic of, 162 'tetragonismus', 83--4 theism see classical theism Third Way, the, 125, 127, 149, 174--5 Tichborne claimant, 44--5 top-down reasoning, 101-2; see also deductive nature of science tradition, 9-10, 99 in religion, 98 in the scientific community, 12 transcendence see God's transcendence 'transcendental causality', 149 transcendentalism, 54 transcendentals, doctrine of, 172-5 trench fever, 188 trust in reason and in authority, 9-12 trustworthiness of authorities, 98 truth eternal or universal, xi, 20, 25, 82, 88, !56 of religion and of reason, 17 ofthings, 173 relationship between different types of, 18-19,32 see also necessary truths ultimate good, 201 'universalisability' of moral judgements, 28 University of Paris, 16 Urizen, 181 veridical usage, 55-8 vicious circles and vicious infinite regress, 167 Victorian optimism, 120 Waterloo, Battle of, 187 wishful thinking, 98-9, 202-3 Wittgenstein, Ludwig, xi, xvi Zeno, 139