Plato's Theory of Knowledge

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Norman Gulley Plato's Theory 0 Kn01vledge

Plato's

Theory of Knowledge BY

NORMAN GULLEY ~

Setlior Lecturer in Classics and Ancient Philosophy jtt the University of Bristol

LONDON: METHUEN & CO LTD NEW YORK: BARNES & NOBLE INC

Plato's Theory of Knowledge

Printed in Great Britain

Contents page

PREFACE I

THE THEORY OF RECOLLECTION

Socratic Doctrine in the Early Dialogues 2 The Mello 3 The Phaedo I

II

THE CRITICISM OF PERCEPTION

Introduction 2 The Symposium 3 The Republic 4 The Cratylus 5 The Theaetetns

I

4 23 48

53

67 76 108

KNOWLEDGE AND BELIEF

Recollection and the New Method of Dialectic 2 The Evaluation of Perception in Plato's Later Theory 3 Knowledge and Belief in the Timaeus 4 The Sophist's Account of Statement and Belief I

IV

I

48 49

I

III

Vll

MATHEMATICAL KNOWLEDGE

Mathematics in the Natural Sciences 2 Mathematics and the Forms 3 The Objects of Mathematical Knowledge 4 Conclusion I

108 120

139 148 169 169 172 177

186

NOTES

188

INDEX

201

v

Preface In this book I have tried to give a systematic accotmt of the development of Plato's theory ofknowledge. So far as I am aware, no previous book in English has tried to do this. There have been books on Plato's theory of Forms and on his method of dialectic which have contributed much to the understanding of his theory of knowledge. But it has not been their concern to deal comprehensively with that theory. They have discussed only those aspects ofit directly relevant to their subject. I hope that the comprehensive examination attempted by this book will do something towards filling the gaps and that it will help at the same time to a clearer understanding of the originality and variety of Plato' s contributions to the theory of knowledge. The plan of the book is a straightforward one. It begins with a consideration of Socratic and other influences which determined the form in which the problem of knowledge first presented itself to Plato. It then works through the dialogues from the Meno to the Laws and examines in detail Plato's progressive attempts to solve the problem. The order in which the dialogues are examined is, with one exception, the same as that which I assume to be the probable order in which they were written, i.e. Meno, Phaedo, Symposium, Republic, Gratylus, Theaetetus, Phaedrus, Timaetls, Sophist, Politicus, Philebus, Laws. The exception is the Politicus. This dialogue is certainly later than the Sophist. But it best suited my exposition to examine the relevant passages in it in conjunction with my examination of certain aspects of the doctrine of the Phaedrus and the Timaeus. If Symposium, Gratylus, Phaedrus, and Timaeus were taken out of my list I assume that there would be little, if any, disagreement between scholars about the order I have given (the views of leading students of the subject are summarised in the first chapter of Sir David Ross's Plato's Theory of Ideas). Something must be said briefly about my placing of the remaining four dialogues. It would be agreed that the Symposium belongs to the middle period of Plato's thought, which is vu

Vlll

PREFACE

specifiable roughly as the period between his first visit to Sicily (389388 D.C.) and his second (367-366 D.C.), and that it is later than the Meno and earlier than the Republic. The only problem which remains is, therefore, whether it precedes or follows the Phaedo. And this problem seems to me to be of little importance in considering the development of Plato's theory of knowledge. My main reason for putting the Phaedo first is that the manner of its introduction of the theory of Forms as an important new feature in the development of the theory of recollection suggests t4at the theory of Forms is being introduced here for the first time. In the Symposium the transcendence of the Form of Beauty is assumed without any suggestion that this is a new assumption or one which demands explanation. The place I have given to the other three dialogues has been determined largely by my views about the development of Plato's theory. Thus my main considerations in each case have been either the dialogue's close affInities in doctrine with a dialogue which can firmly be allotted to a certain period of Plato's thought, or some marked advance in its doctrine which indicates that it is later than such a dialogue. The result is that I take the Cratylus to belong to much the same period of composition as the Theaetetus, the Phaedrus to be later than the Theaetetus, and the Timaeus to be later than the Theaetetus and the Phaedrus but earlier than the Philebus. I am well aware of the hazards of using for this purpose a criterion based on a personal interpretation of the development of Plato's theory. I hope that the arguments I have put forward in support of my interpretation will show that I have been sufficiently cautious in my use of it. I am grateful to Professor W. Beare for his generous help in reading the proofs of this book. I am grateful also to Miss Elizabeth Oatley for her preparation of the typescript. Finally I would like to thank the publishers for the good advice which they gave me with regard to the presentation of my arguments. By persuading me to make my paragraphs much shorter and to introduce sub-headings within each chapter they have considerably eased the task of the reader. For faults of any kind which remain I alone must be blamed. N. G. Bristol October 1961

CHAPTER I

The Theory of Recollection 1. SOCRATIC DOCTRINE IN THE EARLY DIALOGUES

In Plato's early dialogues one of the most characteristic and at the same time most significant features of Socrates' inquiries is the attention which they give to general defmitions. In the Laches, the Charm ides, the Ettthyphro, and the Hippias Major the aim of the discussion is to reach, using a question-and-answer method, the deftnition of a familiar moral or aesthetic concept. Aristotle was right to emphasise that this ftxing of attention on defmitions was an important Socratic influence in the shaping of Plato's theory of Forms (Metaphysics 987bI-7, I078bI7-3I). But in addition to pointing the way to a theory of the nature of the objects of knowledge, Socrates' concern with defmitions raised questions in epistemology which occupied Plato's attention before he first explicitly formulated his theory of Forms. It is these questions which must first be considered. They arose from the association of the Socratic search for deftnitions with (i) a thesis that virtue was knowledge; (ii) the advocacy of a particular method of cross-examination as the best means of attaining knowledge. (i) The thesis that virtue is knowledge is the thesis not merely that to be good it is necessary to know what is good, but that to know what is good is necessarily to do what is good, or at least that to know what is good and yet to do what is bad is to act involuntarily. Associated with this thesis is the thesis that nobody voltmtarily does what is bad. This embraces cases where the agent merely thinks or believes that something is good, without having knowledge of what is good. Subjectively, everyone does what he supposes, according to his own lights, to be good. It is 'not in human nature' to do otherwise (Protagoras 358d). 'Those who are ignorant of what is bad do not desire what is bad, but only what they think to be good, though in fact it is bad; so that those who are ignorant of it and think it good are clearly desiring the good' (Meno 77d-e). Thus the thesis that nobody voluntarily does I

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what is bad is, strictly, the thesis that nobody does what he either thinks or knows to be bad. If what he does is in fact bad, then he is acting in ignorance of what is good, and he is morally responsible, it is assumed, for what he does in that it is ill his power to rid himself of this ignorance. Now these Socratic doctrines may be viewed, initially, simply as statements of what is implicit in the normal Greek view of 'good' (agathon). 'The good', as the most general end of human action, was invariably identified with 'happiness' (etldaimonia), so that 'to say that happiness is the chief good seems a platitude' (Aristotle, Ethica Nicomachea IO~nb). Thus the statement that nobody voluntarily does what he thinks or knows to be bad means that nobody voluntarily does what he thinks or knows to be conducive to his own misery (Meno 78a). The combination of this with what seemed to be the equally obvious truth that to be good it is necessary to know what is good is the basis of the Socratic thesis that virtue is knowledge. But the thesis is more than an emphatic restatement of the utilitarian outlook implicit in the use of Greek ethical terms. It assumes further an ideal of determining what is good by a systematic method of inquiry which is directed principally to the definition of the commonly accepted 'virtues'. This method, it is assumed, will yield knowledge of what is good/as opposed to the many and various opinions as to what is good. Using again a deliberately paradoxical form as a means of emphasising his tenets, Socrates states in the early dialogues that knowledge of what courage is, or of what temperance is, is fundamentally knowledge of what good itself is (Charmides 174a-c, Laches 199d). For in defining the particular virtues one is led to a conception of good as a single end which 'unifies' all the virtues, in the sense that it is common to each of them that full knowledge of it implies knowledge of what good is. Thus good itself is assumed to be definable. The additional testimony of Xenophon and Aristotle confirms that Socrates' ideal of knowledge was closely associated with his search for definitions. 1 Aristotle admirably summarises this ideal when he says that Socrates believed that knowledge of virtue was the end, and inquired what justice is and what courage is, and so with each of the parts of virtue. And he did this with good reason. For he thought that all the virtues were forms of knowledge, so that to know what was just was at the same time to be just. For to have learnt geometry and house-building

THE THEORY OF RECOLLECTION

3

is at the same time to be a geometer and a housebuilder. That is why Socrates inquired what virtue is, and not how and from what conditions it comes into being (Ethica Eudemia 1216b3-IO). The Socratic ideal of morality is, then, an :intellectualist' ideal. It is, principally, an ideal of knowledge through definition, and, moreover, through real defmition. For in seeking to defme the 'virtues' or virtue itself Socrates is seeking to formulate a moral ideal. And it is ill emphasising that real definitions are the object of the discussions of the early dialogues that Plato begins to use the terminology later used for the metaphysical theory of Forms. Thus the attempt to defme piety is represented as an attempt to define a single 'form' (eidos) possessed by all particular instances which are properly described as pious (Euthyphro sd, 6d-e). It is assumed that there are certain general characteristics which constitute the real nature or 'essence' (ousia) of this 'form'; these are its defming characteristics, and are to be distinguished from merely accidental characteristics (Euthyphro IIa). The implication is that the term piety designates a real thing, a 'form', which is the dejiniendum. Thus the knowledge sought by Socrates when he said that virtue was knowledge is described by Plato as a knowledge of 'forms', in this sense. (ii) How, then, is this knowledge to be attained? The Socratic answer would seem to be that it is attained by a question-and-answer method of discussion, seeking a definition which can be considered adequate if it is accepted as correct by the interlocutors. No firmer criterion than this is suggested in the early dialogues. The rules of the Socratic method, as there presented, indicate that its aim is to promote consistency of opinion between the speakers. The rules are that there should be no disagreement between questioner and answerer, and that any opinion expressed should not conflict, either itself or in its consequences, with any other opinion which is held just as strongly. 2 What is Plato's attitude towards this method? The difficulty in answering this is the difficulty of deciding where, in the early dialogues, Socratic portraiture ends and Platonic interpretation begins. There are several features of the discussions of the early dialogues which suggest that the method practised is recognised to be very limited as a means of gaining knowledge. The discussions are inconclusive, and Socrates is represented as despairing of ever reaching any definite truth. He would like to have the arguments 'immovably settled' (Euthyphro lId), but all propositions

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PLATO'S THEORY OF KNOWLEDGE

seem to be shifting and transitory. They all seem to have in them ambiguities and inconsistencies, so that they 'run away' from any systematic attemptto substantiate their truth (Ettthyphro 7b-d, IIb-e). Added to this is an insistence on the ignorance of Socrates. The resultant picture is of a Socrates who himself disclaims knowledge, and habitually shows a lack of confidence in realising it in the minds of others by his method of cross-examination. All that he claims to be able to do is to show others that they are ignorant. Only in the middle dialogues, after the introduction of the theory of recollection, does Plato venture to present Socrates as an intellectual midwife, bringing to birth positive truths in the minds of others (Theaetetus I50b-d). Now since the testimony about Socrates of writers other than Plato contains practically nothing which suggests that Socrates habitually professed ignorance and scepticism, 3 it seems reasonable to conclude that Plato had more serious purposes in introducing these traits than the desire to preserve a realistic portrait, and that, if not invented by him, they are given very special emphasis by him as an indication of his own attitude towards the Socratic method. Thus Plato's insistence on these traits is an insistence on the limitations of the method, and may reasonably be taken to imply an appeal to the need of a constructive theory of knowledge which will provide a more adequate criterion of truth than that upon which the Socratic method relies. It is some confirmation of this view that when, in the Meno, Plato introduces such a theory and thus reaches a position which the evidence of Xenophon and Aristotle sufficiently shows to be an advance in doctrine beyond the position reached by Socrates, he introduces it as a solution of the difficulties inherent in the Socratic method as a means of attaining knowledge. The Meno makes clear, in fact, that the form in which the problem of knowledge first presented itself to plato was determined by his reflections on the limitations of the Socratic method.

2. THE MENO

a] I11troductiol1 of the theory of recollection The Meno marks a trallSition from the thought of the early dialogues, which are largely designed to present and to evaluate the teaching of Socrates, to a much more constructive and theoretical level. Plato is

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5

now putting forward his own positive theory, as an answer to problems implicit in the discussions of the early dialogues. As yet he is not ready to put forward a metaphysical theory; he does this for the first time when he introduces the theory of Forms in the Phaedo, which is later than the Merlo. 4 The problem of the Mello is primarily the problem of whether knowledge is possible at all, and not the problem of specifying the nature of the objects of knowledge. The dialogue begins as an attempt to define virtue. Its first part follows much the same course as those earlier dialogues which aim to define a general term, though it is noticeable that Plato indicates what he considers to be the principles of general defmition more clearly, and with more effective and varied illustration, than had been the case in the earlier dialogues. It is to be noted too that, after explaining that what he seeks to determine is 'the one identical form which all virtues have, whereby they are virtues, and to which it is well for the answerer to look in revealing to the questioner what virtue really is' (72c-d), Plato points out that this principle of distinguishing between a single common 'form', as the dejiniendmn, and the many particulars characterised by it applies to everything- (74b), i.e. to all cases where 'many things are called by a single name' (74d). As for the definitions of virtue put forward in the discussion, each of these is shown to be inadequate, either as failing to satisfy one or other of the principles of defmition, or as involving a contradiction. Meno, whom Socrates is questioning, finally confesses that he is utterly perplexed, and becomes sceptical about the possibility of any defmite conclusion. He doubts whether any criterion of truth exists. If, he says, you do not know what a thing is at the beginning of an inquiry, how are you to decide which is the one you are looking for? (8od). How are you to distinguish a true solution from one which is untrue but plausible?5 To meet Meno's argument the theory is now put forwar~ that the process of gaining knowledge in this life is a process of recollecting what the soul knew prior to this life. Thus it is a theory that knowledge is a priori in the sense that its source is independent of the experience of this life. The idea of recollection is first introduced in terms of Orphic and Pythagorean religious beliefs. plato then presents his own theory in the course of a dialogue in which Socrates leads a slave to the 50lution of a geometrical problem; this dialogue is meant to provide at the same time a practical demonstration of the truth of the theory.

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b1The religious background of the theory The first thing to consider is the general background of the theory. The principal ideas which it contains are that it is the soul which has knowledge, that the soul existed prior to incarnation, and that the source of knowledge is independent of present incarnate experience. So far we have seen that an important Socratic influence on Plato's thought was that it led him to consider the problem of knowledge, and especially of knowled&e through definition, as the fundamep.tal problem in ethics, and at the same time to reflect on the adequacy of the Socratic metnod as a means of attaining knowledge. 'This is the context within which Plato's adoption of a theory of 'transcendent' knowledge must be considered. Convinced as he was that permanent knowledge was attainable, and yet finding in practice that the Socratic method ofinquiry wast unable to yield it, he was perhaps already predisposed to welcome ideas which suggested that the source of knowledge was to be looked for beyond the experience of this life. Amongst these ideas may be counted the Socratic doctrine of the 'caring of the soul' which, in its association with the thesis that virtue was knowledge, identified the soul with man's moral and rational self'. 6 In associating with the soul the intellectual activity which yields knowledge, and making this activity the soul's proper function, Plato is clearly influenced by this Socratic doctrine. And this doctrine, in its turn, reflects in part earlier religious ideas about the soul. It is the influence of these ideas which Plato explicidy acknowledges in introducing his theory of recollection, and it is important to examine them in some detail. This is Plato's description of them in Men 0 8 la-e. They are said to be the views of C

I

those among priests and priestesses whose care it has been to give a rational account of their practices. There is Pindar too, and among poets who are divinely inspired there are many others. As for what they say, it is as follows; consider carefully whether you think they are speaking the truth. They say that the soul of man is immortal, and that at one time it comes to an end (which is what they call dying), and at another is born again, but is never destroyed. That is why it is necessary, they say, to live one's whole life as righteously as possible. Since then the soul is immortal and has been born many times, and has seen both things here on earth and things in Hades, everything in

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7

fact, there is nothing which it has not learned. It is llot surprising therefore that it can recollect all that it kllew previously, both about virtue and about everything else. For since the whole of nature is ~, and the soul has learned all things, there is nothing to prevent a man who has recollected one single thing - this is what men call learning - from discovering everything else, if he pursues this search with courage and does not weary of it. For it seems that research and learning are entirely recollection. J We may take this passage to be an expression of Plato' s indebtedness to religious ideas for such foreshadowings of his own theory as can be found in them. The reference to 'priests and priestesses' is almost certainly to the Orphics. 7 We know from other explicit references in PlatoS that a body of literature associated with the name of Orpheus existed in Plato's time, and that the Orphics held (i) that the soul, in its life on earth, was imprisoned in the body as a punishment, and (ii) that in rites of initiation and purification lay its hope of avoiding further pUllishments in Hades and of achieving blessedness. From references in later authors and from inscriptions9 it becomes clear that the Orphics believed too in transmigration, and that their ultimate ideal was the eternal release of the soul from imprisonment in the body. Similar religious beliefS are attributed to Pythagoras and his school, and it is probable that some kind of sacred literature akin to that of the Orphics existed within the schoo1. 10 It is within the Pythagorean school, with its philosophical as well as religious interests, that a more systematic development of these religious ideas may reasonably be looked for. There is, unfortunately, very little evidencel l to show how far the Pythagoreans developed the ideal of the 'purification' of the soul beyond a purely formal and ritualistic one by associating it with their more specifically philosophical and scientific studies. It is reasonable, however, to assume some initial connexion between the religious and scientific ideals, however much the two tended to separate later; both Burnet and Cornford12 considered the evidence enough to show that the ideal of purification was developed by adding 'the practice of catharsis by science' and 'the purification of the soul by theoria, the contemplation of the divine order of the world'. The spread of these religious ideas from the sixth century onwards seems to have been specially marked in Attica, and in Southern Italy

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and Sicily. Plato himself, reflecting on the implications of Socrates' teaching, and possibly only recently having gained a closer and fuller acquaintance with these religious ideas during his visit to Italy and Sicily in 387 B.C., welcomed them readily, since he saw that they provided the foundation of a theory of the nature of soul to set against the materialistic interpretation of mind and soul characteristic of much pre-Socratic philosophy. The general assumption of pre-Socratic philosophy had been that the soul and mind were of material composition, and that their functions were to be explained in material terms. The functions of the human soul were considered to be all those belonging to consciousness, especially sensible perception and feeling; some philosophers, e.g. Heraclitus, ascribed also to the soul intellectual activity, but the general tendency was to distinguish between soul (as 'consciousness' or simply as 'life') and mind, while at the same time making correctness or acumen of thought dependent on the 'mixture' or 'harmony' of the elements of which the soul was composed. Hence Aristotle's frequent, though unfair, criticism of the pre-Socratics that they virtually equated soul and mind, or perception and knowledge, by treating both as types of physical interaction (e.g. De Anima 404a27 f£; Metaphysics r009a22 f£). This type of philosophy would appear to be irreconcilable with the Orphic-Pythagorean ideas we have discussed; yet the mixture of religious and scientific thought in Empedocles and within the Pythagorean school suggests perhaps that awareness of the inconsistencies was not always felt. ls To Plato, however, the implications of the two ways of thought were such that they represented alternatives fundamentally opposed to one another. It is significant that in the Phaedo, where he puts forward his own conception of soul in declared opposition to the earlier materialistic interpretations, the influence of the religious tradition of thought is most clearly marked. And here in the Meno their influence is acknowledged, and a readiness is expressed to put trust in their truth in conducting the inquiry into the nature of virtue (8re). In precisely the same way, in the Gorgias, after the myth about the judgement of the souls of the dead, Plato expresses his readiness to put trust in its truth (S24br). That his conviction that the soul was immortal included also a belief in re-incarnation is clear from the familiar passage at the end of the myth in the Phaedo (II4d), a myth including the doctrine of re-incarnation. H As an influence of a more particular kind, Plato suggests now in the

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passage of the Mello translated above that these ideas embody a rudimentary theory of recollected lmowledge. Though it is clearly wrong to look here for Plato's own formulation of the theory, it is important to consider what are the earlier forms of the theory to which Plato alludes. Plato introduces the idea that the soul call recollect its knowledge 'of virtue and everything else' as derivative from the theory that the soul is immortal, alternating in its existence between states of 'life' on earth and of 'death' in the other world; 15 for the latter theory is taken to imply that in the course of its numerous 'lives' and 'deaths' the soul has learned everything (SIcj. The idea of the possibility of such recollection from previous existence is, as Burnet says,16 an easy step from the doctrine of Rebirth. For this doctrine quite naturally gave rise to the idea of awareness of the continuity of the soul's existence, and, further, to the envisaging of men of exceptional knowledge who had retained in memory all that they had experienced in a succession of existences. Empedocles refers to such an exceptional person (Pythagoras is probably meant), and claims to remember his own previous existences;17 and Pythagoras himself is said to have claimed that he retained the memory of his previous re-incarnations. 1S plato does little more than repeat these ideas in the present passage. The idea that 'all nature is akin' (sId) - introduced to explain further how everything can be recalled from the remembrance of a single thing - is again dependent on previous theory; it reflects the view ascribed to the followers of Pythagoras and Empedocles that the one spirit which pervades, like a soul, the whole universe, establishes a communion between Gods, men, and animals. 19 plato may well have in mind too the much more profound Pythagorean conception of the Harmony which so orders the elements of the world that they form a systematic unity, thus enabling the mind, through number, to know all things in their universal 'communion' with one another.20 But for the moment he is concerned only with the presentation of more specifically religious ideas, and it is the former view to which he is presumably referring. These then are the antecedents of Plato' s own theory of recollection. But it is easy to over-rate his indebtedness in this particular respect. Though it is possibly true that the Pythagoreans linked their religious and scientific ideals in a very general way, there is no evidence to show that earlier thinkers had formulated anything which can be called a philosophical theory of recollection, and certainly none to support B

f!i)

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Burnet 21 and Taylor22 in their view that the idea of remembering previous existences was developed by the Pythagoreans into a theory of the recollection, through the suggestions of sensible objects, of a transcendent mathematical reality. It is precisely the distinctive character of Plato's theory that he uses it to show how we come to a knowledge of a transcendent reality. On the other side, it is important not to assume that this distinctively Platonic theory was not yet envisaged by plato at the time of the Meno. Several scholars, whose views will be examined later, have been at pains to use the language of the passage we have been discussing to support a purely empirical interpretation of the theory of recollection of the Meno. Others, while recognising the religious tone and form of the passage, and thus avoiding the mistake of constructing from it any precise philosophical theory. have been content to dismiss recollection, as presented in the Meno, as being for Plato at this time a simple religious belief, lacking the rationale given to it later by the theory of Forms. Thus Frutiger 23 contrasts the 'mythical exposition' of the Meno (the whole section on recollection, from 80d-86c, is taken, without discrimination, to be 'mythical') with the 'dialectical exposition' of the Phaedo. The fundamental mistake of both these kinds of interpretation is that they fail to separate the introductory passage (8Ia-e) from what follows. What must be recognised is that in this introductory passage Plato is not presenting his own theory, but using religious ideas to introduce the idea of recollection as a possible description of 'what men call learning' (8Id), acknowledging at the same time his indebtedness to these ideas for such adumbrations of a theory of recollection as can be fOlmd in them. There is no conception within the circle of these ideas of differing levels or kinds of experience, but only the ideal of a progressive accumulation of personal experience at the same level and of the same sort. Thus 'recollection' (anamnesis) is simply the recalling, from the storehouse of personal memory, of the experiences of previous existences. It is certainly true that Plato here orders these ideas to suit his purpose of introducing the idea of recollection. And it is, I think, an exaggeration to say that the idea that everything can be recalled from the remembrance of one single thing is nothing more than 'mythical symbolism'.24 Plato is adding here his own suggestion of the possibility of recalling ideas in a continuous chain, the link at each successive point being the association in memory of two ideas. But the suggestion

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is made within the circle of religious ideas, and provides no reason for taking this introductory passage as a presentation of Plato's own theory.

c] Demonstration that knowledge is recollection The nature of his own theory is made clear in the course of a dialogue between Socrates and a slave-boy, which Plato presents immediately after the introductory passage. The aim of Socrates is to lead the slaveboy, prompted by his questions, to the correct solution of a geometrical problem. The problem is to discover the length of the side of a square which will have twice the area of a square with sides two feet long. The detail of the steps in the solution need not concern us. What is first to be noted is the general effectiveness of Plato's use of a particular geometrical problem as an illustration of the process of recollection. An ignorant slave is chosen for the purpose, as one who clearly has had no previous instruction in geometry. Further, a problem for solution is chosen which will strikingly illustrate the slave's initial disillusionment as he confidently gives the wrong answers. For the problem does not allow an exact arithmetical solution. The solution is that the length of the side of the required square is the length of the diagonal of the original square. And since the square root of 2 is incommensurable with I, the slave is always wrong in his attempts to give an exact arithmetical solution. 25 Yet the problem is, at the same time, one which lends itself so readily to the use of simple sensible diagrams that the slave is immediately made to realise at each point that he is wrong. The method which then leads him to a true solution of the problem combines the use of a sensible diagram with a series of leading questions which suggest most pointedly to him what the solution is. This may, perhaps, seem inconsistent with the profession that no instruction at all is being given (82e).26 Yet it does nothing to invalidate Plato's main point, which is that a previously untutored slave is able to recognise as indubitably true (or false) propositions brought to his notice for the first time. I As for the use of sensible diagrams, this is in accordance with the normal procedure of Greek geometers. 27 I doubt whether any special significance is to be attached to their use here. If Plato had meant in this way to suggest the value of sense-experience as an aid to recollection, it is surprising that no mention at all is made of sense-experience

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either in the dialogue with the slave or in the subsequent discussion of its significance. The emphasis is exclusively on systematic questioning as the means of eliciting truth (82eS; 84cII-d2; 8SC10, d3; 86a7);land when Plato does go on to consider the part played by sense-experience ill recollection, in the Phaedo, he introduces this aspect of the theory as something quite new, and different from what had been said in the Meno (Phaedo 73 b). , Plato's purpose then, in the dialogue with the slave, is to show that by a method of systematic questioning it is possible to elicit the recognition that certain propositions are indubitably true. And he argues that the fact that, without any previous instruction in geometry, the slave is able to recognise the truth of certain propositions in geometry implies that this 'truth' was a possession of the soul before the soul was incarnate in human form (8se-86a). It implies further that the truth is still 'in' the soul in this life (8sc, 86a); it is innate; otherwise there would be no possibility of eliciting it in this life. The final step is the argument that what is true of mathematics is true also of'all other branches oflearning' (8se). Thus Plato's claim is that all knowledge is a priori, in the sense that its source is independent of the experience of present incarnate experience. And if this is so, then the hope that the inquiry of the Meno into the nature of virtue will yield knowledge is justified and Meno's argument is met. I The direction of Plato's argument in this part of the Metto is an indication of one further important influence in the development of his theory of knowledge - the achievements of Greek mathematics. The Meno is the first dialogue to show a pronounced interest in mathematics. Not only is a geometrical problem chosen for the demonstration of the fact of a priori knowledge, but it is to a geometrical method of analysis that plato likens the method of hypothesis which he introduces as a method of philosophical analysis later in the dialogue (86e-87b).~ There is little evidence in dialogues earlier than the Meno of this interest in mathematics. 29 Possibly the important part played by mathematics in the Meno is a reflection of Plato's closer acquaintance with Pythagorean mathematics gained during his visit to Southern Italy and Sicily in 387 B.c.fHowever that may be, it is clear that by the time of the Meno Plato saw that in mathematics, the one field where any systematic and organised knowledge had been achieved, he had .found an example of the permanent and exact truth which he sought

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13

in ethics; and the argument of thdMel10 suggests that reflection on the nature of mathematical truth was perhaps the decisive factor in Plato's adoption of the theory of recollection as a general theory ofknowledge; already led by reflection on other problems and ideas to seek a 'transcendent' source of knowledge, the theory of recollection must have seemed to him perfectly fitted to be an explanation of mathematical knowledge} It is in this field that he attempts to demonstrate the truth of the theory, before arguing for its validity in 'other branches of learning' .'

d] Stages itt the process of recollectiolt One other feature of the theory which must be considered before its metaphysical implications are discussed is Plato's division of the process of recollection into three main stages. The first stage, illustrated in the first part of the dialogue with the slave (8Ie-84c), is the process of disillusionment, a negative stage which elicits the recognition that propositions which at first are believed to be true are in fact false.fThe significance of this is that by explicitly affirming that this process is the first stage in the process of recollection, and assuming that, if the questioning is systematically continued, knowledge will eventually be acquired, Plato makes quite clear that the theory of recollection is introduced as a foundation for the Socratic dialectiq With this basis the method can pass beyond the merely 'purgative' stage and lead to the discovery of truth. For if knowledge is recollected knowledge, then a criterion of truth above mere consistency and individual agreement is available to guide inquiry and save the discussion from inconclusiveness. What this necessary initial process of disillusionment does is to stimulate the search for truth by eliciting a confession of ignorance (84b~).

