In Metaphysics 19 Aristotle mentions several Platonic arguments for forms. These were set out in detail, along with Aristotle's criticisms, in his essay Peri Ideōn, portions of which are preserved in Alexander's commentary on 19. In this chapter I explore the logic of some of these arguments and the interconnections between them.

Aristotle divides the arguments he discusses into two classes, the less and the more accurate arguments; but he says very little about the basis of this division. I shall suggest that the more, but not the less, accurate arguments are valid arguments for Platonic forms; and I shall claim that although Aristotle is no friend of the forms, he concedes to the Platonists that they are valid arguments for forms. But the concession is coy. For, Aristotle argues, these arguments lead to intolerable results and so cannot be sound. One leads to a vicious infinite regress, the third man, and the other produces forms of relatives, ‘of which we say there is no independent class’ (Metaph. 990b16–17). From this point of view, the less accurate arguments are to be preferred. For although they are invalid arguments for forms, they are valid and, so Aristotle seems to believe, sound arguments for his own universals, the koina.

If this interpretation is correct, it suggests an interesting result: that the overall structure of the Peri Ideōn is neatly dilemmatic. The Platonists can rely on two sorts of arguments for forms, their more and their less accurate arguments.

At the very beginning of Plato's Cratylus Hermogenes explains Cratylus' view by saying that it supposes there to be a certain natural correctness (orthotēs) of names; that this correctness is the same for all linguistic groups; and (very strongly) that it has nothing to do with what name anyone actually applies to anything – so that, he is quoted as saying to Hermogenes, ‘your name would not be Hermogenes, even if everyone called you that’ (383B). This last point implies something which explicitly emerges later, that, for Cratylus, the question whether some word ‘N’ is the correct name of a given item is the same as the question whether ‘N’ is that item's name at all.

The assumption that the answers to those questions must be the same is not shared by everyone in the dialogue. It is shared by Hermogenes, for reasons which are (roughly) the opposite of Cratylus'. It is not shared by Socrates, whose final position requires us to distinguish the questions; or rather, to put it more precisely, it requires us to make a distinction which can be handily put by us in terms of a possible divergence between the name of X and the correct name of X, and is often so put in the dialogue, but which can also be expressed, as we shall see later, in terms of two kinds of correctness.

In trying to give some account of Cratylus' theory of names, I shall particularly emphasise that distinction and Cratylus' denial of it.

At the beginning of Book VII of the Nicomachean Ethics, just before his discussion of akrasia, Aristotle pauses to make some observations about his philosophical method:

Here, as in all other cases, we must set down the appearances (phainomena) and, first working through the puzzles (diaporēsantes), in this way go on to show, if possible, the truth of all the beliefs we hold (ta endoxa) about these experiences; and, if this is not possible, the truth of the greatest number and the most authoritative. For if the difficulties are resolved and the beliefs (endoxa) are left in place, we will have done enough showing (1145b1 ff.).

Aristotle tells us that his method, ‘here as in all other cases’, is to set down what he calls phainomena, and what we shall translate as ‘the appearances’. Proper philosophical method is committed to and limited by these. If we work through the difficulties with which the phainomena confront us and leave the greatest number and the most basic intact, we will have gone as far as philosophy can, or should, go.

To further the understanding of the Presocratics, as intelligent beings looking for a theoretical ordering of the world, has been, among the cherished aims of Gwil Owen, one to which he has repeatedly recurred and to which we owe some of his most characteristically illuminating work. To this collection in his honour I offer a set of proposals for the understanding of Heraclitus.

Epistemology: the programme

The hypothesis to be explored claims that at the heart of Heraclitus' thought there lies a remarkable and characteristic epistemology, and that it is this above all that must first be grasped if his account of the world is to be understood. It will help to begin with a statement of what would be agreed about Heraclitus' epistemology by many scholars.