The second stage in the process of recollection is the recognition that certain propositions are true, but not as yet why they are true. This stage is illustrated in the second section of the dialogue with the slave (84c-8sb). The level of apprehension now reached is described as 'true belief' (8sc, 86a). The distinction made here between true belief and knowledge (8sc-d, 86a)\must not be confused with the distinction made later in the Republic (477-480), where the distinction between belief (doxa) and knowledge is said to imply a difference in kind between the objects of knowledge (identified with Forms) and the

14

PLATO'S THEORY OF KNOWLEDGE

objects of belief (identified with sensibles). \This latter sense of' belief' is a specialised sense which Plato continues to use in later dialogues side by side with the non-specialised sense which we find in the Metto~ The distinction between knowledge and belief in the specialised sense is primarily a distinction between a priori and empirical knowledge, the term doxa (belief) being adopted by Plato to describe the latter because of his decision to restrict the application of 'knowledge' to apriori levels of apprehension;' but the distinction between them in the Meuo, and later in the Theaetettts and Politicus, assumes the same kind of distinction as does modern English usage, tJ:lere being no implication of a difference in kind between the objects of belief and those of knowledge. Thus, in the Meno, to have 'true belief' is to believe, correctly, that something is the case, without being able to justify a claim to know that it is the case by giving 'good reasons' why it is the case. Towards/ the end of the dialogue, when Plato takes up again the question of the status of 'true belief', he illustrates the distinction by a distinction between a person who acts as guide to a place using his own experience of the route, and one who does so relying only on reports about the route which happen to be correct (97a-b). The former has knowledge, the latter true belief.30 The nature of the distinction is then explained in general terms which describe how true belief is convertible to knowledge. True belief, it is agreed, is unstable, since it is never able to meet criticism by an explanation of the grounds for its truth. To become knowledge it must be 'tied down' by 'a chain of causal reasoning' or by 'thinking outthe reason why' (97d-98a).31 The reference back (98a4-S) to the earlier distinction between true belief and knowledge in the dialogue with the slave shows that what is said here about the principle of distinction is true also for the earlier distinction. And plato emphasises during the dialogue with the slave that the conversion of true belief to knowledge is dependent on a process of repeated and systematic questioning (8sc-d, 86e). I How, then, precisely, does Plato envisage that the slave, who at the end of the dialogue with Socrates has attained only 'true belief', will attain knowledge? We may give greater precision to Plato's phrase 'a chain of causal reasoning' by associating it with a particular method of analysis, the aim of which is to find the antecedent conditions for the solution of a problem or for the truth of a proposition. There are good 'reasons for making this association. The method appears for the first

THE THEORY OF RECOLLECTION

IS

time in the Meno, and, moreover, is introduced immediately after the section on recollection (86e ff.). It is said to be a method practised by geometers, and the geometrical example given is of a diorismos, the determination of the conditions for the possibility of the solution of a problem. s2 More generally, Greek geometrical analysis was a method of assuming to be true a geometrical proposition which it was required to prove, or assuming a geometrical problem to be solved, and attempting, by analysis or 'resolution backwards', to reach a proposition known independently to be true, or a construction which it was possible to satisfy. lAnd it may fairly be assumed from all the evidence on geometrical method in Aristotle, in Proclus, and in the Greek commentaries on Aristotle, that it was primarily in relation to the ideal of reducing geometry to a system that the Greek geometers viewed the function of non-deductive analysis, S3 and that their formulation of the method, as it was known to Aristotle, reflected principally its function of systematising geometrical knowledge and co-ordinating results by leading propositions back to first principles - to axioms or definitions or something already demonstrated. In the light of this, it is significant that Plato, immediately after arguing from a demonstration of the a priori nature of mathematical knowledge to the a priori nature of knowledge in 'other branches of learning', should attempt to apply to an ethical problem a method of geometrical analysis. It suggests, not only that he envisages the possibility of applying the same exact method of analysis in ethics as was practised in geometry, but that it is in terms of this method that we should interpret the phrase 'a chain of causal reasoning' which is used later in the dialogue as a description of the method by which knowledge is to be attained. Thus the slave, who has acquired merely a number of 'true beliefs' in solving a particular geometrical problem, has still to grasp the proper connexion of the various steps in the solution; he has still, further, to grasp the significance of the solution as an instance of a general theorem, the theorem of Pythagoras; and, taking into account now Plato's great interest, in the Meno, in a method of geometrical analysis as a valuable method of explanation and demonstration, it is probable that Plato here has in mind also the ideal of continuing the analysis until those first principles are reached on which the truth of the theorem itself is based. \ Thus at the level of 'true belief' certain propositions are recognised

16

PLATO'S THEORY OF KNOWLEDGE

to be true, but as yet they are isolated truths in that they have not been .recognised as elements in a coherent system. Knowledge is the comprehension of a system, within which all the elements of the system find their explanation. Thus the status of 'true belief' in the MetlO is akin to the status granted to 'understanding' (dianoia) in the Republic (SIIc-e, S34a), a level of thought which Plato represents as especially characteristic of contemporary mathematics; like 'true belief' in the Metlo, it does not 'give an account' of its assumptions (SIOC, S33c), but is convertible to knowledge if it conErms its assumptions by showing them to be derivative from higher principles. There is a further point of similarity between the relationship of 'understanding' to knowledge in the Republic, and that of true belief to knowledge in the Metto. It is that in each case the difference between the two levels of apprehension is a difference in degree of comprehension, and not a difference based on a difference in kind between the objects apprehended. In the Meno both true belief and knowledge are gained by recollection, and there is nothing to suggest that they are concerned with different kinds of objects. Thus both true belief and knowledge represent a priori levels of apprehension.

e] The objects of true belief and knowledge What, then, is Plato's conception, in the Metto, of the objects of true belief and knowledge? On this important point the Meno gives no explicit guidance. The argument is not a metaphysical argument - it is not concerned to determine the nature of the reality which is known, but to demonstrate the possibility of acquiring knowledge at all. Caution is necessary, therefore, in attempting to draw inferences from the argument to Plato's metaphysical views at this time. One question which immediately arises is whether the metaphysical theory of Forms is here implied. The Meno makes no mention of the Forms in connexion with recollection. Plato does say at one point that 'the truth of things' is always in the soul (86b), and some scholars have taken this to be a certain reference to the Forms, comparing Phaedrus 247C and 249b for similar language in description of the world of Forms. 34 By itself, this argument from terminology is unconvincing. What has first to be considered - and this is clearly the central problem - is whether or not the theory of recollection, as presented in the Mmo, implies the conception of a transcendent world of reality, transcendent in the sense

THE THEORY OF RECOLLECTION

17

that it is the object of an experience of the soul different in kind from, and superior to, the experience of this life. If there is no such implication it would follow that the theory envisages 110 difference in kind between the experience - and the objects of experience - of the non-incarnate soul in a prior existence, and the experience of present life. One argument for the view that the theory does imply some conception of a transcendent reality is that the theory necessarily implies such a conception, since, without it, the theory leads to an infmite regress. 'If all our previous lives were 011 a level with the present, the problem of the origin of knowledge would not be solved, but only thrown back.' 35 This argument is much more obviously applicable to the Phaedo doctrine of recollection than to that of the Meno. In the Phaedo the fact that sensible things can remind us of Forms is said to be explicable only 011 the assumption that the Forms were known in a previous existence. It follows that in that previous existence the Forms were known independently of the suggestion of sensible things. Thus •the theory of anamnesis logically involves belief in transcendent Forms'.36 In the Metto theory, on the other hand, the Forms are not mentioned, and no attempt is made to draw a distinction between perceptual and conceptual levels of apprehension, the distinction on which the argument of the Phaedo is based. Yet there is, I think, in the MellO, a comparable distinction between levels of experience which will allow the argument from an infmite regress to be applied equally well to the doctrine there. It is important, in considering this distinction, to recognise as two separate and different presentations of the theory of recollection the presentation of it in terms of religious ideas (8Ia-d), and the presentation of it on the basis of the dialogue with the slave (8Ie-86c). As we have already seen, we do not have, in the first presentation of the theory, Plato's own ideas at all. The importance of recognising this is that it is on the language of this introductory presentation that scholars often base the view that in the Meno Plato makes no distinction between the experience of the soul in this life and its experience prior to this life. And the assumption of these scholars is that the second presentation of the theory presents fundamentally the same theory as the first and is, at the most, merely complementary to it.37 Now even apart from the initial improbability that Plato is using the dialogue with the slave simply as a demonstration of the truth of ideas which are in no way

18

PLATO'S THEORY OF KNOWLEDGE

distinctively his own, there are many serious difficulties in this assumption. In the first place the whole orientation of this demonstration and of the inferences drawn from it is different from that of the introductory passage. There (8Ia-d) the argument is that the possibility of recollec.tion can be deduced from the religious doctrines of the immortality of the soul and of re-incarnation. In the subsequent presentation (8Ie-86c) the direction of the argument is the opposite of this. It proceeds, from a demonstration of the fact that knowledge can be recollected (8sd), to deduce that the soul must, at the very least, have existed prior to its present life in the body (8sd-e). It reflects, in fact, the direction of the argument from recollection in the Phaedo where Plato discusses a further aspect of the doctrine. And the reason for the complete reversal of the direction of the argument in the second presentation of the doctrine of the Meno would appear to be that Plato is now presenting the doctrine in an entirely new form which is distinctively his own. The whole language of this presentation, and the introduction here of ideas which, as we have seen, point forward to the thought of later dialogues, suggest the same conclusion. Everything suggests, indeed, that Plato is using the dialogue with the slave for a purpose beyond that of illustrating the 'religious' conception of recollection - the idea that recollection is based on the accumulated experience of previous lives, experience no different in kind from that of present life. The choice of a mathematical problem is surely, too, very significant. Plato is singling out mathematical knowledge as a distinctive kind of knowledge. His point is that in this field propositions can be recognised to be true independently of all formal instruction in the subject, independendy, indeed, of the experience of this life altogether, except for the need of systematic questioning to elicit the recognition. And since, for Plato, the existence 'in' us, independently of the experience of this life, of this distinctive knowledge entails the pre-existence of the soul, the conclusion seems inescapable that he is explaining the a priori nature of mathematical knowledge by appealing to a distinctive type of apprehension, which was granted to the soul in a previous existence and is superior to the experience of this life. To be noted also is the distinction in 86b between the time when we were human beings and the time when we were not. As Taylor remarked,38 this 'way of speaking about our ante-natal condition as "the time when we were not yet men" is characteristic of the Phaedo', and implies a distinction between the

19

THE THEORY OF RECOLLECTION

embodied soul and the soul simpliciter. This again implies a distinction between two radically different kin.ds of experience. Thus the recollection theory of the Men.o, though not directly a metaphysical argument, does imply a transcendent reality as the object both of true belief and of knowledge. This does not, however, allow us to infer that at the time of the Meno Plato had already formulated a metaphysical doctrine of Forms. None of the metaphysical distinctions associated with that doctrine when it is explicitly presented in the Phaedo and later dialogues are to be found in the Metto. Thus no attempt is made in the Meno to distinguish the perceptual and conceptual elements in experience, or to contrast the instability and imperfection of sensibles with the flxity and permanence of a separate world of non-sensible objects. Nor, indeed, in the section on recollection, does Plato associate his theory of a priori knowledge with any of the logical distinctions which were made in the earlier part of the dialogue in the attempt to work out principles of definition. It may, of course, be argued that since Flato is arguing in the Meno from the possibility of attaining knowledge in mathematics to the possibility of attaining it in other 'branches of learning', among which he presumably includes ethics, and since, in particular, he wishes to show that it is possible, through recollection, to know the 'form' of virtue, then the recollected knowledge of a transcendent reality, if not exclusively knowledge of 'forms', includes knowledge 'forms'. Yet, if this is granted, it is difficult to argue further that this amounts to the assumption of a metaphysical doctrine of 'forms'. There is, as we have seen, no explicit association between recollection and 'forms', and no evidence in the dialogue that Plato had given any consideration to the question of the metaphysical status of 'forms', as contrasted with particulars. His primary concern is to show that knowledge is possible, and the important feature of his theory is that it appeals to a transcendent source of knowledge and implies a transcendent reality as the object of knowledge, transcendent in the sense that it is superior to and different in kind from the 'reality' which belongs to the objects of the incarnate experience of this life. But no attempt is made to analyse this latter experience or to specify the nature of its objects; in particular no attempt is made to associate it with specifically sensible experience. Such specification, together with specification of the objects of knowledge, comes with the theory of Forms.

or

,

20

PLATO S THEORY OF KNOWLEDGE

Before leaving the question of the metaphysical implications of Plato's theory of knowledge in the Meno, it is important to deal with a particular argument in favour of a purely empirical interpretation of the theory. As we have seen, the difference between true belief and knowledge in the Meuo is a difference in degree of comprehension, and not a difference in their objects. It is sometimes argued that this in itself is enough to show, not only that the metaphysical theory of Forms is not to be looked for in the Meno, but that no implication of a transcendent reality is to be looked for. Since the argument is that the theory of the Meno is inconsistent with the theory of Forms, it would appear to be assumed that the fact that the theory of Forms is the first explicit presentation in the dialogues of a theory of a transcendent reality entails that until Plato formulated this theory his theory of knowledge was a naive empirical theory substantially the same as that implied in the Orphic-Pythagorean religious ideas described in 8la-d. But this assumption is clearly groundless. There is no such entailment. Nor indeed is the argument valid against the view that the Meno implies the theory of Forms. It is argued39 that, if that was the case, then Plato would be assuming that belief, as well as knowledge, was directed to Forms, and thus would be contradicting a fundamental thesis of the theory of Forms, the thesis that there is an absolute distinction between knowledge and belief in that knowledge has Forms as objects, and belief sensibles. But it is not the case that, once the theory of Forms has been formulated, Plato consistendy uses 'belief' (doxa) with the implication that its objects are exclusively sensible objects. As has already been noted, such a use of 'belief' is a specialised one which is found in dialogues from the Republic onwards side by side with the nonspecialised use which we have in the Meno. Even in the Republic, where the distinction between knowledge and belief in the specialised sense is first clearly presented, 'true belief' is also used without any of the implications belonging to the specialised sense (413a; c£ 603a) ..~o It is, in any case, quite clear that a special application of 'belief' adopted by Plato when marking the distinction between sensibles and Forms has no necessary relevance to the interpretation of its meaning in a dialogue from which such a distinction is absent. The final step in this type of argument is (i) to assume that the apparent inconsistency in the view that the Meno appeals to a transcendent world of Forms implies that ·Plato's theory is as yet at the stage of a naive empiricism, and (ii) to use

THE THEORY OF RECOLLECTION

21

the language of the religious ideas introduced ill 8Ja-d as direct evidence from the text for an empirical interpretation of the theory of the Metlo. Yet there is, as we have seen, every reason for discounting this passage as an expression of Plato's own ideas. There is, consequently, no force in the appeal to the indiscriminate nature of the reference to 'all things, both things here on earth and things in Hades' (8IC), to support the view that plato makes no distinction between what is experienced in this life and what is experienced prior to incarnatiOl1;u nor in the appeal to the reference to 'seeil1g all things' (8IC), to support the view that Plato's theory embraces no kind of experience other than sensible experience. 42

fJ

The argument for the immortality of the soul

There is one further step in Plato's argument to be considered. When the geometrical problem has been solved, Plato argues that the slave must either have acquired at one time the knowledge he now has, or have always had it (8sd). He then argues for the second alternative, and, since he assumes that it is the soul which has this knowledge, infers that the soul must be immortal (86b). The steps in the argument are as follows: (i) Since the slave has never been taught geometry in his present life, he must have been in possession of the truth when he was not of human form. (ii) Since the truth is clearly 'in' his soul during this life, needing only the stimulus of systematic questioning to elicit it, it follows that he has possessed the truth both when he was of human form and when he was not. (iii) 'Time when existent as a man' plus 'timewhen existent not as a man' = all time (86a), which means that for all time the truth has been in the soul. (iv) The soul is, therefore, immortal. Step (iii) is clearly invalid. If we grant (i) and (ii) we may infer that the soul existed for some indefmite time prior to its incarnation. This is, in fact, all that Plato thinks it legitimate to infer from the argument from recollection in the Phaedo (77a-c). And in the Meno the reservations which he immediately makes (86b-c) after his 'proof' of immortality clearly indicate that the 'proof' is put forward quite tentatively, without any great confidence in its validity. The interest of the argument for immortality is that its obvious inadequacy suggests that Plato is only just beginning to consider what theory of the nature of soul is implied by his theory of knowledge. Later in the Phaedo a clearly formulated metaphysical theory, based on a distinction between

22

PLATO'S THEORY OF KNOWLEDGE

illtelligibles and sensibles, is linked with a clearly formulated theory of the nature of soul, based on a distinction between soul and body as the seat of reason and of the senses respectively. And recognising the distinctive characteristics which must be attributed to soul as being that in us which allows us to have knowledge of Forms, Plato is now reasonably confident that he can prove the immortality of the individual soul. In the MellO a radical dualism of this kind is absent. Yet we do have an appeal to a transcendent source of knowledge; we do have an implicit distinction between the soul simpliciter and the soul incarnate; and Plato, in granting to soul the capacity for a priori knowledge, is already recognising this distinctive ability as a ground for thinking of the soul as immortal.

g] Plato's reservatiol1S about the theory of recollection. The discussion of recollection closes with an indication by Plato that the theory is put forward quite tentatively. He emphasises his conviction that truth is attainable, but at the same time appears to express doubt as to whether the theory of recollection is adequate as a justification for this conviction (86b-c). This note of reservation occurs again in 98b, with perhaps even stronger emphasis on the cOl1jectural nature of the theory that recollection is able to provide a criterion of knowledge" These expressions of doubt should be taken as expressions of Plato's own feelings, and not as a dramatic compromise in favour of Socrates' agnosticism. Thus we need not assume that the reservations extend only to the religious ideas of 8la-d, or to the proof of the immortality of the soul in 8sd-86b. 43 Plato is putting forward a positive theory of knowledge for the first time, in a form which suggests that many of its implications have still to be worked out. A tentative approach is therefore natural, and Plato is right to emphasise this. It is, indeed, noticeable that in the rest of the dialogue the discussion of the question whether virtue can be taught is conducted with much less confidence and success than had been the case in solving the geometrical problem~:Ve should, perhaps, take this last part of the dialogue as an illustration of the initial stage in the process of recollection, an exploration of the different aspects of the problem and the difficulties involved, prior to the approach to a positive solution. Perhaps, too, Plato is illustrating the point that the application of an exact method of analysis to ethicaJ. questions is not, in practice, so straightforward and clear-cut as it

THE THEORY OF RECOLLECTION

23

m mathematics. Yet his conviction remains that knowledge is attainable, and there is no reason to doubt that this conviction extends to ethical knowledge. Plato does not, however, attemptin the Meno to specify the extent of a priori knowledge. All that he says is that what is true of mathematics is true of all other branches oflearning (mathemata: 8se). This is a question-begging phrase,44 sin~e the theory of recollection in the Mel10 has been concerned to show that learning, or the acquisition of knowledge, is to be equated with recollection. It indicates one of the ways in which Plato's theory of knowledge is, as yet, lacking in precision. What is needed now, if the question of the extent of a priori knowledge is to be seriously faced, is a more precise determination of the nature of a priori knowledge and, as complementary to this, an examination of the nature of non-a priori levels of apprehension, most particularly of the nature of sense-perception and its status in relation to knowledge.

IS

3.

THE PHAEDO

a] The moral orietltatiol'l of the argt,ment

.

The Phaedo, with its introduction of the theory of Forms and its new approach to the theory of recollection, makes some attempt to deal with these points, although there is no systematic examination of them as problems in a theory of knowledge. Indeed, the moral fervour which permeates the whole of the discussion in the Phaedo and the practical moral significance which is assumed to belong to the arguments may be said to constitute a hindrance to any disinterested attempt to deal with these points. It is essentiaL before trying to assess the developments made in the Phaedo, to describe very generally the nature of this moral background. In the first part of the dialogue, where Socrates is stating the assumptions on which he bases his conviction that the philosopher welcomes death as a separation of the soul from the body, a radical contrast is made between the soul, as the seat of 'pure reason' or 'pure thought', and the body, as the seat of desire, pleasure, and the senses (64d-66e). It is assumed that the life of philosophical 'reasoning' and 'thought', which are activities of the soul, is a good life, and that the life of bodily indulgence is bad, in that it is a hindrance to the good life. Thus it

24

PLATO'S THEORY OF KNOWLEDGE

deprives men of the leisure for philosophical thought (66c); in a later reference it is argued further that indulgence in bodily pleasures results in a false conception of the truth (83c-d), which presumably means that it results in a false conception of what good is. Now it is within this general condemnation of the body that the senses are morally condemned as a hindrance to the life of reason. 'Reality' is not apprehensible by the senses, but only by 'pure and simple' thought, uncontaminated by the senses, which are inaccurate, unreliable, and convey no truth (6 Sb-66b). This tone of moral condemnation would seem to be singularly inauspicious for any subsequent attempt to evaluate sense-perception from a more specifically epistemological point of view. Indeed, an apparently paradoxical aspect of Plato's position here is that, while he is ready to condemn morally the body, its 'flesh' and its senses, and to identify man's good with the soul's activity of disinterested pursuit of truth through 'pure reasoning', yet he represents 'the good itself' (6sd) as something to be known by the soul as a result of its inquiry, as if the goal of its inquiry here is to justify its assumption that its 'good' lies in the activity of 'pure reasoning'. He appears, in fact, to be prejudging the issue. This is perfectly true. Yet it is important to add that this first part of the Phaedo is merely a statement of Plato's assumptions, and that the remainder of its argument is the first instalment of a task, continued throughout the dialogues, directed to the substantiation of these assumptions. It is also important to examine briefly the reasons for the emphatically moral orientation of the arguments of the Phaedo. An obvious influence here is the body of religious ideas which had already influenced Plato in the Metlo, especially the ideal of the 'purification' of the soul from bodily contamination as a preparation for future discarnate life. The association of this ideal with the intellectualism of the Socratic thesis that virtue is knowledge does much to explain Plato's conception of the soul's activity as an essentially intellectual or theoretical activity, his association of this activity with 'goodness', and his moral condemnation of bodily activities. His own justification of this ideal, on the basis of his own theory, links the soul's activity with knowledge of Forms and, further, with a teleological conception of the 'goodness' of the order and intelligibility of the world, a conception which first assumes prominence in the Phaedo. It is, indeed, in the last resort, his assumption that the systematic order of the world, which alone permits its intelligibility, is 'better' than dis-

THE THEORY OF RECOLLECTION

25

order and 'irrationality' which justifies his assumption that man's 'good' is to direct his activities to knowing the Forms, to live the life of philosophy. For the affinity of the individual soul's function to that of the cosmic soul, the activity of which is implied, for Plato, by the fact of rational design and order in the world, implies that its 'goodness' is to be achieved by assimilating its activity to the activity of dIe cosmic soul, since the cosmic soul is 'good' in that it is directed to the maintenance of an order assumed to be 'good', and uses, as its 'model', the world of Forms. These very general assumptions are not all explicit in the Phaedo, but it is certainly within the teleological conception of the 'goodness' of an ordered and intelligible world that Plato, in the Phaedo, wishes man's individual goodness to be assessed. This explains several important aspects of the moral orientation of much of Plato's theory of knowledge, especially as it is developed in the middle dialogues. It explains, in the first place, why it is possible, in the Republic, to present knowledge of 'the good' as the culmination of dialectical investigation. Within the broad conception of the' goodness' of the systematic order of the world, knowledge of 'the good' is the systematic comprehension of the world of Forms, which alone makes the order of the physical world fully intelligible. It presumably includes the realisation that 'goodness' is constituted by the systematic order of the world of Forms, and that the' goodness' of the order of the physical world is derivative from this. It explains at the same time that, although Plato tends to approach the question of the conditions for the attainment of knowledge from a moral point of view and with moral assumptions which seem to us inappropriate to an examination of problems in a theory of knowledge, yet it is not specifically moral knowledge, as opposed to other fields of knowledge, which is being considered. It is a mistake to think of Plato's theory of knowledge in the middle dialogues as being very specially concerned with the question of the nature of knowledge of specifically moral principles, or of specwcally moral Forms. The theory of Forms, and the theory of knowledge associated with it, are, as we shall see, theories of a wide general application. Though Plato, from the point of view we have now examined, thinks of the activity of soul which aims to gain knowledge of Forms as a 'good' way of life, the content of this knowledge is not in any way specially restricted to what is specifically moral. Thus the moral orientation of Plato's theory in the Phaedo does not affect in c

26

,

PLATO S THEORY OF KNOWLEDGE

any way his conception of the extent of a priori knowledge. Where it does affect his theory is in its assessment of the cognitive value of senseperception. The result is an inconsistency on this point throughout the middle dialogues. On the one side is a moral condemnation of the senses as systematically misleading and inaccurate. On the other is a more serious assessment of the value of sense-perception and its objects as aids to knowledge. In this respect it is not, I think, an exaggeration to say that in the middle dialogues Plato's moral puritanism bedevils his theory of knowledge. One further influence must be briefly considered before the theory of the Phaedo is examined. In the Metaphysics Aristotle states that an important factor in the development of Plato' s theory of Forms was an acquaintance, through Cratylus, with the Heraclitean doctrine of universal 'flux', which led Plato to the conviction that, since all sensible things are always in flux, then they cannot be the objects of knowledge, and, consequently, that there must be other things to serve as objects of knowledge which are not sensible and not subject to changes (987a32-4; I078bI2-16). There are no adequate grounds for questioning the general truth of Aristotle's statement. Plato, as we shall see later, did in fact accept the Heraclitean doctrine of flux as true for sensibles, and there is no reason to doubt that consideration of this doctrine first led him to reflect on the adequacy of sensibles as objects of knowledge. Nor need we doubt Aristotle's further statement that Plato was led to the formulation of the theory of Forms by combining reflection on the Heraclitean doctrine of flux, as applied to sensibles, with reflection on the Socratic search for general definitions. Yet though Aristotle says that Plato became acquainted with the Heraclitean doctrine in his youth, the dialogues suggest that only at a date subsequent to the time of writing the Meno did reflection on the application of the doctrine to sensibles begin to influence the development of Plato's theory of knowledge. There is no consideration of, indeed no reference at all to sense-perception in the discussion of recollection in the Meno, and there is no metaphysical doctrine of Forms. And it is difficult to imagine that Plato's first theory of knowledge would have taken the form of the Meno theory if he had already come to any conclusions at all about the relation between sense-experience and knowledge, much more difficult if he had already formulated the doctrine of Forms. The important thing to note here is that Plato's theory of knowledge as a priori is

THE THEORY OF RECOLLECTION

27

initially quite independent either of a theory of Forms or of any theory about the nature of sense-perception. It is only when he tries to give greater precision to his theory of knowledge that he introduces, as a newly developed doctrine, a doctrine which tries to give a more clearcut distinction between a priori knowledge and non-a priori levels of apprehension by basing it on a distinction between non-sensibles and sensibles, and, from the epistemological point of view, between concepts and percepts. This is the significant development made by the theory of recollection in the Phaedo, which makes, for the fIrst time, a distinction between sensibles and transcendent Forms. 45 A fInal point to be made about the influence on Plato's theory of his consideration of the application of Heraclitean doctrine to sensibles is that acceptance of the doctrine as true for sensibles does not itself imply acceptance of the view that sense-perception is systematically misleading and erroneous, or that sensibles have no determinate characteristics, both of which views are put forward in the middle dialogues as derivative from the flux theory of sensibles. In the late dialogues it is no longer assumed that acceptance of the flux theory carries with it acceptance of these views. Thus it is especially in considering the middle dialogues that we have to recognise that Plato's disparagement of sensibles is sometimes a moral disparagement of them, and that this factor Calmot be neglected in accounting for the exaggerations into which he is sometimes led.

b] Recollection and the Forms The detail of the theory of recollection in the Phaedo must now be examined. The discussion begins by repeating what the Meno had said about the way in which knowledge is elicited. Proper questions will elicit correct answers about everything (73 a); this points to the existence in us of knowledge and of 'a right account'. 46 The way in which geometrical problems can be solved provides, it is suggested, the clearest proof of this. Having thus briefly reviewed the theory of the Meno, Plato now introduces an entirely new development in the theory of recollection, indicating its novelty by his suggestion that, if Simmias is not convinced by it in its presentation so far, then perhaps he will agree if it is presented in another way (73 b). plato begins by considering examples of association, where the present perception of something reminds a person of something else, not at the moment perceived, which is associated in his mind with what is perceived, either by

28

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resemblance (e.g. the association between a portrait and its original) or by contiguity (e.g. the association between a lyre and its owner). In this way recollection comes from dungs 'either like or unlike' (74a), and is possible only if a person has prior knowledge of what he is reminded of (73c). In cases of association by resemblance the question inevitably arises 'whether the similarity between the object and the thing it reminds us of is defective or not' (74a). It is at this point that Plato introduces a special case of the distinction between perceiving and conceiving. In the earlier illustrations this distinction (73c, d) seems to have been viewed by Plato as a distinction between the present perception of a particular sensible thing and the calling to mind of a particular memory image. We now have a distinction between the present perception of particular equal things and the conception of' the equal itself' or 'equality' (74c); being reminded of the latter by the former is taken to be a case of association by resemblance. This is a distinction between Forms (though the technical term is not introduced until much later in the dialogue) and sensible particulars. The logical basis of it is a distinction between universals and particulars, and, from an epistemological point of view, between concepts and percepts. With the added metaphysical assumption which Plato makes (74a, 7sd, 76d), it becomes a distinction between what is perfectly reaL having an independent existence and constituting an ideal standard or archetype, and what is necessarily inferior, resembling the archetype but only approximating to it in its perfection (74a-c, 7Sa-b). The distinction is of general application, valid for all cases where we apply to the general term 'our seal and mark as being "the thing itself'" (7Sd). On this distinction Plato bases his argument for the pre-existence of the soul. He assumes that in ordinary experience it is inevitable that sensible particulars are recognised to be defective in their resemblance to the ideal standards or Forms (74d-7Sb). He assumes further thatno Form can be recollected without the reminders given in sense-experience (74b, 7Sa-e, 76d-e). And since reference to an ideal standard, which all perception involves, implies previous knowledge of the standard, then tllat knowledge, it is argued, must precede the first use of the senses; it must, therefore, have been possessed before birth (74e-75c). This argument relies on a distinction between sensation and a conceptuallevel of apprehension. But the appeal to the distinctive nature of conceptual thought does not imply that allY concept designates a

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Form. What it does, apparently, imply is that all concepts which have sensible instances designate Forms, but no others do SO.47 This is a very general claim, and its implications must be carefully considered. In the first place, what is tlle precise nature of the ideal standards or Forms? The Phaedo theory of recollection clearly falls down unless they have separate existence, in a non-sensible (form. 'The doctrine of anamnesis, if it is to be of any use, implies a previous direct knowledge of disembodied Ideas.' 48 It implies their separate existence in this form, since if in a previous existence 'we knew them only on the suggestion of things of sense, the reference to a former existence does nothing to explain the process of coming to know them'. 49 Plato acknowledges that the postulate that Forms exist is the fundamental premiss of his argument (76e-77a). In what way, then, does he make the distinction between Forms and sensibles? As an argument for the view that sensible instances of a Form are distinct from the Form itself and necessarily imperfect exemplifications of the Form, he says that whereas equal stones or pieces of wood sometimes seem equal to one man, but not to another, 50 though they have not changed, yet 'equals themselves' never appear to be unequal, nor equality to be inequality (74b-c). Since it is said that the two sticks or stones are in fact equal and remain so, it is presumably meant that it is some difference in perspective or some difference between the individual percipients which leads one to judge that they are equal, the other that they are unequal. Thus it is difficult to see the force of the argument as an argument for the imperfection of the objects of perception. For it implies that there is nothing inconsistent in two things being perfectly equal and at the same time appearing equal to one man and unequal to another. Yet there is no doubt that this type of argument was considered by plato to constitute an important reason for postulating the existence of non-sensible Forms, and for condemning sensibles as 'imperfect'. To postulate a Form is to postulate the existence of something which, unlike sensibles, can never have its contrary predicated of it. The principle by which Forms are thus postulated as nonsensibles is that each pair of opposites contains two members, different from one another, and hence, since experience shows that any sensible deserving to be called by the name of the one opposite may with equal

30

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propriety be called by the name of the other opposite, no such sensible is genuinely identical with either of the opposites (otherwise they would not be two at all, but coincide with one another

contra hypothesim). 51 What makes the use of the principle particularly surprising in the present passage of the Phaedo is not only that Plato carefully specifies, and hence recognises, the particular conditions which allow a pair of contraries to be here predicated of the same sensible instance, but also that he makes the fact that the sensible instances are instances of one contrary, and not the other, the foundation of his argument for recollection. For having used, in 74b-c, the argument that equal sticks or stones sometimes seem to possess a pair of contrary predicates as an argument for distinguishing 'equality itself' from sensible instances of equality, he then proceeds (74c-7Sb) to show that the equal sticks, in that they are equal, do possess the determinate characteristic of equality, and do not possess the characteristic of inequality. As far as the sensible objects themselves are concerned, the imperfection is said to be their failure to exemplify perfectly in their characteristics the standards constituted by the archetypal Forms, and this imperfection does not include the exemplification of the contrary of the Form to which they approximate. Moreover, the theory of recollection here is that the function of the senses is to prompt recollection of Forms through experience of sensible instances which are imperfect in this sense. Thus the argument of 74c-7Sb makes perfectly clear that the earlier argument of 74b-c is now left out of account, and that Plato is not suggesting that the experience of apparent unequals can just as well remind us of equality as the experience of apparent equals. What he is presenting is the conception of Forms as ideal standards or archetypes, and of sensibles as 'copies' or 'images' (though these descriptions are used only in later dialogues) which resemble the Forms. It is the fact of this resemblance which allows the possibility of recollection of Forms from experience of sensible particulars. Later in the dialogue the relationship between Forms and sensible instances of Forms is described in different terms, but in a way which implies a relation of resemblance or similarity between Forms and sensibles in respect of the determinate characteristics which sensibles possess. Thus the reason why a particular thing is beautiful is said to be that it participates in 'the beautiful

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itself'; it is the 'presence' of the Form which makes it beautiful (Iooc-d). The assumptions, then, on which the theory of recollection in the Phaedo is based are (i) that non-sensible Forms exist: (ii) that sensible instances of Forms are imperfect 'copies' of Forms: (iii) that these instances, in virtue of their resemblance to Forms, are able to act as 'reminders' of Forms. Thus the ability to recogllise instances and to apply concepts to experience is given a metaphysical interpretation, and becomes the basis now of Plato' s theory of knowledge. The concept of knowledge is prominent in the discussion, both in the initial illustrations of association in terms of a distinction between perceiving and conceiving (73c-d), and in the following argument (74b-c). It is, says Plato, from the experience of sensible instances that knowledge is acquired. It is unfortunate, therefore, that, having established as fundamental for his theory the relation of resemblance between Forms and particulars, Plato should complicate this thesis unnecessarily by adding that 'so long as the sight of one thing leads you to conceive another, whether like it or unlike, a case of reminder must have occurred' (74c-d). Comparison of the phrase 'like or unlike' with similar phrases in 74a and 76a shows that Plato is referring in this phrase to association by resemblance and association by contiguity respectively. Thus it appears that Plato now wishes to include within his theory of how recollection of Forms is effected the factor of association by contiguity, which he had mentioned earlier in order to illustrate the idea of association (73d-e) but had then left aside when he went on to make association by resemblance fundamental to his argument. It appears, in fact, that he is now saying that it does not matter whether you are reminded of equality by seeing two equal sticks or reminded of it by seeing a box which you associate with equality because it once happened that you saw two equal sticks in it. In that case the theory of recollection includes cases where a Form is recollected from experience of sensible particulars which are not instances of the Form, but are instances, presumably, of another Form related in only a trivial and accidental way to the Form of which they are 'reminders'. It would have been much better for his argument if Plato had restricted his use of the idea of association by contiguity to the illustrations of 73d-e. 52 To introduce it as part of the theory of recollection is to introduce something which not only is tlllnecessary to the argument, but also complicates it in a way which

PLATO'S THEORY OF KNOWLEDGE 32 tends to divert attention from the fundamental point of the theory. And the fundamental point is that recognition of sensible instances is made possible by their resembla11ce to a Form, and that this recognition is not only the indispensable basis of the possession of a Form in this life (7Sa), but in fact implies that possession prior to this life (74e, 7Sa). Indeed, immediately after introducing the above complication, plato goes 011 to stress that the judgement of the deficiency of sensible particulars to Forms necessarily follows upon our application of concepts to experience, and that the ability to apply concepts to experience thus implies, for each concept, the possession of a standard of reference whose perfection is to be contrasted with the imperfection of the particulars (74d-7Sb). And in making this point he reaffirms that the relation between Form and sensible instances is one of resemblance. For it is the relation of imitation which is implicit in Plato's remarks when he says here that sensibles strive to achieve perfect realisation of the Form. This examination of the theory of recollection in the Phaedo has attempted to show the kind of metaphysical interpretation which Plato gives to the fact that sensible characteristics are recognisable. He assumes that this recognition is possible only at a conceptual level of apprehension, and that the ability to apply concepts to what is given in sensation implies the possession of a Form, an ideal standard or archetype which sensible instances resemble but never perfecdy exemplify. The main distinction employed in the argument is between percept and concept, or between sensation and a conceptual level of apprehension. The function of the Form as a universal is not Plato's concern here, though he always assumes that it is a universal in the sense that it is applicable to all its sensible instances (c£ 74aII-I2, 7sa2, bI-2, 7-8). Now the distinctions which Plato makes in this part of the Phaedo are important distinctions for his theory of knowledge, but before they are considered further from dlis point of view it is important to consider briefly the difficulties in his conception of Forms as ideal standards or archetypes. The principal difficulty, as far as the theory of recollection is concerned, is clearly stated by Plato himse1fin the Parmenides (Ipd-I 33 a), the first part of which is devoted to a criticism of the theory of Forms as it is presented in the Phaedo. The difficulty is that if sensible characteristics are explained in terms of 'participation' of sensible objects in

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Forms, and if, further, this 'participation' establishes a relation of resemblance between sensible objects, in respect of their characteristics, and Forms, then an infinite regress arises. For the resemblance between all sensible instances of a Form is explained, on Plato's theory, as derivative; they have a common resemblance to the same Form. But the principle that the resemblance between two or more things is to be explained as thus derivative is applicable to cases of resemblance between Form and sensible instances of Form. Hence the inftnite regress. Thus the implicit criticism is that to conceive the Form as an archetype which its sensible instances resemble is to conceive it as a perfect particular object possessing the same characteristic as its sensible instances. Later in the Phaedo Plato does in fact affirm that 'the beautiful itself'is beautiful (100C). If the criticism is valid then Plato's attempt to distinguish, in his theory of recollection, the Form from the objects which resemble it, and to separate it from the class of those objects, fails, and the theory itself, as a theory of knowledge as a priori, falls down. And the criticism is, in fact, valid against Plato's theory here, in so far as he fails to distinguish between the Form and perfect instances of the Form. One indication of this is that he refers to the Form of Equality indiscriminately as 'equality' and 'the equals themselves' (74c), the latter phrase being used because 'a perfect instance of Equality is not one single perfectly equal thing but rather a pair of things that are perfectly equal to one another'. 53 Later in the dialogue Plato further ascribes to the Forms, in contrast with sensibles, the characteristics of being simple, non-composite, immutable, and eternal (78c-d). Yet these further distinctions are not sufficient, or indeed of the right kind, to rid Plato's theory of the difficulty we have been discussing. They serve rather to reaffirm that Plato conceives the Forms as ideal objects, of a kind which makes it difficult for them to perform the logical functions which plato apparently assumed that they could perform. For it must be remembered that it was by appeal to the distinctive nature of a conceptual level of apprehension that Plato argued for the existence of archetypal Forms as the objects of thought. And though the Form is distinct from the concept, Plato assumes that it shares, as an object of thought, the virtues of the concept, as a unit of thought, in the task of acquiring knowledge. Yet in attempting, in this later part of the Phaedo, to distinguish it as a non-sensible object from sensible objects by ascribing to it, in terms which point to

PLATO'S THEORY OF KNOWLEDGE 34 Parmenidean influence, 54 characteristics chosen as opposites to those which belong to sensibles, he is at the same time in danger of depriving it of those characteristics of complexity of structure and of relation which would seem to be indispensable to it as an object of thought, at least if the ideal of systematic knowledge put forward in the Metto is to be realised.

c] The contributioll of set1se-perception to kttowledge It is now time to examine more fully the implications for his theory of knowledge ofPlato ,s conception ofForms and their relation to sensibles. We have seen that Plato's argument is that sensible instances of a Form resemble the Form, and that it is in virtue of this resemblance that sensibles can act as 'reminders' of Forms. There is, further, the apparent assumption that to be reminded of the archetype by the sensibles which resemble it is to acquire knowledge of the archetype (74b-c). In discussing this argument elsewhere 55 I argued that the assumptions necessary to justify the role which Plato here assigns to the senses were '(i) that there are Forms, (ii) that the soul has at some time known them,56 (iii) that the sensible world, in all relevant 57 instances, is a sufficiently approximate copy of the world of Forms to be able to give correct suggestions of that world, and (iv) that the senses are to be always trusted'. And I concluded that the main fault of the theory was that 'Plato is apparently assuming that the fact that we attain a conceptuallevel of apprehension automatically affords a recollection of Forms, and thus implicitly assumes also the impossibility of false judgement' . Professor Hackforth agreed that this conclusion is 'undoubtedly justified' if the references to knowledge in 74b-c are taken 'at their face value', but argued that there is no need so to take them. 58 I accept this argument. But I did in fact argue then that, even if we assume that knowledge is not there being used in a sense which implies that the Forms are known as fully as they can be known, Plato's argument still appears to lead to the above conclusion. My argument was that if we assume that the Phaedo implies a very wide gap between (a) the ability to recognise sensible instances and to apply concepts to experience as a mark of that recognition, and (b) knowledge ofFonns, yet the validity of Plato's argument from recollection still depends on stage (a) being all accurate pointer to stage (b).59 Thus I would still defend assumption

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3S

(iii) above. It may be argued, against it, that it is enough for Plato's argument if some sensible instances are sufficiently approximate copies to act as 're1l1inders' of Forms, or, more generally, that the argument for the pre-existence of the soul rests on the possibility of recollection of Forms, so that it is enough for the argument if we ever recollect Forms. Yet Plato's argument ill fact atte1l1pts to establish much more than this minimum requirement. He makes it clear that the relation of resemblance between Form and sensible instances exists in the case of all 'things-in-themselves', and that it is only through sense-perception that recollection can be initiated (7Sa-d, 76d-e). And remembering the very general distinction between conceptual and perceptual apprehension which is the basis of the argument, it would appear to follow that any sensible particulars to which a concept is applicable are, ipso facto, in respect of any given characteristic, instances of a Form, and consequently resemble the Form. In other words, any recognisable characteristic which belongs to sensibles qualifies the sensibles, in respect of that characteristic, to be a copy of a Form. And the fact that the resemblance is said to belong to all instances of a Form, and that the fact of this resemblance is assumed to be unaffected by any variability in the conditions of perception, implies that in all cases sensibles are 'sufficiently approximate copies'. Otherwise they are not, on Plato's premisses, instances of anything, and do not come within human cognisance at all. As for assumption (iv) - that the senses are to be always trusted - my thesis here, I would now agree, needs further clarification. In stating it I did not, of course, wish to suggest that Plato was unaware that people make mistakes and misapply concepts, or that he was consciously arguing that any application of a concept to experience is a correct one. What I did wish to suggest was that the generality of the distinction which is the foundation of Plato's argument leaves the possibility of making mistakes out of account, in that it does not include any criterion for distinguishing genuine cases of being reminded of a Form from spurious cases. Thus, if plato is assuming that 'copies' of Forms are not always seen as they actually are, he is assuming that recollection supervenes only when the 'copies' are seen as they actually are, and that apparent cases of recognition of sensible characteristics where the characteristic does not in fact belong to the sensible object are not cases of recollection of Forms (assuming, as we lllust, that recollection of a

PLATO'S THEORY OF KNOWLEDGE

Fonll means correct recognition). If this is the case, then there is an implicit distinction between one class of instances of recognition (incorrect ones), and another class (recollection of Forms). But the distinction between sensation and a conceptual level of apprehension on which Plato's argument rests does not include this distinction, so that unless it is given further qualification the argument is one which treats all cases of recognition as a single class, and, further, as cases of recollection of Forms. It is on this basis that I argued that assumption (iv) is an implicit condition of the validity of Plato' s argument. I might add that it is implausible to assume that Plato is arguing that correct alld incorrect recognition constitute recollection of Forms, in that even incorrect recognition puts us in mind of some Form, even though the sensible stimulus is not an instance of it. For his argument is that recollection is dependent 011 actual resemblance between sensible instance and Form. If, however, assumption (iv) is an implicit condition of the validity of the argument, yet it is one which plato seems to have been unaware o£ It is logically implied by his argument, but clearly not an indication of his views on the reliability of sense-perception. This may readily be granted. But, even allowing that plato intends no more than that recollection supervenes only when the 'copies' are seen as they actually are, his argument, in the claims which it makes for sense-perception and its objects as pointers to reality, remains inconsistent with earlier and later passages in the dialogue where the senses are condemned in a tone of fierce moral disparagement as unreliable, inaccurate, and devoid of all truth, and their objects condemned as devoid of all truth and constancy (64d-66e, 79C, 83a-b). For his argument presupposes at least a relative stability and constancy in sensibles, and also presupposes that the senses are not ineradicably and systematically misleading. As Cornford remarked, in commenting on 79C, 'the fact that sensible experience may be the occasion of Recollection is lost sight of'. 60 In this examination of Plato' s conception in the Phaedo of the relation between sense-perception and knowledge it is now necessary to consider whether Plato says or implies anything in his account of the method whereby knowledge is attained to show that he conceived knowledge to be something more than the immediate apprehension of a Form following the prompting of a sensible reminder. In 74b-c he says that to recollect a Form, in the way that he has described, as a

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result of the 'reminders' given in sense-perception, is to acquire knowledge. How is this to be interpreted? The first thing to note about the contribution of sense-perception to knowledge, according to Plato's argument, is that Plato does not have in mind any process of reasoned generalisation from repeated sensible instances, or any process of systematic use of sense-perception in acquiring knowledge. He interprets conceptual apprehension as being reminded of an archetypal Form by any olte of its sensible copies. Perception of a single instance is assumed to be sufficient as a reminder, and the question of reflective comparison and progressive clarification does not enter into the argument. Now if the knowledge mentioned in 74b-c is taken to mean full knowledge of Forms, the argument would imply a direct and immediate transition from a single instance of perception to knowledge, or from sensible to Form. What grounds are there for ascribing this apparently implausible doctrine to Plato? It might be argued that in his argument for recollection Plato is postulating Forms only for simple characteristics of sensible things, characteristics which, in that they have no complexity, are not able to be analysed, and that this is implied by his subsequent description of Forms as simple, non-composite objects. 'Absolute simplicity would belong only to Forms of qualities, hot, cold, etc., whilst things having a derivative reality from these and hence in fact being composite would not perhaps be counted as Forms.'61 In that case, recollection of Forms from sensible reminders could be said to afford full and immediate knowledge of Forms, as a direct acquaintance with absolutely simple Forms. There is, admittedly, a contradiction in thinking of analysis of objects which are absolutely simple. But there is nothing at all in Plato's argument from recollection in the Phaedo to suggest that he means to restrict the number of Forms in this way, and the evidence of the dialogues indicates clearly that it was not unti11ater dialogues that he became aware of the difficulties involved in his conception of the analysis of 'simple' Forms. It is true that in his argument he has particularly in mind terms for qualities and relations rather than terms denoting concrete 'things', i.e. common nouns. But he is clearly not thinking of them here as essentially simple, and his argument, from its very nature, is not in fact restricted, in its application, to terms of this kind. Assuming, then, that no such restriction is implied, what evidence is there in Plato's description of recollection that his conception of the

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process of attaining knowledge goes beyond the conception of a direct recollection of Forms from sensible reminders? At 76b he says that knowledge of Form implies the ability to 'give an account' of it. This seems to suggest that knowledge is something more than what is afforded by reminders from sense-perception. It is in asking the question whether we are born with knowledge or recollect what we knew before birth that Plato says that a condition of knowledge is that a man should be able to 'give an account' of what he knows. And since it is agreed that all men cannot give that account, it is concluded that they do not have knowledge now, but must recollect what they once learned; what they knew is forgotten at birth and has to be recovered. Does the phrase 'to give an account' indicate the method of analysis introduced in the Meno, and further described later in the Phaedo (99d-r02a; the phrase 'to give an account' is in fact used in rord and interpreted as the process of analysis earlier described in the Meno)? If so, then 'giving an account' of a Form would presumably be analysing it so as to explicate its meaning. In this way knowledge of the Form would be acquired. And if this were the case then the question of the extent of the contribution of sense-perception to knowledge would become the question of the extent of its contribution to this process of 'giving an account'. Now whether the phrase 'to give an account' should be interpreted in terms of the method of analysis described in the Phaedo at 99d-r02a is a question which can better be answered after a detailed examination of that passage. But it is worth while at this point to consider at least what is implied about the role of sense-perception in the attainment of knowledge by Plato's conception of the relation between Forms and sensibles, assuming that the Form is amenable to systematic analysis. In the first place systematic analysis would be possible only if the Form was complex. Now if the Forms are archetypal objects, and sensible characteristics are 'copies' of Forms and resemble them, it would seem to follow that the sensible 'copies' resemble the Forms in their complexity. In other words, the fact of being a 'copy' of a Form would seem to entail a relation of complete, though imperfect, resemblance between 'copy' and Form. The imperfection would consist only in the fact that the 'copies' never perfectly, or exactly, match the ideal standard constituted by the Form. I think it is quite clearly implied in Plato's argument that the imperfection or deficiency of

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39 sensibles is imperfection in this sense. Thus if the recollection of a Form is effected initially by perception of anyone' copy' of a Form, and if the complexity of the Form is reflected in the complexity of its' copies' , then there would seem to be no reason why the recollection of the complexity of the Form should not be similarly effected by perception of the complexity of the 'copy'. Now this implicit assumption of a parallelism in structure between archetypal Form and sensible instances serves to emphasise a major difficulty in Plato's theory. He has formulated his conception of a priori knowledge in terms of the characteristics of archetypal non-sensible Forms as objects of that knowledge. But the Forms have been conceived in such a way in their relation to particulars that it becomes immediately implausible to assume that the propositions which would figure in the analysis of the Form have a formal validity which makes their truth independent of sense-experience. The 'copies' are tied too closely and systematically to the Forms, and hence similarly is sense-perception tied to knowledge, to make plausible a thesis that knowledge is a priori. Indeed, if we add the fact that Plato's theory fails to distinguish, as it should have done, between Forms and perfect instances of Forms, it becomes clear that his analysis of recollection in the Phaedo attempts an analysis of conceptual experience and of recognition of sensible characteristics which is more consistently plausible as part of an empirical theory of knowledge. It is an analysis very much akin, in its implications, to what Professor Price has called the Philosophy of Ultimate Resemblances which, instead of explaining the resemblance between sensible objects in respect of given characteristics as derivative, from the fact that the characteristics are instances of the same universal, explains it in terms of standard objects or class-exemplars within the class of sensible instances. 62 As we have already seen, plato himself, in the Parmenides, questioned the legitimacy of raising the Forms, as conceived by him in the Phaedo, to the rank of independent universals, separate from the class of their sensible instances. Even if we grant the legitimacy of this the fact remains that the distinction on which Plato's theory rests, the distinction between, on the one hand, universal and sensible particular, and, on the other, concept and percept, is far too general a distinction on which to base a theory of knowledge as a priori; the theory needs such further qualification as will distinguish further, within the fIeld of conceptual thought, a priori from non-a priori truths.

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As it is, the impression left by the middle dialogues is that Plato, after presenting the relation of Forms to their sensible instances as a relation of archetypal objects to sensible 'copies', strives, at the cost of much inconsistency, to keep Forms radically separate from sensibles, and knowledge radically separate from perception (i) by a fierce disparagement of sensibles as utterly untrustworthy, and (ii) by assuming that the analysis which yields knowledge of Forms is entirely independent of perception and appeal to empirical evidence. (i) is already clearly evident in the Phaedo. (ii) also, it may be argued, is already implicit in the passages where Plato, while disparaging the senses, gives high moral praise to the activity of 'pure reason' or 'pure thought' which belongs to the soul (64d-66e). But it is in fact only much later in the dialogue that Plato properly considers the question of philosophical method, and presents the best method explicitly as a method whose practice is independent of perception and appeal to empirical evidence.

d] The method of hypothesis The significant thing about this later passage is that the method is described and assessed independently of the theory of Forms, in a way which clearly suggests that Plato has not, at this stage, integrated the method and the theory, and, consequently, that he has not yet begun to consider the possible inconsistencies which would arise from any attempt to integrate them. This point is an important one in assessing the development of his theory of knowledge, and this passage of the Phaedo (99d-I02a) deserves detailed examination, the more so since there has often been confusion in the interpretation of it. Plato has just argued that the method of previous mechanical types of scientific explanation was a method of direct sensible observation. He now presents as an alternative and preferable method and type of explanation the method of analysis of propositions (logo;, 9ge). This involves, in the first place, an examination of the logical consequences of the initial hypothesis, in order to see not only what those consequences are, but also what inconsistencies with other propositions acceptance of the hypothesis entails, and whether there is any contradiction implicit within the hypothesis itself It involves further an analysis which will discover the propositions from which the hypothesis itself is deducible (lOoa, IOId-e). If we take the illustration of the

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method of analysis ill the MellO (86d-89a) as evidence for the form of the analysis mentioned in the Phaedo, then the analysis will be a syllogistic analysis which seeks the premisses necessary to substantiate a given conclusion. 63 The ideal put forward here is, then, an ideal of propositional analysis. Now when Cebes, to whom Socrates is explaining it, confesses, not unnaturally, that he would welcome further clarification of Socrates' meaning, Socrates immediately goes on to introduce the thesis that the Forms are 'causes' of the sensible characteristics of the world, since it is by 'participation' in Forms that sensibles possess characteristics (IOOb-IOlC). The difficulty is to see in what way this thesis clarifies the thesis that 'studying things in propositions' is a better method than studying things by observation of sensible objects. The only way in which Plato connects them with one another seems to be that the thesis that Forms are 'causes' of sensible characteristics is treated as an instance of a hypothesis to be examined in the way described (lOlC-d), with the added suggestion that the hypothesis that Forms exist will possibly yield the conclusion that the soul is immortal (loob). And the statement in looa that the method of hypothesis follows the same procedure 'whether the question is about causes or anything else' appears to emphasise that, although the present argument is about causality and although it is as 'causes' that the Forms are presendy introduced, the method does not derive its virtues from its association ",rith any particular assumptions about 'causes', whether in terms of Forms or not. Hence there appears to be some ground for the contention that the medlod of hypothesis, as introduced here, 'seems a mere excrescence', and that its connexion with what precedes and with the following thesis that the Forms are 'causes' seems 'perfectly accidental'.64 For if the connexion between the method and the thesis that Forms are 'causes' is merely that this thesis may be selected as a hypothesis for examination, then the connexion is accidental. Moreover, when it might have been expected that Plato would immediately contrast the physicists' mode of explanation through the study of sensibles with his own mode of explanation through the study of non-sensible Forms, it appears surprising that he should first contrast the physicists' procedure with a method which call be practised just as well in conJunction with that procedure as in conJunction with his own postulate of the existence of Forms. It is this point, however, D

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which Plato refuses to concede. He makes clear that the method is incompatible with the physicists' procedure of relying on sensible observation. We need not concern ourselves here with the question of the historical justification of Plato's argument that a method of direct observation was characteristic of pre-Socratic thought. 65 The important thing to note is that Plato assumes that if you rely on sensible observation as a criterion in determining 'the truth of things', then you cannot at the same time rely on a method of propositional analysis. For he assumes that the method of propositional analysis entails the rejection of any empirical criterion of truth; this is made clear in 99d-rooa. Logical consistency is now the criterion, with the qualification that the interlocutor must agree that there are no grounds for doubting the truth of the 'primary assumptions' (the 'adequacy' mentioned in rore appears to mean adequacy in the sense of being satisfactory to the interlocutor). Thus the aim of the new method, and the criteria on which it relies, are the same as those of the Socratic method which we examined earlier, but Plato adds (i) a systematic formulation of the method, incorporating the procedure of finding by analysis the prior assumptions on which the truth of the initial assumption depends; (ii) a radical contrast of the method with the method of direct observation. He then goes on to say that this is the method to use in the examination of any question, whether about causes or anything else (rooa). How far is it true to say, then, that the introduction of the method of hypothesis is 'a mere excrescence'? It must clearly be granted that the method has an important relevance to Plato's argument. His purpose is to satisfy Cebes' request for a demonstration that the soul is immortal (95b), and the relevance of the description of the method of hypothesis to this is the obvious relevance that it prescribes the method whIch plato intends to follow in the demonstration. Thus it shows to Cebes that the demonstration will eschew any appeal to sensible observation and that it will be effected in accordance with the rules of this method. And against the objection that the natural place for its introduction would have been at the very beginning of the argument, it can reasonably be said that it is perfecdy legitimate that plato, since he intends to contrast the method with the method of explanation adopted by the physical scientists, should first give a full account of the scientists' method. This does, however, over-simplify Plato's purpose in describing the

THE THEORY OF RECOLLECTION

43 scientists' method. For he wants his description to serve a double purpose, and it is his failure clearly to separate these two purposes which is responsible for the apparent confusion in his argument and for the impression that the introduction of the method of hypothesis is an excrescence. It can be counted an excrescence only ifit is assumed, wrongly, that the scientists' mode of explanation is described for the single purpose of making a contrast with the mode of explanation offered by the theory of Forms. In fact Plato has two purposes in describing it: (i) to contrast it with the method of hypothesis, and (ii) to contrast it with the explanation of the characteristics of the world in terms of the Forms, as 'causes' of those characteristics; but apart from the fact that they are each incompatible in their assumptions with the scientists' mode of explanation, the method of hypothesis and the thesis that Forms are 'causes' are connected only accidentally in Plato's argument. Only when these two purposes are distinguished, and the nature of the connexion between them realised, is it possible to assess the significance of his argument for his theory of knowledge. The first point to note is that Plato's treatment of the thesis that Forms exist as a postulate subject to examination by the method of hypothesis is simply one indication among others in the dialogue that Plato is not putting forward the theory of Forms or the theory of knowledge which depends on it dogmatically, as theories of which he considers there are no grounds for criticism or further examination. He is sufficiently confident of the truth of the postulate that Forms exist to use it as the basis of a theory of recollection, or as the basis of his final attempt in the dialogue to prove the immortality of the soul. It is a postulate which 'deserves acceptance' (92e), but is subject, as the 'primary postulate' ofany argument is subject, to further examination and criticism (ro7b). plato recognises, moreover, the limitations of the method of hypothesis, and of human argument in general, as a means of establishing with certainty the truth of any postulate. Short of 'divine inspiration', the method of hypothesis is, for Plato, the best philosophical method for attaining knowledge, but he acknowledges that certainty is either impossible or extremely difficult to attain by any method of human argument (8sc-d, I07b). Yet this profession of an ideal of disinterested inquiry, ready to examine systematically all assumptions, is qualified itself by one important assumption. Plato assumes that in practice the method is

PLATO'S THEORY OF KNOWLEDGE 44 independent of sensible observation, and assumes that this makes it a better method than the method of using sensible observation as a guide to 'the truth of things'. The two methods are, for him, incompatible. Moreover, this assumption about the method is made independently of the theory of Forms. The cOlmexion between the method and this theory is, as we have seen, accidental; the theory that Forms exist and that they are the 'causes' of sensible characteristics is introduced as a postulate which may he used as the starting-point in an application of the method. This rules out the idea that when plato introduces the theory of Forms as 'causes' he is suggesting that the way to get to 'the truth of things' is to analyse, by the method he has just described, the meaning of 'good', 'great', 'unity', and so on, and thus to attain knowledge by coming to know the Forms by an analysis conducted without any appeal to sensible observation. All that Plato says is that the postulate that Forms exist may be examined by the method he has just described and thus without appeal to sensible observation - he has particularly in mind the demonstration of the immortality of the soul from this postulate. The important point here is that the merely accidental connexion between the method of hypothesis and the theory of Forms shows that Plato is not ready to integrate them by making the theory of Forms and the theory of recollection based on it the basis of the method and the condition of its successful practice. He is ready to do this in the Republic and hence to assert that the task of the method is the examination of the world of Forms. And previously in the MellO it was clearly implied that the systematic conversion of true belief to knowledge, which is the fmal stage of the process of recollection, was effected by means of a method of analysis which in its essential features is clearly the forerUl11ler of the Phaedo's method of hypothesis. There is no theory of Forms in the Mello, but at least the conception of a transcendent reality is implicit in its theory of recollection. Thus the assumption that the analysis which will yield knowledge is part of a process of recollecting is the assumption that recollection affords that recognition of truth which will guide the steps of the analysis and ensure the correctness of its results. We noted, however, that plato makes important reservations about his belief in the theory of recollection, and stresses its very tentative nature. And these doubts affect his view of the efficacy of the method of analysis. For doubt about the theory of recollection is doubt about the founda-

THE THEORY OF RECOLLECTION

45 tion on which rests the conviction that analysis will convert true belief to knowledge. The position in thePhaedo is that the theory ofrecollection is now based on the postulate that Forms exist, but that the theory is not linked with the method in the way implied by the Meno. It is linked only accidentally, in the sense already exa~ned. And we may reasonably assume that if plato had made the link more than an accidental one by making the theory of recollection a presupposition for the effective practice of the method, and the world of Forms the objects of its analysis, then his doubts about the efficacy of human argument would have largely disappeared. As it is, the virtues of the method and of the theory are assessed independently, and this itself is an indication that Plato has not as yet begun to consider them in relation to one another except in an accidental way, and thus has not begun to consider the possible inconsistencies arising from an attempt to integrate them. Plato's appreciation of the serious difficulties involved in integrating them is subsequent to a transition in his thought fro111 a position where he treats the theory of Forms and the theory of recollection as hypotheses to be examined by the method to a position where he treats them as presuppositions for the effective practice of the method. The former position appears to be his position in the Phaedo. The latter position is his position in the Republic, where the method of hypothesis is the science of dialectic which explores the world of Forms. 66 But only in the late dialogues does he begin to appreciate the difficulties in the assumption that a method divorced fro111 sense-perception is the best method for analysing Forms related to sensibles in a way which suggests that in the process of the recovery of knowledge perception is the key to their analysis. What is particularly significant about his position in the Phaedo is that it shows that his assumption that the method of hypothesis is to be practised without resort to sensible observation is made in assessing the method independently of the theory of Forms. And when the method later becomes the instrument of the analysis of the world of Forms, this independent assumption about it is retained, without at first any awareness of its apparent contradiction of what is implied by the theory of Forms and the theory of recollection based on it.

PLATO'S THEORY OF KNOWLEDGE

e] Giving all account of the Form W c may now return to the point from which this discussion beganPlato's assertion during his presentation of the theory of recollection that knowing a Form implies the ability to 'give an account' of it (76b). The results of this discussion should make us hesitate to interpret the phrase in terms of the Republic's conception of dialectic, and thel1 to say that it means to state a Form's 'resemblances to and differences from odlcr - ultimately all other - Forms', 67 thus implying that a condition of knowledge of any Form is the comprehension of the whole system of Forms, which is called in the Republic knowledge of the Good. Indeed any interpretation in terms of the method of analysis described in 99d-Io2a would now seem to be implausible. A much less ambitious interpretation must be looked for. At 75C Plato has established that knowledge of 'the equal' (and of 'everything upon which we fix our seal and mark as being "the thing itself" ': 7Sd) must have been possessed before birth. He now wishes to establish as a feature of the theory of recollection that this knowledge is forgotten at birth, and has to be recovered. The alternative, inconsistent with the recollection theory, is that the soul's prior knowledge is unaffected at incarnation, and is retained throughout incarnate existence (76a). This alternative is refuted ifit is not the case that everyone can 'give an account' of any Form, since it is assumed (i) that everyone's soul knew the Forms before birth, and (ii) that the ability 'to give an account' is a condition of having knowledge. Since it is agreed that it is not the case that everyone can give such an account, then it must be that knowledge is recollected (76c). Thus it is assumed that recollection brings with it the ability 'to give an account' of what is recollected. Now it is reasonable to assume that in his presentation of the recollection theory Plato's use of the term knowledge, whether precise or not (i.e. whether implying full knowledge of Fonn or not), is at least consistent. Hence, if to know a Form brings with it the ability 'to give an account', and if to know a Form is to be reminded of it by the sensibles which resemble it (74b-c), the 'giving of an account' must be explicable within the conception of 'knowledge' implied in the use of the term in 74b-c. This suggests that 'to give an account' is to explain one's possession of a Form by showing that it is necessarily implied by that judgement of the 'defIciency' of sensible characteristics which

THE THEORY OF RECOLLECTION

47

arises as soon as they are recogllised. The fact that some people are not able 'to give an account' of a Form means that they have not yet realised it for themselves in this way, so that the concept which designates it has no meaning for them. There is one further point. 'To give an account' of a Form in this way is at the same time 'to give an account' of the sensible characteristics which are recognised. These characteristics are explicable only by reference to the archetypal Forms, whose 'presence' in sensibles is the 'cause' of the characteristics (lOcb-e). Thus it appears that, whereas the process of 'thinking out the reason why' (aitias logismos) in the Mello's recollection theory or the process of 'giving an account' within the Phaedo's method of hypothesis are both to be explained in terms of the analysis of propositions, yet within the theory of Forms, as far as it is taken in the Phaedo, the only type of account possible is one in terms of a relation of resemblance between archetypal Forms and sensible characteristics or in terms of the 'participation' of sensibles in Forms. 68 And since it is assumed both in the Meno and the Phaedo that a method of propositional analysis is the best means of attaining knowledge, while at the same time it is assumed in the Phaedo that the objects of knowledge are the Forms, to be recognised through their sensible 'copies', it becomes clear that a consistent development of Plato's theory of knowledge from this position will depend on the consistency with which Plato can reconcile the above two types of 'account'. In attempting to trace this development in the remaining chapters the first aspect of it to be considered will be the developments in Plato's views on the cognitive value of sense-perception. The inconsistencies in his views about this in the Phaedo are serious inconsistencies, and it is important, having first considered evidence from other middle dialogues which indicates more precisely the nature and extent of this inconsistency, to see to what extent Plato is able to remedy this fault in his theory in the late dialogues.

CHAPTER II

The Criticism of Perception I. INTRODUCTION

In Greek the general term for perception, aisthesis, is imprecise, and the possibility of giving any exactness of meaning to it depends entirely on the context in which it is used. Thus in the Phaedo, where it is clear that plato is distinguishing between sensation and a conceptual level of apprehension, it is possible to say that aisthesis means sensation (7Sa-b). Again, in certain parts of the examination of aisthesis in the Theaetetus, it is possible, as we shall see, to allot this meaning to it. In other contexts it has that much wider sense of perception which includes judgement. When plato condemns perception it is usually the case that he is including in his condemnation both 'the sensations and the judgements in accordance with them'.1 Thus in the Republic belief (doxa), as Plato calls the level of apprehension which has only sensibles as its objects, includes judgement and is apparently assumed to be propositional. And the reasons for treating it as unstable and unreliable are substantially the same, for Plato, as those for treating sensation as unstable and unreliable. Sensation, perception, and belief (in the above specialised sense) have a common basis in the 'experience' (pathos) which results from the interaction between the physical senses and external sensible objects, and each is equally inadequate to afford insight into 'reality' to the extent that this basis is inadequate for this purpose. In the middle dialogues it is only in the Theaetetus that there is any detailed examination of the nature of this basis. Outside the TheaetetHs discussion of sense-perception and its objects is of a very general kind, with little detailed analysis. What I propose to do in this chapter is to examine what Plato says about sense-perception and its objects in the Symposium, the Republic, the Cratylus, and the Tizeaetettts, and to consider in the light of this what developments in his theory of knowledge can be traced in this middle period of his thought.

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49

2. THE SYMPOSIUM

The important passage in the Symposium is that ill which Plato describes the 'ascent', through progressively more abstract levels of generalisation, to the apprehension of the Form ofbeapty (21oa4-212a7). In this passage he states more clearly and emphasises more insistendy than anywhere else in the middle dialogues that the process of acquiring knowledge of Fonn is a process of generalisation and abstraction. Thus, at the initial level of sensible exemplification of beauty, sense-experience of repeated instances of beauty brings first the recognition of the similarity of one instance to another (2 I oa7-bI ), and then the recognition of beauty as a general characteristic or universal (210b2-3). This process of generalisation is repeated at progressively more abstract levels of exemplification of beauty, and sense-experience gradually ceases to play a part in it. It is at least implicit that sense-experience plays no part at the higher levels of abstraction. After the generalisation which follows the recognition of instances of beauty in 'occupations and laws' (21oc3-5), a much wider (d4) fIeld of exemplification of beauty is found in the intellectual 'beauty' which belongs to the various sciences; and at this level the ability to recognise the similarity of the different sciences as instances of beauty and from this to recognise beauty as a universal character is said to result in knowledge of Beauty itself (2 1oc6-e I ; 21 1c6-d1). It is clear from what plato says here that knowledge of Beauty has the same wide comprehension as knowledge of the Good has in the Republic; it is a comprehension of the whole fIeld of knowledge which is at the same time a recognition of its Goodness or Beauty. And just as, in the Republic, the highest level of apprehension is divorced from sense-perception, so, we may assume, are the fmal stages of the' ascent' in the Symposium. Yet if the Symposium invites comparison with the Republic in this respect, there is a radical contrast between the two dialogues in respect of the method prescribed for attaining knowledge. This arises from a difference in the points of view from which the approach to knowledge is considered. The Republic is concerned to depict the method of systematic analysis by which the dialectician explores the content and structure of the world of Forms and finally comprehends that world as a single system; the Symposium is concerned to depict the process of generalisation from particular instances to

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universal, and though it is 110 doubt assumed that, at the most abstract level ofinstantiatioll, the recognition of particular 'branches oflearning' as instances of beauty is possible only at the conclusion of a comprehensive analysis of these 'branches of learning', it is the generalisation marked by the recognition that beauty is a universal which the Symposium emphasises, and not the prior analysis which makes such recognition possible. Moreover, though it is true that the Symposium describes the generalisation from particulars to universal at various levels of abstraction, it is primarily the generalisation from present sensible particulars to non-sensible Form which it is concerned to emphasise. And in emphasising this Plato contrasts, in much the same language as he had used in the Phaedo in contrasting Forms and sensible instances of Forms, the permanence, immutability, purity, and uniformity of the Form with the transitoriness, mutability, and imperfection of its particular insta.nces, which present different appearances to different people at different times and in different relations (2IIa-b, e). The language of 'participation' to describe the relation betweel1 particulars and Form also recurs (2IIb2). One further and important similarity between the Phaedo and Symposium is that the Phaedo's doctrine of recollection and the Symposium's account of the 'ascent' to the Form of beauty both describe the way in which the Form is apprehended in terms of the recognition of a 'perfect' and tmiform object, and not in terms of the analysis of propositions. Yet there is an important difference in emphasis between the two dialogues. The Symposium emphasises, unlike the Phaedo, the function of the Form as a universal; for whereas the Phaedo explains the recognition of a Form as being reminded of it by any one of its sensible instances, the Symposium makes it dependent on a generalisation from the experience of several instances recognised as like one another. Does this mean that there is an inconsistency here between the Phaedo and the Symposium? It is true that, granting the premisses of the theory of recollection, that theory, as put forward in the Phaedo, is able to explain the recognition of Forms without appeal to a process of generalisation and hence to the personal memory of previous sensible instances. The Phaedo is thus arguing that the experience of more than one instance of a Form is not a necessary condition of the apprehensioll of a Form, and the Symposium is apparently arguing that it is a necessary condition. In other words the Phacdo, in basing

51 recognition on a relation of similarity between a previously known archetypal Form and a present sensible instance of it, seems to be assuming that the Form can be apprehended without awareness that it is a universal. The Symposium, on the other hand, makes the initial recognition a recognition of the similarity between two sensible instances; the recognition of the Form is subsequent to the recognition of several instances and is the recognition of it as a universal, as the result of a generalisation. This inconsistency between the two dialogues underlines the difficulty of reconciling the nature of the Form as all archetypal object which resembles its instances with its function as a lUllversal. If, on the one hand, the apprehension of the Form is the result of a generalisation from particulars, it is difficult to see the justification for postulating its separate existence as a perfect archetype. On the other hand, if recognition is explained as the recognition of a Form from the experience of a single sensible copy of it, not only is this not an account of how a general characteristic comes to be recognised, but the relation of resemblance between archetype and copy makes it difficult to avoid the argument from an infinite regress raised later in the Parmenides (I32d-I33a) if an attempt to maintain that the Form functions as a universal is based on this account of recognition. We must now consider further what part is allotted by the Symposium to sense-perception in the process of apprehending the Form. Implicit in the Symposium is the same relation of sinlllarity between perfect Form and imperfect particulars as is explicit in the Phaedo. And though Plato stresses, as a mark of the imperfection of particulars, that they present different appearances to different people at different times and in different relations, yet he assumes at the same time that the relativity of the appearance of sensible particulars to the individual percipient and to particular circumstances does not affect the status of the particulars themselves as 'images' of Forms, and assumes further that the perception of these particulars is the initial basis of the generalisation to the Form. Now this is to grant an important role to sense-perception in the attainment of knowledge. It is true that in the case of the Form of beauty with which the Symposium is concerned the process of generalisation is extended to levels beyond the range of direct perception. But this Form has, as we have seen, an extremely wide extension, comparable to that of the Good in the Republic, and is to THE CRITICISM OF PERCEPTION

52

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be treated as a special case. If we consider other examples of Forms it is clear that there are very many cases where the process of apprehending the Form will rely throughout on sense-experience. Thus many Forms designated by concrete terms - and the Phaedo theory assumes that such Forms are properly postulated - will, it would follow from the Symposium doctrine, be apprehended as the result of a generalisation from the perception of a number of their sensible images. And though the Symposium does not represent the apprehension of the Form as something achieved by an analysis of the complexity of a universal but only as the recognition that it is a 'perfect' and 'uniform' universal, it seems clear that any possible analysis of the Form subsequent to its abstraction from particulars would rely on sense-perception of the particulars. Indeed the Symposium, by combining a doctrine that the Form is apprehended through generalisation from particulars with a doctrine that the Form is an archetypal object which particulars resemble, comes dangerously near to bridging the wide gap between Form and sensibles which the dleory of Forms wishes to maintain. For it is implicit in that theory that no abstraction of Form from sensible particulars is ever possible. In this way the Symposium raises even more emphatically than the Phaedo had done the problems introduced into Plato's theory of knowledge once the objects of knowledge are specified as archetypal Forms. For it must be remembered that the theory of Forms is meant to give greater precision to the thesis first put forward in the Metto - that the only real knowledge is a priori knowledge. It is to be noted further that the fierce moral condemnation of the senses which characterises parts of the Phaedo is absent from the Symposium. It is not argued in the Symposium that the senses are utterly unreliable and deceptive. What is argued is that sensibles are imperfect when measured by the standard of the Forms, and the arguments here (2 I I a-b ) are comparable with those within the Phaedo's theory of recollection, and quite different in their purpose and doctrine from those other passages of the Phaedo which so fiercely condemn the senses and their objects from a moral point of view. Is it the case, then, that Plato consistently holds throughout this passage of the Symposium (2Ioa-212a) that the perception of sensible characteristics is an adequate guide to the apprehension of the Form? The general impression given by the passage is that he does hold this view. But he does in fact make one

THE CRITICISM OF PERCEPTION

53 reservation, which is repeated in the Republic. It is that the 'ascent' to the apprehension of the Form must be made under another's guidance (2Ioa6-7; C2-3, 6-7; e3). The fact that Plato makes several appeals here to the need of a guide or director suggests that he considered this point to be of some importance. But since, it recurs in the Republic any further assessment of its importance is best postponed until after an examination of what the Republic has to say about perception and 'images' of Forms. 3.

THE REPUBLIC

a] Perceptioll and the method of dialectic It is in the Republic that Plato begins to speak regularly of 'copies', 'images', or 'likenesses' of Forms. 2 This in itself indicates that he continues to think of the relation between Form and particulars in the same way as when he first formulated the theory in the Phaedo, a relation of resemblance between archetypal Form and 'copies' of it, 3 and this is explicit at 476c-d. Moreover in the Republic the theory of recollection is implicit in Plato's remarks about the nature of education at the beginning of Book VII. Thus the language used to refer to the knowledge residing in the soul immediately recalls the language in which the theory of recollection is introduced in the phaedo, 4 and the doctrine that education consists not in putting knowledge into the soul as if one were putting sight into blind eyes but in turning the soul already having latent knowledge in the right direction is a doctrine presenting, as Adam noted, 5 fundamentally the same view as that implied by the theory of recollection. But although the language of 'images' of Forms is prominent in the dialogue and although a theory of recollection is implicit in it, the doctrine of the Republic about the contribution of sense-perception to knowledge appears in many important respects to be opposed to what is implied in the Phaedo's theory of recollection. In the flrst place Plato's ideal of philosophical analysis, or 'dialectic', which yields knowledge, is an ideal which repudiates empirical aids to knowledge (5IOb, 5HC, 532a), just as the method of hypothesis of the Phaedo had done. But whereas the method of hypothesis in the Phaedo was connected only accidentally with the theory of Forms, the method of dialectic in

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the Republic is essentially a method which has Forms and nothing else as the objects of its interpretation and analysis (5 IO-S II). The truth of the theory of Forms is now assumed to be a guarantee of the certainty of the truths which dialectic brings to light. Hence dialectic has no need to rely, as the method of hypothesis of the Phaedo had relied, merely on personal agreement as a criterion of truth. Yet it retains certain important characteristics of the method of hypothesis of the Phaedo - (i) it is a method of analysis of 'hypotheses' and hence, as is clear from its afftnities with the method both of the Phaedo and the Mel1o, a method of analysis of propositions, and (ii) it is independent in practice of perception. Plato's ideal of dialectic here is an ideal of 'pure thought', which is aware that its objects are non-sensible Forms and is able, without resort to sensible 'images', confidently to prosecute its work of analysis with a clear recognition of the correctness of its results at each step until a systematic comprehension of the whole world of Forms is achieved. It is primarily in order to emphasise the distinctive virtues of this highest level of apprehension that Plato contrasts it with. lower levels which rely in differing degrees on sensible 'images' of Forms. Thus below the level of 'pure thought' are (i) a level of thought which is aware that its proper objects are non-sensibles but has not achieved that independence of perception which will allow it to dispense with sensible images of Forms as an aid to thinking; it is 'compelled' to use sensibles (SIOb-SIIa); (ii) a level of thought, lower than (i), which is not aware of Forms at all, but takes sensible images of Forms as constituting 'reality', and hence lays claim to knowledge from experienc;e of sensibles (476, 479-80, 509d-5IOa). And the task of education, as Plato envisages it in the Republic, is to effect a 'conversion' of the soul by leading it to the highest level of thought. It is clearly assumed here that the possibility of attaining knowledge of any Form is dependent on the possibility of attaining a level of thought which is entirely independent in its operations of sense-perception. Moreover, Plato does not suggest that the process of acquiring knowledge of Forms begins with the experience of 'images' of Forms, in the way described by the Phaedo in its theory of recollection. When he describes the two levels of thought mentioned above ( (i) and (ii) ), he does not recommend them as stages in the acquisition of knowledge, but criticises them as those most commonly mistaken to be the levels of thought at

THE CRITICISM OF PERCEPTION

SS

which knowledge is acquired or becomes possible. what we now have to consider is what Plato's examination of these two levels of thought reveals about his views on sense-perception and its objects.

b] Perception and mathematics Level (i) is first described (slOb-sIId) as one of the subdivisions in the divided Line, the diagram used by plato in an attempt to schematise the various levels of apprehension inferior to that which the practice of dialectic affords. It is the level of contemporary mathematical thought, and is called by Plato dianoia ('understanding') in distinction from that highest level of intelligence or nous which yields knowledge (SIId, S34a). It was natural that he should give great prominence in the Line to the procedure of contemporary mathematics. This was the main field in which the Greeks were making systematic advances towards the ideal of a precisely organised body of knowledge, and it was here that a claim to have reached certainty seemed most justified. But it is Plato's thesis that only for the results of the practice of dialectic can a claim of certainty be fully justified, and he makes it a principal criticism of the mathematicians' procedure that it fails to substantiate the assumptions on which the truth of its results depends. Further analysis, he argues, would show that what the mathematician uncritically takes for granted is in fact derivative from higher principles. Thus the mathematicians' claim that their results are certainly true rests on nothing more than the uncritical acceptance of the truth of the premisses from which those results are deduced. To this criticism that the mathematicians' results are never more than deductions from 'hypotheses' simply assumed to be certain, Plato adds the criticism that the mathematician always uses sensible 'images'. By 'images' he means 'images' of Forms. While criticising this use ofimages, he grants that the objects of mathematical thought are non-sensibles, and his description of examples of these as 'the square itself' and 'the diagonal itself'is characteristic of his way of describing Forms (Slod). Moreover he grants that these objects, though apprehended at the level of dianoia so long as the assumptions about them are left uncriticised, are fully intelligible when apprehended 'in connexion with a first principle' (SlId). In other words, the distinction between t1.0tlS and dianoia is a distinction between levels of apprehension of the same kind of objects, and not a distinction implying a different kiud of object for each level.

PLATO'S THEORY OF KNOWLEDGE

The 'images' which he has in mind are especially geometric figures, but he implies further (SIOc3 with SIOdS) that arithmetical thinking is tied to sensible images (presumably the visual representation of numbers by dots); also at SIoC3 he implies the same for 'similar subjects', no doubt the subjects of astronomy and harnlonics which he describes later with a consideration of the kind of sensible aids which they use (527d ff.). These, then, are the two criticisms which he makes of contemporary mathematical thought. I see no reason to doubt that plato is giving here a fair description of the actual.practice of contemporary mathematicians. It may seem, perhaps, that the insistence that the mathematician invariably uses sensible images as an aid to thought is rather exaggerated through a concern to make the distinction between contemporary mathematics and dialectic as clear-cut as possible. For though the point that the geometrician always relies on the spatial intuition provided by sensible figures may readily be granted, it appears more questionable that the arithmetician invariably has to rely on sensible intuition. But Plato's contention is at least understandable if we assume, as is reasonable, that he is influenced in his description here by Pythagorean theories of figured numbers and by the general Greek manner of representing units by points. 6 Hence, while allowing that there is some exaggeration in Plato's statement of the extent of the arithmetician's reliance on sensible 'images', we need not doubt that he is giving in this passage what he considers to be a fair description of contemporary mathematical practice. And he condemns it as bad practice. It is quite wrong to interpret this part of the Line as granting to mathematics a specially valuable status as the ideal intermediary between sensible and intelligible worlds, ideal in that its use of sensible 'images' is more efficacious in prompting the mind to recollect the Forms than is the case with sensible images of nonmathematical Forms. 7 For when Plato later discusses (525a ff.) the way in which mathematics can serve as a useful 'handmaiden' in leading the soul to the highest level of apprehension he makes clear that this usefulness is dependent on the divorce of the mathematical sciences from perception. Thus his criticism of the use of sensible 'images' in arithmetic, geometry, and 'similar subjects' is not a criticism of an essential and ineradicable feature of the method of these sciences, but a criticism of a feature of contemporary practice which can be eradi-

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cated, and must be eradicated if these sciences are to lead the soul towards the attainment of knowledge. Hence it is not the case that Plato, in the diagram of the Line, 'insists 011 the necessity of diagrams for the study of geometry', nor is it the case that he there 'opposes' both empirical and rationalistic theories of ~he nature of geometrical knowledge. 8 What he does oppose is contemporary practice, and what he advocates subsequently (525a £f.) is 'the rationalistic or logistic theory' of the nature of the mathematical sciences. In this later section of the Republic he assesses the value of arithmetic, geometry, astronomy, and harmonics, the last two being, almost certainly, the subjects he had in mind when he referred ill the Line, after arithmetic and geometry, to 'similar subjects'. And what he envisages is a unification of these sciences as the result of an inquiry which reveals their mutual relationship and 'kinship' (53Id), a result clearly dependent for Plato on the possibility of treating each of them as different but related branches of pure mathematics. Moreover the value of these sciences in turning the soul towards knowledge is dependent on the attainment of this result (53Id). This amounts to a repudiation of the use of sensible images in this field as a guide to knowledge. The point is made explicitly in Plato's discussion of the particular sciences, and is in fact most explicit where it is least plausible - in the case of astronomy and harmonics. 'Astronomy,' says Plato, 'like geometry, we shall pursue by the use of problems, and leave the heavens alone' (530b), and he immediately points out the radical change from the methods of contemporary astronomy which this demands. Similarly he advocates a purely rational study of harmonics, condemning the appeal to sensible observation and recommending again the use of problems; the student must investigate 'which numbers are consonant and which not, and for what reasons' (53Ic). In the case of astronomy Plato does indeed grant that there is a striking constancy and regularity in the movements of the heavenly bodies, but insists that this falls far short of the exactness which a mathematical description affords (529c-d, 530a-b), and concludes, not simply that all results of investigation in this field should ideally be expressed in mathematical terms, but that the only true results are attained through a purely mathematical study which dispenses with observation. In the previous discussion of arithmetic and geometry there is the same kind of contrast between empirical and rational methods of study as in the discussion E

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of astronomy and harmonics. It is 'numbers themselves' which the arithmetician must study, not allowing any discussion which deals with 'numbers with bodies that can be seen or touched' (52Sd). So in geometry the proper object of study is what is eternally real, and not 'what comes to be and passes away' (S27b). Hence, Plato asserts, the normal language of geometry, which is fitted to describe methods of practical construction, is quite ludicrous as an expression of its true purpose. Here again we may assume that he is recommending what he recommends for the other sciences - a method of pure mathematics, a recommendation clearly implied for geometry at 530b. We are now able to see that in this part of the Republic Plato is sketching a programme of research which is intended to eradicate at least some of the faults which, he had asserted in the Line, belonged to contemporary mathematics, and it is natural to associate what he envisages here with some programme of mathematical research being prosecuted within the Academy.9 But the Republic makes it clear that its mathematical studies are only a 'prelude' to dialectic (53 Id). In many ways this attempt to maintain a distinction between mathematics and dialectic appears at this point to have lost the justification which it had in the Line, and to remain merely as an artificial division to suit the plan of separating a programme of progressive education into distinct 'grades'. For the inferiority of contemporary mathematics to dialectic, as described in the Line, was essentially an inferiority in method, and this inferiority appears to have been largely eradicated from the method of the mathematical sciences described in S25a if. The 'eternally real' is now studied without reliance on sensible observation, and is studied with a systematic thoroughness which will obviously demand an extensive use of that type of analysis which the Line represented as the exclusive mark of dialectic. 10 In what way, then, does plato now mark off mathematics from dialectic? He says only that the mathematician is still 'unable to give and receive an account' {53 Ie). And this must mean 'unable to give and receive afinal account', in the sense that the mathematician is confmed in his investigations within the limits set by his acceptance of the primary assumptions of his science. Within these limits his procedure shares the characteristics of dialectic - independence of observation, and systematic analysis. And what remains as the distinctive mark of dialectic can only be an extension in the scope of analysis which will take it beyond the primary

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59 assumptions of the mathematical sciences and allow it to complete the task of systematisation by a discovery of the systematic unity of the whole world of Forms. Thus Plato assumes that there is a point at which the mathematician ceases to be a mathematician and becomes a dialectician. This does not, I think, imply th~t at tllls point the mathematician ceases to deal with specifically mathematical Forms, but rather that at this point he begins to relate mathematical Forms to nonmathematical Forms within a more comprehensive analysis. And this implies that the distinction between dialectic and the mathematical sciences as conceived in 525a ff. is essentially a distinction between degrees of comprehension of Forms, the assumption being that knowledge of any Form is possible only within the comprehension of all Forms as a single system. If this is the case, it is reasonable to assume that what is true of mathematics is true also of' all other branches of learning', as the Meuo would put it. For we must remember that the theory of Forms is a theory of very wide application, and that it is a principle stated in the Republic that the existence is assumed of one Form for each set of things to which the same name is applied (596a). And since it is Plato's invariable assumption that the only objects of knowledge are the Forms, it is a fair inference that what Plato says about the progressive stages of comprehension necessary in attaining knowledge of mathematical Forms is true also for all other, non-mathematical Forms. As Ross has pointed out in regard to Plato's description of contemporary mathematics in the Line, 'in principle his accotmt (so far as the use of hypotheses is concerned) is applicable to all sciences which study a particular subject without raising ultimate questions about the status in reality of the subject-matter, and its relation to other subject-matters'. 11 And we can fairly say, in a similar way, of the account of the mathematical sciences in 525a ff. that in principle this account is applicable to all Forms, and that for all Forms there are two mail1 stages in the comprehension of them - firstly the comprehension of them within the limits of various groups of Forms which constitute general 'subjects' and into which the Forms are initially separable; secondly the fuller comprehension of them within the single system which relates all 'subjects' and hence all Forms to one another. As for Plato's choice of mathematics as an illustration of what may fairly be taken to be a general thesis, this is explained by the fact that mathematics was at

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this time the only subject studied systematically enough to provide such an illustration. A consequence of this generalisation would be that plato makes the method of attaining knowledge of any Form, even at the lower level of comprehension, completely independent of perception. Against this it might be argued that the choice of mathematics to illustrate the lower stage of comprehension is a mark of Plato's recognition of its distinctive features as a subject which, unlike others, can be studied from the earliest stage by purely rational methods, and that consequently (i) it is for this l:'eason that mathematics alone is fitted to be a 'prelude' to the purely rational method of coming to know all Forms at the dialectical level; (ii) the choice of mathematics as a 'prelude' implies nothing about the method by which the approach to knowledge of non-mathematical Forms is made below the level of dialectic, and thus cannot imply that that method is divorced from perception. There is much plausibility in this argument. Yet it can be objected to it that (i) it is not only by a generalisation from what Plato says about mathematics that it can be established that the approach to knowledge of any Form is made independently of perception; there is other evidence to support such a thesis; (ii) since it is not in doubt that Plato conceives die attainment of knowledge of Forms as the culmination of a process of comprehending them within an everwidening fleld of relations, it is quite naturally assumed, apart from any consideration of Plato's explicit description of the process in the particular case of mathematics, that the earlier stages in the comprehension of any Form will be a tracing of the more obvious relations with other Forms which establish its place within the limited system of a particular 'subject'. Together (i) and (ii) afford the same conclusion as is afforded by the generalisation from Plato's description of the mathematical sciences, and thus suggest that the generalisation is justified. It remains only to consider the 'other evidence' mentioned in (i). nIcre is, in the first place, the evidence provided within the description of the mathematical sciences in 525a ff. What is especially remarkable here is, of course, Plato's failure to make any clear distinction between pure and applied mathematics. The distinction was, however, a difficult one for Plato to make within the theory of Forms, iiI view of the association made by that theory of a distinction between

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Forms and sensible instances of Forms with a distinction between a priori and empirical knowledge. Thus we find that arithmetic, geometry, astronomy, and harmonics are treated on essentially the same footing as sciences which investigate an eternally real world of perfect objects which are imperfectly instantirted in the sensible 'copies' of the physical world, the main distinction in each case being between the empirical and practical type of study directed to sensibles, and the theoretical and non-practical type of study directed to non-sensibles. And the most unfortunate consequence of the failure to distinguish between pure and applied mathematics is the assumption that the tmth of the applied mathematical systems of astronomy and harmonics call be established independently of sensible observation. The significance of this for our present argument is that in studies where Plato acknowledges that the sensible 'image' of the model constituted by the relevant Forms is, though imperfect, closer in its approximation to the perfect standard of the model than is the case with other sensible 'images', it is yet emphasised that the method of study must be independent of sensible observation. Thus he asserts that in the heavenly bodies and their movements we have what is more beautiful and perfect than anything else visible (S29c-d), but still insists that in studying astronomy 'we will dispense with the starry heavens' (S30b-c). Hence it can be argued a fortiori that the study of other Forms, in that their sensible copies will be less 'beautiful and perfect', will be independent of sensible observation.

c] Perceptio1l a1ld 'beliif' (doxa) Plato's remarks on perception outside his discussion of the mathematical sciences point to the same conclusion. We have already seen that one of the levels of apprehension ranked by plato below the level attained at the dialectical stage, and also, quite certainly, below the level attained by the systematic study which is a 'prelude' to dialectic, is the level which takes sensible images of Forms ~s constituting reality and hence lays claim to knowledge from experience of sensibles. Plato describes this level as doxa (belief). In the passage (476a £f.) in which he distinguishes doxa from knowledge he associates this distinction with a distinction between types of object, arguing that whereas knowledge is directed to Forms, doxa is directed to sensibles. His explicit assumption here is that the fact that knowledge and doxa are distinguishable implies

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that their respective objects are distinguishable (477e-478b). And on this assumption he associates, by analogy, the certainty and infallibility of knowledge with the invariability and permanence of the Forms, and the inconstancy and fallibility of doxa with the inconstancy and inconsistencies which belong to sensibles (477a ff.). The use of doxa here is in every wayan unfortunate one. Its departure from normal usage would have been pardonable if Plato had consistently maintained this specialised usage after its first introduction. But in fact he continues to use doxa elsewhere, as we saw in the last chapter, in the normal sense which carries no implication that its ,objects are different in kind from those of knowledge. In view of this, it is important to note that the specialised use of the term does not imply, as the normal use does for Plato, the possibility of converting doxa to knowledge by 'giving an account' which will establish that what is 'believed' to be the case is in fact the case. Wherever Plato uses the term in its specialised sense, he neither says nor implies that this is so. Hence we must not read into his use of it in this passage of the Republic the implication that it is possible to substantiate what is asserted to be true at the level of doxa, i.e. an empirical proposition, and thus to know it to be true. The best way to understand Plato's distinction here between doxa and knowledge is as a distinction between empirical and a priori knowledge, carrying with it the clear implication that the one is not convertible to the other. Plato's decision to use the term knowledge for a priori knowledge only is not always consistently maintained in later dialogues, but when he does use it of empirical knowledge he is using it in a general nonspecialised sense, and is not in any way contradicting what he says in the Republic, and repeats in dialogues of the latest period, the Timaeus and the Philebus, about the distinction between knowledge and doxa. The next point to consider is what Plato says in the passage of the Republic we are discussing about the objects of doxa, which are, as we have seen, sensible objects. His arguments here are of the same type as he used in the Phaedo (74b-c) and the Symposium (2IIa-b) in giving reasons for the imperfection of sensible particulars. Thus he argues that each sensible particular can have contrary predicates applied to it, and that this makes it impossible to have any firm conviction that one of the contrary predicates is properly applied to the particular, to the exclusion of the other predicate (479a-c). He concludes from this that sensibles belong to a 'shifting intermediate world' between 'Being' and

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'not-Being'; the world of 'Being' is the world of Forms (479c-d). His argument here has 110 more validity than had his argument for the imperfection of sensibles in the Pltaeio (74b-c), a passage which was examined in detail in the last chapter\He makes no attempt to consider the qualifications which would resoLVe the ,puzzle of this apparently contradictory feature of sensibles; and it is particularly surprising that he fails to note that some of the terms which he nses as illustration are relative terms (double and half, great and small, heavy and light), for in these cases the merely apparent nature of the contradiction is more. immediately obvious than in other cases. Plato's view is, then, that the contradictions which appear in sense-experience imply that sensibles are not fully 'real' in the sense in which the Forms are fully 'real'. But does this imply further that sense-perception is of no value as a guide of knowledge? Both the Phaedo, in its theory of recollection, and the Symposium had denied this, arguing that the status of sensible particulars as 'copies' of Forms enabled them to prompt the recognition of Forms, and thus to play an important part in eliciting knowledge of Forms. The Republic, however, makes no such concession to the senses. Having argued at 479C that contradictions in sense-experience make it impossible ever to have any firm conviction that one rather than the other of two contrary predicates is properly applied to a sensible particular, Plato returns in a later passage (523a-525a) to the discussion of these contradictions. He argues that experience of them prompts the mind to tum away from perception and to inquire, at a level of thought divorced from perception, what 'the large' is and what 'the small' is. The passage is in many ways an admirable illustration of the stimulus provided to philosophical reflection by apparent contradictions and puzzles in experience. But what is important to note for our present argument is that Plato assumes not only that the discovery of 'what "the large" is and what "the small" is' is made independently of perception, but also that what is established as the truth at this level of thought is never in any way true of sensibles. For sensible particulars, while they appear to be instances of two contrary characteristics at the same time, are never in fact instances of either. Thus, while Plato does here credit perception with the useful function of stimulating the mind to escape from it, he denies that sensibles ever reflect in any way what is true, for he implicitly contradicts the theory of recollection in its assumption that sensibles, as 'copies' of Forms, are able to prompt

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recognition of Forms and thus serve as a guide to the truth. It must be noted, however, that Plato does not assert that all instances of perception have the contradictory feature we have just discussed. Yet far from saying that in cases where no contradiction appears perception prompts the recognition of Forms he says that in these cases perception fails to prompt the mind to reflection of any kind on what is given in perception, since in these cases the judgements made by perception itself are 'satisfactory' (S23a-e). As an illustration he uses the case of the perception of several fmgers, and argues that though the mind is prompted by contradictions arising from this perception to inquire what is 'the light' and 'the heavy', 'the soft' and 'the hard', it is not so prompted, since no contradiction here arises, to inquire 'what is a finger'. Thus at a point where we might have expected Plato to grant a positive value to perception as an accurate indication of the truth, he implicitly condemns it as useless since it fails to prompt the mind to seek the truth in independence of perception. It is not possible, of course, to argue that Plato, since he asserts that in cases where no contradiction arises the judgements of perception are 'satisfactory', is here commending perception as itself providing a full answer to the question 'what is a finger'. His point is that the perception is 'satisfactory' to most (S23d4) percipients in the sense that they readily accept what is given in perception without being prompted to inquire at all 'what is a finger'. Contradictions in experience, on the other hand, 'compel' the mind to go beyond perception, and hence in this respect are 'useful'. Plato is thus emphasising yet again that only in independence of perception can the truth be established, and that perception is never to be used as a positive guide in seeking the truth. There is one final aspect of this argument to be considered. It can be maintained with some plausibility that, although plato dismisses as useless for stimulating thought cases of perception where the judgement of perception is 'satisfactory', yet it is implicit, in his assertion that no contradiction is afforded by them, that they are perceptions of ,images' of Forms, unlike the perception of sensibles which are apparently 'images' of two contrary Forms at the same time but in fact are 'images' or instances of neither. Yet even if this is granted it does not at all imply that plato would assume that such 'images' are therefore valuable as an aid to knowledge. All the evidence from the

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6S

Republic which has been considered so far shows that his position is that all perception, whether or l10t its object is properly an 'image' of a Form, is to be eschewed in seeking knowledge. The language of 'images' is in fact very prominent in the Republic - in the Line, the Cave, and elsewhere. Yet, except where PJato uses the term 'image' (eikon) for his own illustrative flgures or examples, it is never suggested that they are of value for the discovery of truth. Before considering some of the passages where he is explicitly discussing images, it is worth noting briefly that an 'image' of a Form, as the term is used in the Republic, is not only a particular sensible instance of a Form (as a particular dog is an 'image' of the Form 'dog'). 'Image' is also used in the sense of verbal 'image', which appears to be equivalent, in the Republic, to an empirical proposition. Thus Plato speaks of the 'images' of justice, beauty, and goodness, which are taken to be real by men whose level of apprehension is the same as that of the prisoners in the Cave (SI7d, S20C), images represented by 'imperfect analogies, popular definitions, suggestive phrases, wellmeant laws and institutions' .12 And this level of apprehension is doxa, for what plato says at SI7b and spa-c makes clear that the prisoners in the Cave have doxa only, which is said in the Line to deal with a world of 'Becoming' and not of 'Being', a world of sensibles and not of Forms (S34a). The 'images' with which doxa deals are in fact those described earlier in the Republic as 'the numerous conventional notions popularly held about beauty and the rest' (479d); and these notions, as the context makes clear, are based on sense-experience. These references suggest that in the Republic doxa is 'propositional', including in the scope of its expression both particular and general statements, and assuming as its basis a combination of perception and thought which reasons and sometimes makes 'clever conjectures' (SI6d) from its sensible data, but is always tied to such data as the only criterion of the truth of its results. Thus, as we noted earlier in the discussion of 476a fE, the distinction between doxa and knowledge is essentially a distinction between empirical and a priori knowledge, and it is important to see, especially for the purpose of contrasting Plato's position here with his position in the Phaedo, that just as by the intimate link which he appears to make in the Republic between the Forms and the method of hypothesis plato implies that knowledge is 'propositional', so by what he says about doxa and the 'images' with which it deals he implies

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that doxa is 'propositional'. This represents an important shift from the view taken in the Phaedo. There the distinction fundamental to the theory of recollection was a distinction between sensation and a conceptuallevel of apprehension, and the apprehension of Form was represented as a recognition of Form marked by the transition from sensation to a conceptual level. Thus the doxa of the Republic would be, according to the Phaedo doctrine, already a level of thought involving apprehension ofand reasoning about Forms. And this raises immediately the problem of what distinctions can be made to separate sharply doxa from knowledge consistently with the theory of Forms, especially with its assumption of an archetype-copy "relationship between Forms and sensibles. This problem will be discussed in the next chapter. For the present all that should be noted is that the main reason why the problem is avoided in the Republic is that by his severe disparagement of perception and its objects and his refusal to allow perception to play a positive part in the approach to knowledge Plato succeeds, at the cost of some inconsistency with his theory of Forms, in keeping doxa sharply separate from knowledge. In the light of this discussion of doxa and the 'images' with which it deals, we now see that 'image' is used to denote not only particular objects of perception but also verbal 'images', particular or general statements having their basis in perception. It is very difficult to say in some places what weight should be placed on the use of' image' in the Republic - whether it should be taken to mean 'image' of a Form in a sense which implies that it properly reflects the Form and preserves its similarity to the Form, or whether it is used more loosely to describe what appears to have this or that characteristic, or to be true of what is perceived, but is in fact a false and deceptive 'image' of what is 'real' (elsewhere in the middle dialogues Plato certainly does use 'image' (eid81on) in this latter sense, e.g. Theaetetus ISOC, Isoe, ISIC). But it is at least quite clear that, even where it can be assumed that he is using 'image' in the fonner sense, he considers images to be of no value as an aid to knowledge. At least it is only as a teaching aid that he is willing to accord any value to them, his assumption being that only with prior knowledge of the Forms is it possible to recognise whether anything is an 'image' and what it is an 'image' o£ The assumption is apparent in Plato's discussion of the early education of the guardians. It- is the business of the poet and artist, he argues, to produce in their

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work 'images' (40Ib, 402C) of goodness and beauty. The difficulty is that such images cannot properly be recognised for what they are. Thus the images may be images of the bad rather than the good, and though the many impressions of sense may be formed imperceptibly into some kind of unity, it is without consFious recognition of their meaning (40Ib-c). And Plato clearly implies that it is only when the Forms themselves are known that it is possible to recognise the images properly (402b-c). We can, in fact, be right, though without knowing why, in our appreciation of images only if our training is rightly directed from above (40Id-e). And those alone who have 'seen the truth concerning what is beautiful and just and good' will 'know what each of the images is, and of what it is an image' (S20C). It is, of course, natural that within a context where an educational programme is being discussed an emphasis should be placed on the use of images as aids in teaching rather than in other ways. But Plato insists that this should not be taken to imply that images are of value outside this limited use of them. Thus what he says about 'images' in these passages accords with all the other evidence from the Republic about his views on perception and its objects. Advocating an ideal of 'pure thought', he dismisses the claim that perception provides knowledge, and divorces perception completely from the method by which knowledge is to be attained. It is only by severely disparaging perception in this way that he is able to maintain a radical distinction between doxa and knowledge. For ifhe had seriously considered the claim that perception provides knowledge in the light of the implications of the Phaedo's doctrine of recollection, he would have been led to question the adequacy of the theory of Forms as the basis of a distinction between a priori and empirical knowledge. 4.

THE eRA TYLUS

a] Plato's criticism of verbal 'images' We must now consider other criticisms of perception made by Plato in the middle dialogues. In the Republic the only positive criticism is that the objects of perception have the contradictory character of allowing two contrary predicates to be applied to them at the same time. We may add to this the general assumption that the objects

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studied by dialectic and the mathematical sciences have an invariability and permanence which do not belong to sensibles. But no attempt is made to offer an explanation of the apparent contradictions arising in perception. The Theaetetus is the first dialogue in which such an attempt is made. Before examining it, however, the Cratylus, a dialogue which has many clear affInities with the Theaetelus, must be considered, for its discussion of'images', more especially verbal 'images', as representations of'reality' is both relevant and important, and so too are its remarks on the Heraclitean doctrine of flux. It is in the Cratylus that plato first ~xplicitly distinguishes the verbal image as one important class of images. 13 It must be admitted that he discusses the verbal image here in a particular restricted sense, since he relates his discussion of it to a theory of ' natural' language which makes a name significant by resemblance, resemblance between the form or sound of the letters of which the name is composed and the thing which the name signifies; the discussion explicitly assumes that single words have significance apart from statements, and can be true or false (38 5c). But towards the end of the dialogue (438a f£) the general question is raised whether it is preferable to discover reality through verbal 'images' of it or through the things which are themselves 'real', and it is clear that in interpreting Plato's answer to this there is no need to restrict the sense of 'image' to the narrow sense just described. His answer is that 'the truth of things' must be discovered through a study of the realities themselves. For since the difficulty of distinguishing true from false images seems to arise in the case of all verbal images we cannot resort to other verbal images as a criterion but must have knowledge of things indepe11dently of the use of verbal images if we are to decide whether a particular verbal image is true or false (438d-e). This answer recalls the implicit assumption in the Republic that independent knowledge of the Form is essential to the recognition of the image. In the Republic, however, the assumption was made only for those verbal 'images' which were empirical statements. It was not made for the propositions examined by the mathematical sciences and by dialectic, for though these too can be described as 'images' or 'representations' of'reality' plato does not suggest in any way that the study of them is other than the best way of attaining knowledge. The Cratylus, then, appears to make a much more sweeping condemnation of images than the Republic. Indeed, if one assumes that the realities are the Forms

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(and that this is so is suggested by the way in which the Forms are introduced at the very end of the dialogue) it is extremely difficult to imagine how one can practise, independently of all words or symbols, the direct inspection of realities which plato asserts to be the best way to attain knowledge. The probability is that Plato has been led to exaggerate here in his concern to protest 'against the view that the nature of reality can be discovered through a study of language alone, more particularly through a study of the Greek language of his time. For the Cratyltls seems to be mainly concerned to show the inadequacy of existing language as an instrument of inquiry into 'the truth of things', whether that language is interpreted from the point of view that names are significant 'by nature', or from the point of view that they are significant 'by convention'. Plato clearly assumes the possibility of a reform of existing language which will make it an adequate instrument of inquiry. Hence his appeal to the dialectician as the ideal 'superintendent' in the task of reformation (390c-d). Against this important assumption the question of whether language is 'natural' or 'conventional' is relatively unimportant. It is clear that Plato's view is that it is impossible to interpret an existing language exclusively on the basis of either of these theories, and that it is equally impossible to restrict the reform of language to a pattern dictated by exclusive adherence to either theory (435b-d). If, then, Plato thinks that language must be reformed to make it an adequate instrument of inquiry into 'the truth of things', what reasons does he give for this? In other words, what are the inadequacies that he fInds in existing language? His answer here is important as an explanation of his mistrust of verbal 'images', and points forward to what he says in the Theaetetlls in criticism of perception and its objects. His main criticism of existing language is that it possesses merely relative significance. Thus, on the theory that language is conventional, the correctness of words becomes relative to the particular individuals or particular societies establishing the convention (384c-39Ia, 433e). plato does not conclude from this that convention should be allowed no part in determining the' correctness' of words. He grants that it lllust play a part (435b-c). But since his assumption is that it is possible to establish a vocabulary which is adequate for the expression of 'the truth of things' he refuses to grant that the establishment of the' correctness' of words is properly left to 'any chance person' (390d).14 And he argues

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that since the 'conventionalists' wrongly assume that their theory implies that 'any chance person' is an adequate arbiter of correctness, then a natural corollary of their theory on the metaphysical side is a subjectivist theory of a Protagorean kind, which makes 'any chance person' an adequate arbiter of what is 'real' (38se-386a). Hence the weakness of existing language, in so far as its vocabulary is established by convention, is that its adequacy for the expression of the truth is entirely relative to what any ordinary person conceives to be the truth, or to be 'real'. Much the same kind of criticism can be brought ifit is assumed that words have a natural aptitude, through their form or sound, to signify their proper objects: For the signi£cance of the words will be relative to a particular interpretation of the nature of the 'reality' which the language is to mirror, and will constantly be subject to changes and transpositions dictated by individual fancy (414c-d, 436b ff.). The Greek language, in so far as it reflects a particular conception of 'reality', suggests that it is largely based on a Heraclitean flux theory of the nature of the world (402a, 4IIb-c, 439c); Plato's remarks at 439C seem to make clear that he is putting this forward seriously as his own view.

b] Plato's assumption that sensibles are i11 flux Now in criticising in these various ways the adequacy of current vocabulary to express 'the truth of things' plato appears to be advocating as an ideal of universal application what he had advocated in the Republic in particular application to geometry, when he argued that the normal language of geometry, fitted only to describe methods of practical construction, was ludicrously inadequate as a description of geometrical reality (S27a). Thus he is advocating a general reform of current language so as to make it adequate to express the truth as he himself sees it, i.e. to describe the eternal and immutable reality of the Forms. What is particularly signi£cant in his criticism of existing language is his view of the conception of 'reality' which is implicit in its terminology and usage. In the first place he argues that existing language can claim that it is c01lsistently adequate to express the truth only if it assumes a subjectivist theory of truth, such as that of Protagoras. In the second place he argues that, in so far as it does in fact imply with at least some consistency one particular objective theory of the nature of 'reality', it implies a Heraclitean doctrine of flux. Thus

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he links his criticism of the adequacy of existing verbal 'imagery' with the two theories which he will subsequently show, in the Theaetettls, to be essential to the consistency of any claim that 'knowledge is perception'. And in the Cratylus he sets against each of these theories his own theory of Forms. Against the subjectivism , of Protagoras he asserts that things 'have a fixed reality of their own, not in relation to us nor constituted by us' (386d-e). Against the flux theory of Heraclitus he asserts that knowledge is impossible if all things are in flux, for what is in flux is never in any determinate condition, and cannot significantly be named at all (439d-e). Hence, once we grant the possibility of knowledge, we must grant that its objects are not in flux, but are immutable, and agree that 'the beautiful itself', 'the good itself', and the other 'realities' are the objects of knowledge (43ge-44oc). Here for the first time the theory of Forms is explicitly opposed to the Heraclitean theory that all things are in flux. And what is to be especially noted is that Plato, having argued that to accept that knowledge exists and hence that objects of knowledge exist is to accept that knowledge itself and its objects are not in flux, assumes without question that the objects of knowledge are 'beauty itself, good itself, and all the other realities' (440b). For he is not arguing simply that to accept the existence of knowledge is to accept that its objects have some stability. This in itself would give him no greater justification for assuming that 'beauty itself', 'good itself', etc., 'realities' different from sensible particulars, are objects of knowledge, and hence stable, than for assuming that sensible particulars are objects of knowledge, and hence stable. But in fact his argument begins with the assumption that these 'realities' exist, that they are different from sensibles and that they 'are always such as they are' (439c7-d6). He then argues that if it is asserted that these 'realities' are in flux, then they cannot keep their own, or indeed any determinate form, and hence cannot be known. Indeed, he goes on, the existence of knowledge will have to be denied if all things are in flux. But, he concludes, on the assumption that knowledge, and hence objects of knowledge exist, and that 'the beautiful, the good, and all the other realities' exist, then there do exist things which are not in flux (44ob4-cr). Thus the argument begins and ends with an assertion of the thesis that non-sensible realities exist, and it is clear that plato considered the assumption of their existence essential in opposing the flux doctrine.

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Why is this assumption considered essential? It is obvious that plato does not think it enough, in opposing the flux doctrine, to put forward the logical argument that the doctrine has the apparently absurd consequence that nothing can be known, but thinks it necessary to select one special class of objects, the non-sensible 'realities', and to emphasise that these cannot be known if they are in flux. And his reason for thinking this necessary must be that he considered that if these nonsensible 'realities' were in flux then it would in fact be the case that nothing can be known. His argument thus implies his acceptance of the flux doctrine as true for sensibles. Hence the assumption made at the beginning of the argument - that there are non-sensible 'realities' which 'are always such as they are' - is essential for plato in that only on this assumption is knowledge possible. The important feature of this argument for our present inquiry is its implication that Plato accepts the flux doctrine as true for sensibles. The need to stress that this is clearly implicit in the argument arises only because an ambiguity in the text at the beginning of the argument allows the possibility of doubt as to whether Plato is there explicitly asserting that he accepts the doctrine as true for sensibles, and hence accepts as true for sensibles what he asserts to be true for anything in flux. The ambiguity arises at 439d4. Having asserted that there exists 'beauty itself, good itself, and all the other realities', Plato goes on: 'then let us consider beauty itself, not asking whether a particular face, or anything of that sort, is beautiful, and all these things appear to be in flux'. Is 'whether' (ei) to be understood with the last clause (... and [whether] all these things ... )? Grammatically this would seem the more obvious interpretation. 15 Yet for the sake of the logical sequence of Plato's argument there are very strong reasons for taking this clause in an explanatory sense: '(for) all these things appear to be in flux'.16 So taken it is a statement by Flato that he accepts the doctrine of flux as true for sensibles. Such a statement is obviously called for at this point. For since Plato has just asserted that, in the argument against the flux theory which is to follow, he is excluding sensible particulars from consideration, it is natural to expect that some reason will immediately be given for this exclusion. The clause 'all these things appear to be in flux' would provide such a reason, and once accepted as the statement of a reason for excluding sensibles from consideration it makes much clearer than would otherwise be the case the purpose and sequence of

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the argument which follows. These, to me, are very good groWlds for interpreting the clause in this sense. The position is, then, that Plato, at least implicitly and ahnost certainly explicitly also, is accepting the flux doctrine as true for sensibles. He had, of course, earlier in the Phaedo made clear , his view that sensibles are constantly changing and that this is a reason for condemning perception as incapable of yielding truth (78c-8ob, 83 b). And that he accepted the flux doctrine as true for sensibles is stated by Aristotle in two passages in the .J.\1efaphysics (987a32-b7, I078bI2-I7) where he is explaining that Plato's acceptance of the flux doctrine as true for sensibles led him to postulate non-sensible Forms in order to save the possibility of knowledge. Moreover Aristotle's statement that Plato continued in later life to believe that sensibles were in flux seems to be confIrmed by passages in late dialogues such as the Timaetls (49d-e) and the P/tilebtls (S9b) , which affirm that sensibles are constantly changing. Thus the evidence of the Cratylus is by no means the only evidence for Plato's acceptance of the flux doctrine. Yet it does deserve special emphasis and consideration. For it is the only place in the dialogues where Plato clearly shows that he considered the specifIcally Heraclitean doctrine of flux to be true for sensibles. The fact that in the Theaetettls he makes this Heraclitean doctrine an essential part of the basis of the claim that 'knowledge is perception' does not itself show that he himself accepted it as true for sensibles. But the evidence of the Cratyitts, confIrming from the dialogues themselves Aristotle's testimony, allows us to assume that in the Theaetetus too Plato accepts the doctrine and hence accepts the implications which he there finds in it. This last point is important in assessing the severity of Plato's condemnation of perception and its objects in the middle dialogues. The Cratylus and the Theaetetus are the only two dialogues where Plato discusses the flux doctrine as a specifIcally Heraclitean doctrine, and in each case his attempt to reduce to absurdity the claim that what is in flux can be known leads him to the extreme position of denying that there are any determinate sensible characteristics. For his argument, both in the Cratyltls and the Theaetettls, includes a denial that what is in flux is in any way determinate. And this, assuming as Plato does that sensibles are in flux, is a denial that there are any determinate sensible characteristics. Thus in the Cmtylus Plato affirms that no signifIcant description can be applied to what is in flux; one cannot F

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describe it as 'that' or as 'of such a kind', because it is never in any determinate condition. The same argument appears again in the Theaetetus (I57b, 182d-I83b; c£ 152d). Hence to agree that sensibles are in flux is to agree that it is impossible to describe them. What then becomes of the doctrine that sensible characteristics are 'copies' or 'images' of Forms, that they are recognisable and hence are able to prompt the recollection of Forms? This doctrine clearly assumes that there are determinate and recognisable sensible characteristics; indeed it is a doctrine that sensibles are determinate and recognisable in so far as they 'participate in' and hence 'resemble' Forms. There is a serious inconsistency, then, between this doctrine and the consequences drawn by plato from the fact that sensibles are in flux. It is an inconsistency which some scholars are reluctant to admit, and attempts have been made to resolve it by denying that plato ever accepted the flux doctrine as true for sensibles. Thus it has been argued that when plato in the Theaetetus (I82d-r83c) attempts to reduce to absurdity the thesis that 'all things are in flux' by showing that it implies that no significant description can be applied to anything, and that all answers to any question about anything are equally right, 'we are tacitly given to understand that these consequences are obviously false and therefore the view which entails them must be false also'. 17 So far there can be no quarrel with this argument. Plato does intend here to reduce to absurdity the view that 'all things are in flux'. But to reduce this view to absurdity is not equivalent to reducing to absurdity 'the proposition that everything in this world is always changing', though the argument assumes this when it goes on to assert that Plato's argument shows 'that there is something stable in tltis world. For a refutation of the proposition that everything ill this world is always changing both its place and character would be a proof of the proposition that something itt this world is sometimes stable in respect of either its place or character or both.' 18 plato is clearly Hot, however, refuting the proposition that everything in tltis world is always changing. Both in the Cratylus and the Theaetetus it is perfectly explicit that the thesis which Plato attacks is 'that all things are in flux', and in each case his main concern is to show that what is in flux cannot be known (for it cannot even be described in any way), and hence that, if all things are in flux, l1othi11g can be lu"1own. But the possibility of using the absurdity of this final consequence as an argument for the view

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75 that 'there is something stable in this world' arises only if the thesis 'that all things are in flux' is associated with the thesis 'that all things are things in this world' (i.e., presumably, sensibles). In that case to argue, from the absurdity of its consequences, that the proposition that 'all things are in flux' is false is to argue that one of two theses is false - that either'all sensibles (= all things) are in flux' is false (hence some sensibles are not in flux) or 'all things are sensibles' is false (hence some things are non-sensibles and are not in flux). But the fact that the view that 'all things are ill flux' (where all things are sensibles) entails absurdities does not itself allow us to assert which one of the above two theses is false. Nor does Plato, in the Theaetetus, suggest in any way that it does. In 182d-I83c he is attacking the view that all things are in flux as the basis of the thesis that knowledge is perception, and as the basis of such a thesis it can readily be admitted that the view that all things are in flux appears to be associated with the view that all things are sensibles; but all that Plato concludes from the absurd consequences of the view that all things are in flux is that the thesis that knowledge is perception is false in so far as it is based on that view (183 c). Only by agreeing that 'all things are sensibles' must continue to be accepted as true would he be able to argue further that 'all sensibles are in flux' must be false, and hence that some sensibles are not in flux. And he neither says nor implies that he agrees with this. In fact, once we compare the argument of the Theaetetus with the very similar argument at the end of the Cratylus, we see that what plato accepts as true is that all sensibles are in flux, and hence that he can argue from the absurdity of the consequences of the view that all things are in flux to the falsity of the view that all things are sensibles, and thus give reasons for assuming that there are non-sensibles which are not in flux. We may conclude, then, that the Theaetetus does not show 'that there is something stable in this world', and that the Cratylus clearly shows that plato accepted the Heraclitean doctrine of flux as true for sensibles, and hence accepted as true for sensibles the consequences that what is in flux has no determinate characteristics and can have no significant description applied to it. As we noted earlier, it is only in the Gratylus and the Theaetetus that plato examines the specifically Heraclitean flux doctrine and only in those dialogues uses against a flux doctrine a particular reductio ad absurdum type of argument implying

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an extremely severe condemnation of sensibles. But this does not, I think, imply that his acceptance of the Heraclitean view as true for sensibles is to be differentiated from his view that sensibles are constantly in change, a view which he expresses in later dialogues without any of the severe condemnation of sensibles characteristic of the middle dialogues. In other words I do not think that at one time Plato thinks of sensibles as subject to a sort of change which precludes the possibility of describing them, and at another time thinks of them as subject to an essentially different sort of change which allows them to be significantly described. The truth appears to be that, while in later dialogues he acknowledges that the fact that sensibles are in flux is not inconsistent with their function as 'images' of Forms, his attitude of severe disparagement of sensibles in the middle dialogues leads him to exaggeration ill examining the consequences of the fact that they are in flux, and thus leads him to a view of them inconsistent with the view that they 'participate in' and 'resemble' Forms. In this respect the Gratylus, with its introduction of arguments from the doctrine of flux, illustrates even more strikingly than the Republic had done the serious difficulties which arise for Plato's theory of knowledge from his uncompromising attitude of contempt for perception and its objects. And it is as well to recall, in concluding this examination of the Gratylus, that Plato's argument at the end of the dialogue is a criticism of the flux theory as a theory representing that conception of 'reality' which is, Plato appears to assume, implicit in the present form of the Greek language. Hence his fmal remarks associate a condemnation of the flux doctrine with a plea not to put trust in names (44oc-d). Thus, when we note further that he asserts that what he says about the adequacy of single names to represent 'reality' is true also for propositions (logoi: 43Ib), we can see that his criticism of existing language as an adequate instrument of inquiry into 'the truth of things' implies ultimately that all propositions expressing what is apprehended at the empirical level described as doxa in the Republic are meaningless.

s.

THE THEAETETUS

a] The thesis that knowledge is perceptio11 This examination of the Gratylus has enabled us to dispose of one of

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77 the difficulties which arise from the discussion of perception in the first part of the Theaetettls. For the evidence of the Cratyltls that Plato accepts the Heraclitean doctrine of flux as true for sensibles clearly justifies the inference that his argument in the Theaetettls that what is in flux is valueless as a basis of knowledge represents his own conviction about sensibles. The point is, as we have seen, important. For the first part of the Theaetettls is not a direct presentation of Plato's views on the nature of perception and its objects, but rather an examination of the assumptions necessary to make fully consistent the thesis that 'knowledge is perception'; and the fact that Plato, having stated the assumptions, attempts to reduce them to absurdity obviously does not imply that he accepted any of them, or any part of any of them, as true of perception or of the objects of perception. This purpose of the first part of the dialogue makes it, indeed, an excellent example of the application of the method of 'hypothesis' to a particular thesis. The 'hypothesis' from which the discussion starts is that 'knowledge is perception'. Plato interprets this as a claim that whatever anyone asserts to be the case on the basis of what he is at the moment perceiving or of what he has perceived in the past is necessarily true, and not only this but that this basis in perception is both a necessary and a sufficient basis of knowledge; there is no knowledge other than what is based on perception. It is true that Plato's examination is directed initially to 'pure' sensation, but it becomes clear that 'perception', in the claim that 'knowledge is perception', is meant to include memoryimages (163d-166c) and judgement (158b, 161d, 178b, 179c). Once the hypothesis is interpreted in the above sense, and it is recognised that it is impossible to know and yet to be wrong (I 52C), the hypothesis is seen to be assuming that perception is infallible. Plato therefore makes it his first task to see what further assumptions must be made to allow this assumption to be consistently maintained. He says firstly that the claim that knowledge is perception implies acceptance of the thesis of Protagoras that 'man is the measure of all things' (I52a). For it follows from this thesis that perception is infallible, which is assumed in the claim that knowledge is perception. Thus, according to Protagoras, what appears to be the case is the case, and hence what is perceived to be the case is the case, for all instances of perception (I52a-c). Plato argues further that the Protagorean thesis rests in turn on the thesis that all things are in motion and perpetually changing (I5 2C- I 53 d ).

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This latter thesis is not, of course, implied by the Protagorean thesis, which in fact denies the validity of any claim to be able to specify the general characteristics of an external 'real' world which is common to everyone as the object of their perceptions. However, Plato is no doubt sincere in his contention that it is only if everything is in fact in flux that the thesis that knowledge is perception becomes consistently tenable, and for this reason, having already argued that the claim that knowledge is perception implies acceptance of the Protagorean thesis that 'man is the measure of all things', he develops the Protagorean thesis as a thesis based on a flux doctrine, though there is no reliable independent evidence that Protagoras himself based his thesis on such a doctrine. In what way, then, does a flux doctrine support the claim that knowledge is perception? According to Plato the infallibility of perception can be shown to be a consequence of the doctrine that all things are in flux. For if everything is in flux, then, assuming that perception implies an interaction between the individual percipient and his environment, it will follow that all percepts are the result of an interaction between constantly changing sense-organs and a constantly changing environment (I53d-I54b, Issd-IS7c). The relativity of the percept at once to the individual percipient and to particular circumstances could, of course, have been argued independently of any theory of flux. And this relativity, since it points to the difficulty of trying to justify the claim of anyone 'perception' over another to yield knowledge, could plausibly have been used to support an argument that all cases of perception have an equally strong claim to be able to yield knowledge, and hence are all equally 'true'. What, then, does the assumption that all things are in flux add to the plausibility of such an argument? The flux doctrine itself does not entail that each individual percipient is restricted ill what he perceives to a private world different from that of any other percipient. In other words it is not a doctrine necessarily inconsistent with the doctrine that what is perceived is the same for all percipients in the same situation. It is clear, however, that Plato does consider that the two doctrines are inconsistent. His assumptions appear to be: (i) if everything is in flux, then 'nothing is ever the same'; (ii) if 'nothing is ever the same', then no two percepts are ever the same; (iii) if no two percepts are ever the same, then the percepts of one individual are always all different from those of any other indi-

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vidual, and hence are private and peculiar to that individual. The confusion here is in the interpretation of 'nothing is ever the same'. If everything is perpetually changing, then it is true to say that no particular event in a process of change is 'the same' as the one immediately preceding it or the one immediately following it, and that no particular event ever remains 'the same', in the sense that it preserves its identity and is not subject to change; it must necessarily be succeeded by another and a different event. In these two senses of 'the same' the doctrine of perpetual change appears to entail that 'nothing is ever the same'. But it does not entail that no particular event or series of events recurs or is repeated at another time or in another place at the same time. Hence it does not entail that no particular event or series of events is ever 'like' (see 159b) any other event or series of events; in this sense it does not entail that 'nothing is ever the same'. Later, in the Timaeus (49d-e), Plato came to recognise this, but here in the Theaetetus he apparently does not. If he had done, he would have seen that the individual's percepts, viewed as the result of the interaction between constantly changing sense-organs and constantly changing environment, may be 'like' the percepts of another individuaL possibly of all other individuals, and that they are not necessarily 'unlike' those of any other individual, and hence private and peculiar to him. If, however, there is some confusion in the way in which Plato links the thesis that' man is the measure of all things' with a doctrine of flux, it is not difficult to see, from his discussion, what considerations initially led him to assume a connexion between the two doctrines. It is significant that in illustrating the connexion Plato relies almost exclusively on the fact of the relativity of the individual's percepts to his bodily condition. Thus changes in bodily condition imply changes in the percept, and a perpetually changing bodily condition implies perpetually changing percepts. Socrates-ill, says Plato, has different percepts from Socrates-well, and so on (I58e-I5ge). This immediately establishes one sort of connexion between the concepts of change and of relativity, and it is clearly one to which Plato attaches great importance. And his earlier remarks in 154a almost suggest that this sort of connexion constitutes for him an afortiori argument for the view that the percepts of each individual are private and peculiar to him in a way which excludes the possibility that they are 'like' the percepts of any other individual. For having given the flrst summary account of

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the percept as the result of interaction between sense-organ and external 'motions' (IS3d-IS4a) he assumes immediately that this account implies that percepts are peculiar to the individual percipient (IS4a). And to counter any possible doubt about the truth of this consequence, he asserts that one can actually affirm with certainty that 110t eVe11 to oneself does anything ever appear 'the same', since one is never in the same condition. Aristotle too, in the Metaphysics (Ioo9b), presents the fact of the relativity of the individual's percepts to his bodily condition as the principal argument in support of the subjectivist view that what appears to the senses must be true. 19 So far, then, Plato has argued that the thesis that knowledge is perception, implying, as he interprets it, the infallibility of perception, must, if it is to be consistently tenable, assume the truth of the Protagorean doctrine that 'man is the measure of all things', and that this doctrine in turn assumes that everything is in perpetual change. His reason for interpreting it as a thesis that perception is infallible is presumably that he considered that only in that sense could it plausibly be maintained in the face of all the apparent contradictions and inconsistencies arising from perception. For he is concerned to emphasise that, once it is interpreted in that sense, then any apparent contradictions and inconsistencies are resolved (IS4b-Issd, IS7e-Is8e). It seems possible to argue, therefore, that plato is honestly trying to make out as consistent a case as possible for the claim of perception to yield knowledge, and that any confusion in his manner of associating it with a doctrine of flux is inadvertent confusion rather than deliberate perverSIOn. Yet in one respect at least it is difficult to avoid the conclusion that he is deliberately weighting the scales against perception. Thus he refuses to apply the term 'is' or 'being' to what is perceived; 'nothing is, but is always becomillg' (I52d-e, I 57a-b, 157d). 'Becoming' is associated (I57b) with 'being produced', 'perishing', and 'changing'; it is contrasted with what is defmite or determinate, Plato's assumptions being (i) that only to what is definite or determinate can the terms 'is' or 'being' be properly applied, (ii) that 'becoming' excludes 'being determinate' (I52d-e, 157a-c). By this manner of presentation he is already preparing the way for his criticism later in the dialogue of the thesis that knowledge is perception, in particular for the argument that 'being determinate' is a condition of 'being known'.

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In considering this stipulation about the proper application of 'is' it is important, in the first place, to distinguish it from the stipulation that 'Being' (to Oil) is to be ascribed to Forms but not to sensibles, which belong to a world of 'Becoming' (gellesis). For this latter stipulation does not include the stipulation, that 'becoming' excludes 'being determinate'. It uses gellesis as a general description of a world of changing and hence impermanent characteristics, this change and impermanence being contrasted with the immutability and permanence which Plato assumes to belong to the 'really real' (to 011tOS Oil). For as a term properly used to describe the process of attaining some determinate state, genesis is naturally associated with change, and hence is a suitable enough term for Plato's purpose here. This is, of course, a stipulation which would become unwieldy if an attempt was made to adhere to it ,vith rigorous consistency in discussion, as Plato well realised,20 and he does not pretend to maintain such rigorous consistency. In particular, since this distinction between 'Being' and 'Becoming' is not meant to imply that 'Becoming' excludes 'being determinate', he is quite ready to use 'is' and 'being' for what is determinate in the world of 'Becoming', and to use 'becoming' for the process of attaining a determinate state, a narrower sense than that given to it in the original distinction. Moreover, he makes clear that the world of 'Becoming', within which this subsidiary distinction between 'being' and 'becoming' is made, is a world of perpetual change. Thus in the Phaedo, where he emphasises that the visible world is one of perpetual change (78c-79c), he discusses the causes of ' comingto-be' and 'perishing' within this world (96a ff.), or, more fully, the causes of 'coming-to-be' and 'perishing' and 'being' (97c). And in giving his own explanation in terms of the theory of Forms he sees his task as that of explaining the fact of the determinate, yet impermanent characteristics of sensible things. Thus he says that the only way in which anything 'comes to be' is 'by participation in the proper reality of any given form in which it participates' (IOIC).21 For example, anything that is to be two (ta mellotlta duo esesthai) must participate in 'duality', and similarly anything that is to be one must participate in unity (IOIC). Here Plato accepts the fact that the world of 'Becoming' has determinate characteristics and readily uses the verb 'to be' to designate the 'being' of the determinate characteristics which are the end result of the process of 'coming-into-being' (ge11esis). The same

PLATO'S THEORY OF KNOWLEDGE

kind of distinction is found later in the Philebus when Plato is again explaining the determinate characteristics of the world of 'Becoming' . Here the process of 'coming-into-being' is described not simply as genesis, but more fully and precisely, so as to distinguish the process of 'becoming' from the resultant 'being', as gellesis eis otlsian. (26d); the same distinction is found also in the phrase used to describe this resultant 'being' - gegel1.emene ousia (,the being that has come to be': 27b). In the Philebus too it is made clear that the world to which the two terms in this distinction are applied is a world of perpetual change (S9a-b). Now that we have distinguished (i) the stipulation that 'Being' is to be distinguished from 'Becoming' as the permanent and immutable (Forms) from the impermanent and changing (sensibles): and (ii) the subsidiary distinction, within 'Becoming', of 'becoming' and 'being' as a distinction between 'coming-to-be determinate' and 'being determinate', it is clear that it is the distinction in (ii) which is relevant to the assessment of Plato's argument in the Theaetetus. For his argument is that what is in perpetual change and motion is never in any determinate condition, and that consequently 'being', as defined in (ii), is never applicable to it. Hence he says that no predicate can ever be properly applied as a description of what is in flux, so that to say 'it is X' of any part of the flux, where 'it is X' means 'it has the determinate characteristic X' , is always improper (I s2d, I S7a-b). Thus he is contradicting what he says in the Phaedo and the Philebus; whereas in those dialogues he finds no incompatibility in the view that a world of perpetual change has determinate characteristics, he asserts in the Theaetetus that 'being in flux' is incompatible with 'being determinate'. It is no doubt true that for Plato the only explanation of the existence of determinate characteristics in the sensible world is in terms of Forms, and it may be argued that this has led him to believe that to hold that everything is in flux and thus not to accept the existence of Forms is to exclude the possibility of the existence of determinate sensible characteristics. It is possible, I think, that this kind of reasoning may have influenced Plato in his presentation of the case for perception in the Theaetetus. But it does nodling to resolve the serious inconsistency between what Plato says in the Theaetetus and what he says in other dialogues such as the Phaedo and the Philebus. For, as we saw in considering the CratyIus, Plato does accept that the sensible world is in flux, and uses the argument that what is in flux is never in any deter-

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minate condition as an argument for postulating the existence of nonsensible 'realities' not subject to change, on the ground that otherwise knowledge is impossible. Thus at the same time he asserts that Forms exist and denies that the sensible world has any determinate characteristics. This in itself is implicitly to acknowleqge that the argument that 'being in flux' is incompatible with 'being determinate' is equally valid whether or not it is assumed that Forms exist. Nor indeed is it the case that when Plato accepts that the sensible world has determinate characteristics and explains these in terms of 'participation' in Forms he is thereby absolving them from change and impermanence. It is part of the 'imperfection' of these sensible 'copies' of Forms that they lack the constancy and permanence of their archetypes, and there is no warrant at all, as we shall see in more detail when considering the Timaeus, for assuming that 'copies' of Forms are not subject to change and are permanent, and thus resolving the inconsistency between the Tlteaetettls and other dialogues; the determinate characteristics of the sensible world are characteristics of a perpetually changing world and are themselves perpetually changing; this the Phaedo, Timaeus, and Philebus quite clearly assume. Thus, in the light of the inconsistency between these dialogues and the Theaetetus, it becomes clear that Plato is ready to use against the thesis that knowledge is perception an argument which, except in the Cratylus, he invariably assumes to be invalid when he is presenting his own theory of Forms. And this suggests that he is deliberately weighting the scales against perception.

b] Plato's criticism of the thesis So far we have considered the manner of Plato's presentation of the claim that knowledge is perception, and concluded that, although in general it may be considered a fair presentation in the sense that it appears to be a serious attempt to state the assumptions which would make the claim as consistently tenable as is possible, it does in one important respect seem to be less than fair. We must now consider the criticisms which Plato makes of the claim, as thus presented. In the first place he develops the point that 'being in flux' is incompatible with 'being determinate', arguing that, since what is perpetually changing both its place and character is never in any determinate condition, then what is perpetually changing cannot be known. And since it has been shown to be a necessary assumption of

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the claim that knowledge is perception that what is perceived is thus perpetually changing, then what is perceived cannot be known (I8Ib183c). Thus the claim that knowledge is perception is disproved in so far as it is based 011 the view that all things are in flux (I83c). The main point which he makes in the course of this argument is that unless what is perceived has some stability and fixity it is impossible to apply any significant description to it, and he assumes that unless this possibility exists, it is impossible to claim to know that something is the case. He is clearly thinking of simple perceptual judgements of the kind 'this is yellow' or 'this is a stone' (I82d, 183a). Now we have already seen, in considering the argument at the end of the CratyIus, that this argument, which is closely similar to the present argument in the Theaetetus, shows that Plato accepts as true that all sensibles are in flux, and hence can argue that if knowledge is to be possible it is necessary to assume the existence of some determinate non-sensible 'realities'. Though the Theaetettls does not make this explicit, it is legitimate to say, on the evidence of the CratyIus, that it implies it. It would follow that any significant judgement, however simple, implies the existence of such non-sensible 'realities'. It would follow also that such judgements have no application to the sensible world. This last consequence is, however, apparently denied in Plato's next argument (I84b-I87a). He begins it by pointing out that we see and hear, not with our eyes and ears, but through them. There is a unitary 'soul' with which we perceive all the objects of perception through the senses as instruments (I84d). Perception (aisthisis) is, however, limited to the isolated 'impressions' (pathimata) which are conveyed to the 'soul' through one or other of the particular senses, and it is the distinctive feature of the perceptual activity of 'soul' or ruind 22 that each impression is conveyed through a single sense-organ. Plato is here attempting to specify the purely perceptual elements in cognition, and he now goes 011 to distinguish as non-perceptual the 'thought' (dialloia) and 'reasoning' (syllogismos) of the mind when it is 'occupied with things by itself' independently of any bodily 'instrument' (I8sa ff.). This is an important distinction, and enables Plato to defme aisthesis with some precision before considering whether knowledge is aisthesis as thus defined. Examples which he gives of the 'impressions' to which aisthesis is limited, and which are exclusive to one or other of the particular sense-organs, are warm, cold, hard, soft, light, sweet, white,

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black (I84b-e, 186b, d). These, he says, can be perceived by animals as well as men from the moment of birth (I86c). Contrasted with aistMsis are the thought and reasoning of the mind 'by itself', and the nature of this independent activity of mind is defined in the following way. If there is a characteristic applicable to the qbjects of more than one sense-organ, that characteristic is apprehended by the mind per se, without the mediation of the senses. Being and non-being, difference and sameness, oneness and twoness, likeness and unlikeness, evenness and oddness, beauty and ugliness, goodness and badness are instances of such characteristics (I85a-I86a). These are 'common' characteristics in the sense that, unlike perceived characteristics, they are applicable to the objects of more than one of the senses (I85b-e). And they may be described as a priori, in the sense that, though certainly applicable to perceived characteristics (e.g. 'white is different from black'), they are never, according to Plato, given in perception but apprehended independently of it. It is by particular appeal to the characteristic of 'being' that this distinction is used to refute the thesis that knowledge is perception. Thus, since (a) 'being' is an instance of a 'conunon' characteristic and hence, by definition, not given in perception, and (b) to know is to know what is or what is true, and hence to apprehend 'being' or truth (I86c, e), then knowledge is impossible if apprehension is limited to the isolated impressions of one or other of the particular senses. plato concludes that knowledge is not to be found in the 'impressions' afforded by perception, but in the mind's reflection (syllogismos) about them (I86d). This reflection includes all discrimination and comparison not only of what is given in perception (I86b-c), but also of the common characteristics themselves (I86a), and is subsequently described as 'believing' (doxazein, 187a). More precisely, belief is the restllt of reflection, which is further described in 18ge-I90a as an internal debate in the mind issuing in affirmations or denials, unspoken statements (logo i). These statements are expressions of doxa or belief, and it is the thesis that knowledge is true belief which now replaces the thesis that knowledge is perception. The point of similarity between this present argument and the previous argument against the doctrine of flux is that each is assuming that the problem of knowledge is to be approached initially as the problem of the conditions for the application of predicates significantly to what is perceived. The argument against the flux doctrine was that if

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everything is in flux, then no significant description can ever be applied to what is perceived, so that even the simplest judgements such as 'this is yellow' or 'this is a stone' become inapplicable. And it appears to be assumed that knowledge includes judging significantly that something is the case, a condition of the significance of the judgement being that its reference is to what is determinate. Since it is impossible to satisfy this cOl1dition if the flux doctrine is true, then the thesis that knowledge is perception is refuted in so far as it rests on that doctrine. The thesis, as we have seen, does not limit perception (aisthesis) to 'sensation', but takes it to include 'sensations and the judgements in accordance with them' (I79c). In this argument against the flux doctrine Plato has concerned himself primarily with what he distinguishes in his next argument as strictly perceptible qualities. He now goes on to show, in this next argument, that, even if it is assumed that there are determinate sensible characteristics, yet aisthesis cannot legitimately be said to include anything other than the isolated 'impressions' of these characteristics, conveyed by the senses to the mind, since to go beyond the impressions and to make Judgements in accordance with them' involves an independent activity of mind; hence it is illegitimate to construe aisthesis as 'sensations and the judgements in accordance with them'. And since it cOl1tinues to be assumed that knowledge includes judging significantly that something is the case, then, since any judgement involves an independent activity of mind, knowledge cannot be equated with perception. We have already seen that in making this distinction between aisthesis and the 'thought' and 'reasoning' of the mind Plato is primarily concerned to show that there are concepts which, though not derived from perception, are nevertheless applicable to what is perceived. 'Being' (ousia) is such a concept, and in assuming its applicability to strictly perceptible characteristics (18 sa, I 86b ) Plato seems to be contradicting what he had argued earlier in refusing to apply 'being' to what was in flux (IS2d-e, IS7a-b, 182b, 183a), and hence to sensibles. It might be argued that this assumption is simply an instance of the bad habit of using the term 'being' loosely, a habit which Plato recognises in IS7b as one responsible for a lack of precision at several points in his exposition so far. This is a possible and in some ways plausible explanation. But I am inclined to think that the explanation is that Plato readily and naturally assumes, as he did earlier in the

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Phaedo, that there are determinate sensible characteristics, overlooking the fact that in his previous argument he had implicitly denied their existence. And he is now arguing, as we have seen, that, assuming that there are determinate sensible characteristics, yet aistMsis itself never affords knowledge. , It is, I think, important to note that plato is not arguing that, while some knowledge is derived exclusively from perception, some is not. His argument is that 110 knowledge is derived exclusively from perception. Thus, to take again the examples 'this is yellow' or 'this is a stone', plato would say that, while 'yellow' and 'stone' are perceptible characteristics, the simple judgement 'this is yellow' or 'this is a stone' includes the application of 'being', which is apprehended by the mind independently of perception. It is true, of course, that the 'is' in these examples is not used existentially. Yet it is clear, from Plato's previous discussion of the distinction between 'being' and 'becoming' in the Theaetetus, that 'this is yellow' is, for Plato, an implicit assertion of the 'being' of yellow, in the sense of 'being a determinate characteristic', and this is equally clear from the discussion of the distinction between 'being' and 'becoming' in the passages of the Phaedo and the Philebus examined earlier. Moreover in I87a plato describes as doxa the level of apprehension attained by the mind when its activity is directed to 'things' (ta onta) independently of perception. I am not convinced, incidentally, that it is right to translate doxa here as Judgement'. I have myself frequently used the term Judgement' in discussing Plato's argument, but without intending it to be assumed that it is a translation of Plato's doxa. I prefer to translate doxa as 'belief'. The way in which plato illustrates the distinction between true doxa and knowledge in 20 I a-c, and his phrase 'true doxa with an account' as a proposed defInition of knowledge (20Id ff.), both suggest that he is using doxa in the Theaetetus for 'belief', in the non-specialised sense in which it is regularly distinguished from knowledge in other dialogues by its inability to 'give an account' of itself. Doxa, in this sense, does, of course, include judgement, but only an explicit distinction between doxabelief and doxa-judgement would justify a translation of doxa as judgement, either here in the Theaetetus or later in the Sophist. Now Plato's point that doxa is a proper description of the mind's level of apprehension when it is occupied with things 'by itself' indicates that in his view any belief that something is the case involves the application of

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characteristics which are apprehended independently of perception, and, of course, his argument that the fact of this independent form of apprehension refutes the hypothesis that knowledge is perception indicates that any knowledge that something is the case similarly involves such application, and hence is never derived exclusively from perception. The question which now arises is whether this argument is intended to imply what the previous argument implied - that if we assume the possibility of knowledge it is necessary to assume the existence of nonsensible 'realities'. For since Plato has explicitly distinguished some characteristics as apprehended a priori, in the sense that the apprehension of them is independent of perception, it is natural to ask whether he considers that they have a 'reality' independently of the mind's apprehension of them. Clearly the argument itself does not commit him to any deftnite view on this question. If it is granted that aisthesis is limited to the isolated 'impressions' conveyed through the senses, and that knowledge necessarily involves an independent activity of mind not included in sensation, then the thesis that knowledge is aisthesis is refuted, no matter what further interpretation is given to the mind's independent activity. And though I consider it highly probable that Plato's argument is meant to point to the need to assume nonsensible 'realities' if knowledge is to be possible, I do not feel there is sufficient warrant for assuming that he is here consciously arguing from the standpoint of his theory of Forms. The validity and importance of the argument should be assessed quite independently of that theory. It is interesting, however, to compare what he says here with what he has said earlier about knowledge of Forms, especially as regards the part played by perception. We have seen that in the Republic the existence is assumed of one Form for each set of things to which the same name is applied. It is further assumed (i) that knowledge is of Forms, and Forms only; (ii) that there is an inferior level of apprehension which is not directed to Forms at all but exclusively to sensibles; Plato calls this doxa, and clearly takes it to be 'propositional'; (iii) that perception has no contribution to make to knowledge. In the Phaedo there is far less consistency in Plato's argument. Though Plato appears to make assumption (iii) when condemning the senses from a moral standpoint and when discussing the method of hypothesis, he

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asserts in his discussion of Recollection that perception of sensible 'likenesses' of Forms is essential to the recognition of Forms. As for his view of the extent of the world of Forms, this is not made so explicit in the Phaedo as in the Republic. But he does at least assume that each Form has perceptible instances. If we co,mpare the Phaedo and the Republic in these respects widl the TheaetettlS, it is clear in the first place that the Theaetettls is introducing distinctions which are not found in either the Phaedo or the Republic, and which it would be difficult to incorporate within the theory of Forms of either the Phaedo or the Republic. Thus if we assume, as we have good right to assume, that the hypothesis that at least some knowledge is derived from reflection about sense-impressions is intended to be a serious contribution to the question of the nature of knowledge, then the hypothesis is at variance with the thesis of the Republic that perception has no contribution to make to knowledge. On the other hand, if compared with the Phaedo's doctrine of Recollection, which does acknowledge the value of perception as an aid to knowledge, the hypothesis is at variance with the apparent assumption of the Phaedo that each Form has perceptible instances and that these initially prompt recognition of the Form; for it maintains that independently of perception the mind apprehends 'by itself' characteristics which, unlike others which are perceptibles, are not given in perception at all. There is, finally, the interesting question whether the hypothesis is at variance with the thesis of the Republic that there is a 'propositional' level of apprehension (to describe which the Republic uses doxa in a specialised sense) which is distinctively empirical, directed exclusively to sensibles. According to the hypothesis this level of apprehension would, from its 'propositional' nature, include the apprehension by the mind 'by itself' of some things not given in perception and thus would, in that respect, be a priori. It is true that the Titeaetetus emphasises that a full understanding of what is apprehensible only by the mind 'by itself' is the result oflong and intensive study (I 86c). Hence it could be maintained that the doxa of the Republic, while including an independent activity of mind, never includes any full apprehension of what is distinctively intelligible, and never perceptible, and is thus still properly described as empirical. This would, however, be a doxa which it is possible to convert to knowledge, at least to the kind of knowledge envisaged in the hypothesis of the Theaetetus, for its nature would imply that the dividing line between G

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what is doxa and what is not doxa is determined by the degree of comprehension of the distinctively intelligible elements present in any doxa. Thus the doxa of the Republic, in that it is meant to exclude the possibility of conversion, even in part, to an a priori level of apprehension, cannot consistently be interpreted in terms of the distinctions of the Theaetetus. The fact is that the argument of the Theaetetus which we are considering, advanced independently of the theory of Forms, points not only to a reinterpretation of what Plato has hitherto taken to be exclusively perceptual judgements, but also to a reformulation of the distinction between such judgements and exclusively a priori judgements. And if this new approach is to be formulated in terms of a theory of Forms, it follows that new distinctions within the theory of Forms of the Phaedo and the Republic are necessary. It is, in the first place, impossible, on the basis of the argument of the Theaetetus, to distinguish doxa (in the Republic's sense) from knowledge by correlating each with a different sort of object. For doxa is now shown necessarily to involve the apprehension of 'objects' which, according to the Republic, were exclusively objects of knowledge; I assume here that if the argument of the Theaetettts is formulated in terms of the Forms theory Plato would at least grant that what is, according to the Theaetettts, apprehended a priori in any judgement has the status of a Form. And if it is granted that doxa, while being about sensibles, includes the apprehension of Forms, its difference from knowledge will presumably be that knowledge is about Forms, and not at all about sensibles, being exclusively apriori. Now to maintain this distinction consistently within a theory of Forms Plato, ifhe is to retain his thesis that apprehension of Forms is an a priori form of apprehension, and that any other form of apprehension is of something other than Forms, appears to be committed to disallowing the claim to designate Forms of some concepts which, according to the Phaedo and the Republic, do designate Forms. For the argument of the Theaetetus appears to be distinguishing types of concepts, specifying some as empirical and others as a priori. Empirical concepts are those which are applicable only to the objects of a single sense; a priori concepts are those applicable to objects of more than one of the senses and hence, according to Plato, apprehended by the mind 'by itself'. It is true that Plato does not deal at all in his argument with the question of the way in which characteristics other than those

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apprehended by the mind 'by itself' are themselves apprehended. It does in fact follow from his reduction of aisthesis to bare sensation that to possess those concepts which designate sensible characteristics involves an independent activity of mind, since any comparison and generalisation necessarily involves such activfty. Yet Plato has no need, for the purpose of defittillg independent activity of mind, to distinguish between the isolated impressions of the senses and the explicit abstraction of the concepts describing those sensa. And the premisses of his argument, even if such a distinction had been made, would still imply a radical distinction between concepts which simply describe what is given through the senses and concepts applicable to the objects of more than one of the senses. Thus, if the distinction between empirical and a priori concepts implies that apprehension of the former is not a priori, it would seem difficult to continue to maintain that they designate Forms. Hence the argument of the Theaetetus, if used as the basis of a revision of the theory of Forms, suggests the rule that the existence of a Form is to be postulated only for concepts which satisfy the condition that they are applicable to the objects of more than one of the senses. The evidence that Plato attempted any such revision in later dialogues is not, however, very strong. There is, as we shall see, some suggestion in the Politicus that concepts can be distinguished as empirical and a priori, and that only the latter designate Forms. Apart from this Plato, while recognising the importance of distinguishing types of concepts, seems reluctant to disallow the claim of the 'empirical' concepts of the Theaetettls to designate Forms; thus a distinction which assumes importance in later dialogues and which has some correspondence with the distinction of the Theaetetus is a distinction between Forms which have 'clear sensible images' and those which have not.

c] False belief This argument of the Theaetetus is the final criticism which Plato makes in the dialogue of the claim that knowledge is perception; the only other serious criticism is the criticism of it as a thesis implicitly based on a doctrine of flux. One further question which must now be considered is whether the argument is fruitfully developed in the rest of the dialogue once it has prompted the new hypothesis that knowledge is definable as 'true belief'. What we might reasonably have expected would have been, as a preliminary to the examination of the claim of

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true belief to constitute knowledge, further illustration and elucidation of the relation between what is contributed by the senses and what is contributed by the independent activity of mind in coming to believe that something is the case. This expectation is, however, disappointed, and little of the discussion of the rest of the dialogue appears to be a development of the ideas in the fmal argument against aisthesis. The principal reason for this is that the rest of the discussion is limited to an examination of knowledge as knowledge of particular objects; this raises entirely new problems which seem to have little connexion with the problems implicit in the critici.sm of aisthesis, when Plato was apparently treating knowledge in a much more general way as knowledge of facts, without any restriction of it to knowledge of particular objects. The first new problem which the discussion raises is the problem of how false belief is possible. Limited as it now is to an examination of knowledge of particular objects, the discussion construes true belief as the correct identification of a person or thing. Hence false belief is incorrect identification - confusing one thing with another; it is a belief that a thing is other than what it is (allodoxia, I89b). Now if it is assumed that a person either knows or does not know the objects confused, in the sense of being acquainted with or not acquainted with them, me problem arises of how confusion is possible between two objects when it must be the case that a person is either acquainted with one and not acquainted with the other or acquainted with both or not acquainted with either (I88a-c). It is to be noted that before dealing with this problem Plato dismisses the objection that, since to believe falsely is to believe 'what is not', to believe falsely is impossible. While agreeing that, if 'what is not' is interpreted as 'what has no being at all', then believing 'what is not' is believing 'nothing' and hence not having a belief at all (I88e-I89a), he assumes that to believe falsely is to believe 'something' and that consequently 'to believe falsely must be something different from believing what is not' (I89b). With this assumption he describes false belief as a belief that something is other than what it is (I89b),23 and returns to what he considers to be the main problem - how the confusion can arise which will result in a false beliefas thus construed. plato sees his main task as that ofexamining the kind of apprehension a person has of each of the two objects confused in cases of incorrect identification. The initial assumption was that

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a person either knows or does not know the objects confused, and since confusion seemed to be impossible on this assumption an escape from this apparent absurdity would appear to depend on either discovering a sense of'knowing' and 'not-knowing' which does not yield the absurdity or revising the initial assumption so as to allow that at least one of the objects is apprehended in a way not equival~nt to either 'knowing' or 'not knowing'. Considering first the fonner alternative, Plato has no difficulty in showing the possibility of confusing two things 'known' (where 'knowing' is 'having acquaintance with and retaining in memory a direct "impression" '); the confusion can arise when one or both of the 'known' objects are subsequently perceived indistinctly. With the same sense of'kllowing' it is easy to show how indistinct perception can give rise to confusion between a 'known' and an 'unknown' object (19Ib194b). Thus the 'known' Theodorus may be confused with the 'known' Theaetetus or with an 'unknown' person. But Plato is not satisfied with this, even though, granting his definition of knowledge, it is a satisfactory reply to the present objection that false belief is impossible. It is not simply that he considers his explanation too narrow to cover all cases of false belief; he considers that unless some other and more satisfactory explanation is given of false belief, the initial problem has not been resolved in the slightest degree (196c). He appears to assume, in fact, that the appeal to indistinct perception is an appeal to merely accidental circumstances which have no proper relevance to the knowing/not-knowing distinction which he is exploring. He therefore suggests another sense of'knowing' which will allow the possibility of confusing one known object with another known object. He distinguishes between (i) 'possessing' and (ii) 'having' knowledge, thus recognising that knowledge is a 'disposition' (possessing) which may be 'actualised' (having) in particular instances of its application (197b198d). This will allow the possibility of the misapplication of what is 'known' (in sense (i) ), resulting in a false belief which may be interpreted as a confusion between one 'known' thing (knowledge which is misapplied) and another 'known' thing (knowledge which would correctly be applied in this particular case). To illustrate this Plato takes as instances of ,known' things intelligibles rather than perceptibles. His two 'known' things are the numbers II and 12, and he says that if II is given as the answer to the question what the sum of 7 and 5 is,

PLATO'S THEORY OF KNOWLEDGE 94 the a.nswerer is confusing I I with 12 and thus believing falsely that I I is 12. This remarkable illustration serves to emphasise the extent of Plato's preoccupation with the idea that knowledge is knowledge of individual objects. It further emphasises his tendency to assimilate all knowledge to acquaintance with individual objects. Just as a perceptible object is 'known' once acquaintance with it through perception has stamped an 'impression' of it in memory, so, it appears, an intelligible object is 'known' once acquaintance with it has introduced a new conception to the storehouse of the mind. It is as if Plato is assuming that once an object is before the mind, or 'possessed' by the mind, no matter whether it is a ·perceptible or intelligible object, then it is 'known' (cf. ISSa). A consequence of this kind of approach to knowledge is that, although Plato asserts at the beginning of his discussion that belief is 'propositional' (18ge-190a), his preoccupation with the question of what it is to 'know' particular objects leads him to neglect what had already been suggested in the fmal criticism of aisthesis - the importance of examining the complexity and structure of what is known. It is true that the suggestion there is not made as explicit as we should have liked. Indeed it could be argued that even there Plato, in distinguishing between a priori and empirical concepts, is thinking primarily in terms of a distinction between different sorts of particular 'objects' - those apprehended a priori and those apprehended empirically. Yet the general impression which his examination gives is that he is viewing knowledge as the result of some sort of interpretation by the mind of what is given in perception, and his specification of the various ways in which the mind contributes to this interpretation appears to mark a recognition not only of the complexity of what is known but also of the fact that the structure of what is known is an important factor in assessing the nature of knowledge.

d] Knowledge as 'true belief with an account' In the final part of the Theaetetus he does, however, enlarge the conception of knowledge which governs his discussion of false belief by exploring the hypothesis that knowledge is acquired as the result of an analysis of a particular perceptible object, and he attempts to specify the method of analysis which will yield this result. The hypothesis is put forward after the breakdown of the attempt to discover a sense of 'knowing' and 'not-knowing' which will allow a satisfactory explana-

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tion of false belief on the basis of the assumption that a person either knows or does not know the objects confused in false belie£ This attempt breaks down because Plato concludes that the distinction between 'possessing' and 'having' knowledge is just as unsatisfactory as his earlier conception of knowledge in te,nns of memory-images as a means of resolving his difficulties about false belie£ For, mistakenly assuming as he does that the false beliefheld by the person who answers that the sum of 7 and 5 is II is the belief that II is 12, he refuses to accept the possibility that a person should misapply what is known, since this is equivalent to confusing two 'objects' with both of which he is acquainted (I99c-d). Consequently, having failed to discover a sense of 'knowing' and 'not-knowing' which does not yield the result that false belief is impossible, he appears to fall back on the alternative method of escape - revising the initial assumption so as to allow that at least one of the two objects is apprehended in a way not equivalent to either 'knowing' or 'not-knowing'. This leads him to suggest that an object cannot be known unless an 'accolUlt' (logos) can be given of it, the implication being that false belief arises when at least one of two objects confused is not 'known' since this new condition of knowledge with regard to it is not satisfied. Thus Plato is still preoccupied with the problem of the nature of knowledge of particular objects, and he decides to abandon altogether at this point his examination of false belief, and to examine further the nature of knowledge of particular objects \vithout regard to any elucidation it might afford of the nature of false belie£ His new hypothesis that to know implies the ability to give an 'account' is, of course, one which he has often adopted previously when specifying a distinctive mark of knowledge. In the Meno it was used to distinguish knowledge from true belief. And Plato does in fact now suggest that knowledge may be defined as 'true belief with an account' though the hypothesis that knowledge is true belief has not yet been examined on its own merits; indeed 'true belief' re-enters the discussion rather unexpectedly, as part of an old formula which Plato wishes to test in application to the problem of what it is to know a particular object. Now what he has said so far about this knowledge has given no positive indication of what he considers to be the cognitive value of perception. He has first attempted to explain false belief by examining cases where perception contributes to the formulation of the false

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belief He has then attempted to explain it by examining cases in which he seems to assume that perception contributes nothing to the formulation of it. Both attempts fail. But in now trying to specify the 'account' which will yield knowledge, he introduces a theory which, despite its limitation to cases of knowledge of individual objects, does seem to have some connexion with what he had said in his final criticism of aistMsis. He suggests that an 'account' (logos) is possible only of what is complex. Thus, to use the analogy of letters and syllables, syllables are complexes of single letters and can have an account given of them, an analysis into their simple components, the letters. But no account can be given of the letters, which cannot be analysed into simpler components. They thus rank as absolute simples. Hence, says Plato, complexes are knowable, simples are unknowable (202b). He further states that the simple components of a complex are (i) nameable, but incapable of having any predicates applied to them, (ii) perceptible (aistMta), but incapable of being an object of either true belief or knowledge. What he says about (i) suggests in many ways a return to the sort of approach made in the fmal criticism of aisthisis, especially since what he says about nameables is true, in view of (ii), of perceptibles, only. Thus, he says, a name is all there is that belongs to a simple element. Even to say 'this is an X', where X is the name, is not permissible, since to 'attach existence to it' or to apply the term 'this' is to apply predicates which, 'running about', are attached to everything and are distinct from the things to which they are applied (202a). Hence it is impossible to describe simples in a statement (logos); here it seems clear that Plato is using logos in the same sense in which he had used it in 190a. Now, remembering that simples are perceptibles, much of this inevitably invites comparison with the fInal argument against aisth~sis, which had limited aistMsis to sensation, and had specified 'being' and various other predicates as ones which 'belong to everything', and which are not perceptible, the apprehension of them being ascribed to an independent activity of mind which reflects 'about' sensibles and issues in statements (logoi). And as ill that argument Plato had shown that perception itself cannot yield either true belief or knowledge, so ill this present argument he asserts that simples are perceptible only, and never the object of either true belief or knowledge (202b-c). What Plato is 1l0W doing, it would seem, is making much more explicit than ill the earlier argument the point that knowledge,

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unlike the direct apprehension of what is 'given' in sensation, is propositional and thus necessarily of what is complex. Hence there appears to be some justiflcation for linking Plato's argument with 'the familiar Aristotelian and mediaeval doctrine that the "complex enunciation", or proposition, is the unit of knowledge' , 24 ~nd assuming that his main point is to contrast the 'simplicity' of what is directly apprehended ill sensation with the complexity of what is known and expressed in propositions (logoi). Yet, though there is much in the manner of Plato's distinction between what is nameable only and what is expressible in a logos which suggests this interpretation, the rest of what he says about the nature of this logos shows quite conclusively that his main point is something quite different from this. Thus in 202b he says that corresponding to the complex thing or object compounded of simple elements which are nameable only is the complex logos or statement, which is a combination of the names of the elements. When he speaks of a 'combination of names' as constituting the logos it is obvious from the context that he means a combination of the names (ol1omata) of the simple elements, each of these names being peculiar to a particular element. It is impossible that he is arguing that the combination of names is a combination of the type 'this is an X' where X is the name of a simple element and 'this', 'is', and 'an' are names of the other simple components of the complex described in the logos. For he has already excluded such an interpretation since (i) by a 'name' he means a name peculiar to each simple element, and (ii) he has specified 'is' and 'this' as terms not peculiar to one particular object or one particular class of objects but 'attached to everything and distinct from the things to which they are applied'. It is clear, in fact, that the main distinction which Plato is trying to make is between the physical complexity of particular objects and the simple constituents of those objects. Thus the fact that knowledge is propositional is irrelevant to the meaning of logos, and this is made explicit at 206d-e. To construe logos, says Plato, as the expression of one's thought in speech 'with names and verbs' is to neglect the fact that the ability to give a logos or account was introduced as a distinctive feature of knowledge, as opposed to true belief; any sense of logos therefore which ascribes a logos to both true belief and knowledge is inadmissible. In this case, since both true belief and knowledge are expre~sible in speech 'with names and verbs', it is inadmissible to

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construe logos in that sense. The conclusion must be, then, that the principal meaning which Plato is giving to logos when he uses the analogy of letters and syllables to distinguish simples and complexes is an account or explication of a complex object which specifies and enumerates its simple components. It is assumed that, if this is done, the object is 'known'. To have 'true belief' with regard to it will be to identify it correctly but without any analysis of it; this will be expressible in the form 'this is X' where X is the name of the complex. It is now possible to see that in the passage 2oId-202c Plato is using logos in two different senses. In the first part of the passage, where he is arguing that simples are nameable only (20 Id-202b2), logos means statement. Both true belief and knowledge are expressible in logoi or statements, and this sense of logos, as we have seen, is irrelevant to the distinction between belief and knowledge. In the second part of the passage (202b2-cs) logos is a specified kind of account or description of a complex object - an enumeration of its simple components. It is this logos which is relevant to the distinction between true belief and knowledge, and Plato, in stressing at some length its relevance to this (b8-cS), indicates that it is the conception of this sort of logos which he is primarily concerned to put forward in the passage 2oId-202C as a contribution to the discussion, which is, we must remember, a discussion of the new hypothesis that knowledge is defmable as 'true belief with an account (logos)'. Moreover, since the rest of the discussion is concerned exclusively with the problem of knowledge of physical objects we may reasonably assume that in his present argument Plato would accept as a proper illustration of it the analysis of a complex physical object by enumeration of its simple component elements. The fact that he says that simples are perceptibles is some confirmation of the assumption that he is here thinking of analysis ofphysical objects, as also is the fact that he says that the simple elements are 'elements of which we and all other things consist' (2oIe). Thus the result of Plato's argument is severely to restrict the scope both of knowledge and true belie£ The only cases of knowledge will be those where this kind of enumerative 'account' has been correctly given, and the only cases of true belief will be those where this kind of account is possible, but not given, and where a complex object has been correctly identified (the complexity of what is believed is the complexity of the object identified and is not the complexity of the propositions which express the

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identification or express any other truth about the object). Perception is wider in scope. All simples are perceptible, and there is nothing in Plato's argument to exclude the perceptibility of complexes. Moreover, it is entirely consistent with this argument that perception should be the criterion of whether or not the enumerative 'account' of the simple constituents, which is a condition df knowledge, is a correct accoUllt and yields knowledge, and that perception should be the criterion of whether or not the belief that the complex is identiftable as this or that is true. And Plato does clearly assume that simples, which are perceptible only, are correctly identified. Hence, it would seem, the statement 'this is X', where X is the name of a simple, is assumed to be true as a direct report of what is given in perception, though it fails to qualify to be the expression of a 'true belief' since Plato has extended his restriction on the application of knowledge to the application of 'true belief', with the result that, for him, 'true belief' is possible only with regard to complexes (202b). It is true that at the beginning of the passage Plato has said that the 'elements' are nameable only, which would make the statement 'this is X' inapplicable to an element. Yet since in the latter part of the passage he is giving a different interpretation of logos or 'account', the objections which he earlier made to saying of an element that 'this is X' become irrelevant. For the conception of the analysis of a particular physical object into its physical elements which now gives meaning to complex and simple makes it absurd to apply to simples in this later context the earlier rule. 25 What we have, then, in this new approach to the problem of knowledge is an attempt to distinguish between three forms of apprehension - perception, true belief, and knowledge, in relation to a particular physical object. An obvious criticism of it would be that its extremely narrow conception of the 'account' (logos) which converts true belief to knowledge, coupled with its assumption that recognition of and correct identification of simples is exclusively the work of perception, makes the distinction between knowledge and perception a merely trivial distinction. And Plato's criticism of the new theory shows clearly that he recognises this. Thus, using again the analogy ofletters and syllables, the syllable is either all its letters or a single entity distinct from the letters. In the first case it will follow that to know the syllable is to know its letters. But since the letters have been assumed to be unknowable, then the syllable too will be unknowable. ill the second

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case the syllable, as a distinct unity, call1lot be analysed into parts, and will thus be simple and unknowable for the same reason as the letters arc (203a-20se). Since Plato clearly finds these consequences of his theory unacceptable and yet continues to assume that to know includes the ability to 'give an account', one possible solution of his difficulties would be to assume that simples as well as complexes are knowable and to find the' account' not in any form of analysis but in verification in perception. This solution makes the distinction between simple and complex irrelevant to the question of what constitutes knowledge. It is not, however, a solution which Plato bothers to explore, the rest of the discussion showing that he continues to assume that the 'account' must be found in some form of analysis. Now since an assumption of the Theaetetus, from the beginning, appears to have been that it is relevant to the inquiry into the definition of knowledge to examine particular hypotheses (e.g. that knowledge is perception) as to what is a satisfactory criterion for knowing, it might seem that in failing to explore the above solution plato is deliberately turning his back on it because it assumes that perception provides a satisfactory criterion for knowing, and that in continuing to seek a defInition of knowledge in terms of a particular form of analysis he is assuming not simply that knowledge, in that it implies an ability to provide a precise conceptual analysis of its object, is superior to perception as a level of apprehension, but also that the provision of this precise analysis itself constitutes a criterion for knowing which is quite independent of perception. My own view is that Plato is making such an assumption. The general impression given by the dialogue as a whole is that, having once refuted the hypothesis that knowledge is perception, Plato's subsequent concern is to fmd some criterion other than perception, and that, even where the discussion leads to a point where the recognition of perception as a criterion would seem to be the most plausible solution of difficulties which have arisen, Plato is unwilling to reassess its claims. Thus such recognition would have allowed him to use the distinction between distinct and indistinct perception to explain how false belief is possible. And such recognition would, as we have noted, have allowed him to offer a plausible solution of the difficulties in the theory put forward in 20rd-202c. If, then, he is unwilling to resort to a solution of this kind, what solution does he actually offer? Retaining his view that the 'account'

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which converts true belief to knowledge is some form of analysis of a complex, and continuing to restrict his discussion to the problem of knowledge of particular physical objects (a cart, a person, the sun), Plato first re-emphasises, by using the illustration of the analysis of a cart into its physical components, the triviality of the distinction between knowledge of the complex and acquaintance with its components if the analysis is a simple enumeration of components (207a20Sb). He then finally suggests that to know a thing is to have a true belief with regard to it (correctly identify it) plus the ability to give an 'accotmt' in the form of a statement of the differentia which distinguishes it from other things (208c-e). The objections that (i) the correct identification of the thing necessarily includes the correct identification of the differentia; (ii) to say that knowledge is true belief plus knowledge of the differentia is to give a circular defmition, are allowed to stand and to bring the dialogue to an inconclusive end. These objections indicate that Plato has not yet succeeded in fmding a satisfactory criterion for knowledge which will clearly dissociate it from perception. The essence of the objections is the same as of those brought against his earlier attempts to specify the 'account' which will convert true belief to knowledge - that the 'account' of the complex is such as to make only a trivial distinction between knowledge of the complex and direct acquaintance through perception either with the components of the complex or with the complex itse]£ For it is to be noted that in this last attempt to specify 'account' Plato is still dealing with individual and perceptible objects. His example is the person Theaetetus, whose differentia is 'snubnosedness', and his difficulty is to distinguish knowledge of Theaetetus from acquaintance with him and with his 'snubnosedness'. But it is clear that, though the difficulty remains here unresolved, this last attempt to specify 'account' gives a significant pointer to the solution which plato offers in later dialogues. It is clear in the first place tllat by the end of the dialogue Plato is very near to thinking of 'account' in terms of definition. Moreover, though in his last example he is certainly not thinking as yet in terms of definition of species and making a distinction between genus and species, it is not difficult to see that his specification of 'account' in terms of the method of division (diairesis) in later dialogues is the fmal result of the inquiry in the Theaetetlls and closely linked with the final part of that inquiry. This link is seennot only in the common assumption

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that the 'accooot' of a thing is to be fowld in its definition, and that definition is through specification of differentiae. It is seen also in the common terminology of the distinction in the Tlteaetetus between complexes and their simple components or parts, and of the description ill later dialogues of Forms as complex 'wholes' divisible into parts (moria, mere).26 It is a distinction between complex and relatively 00analysable and simple which is preserved within the method of division. For in any deflllition or in any scheme of classification by diairesis the illfimae species are indivisible (atomol1);27 they constitute the limit of the analysis necessary for the determination of the' essence' of a particular Form or for the purpose of the classification. And just as they are indivisible relatively to these ends, so they are simple relatively to their genera, the gel1era being for Plato at once wider in extension and richer in complexity than any of their subordinate species, since they necessarily embrace and contain within themselves a greater number of species and sub-species than does anything subordinate to them. Yet though the Form is thus relatively indivisible and simple, it does possess a complexity of structure, and this allows an 'accooot' to be given of it which will separate it and distinguish it from all other Forms. Thus Plato felt that the method of diairesis made it possible to recognise the complexity of what is known, and at the same time to retain his conception of Forms as indivisible and simple. In the Phaedo it was the indivisibility and simplicity of the Forms which had been stressed. They were Wliform (monoeides, 7Sd, Sob) and incomposite (asynthetott, 7Sc), characteristics associated by Plato, Wlder clearly Parmenidean influence, with the immutability and permanence of the unitary Form as contrasted with the mutability and impermanence of the many particulars. And it is just these characteristics which in the TheaetetHs are said to exclude the possibility of knowing the objects to which they belong (20sa-e). Thus it is argued that the elements of a complex are unknowable since they are each Wliform (molloeides) and incomposite (asyntheton), and that the complex too, if regarded as a ooity over and above its elements, is itself Wliform and incomposite and hence Wlknowable. Of neither can an 'account' be given. This precise correspondence of terminology between the argument of the Theaetetus and the description of Forms in the Phaedo 28 clearly establishes an important link between the discussion of the latter half of the Theaetetus (20IC2IOb) and the theory of Fonns. And since the difficulties raised in the

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Theaetetus about the possibility of knowing what is 'uniform' and 'illcomposite' are now seen to be directly relevant to the problem of knowledge of Forms, we have further confirmation that Plato's subsequent development of a new method of attaining knowledge of Forms should be regarded as an answer to, the problems raised, but not solved, by the Theaetettls. It is important to note, finally, that these problems are such as to lead Plato to a re-affirmation of the existence of Forms as the basis of his solution of the problems. A brief review of his position at the end of the Theaetettts will make this clear. He has recognised that the object of knowledge is necessarily complex, and has abandoned as untenable the view that it is absolutely simple and incomposite. But he has not yet found a satisfactory way of distinguishing between perception, true belief, and knowledge. Throughout the discussion of false beliefhe had apparently assumed that all knowledge was knowledge of individuals by direct acquaintance and had found it impossible, as we have seen, to explain on this assumption how confusions could arise. His subsequent attempt to distinguish knowledge from both perception and true belief breaks down because the discussion is still restricted to the problem of knowledge of individuals , and it proves impossible to make anything more than a trivial distinction between knowledge of the complex individual and immediate experience either of this individual as a 'whole' or of its simple 'parts'. Thus Plato has abandoned the earlier conception of knowledge as direct acquaintance but has failed as yet to distinguish it satisfactorily from direct acquaintance. The discussion has, however, brought him to the point where he is seeking a satisfactory method of definition as a solution to his problems. And the fundamental step towards Plato's solution is the recognition that definition is not of individuals but of species, not of the particular but of the general. This, it might well be said, in view of the essays in general definition in some of the earliest dialogues, is hardly a point which plato needs to be led to realise. But we must remember that in the Theaetetus plato, having disposed of the thesis that knowledge is perception, makes a new approach to the problem of knowledge by examining cases of acquaintance with individuals or particulars and endeavouring to find at this level a satisfactory distinction between perception, true belief, and knowledge. What he is led to realise as a result of his failure to find this is the relevauce to the problems raised

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of the point that definition is not of individuals. The perceptible individual or particular is unknowable because it is indefinable. The way is now clear for the re-introduction of the Forms as the objects of knowledge; and with the further introduction of the method of division plato is now able to £nd his'account' in a precise and tilliversally applicable method and on this basis to distinguish clearly between perception, true belief and knowledge. It is easy to see how attractive this solution of the difficulties of the Tlteaetetus would appear to plato. The new method oflogical analysis for defining Forms clearly seemed to him to provide a demonstration of the nature of the Form; and the certainty thus yielded could be plausibly interpreted as a result of the exercise of reason rather than of perception, and, further, as a confirmation of the superiority of reason over perception. Moreover, in the light of this, Plato could explain the triviality of any distinction between knowledge and perception which assumes that knowledge (a) is knowledge of individuals and (b) implies an ability to specify either the constitutive elements or the peculiarities of the individual. The distinction is trivial since the merely contingent nature of the combination of perceptual characteristics which make up the 'being' of the particular or its peculiarity seemed to Plato to allow no other method of coming to 'know' the particular than that of enumerating the perceptual characteristics as they were given in perception. And such an 'account' yields only a trivial distinction since, for Plato, it involves only a trivial application of reason to the interpretation of what is perceived. Hence, since no other 'account' than this is possible for providing knowledge of the particular, and since the claim of perception to provide knowledge has already been dismissed, Plato is ready to conclude that the sensible particular is unknowable. It is not amenable to the systematically rational 'account' which is possible for the Form, and plato can thus relegate it to the level of the indeterminable, below the limits of the exercise of the method of diairesis. 29 In this way the difficulties of the Theaetetus lead plato to a re-affirmation of the 'reality' of the Forms as objects of knowledge and of their superiority to sensible particulars. At the same time they lead him to a recognition of the need to reconcile the earlier assumption of the simplicity and incomposite nature of the Forms with the present assumption that knowledge is the result of an analysis of the structure 'of its object and hence is knowledge of what is complex. It is the new

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method of defmition by diairesis which shows Plato how the reconciliation can be effected. Thus it allows him to meet the difficulties in his theory of knowledge which we raised at the end of the first chapter. There we saw that in the Pltaedo the virtues of the theory of Forms and of the method of analysis of propositions were assessed independently of one another, and that Plato had not yet begun to consider the possible inconsistencies arising from an attempt to integrate them. Within the theory of Forms, as far as it was taken by the Phaedo, the only possible type of 'accotmt' either of the Form or of its sensible instances was one in terms of a relation of resemblance between simple archetypal objects and sensible characteristics, or in terms of the 'participation' of sensibles in the perfectly real archetype. And we suggested that a consistent development of Plato's theory of knowledge from this position would depend on the consistency with which he could reconcile this type of 'account' with the ideal of giving an 'account' in terms of a precise method of analysis. To this reconciliation the Tl,eaetettls, as we have now seen, points the way, and in implicitly rejecting the conception of knowledge as direct acquaintance it rejects the conception of knowledge which would seem to belong naturally to the Pltaedo's conception of the Forms. The objection can readily be raised, of course, that Plato's solution through the method of diairesis is no solution at all, that he has simply substituted a theory of Forms as complex and composite objects of knowledge for his earlier theory of Forms as simple and incomposite objects of knowledge, and that there is strictly no 'reconciliation' between the earlier and later theory. The further objection can also be raised, as Aristotle raised it,30 that the Form, as an individual archetypal object, remains indefmable and unknowable for the same reasons for which the sensible individual is indefmable and unknowable, and hence that the argument for appealing to Forms as objects of definition and knowledge involves an in£nite regress. Certainly plato never meets these objections properly, though it would seem that he was aware of difficulties in his proposed solution. 31 But the important thing for our present purpose has been to see how the problems about knowledge raised by the attempt in the Theaetetus to distinguish knowledge of particulars from both true belief about them and perception of them lead Plato back to the theory of Forms, but lead him also to a new conception of the structure of Forms and the method of attaining H

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knowledge of them. Whatever the objections which can be raised against his proposed solution of his difficulties, there can be no doubt that it marks an important development in his thought.

e] Summary In concluding this examination of the Theaetetus an attempt must be made to review briefly its results. It has been rightly said that 'while the dialogue is concerned not with metaphysics but with epistemology, it furnishes the strongest argument Plato gives anywhere for the foundation of his metaphysical theory'. 32 We have just seen in what way the difficulties raised in the latter half of the dialogue in the attempt to discover a criterion for knowing other than perception point the way to a re-introduction of the theory of Forms, in conjunction with a new method of dialectic, as the basis of the solution of these difficulties; thus the latter half of the dialogue may plausibly be said to point implicitly to the need to postulate the existence of Forms if a satisfactory account of knowledge is to be given. The first half of the dialogue, through its refutation of the thesis that knowledge is perception, points the same way. More systematically than in any other of the middle dialogues it examines the nature of perception and its objects, and attempts to reduce to absurdity the claim that perception yields knowledge. Its criticism of perception is an extremely severe one, its most important criticisms being (i) that the thesis that knowledge is perception, in so far as it rests on the assumption that all things are in flux (and Plato himself accepts tlle flux theory as true of sensibles), implicitly denies the existence of determinate sensible characteristics and hence the possibility of knowledge; (ii) that perception (aisthesis) is strictly limited to the isolated 'impressions' of the particular senses and call110t be equated with knowledge since any knowledge includes the apprehension by the mind 'by itself' of non-perceptual characteristics. Thus the Theaetetus matches in the severity of its criticism the Phaedo, which had condemned perception and its objects from a moral point of view, and it reflects generally the Republic's attitude of uncompromising renunciation of perception as a guide to knowledge. We have noted at several points in this examination of perception in the middle dialogues the difficulties of reconciling the major criticisms of perception made there with the assumption of the theory of recollection that sensible characteristics are 'images' of Forms and that

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perception of these characteristics is an essential first step to the attainment of knowledge. There is a fundamental inconsistency here, and the first task in the next chapter will be to see to what extent this inconsistency is resolved within the new conception of dialectic in the late dialogues; this will serve as a preliminary to a discussion of the problem of the relation between belief and knowledge in those dialogues.

CHAPTER III

Knowledge and Belief 1. RECOLLECTION AND THE NEW METHOD OF DIALECTIC

The first formal exposition of the methods of collection and division is found in the Phaedrus. It is now generally agreed by scholars that this dialogue is later than the Repllblic. 1 It is also generally agreed that in several important respects its doctrine links it with the group of late dialogues which begins with the Sophist. 2 As for the question ofwhether it precedes or follows the Parmenides and the Theaetetus, I have already attempted to show how Plato's new method of dialectic is designed to meet problems raised, but not solved, in the latter half of the Theaetetus, and this, in my opinion, is good reason for assuming that the Pltaedrus is later than the Theaetetus. 3 Together with the new method of dialectic the Phaedms re-introduces the theory of recollection. The close link between method and theory is established at 249b-c, where Plato first describes the method of collection (synag8ge) in its application to sensible particulars, a process of generalisation and abstraction culminating in the recognition of a single common Form. This recognition is then said to be the recollection of that 'true reality' which the soul once knew. And though recollection is melltioned only with this first description of collection it is clear that this first description is closely related to the later description ofit in 26Sd:lf., where it is linked with the method of division; and this passage is closely related in tum to descriptions of the method in the Sophist (2S3d) and the Politictls (28sa-b). It is to be noted too that, although it is to 'collection' as a process of direct abstraction from sensibles that recollection is explicidy related, Plato indicates that this process of abstraction is simply a first step in recollection, to be followed by a further stage of methodical analysis (249c-d). The obvious implication, once we take into account the relation between the earlier and later descriptions of 'collection', is that this further stage in the process of recollection has as its instruments the methods of collection and 108

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division. And the descriptions of these methods, in the Phaedms and in later dialogues, suggest that fundamental in the process of recollection will be the recognition of relevant resemblances and differences between Forms in attaining knowledge of any particular Form. It is extremely important, I think, to see that there is this clqse association between the new conception of dialectic and the theory of recollection. Many scholars have argued that the theory of recollection is abandoned in the late dialogues. And it is essential to any examination of Plato's theory of knowledge in the late dialogues to consider first the evidence for and against this view. This will lead to a discussion of Plato's evaluation of perception within his new conception of dialectic. And this discussion in turn, by bringing to light the problems involved in Plato's retention of the distinction between knowledge and belief, will lead to an examination ofwhat Plato has to say about the distinction in the late dialogues. We have already seen that the descriptions of the new method suggest that fundamental to the successful practice of the method in attaining knowledge of Forms is the recogllitioll of relevant resemblances and differences between Forms. This concept of ,likeness' or 'resemblance' (homoiotes) has an important place in the dialectic of the late dialogues. It is used not only with reference to sensible particulars which have derivative resemblances to one another as instances of the same Form, but also, in conjunction with its opposite 'dissimilarity' (anomoiotes), ,vith reference to species of the same genus; and the genus itself is describable as a 'likeness' in that it constitutes the common point of resemblance between its different species.