I shall treat as non-controversial the position summarised in the rest of the present paragraph. Heraclitus is deeply interested in the problem of knowledge. He sharply rejects the claims to be guides to knowledge of (a) ordinary common sense; (b) popular and traditional beliefs; (c) much of traditional Greek religion; (d) the older accepted authorities, Homer and Hesiod; (e) more recent claimants of such diverse kinds as Archilochus, Xenophanes, Hecataeus and Pythagoras. Against all these, and in support of his own account of the world, Heraclitus appeals in the first place to the evidence of the senses. ‘All of which the learning is seeing and hearing, to that I give preference’ (B55).

In this chapter I suggest that some passages in the Cratylus may give us insight into certain of the difficulties in the notorious ‘dream’ passage in the Theaetetus. This is a modest point, but it has, I hope, less modest implications for our understanding of what Plato is after when he looks for a definition of knowledge. Whatever the merits of this paper, it has a certain appropriateness as my contribution to a volume honouring Gwil Owen; my introduction to working with him, when I was a graduate student at Harvard, was a class on the Theaetetus and a paper I wrote on the Cratylus. Nothing here survives, I am glad to say, of the content of my early efforts; what I do hope survive are some effects of those lessons in rigour, in patience with the text and in Platonic readiness to lay aside one's own concerns in the attempt to see Plato's as they are. This paper is offered to Gwil as a token, however inadequate, of truly Socratic teaching and friendship.

What is the dream theory doing in the Theaetetus? At 201C8, Theaetetus, having been convinced that knowledge cannot just be true belief, suggests that it may be true belief plus logos or account. This is not an unexpected suggestion to those familiar with Plato's earlier attempts to show that knowledge is the kind of improvement over true belief that results from being able to offer certain kinds of reason and grounds for what is believed.

Heraclitus and the Milesians

In recent decades there has been a tendency among scholars to question whether Heraclitus was, in the same sense as the Milesians were, a cosmologist: ‘[Heraclitus'] real subject is not the physical world but the human condition, which for the Greeks means the condition of mortality … Like [his] substitution of Fire for [Anaximenes'] Air, any changes in detail must have been designed not to improve the physical scheme in a scientific sense but to render its symbolic function more drastic.’

It would be foolish to deny that problems about mortality, fallibility and the human perspective were an important part of Heraclitus' main subject. But this is not inconsistent with his having seen himself as answerable in the first instance to the same questions as the Milesians, whatever his reservations about their would-be polymathiē:

One thing is wisdom: to understand the plan by which all things are steered through all things (B41).

Since the end of the Second World War, the academic study of Greek philosophy in Britain and North America has changed almost out of recognition. One fairly crude index of the change is the huge growth in the numbers of scholars active in the subject, the volume of their publications, and the variety of their interests. Harder to characterise is the way in which scholarly study of the ancient texts has, without losing in historical scrupulousness or historical imagination, become much more a first-order philosophical activity than it was in the first half of the century. Such changes require moving causes. This volume salutes the work of a scholar and philosopher whose influence on the development of study of Greek philosophy in the last 30 years is second to none.

There have been three major channels through which G. E. L. Owen has made his influence felt. Pride of place must go to the series of masterly essays which he has given us since the early fifties, transforming the state of the art. In Parmenides and Zeno he has shown us, in place of the dogmatic monist and the sophist of the textbooks, the inventors of philosophy as we now understand it, or more specifically of a tradition of profound and subtle metaphysical argument. He has demonstrated how Plato in the theory of Forms gave classic expression to a seductively simple picture of the relations between language and the world, but then in his later dialogues fought his way self-critically to a more penetrating understanding of their complexities.

The ancients were already well aware that the sorites is not just about heaps. It brings into question the very existence of the gods, or at least the rationality of religious belief. If modern philosophers of language (who in recent years have been much preoccupied with the sorites paradox) seldom know this, a magisterial paper by Jonathan Barnes has now made clear the range and richness of the ancient material on the subject. Some of this material looks strange by modern lights. All the more reason, therefore, why enthusiasts for the sorites should take an interest in its history.

The history begins, as everybody knows, with a memorable example fashioned by the past master of paradox, Eubulides of Miletus (4th cent. b.c.), known also for his purveying of the Liar, the Bald Man, the Nobody, and other logical delights (D.L. 11 108).

Aristotle opens Physics I by stating that an inquiry into nature (peri phuseōs), like other inquiries, should begin with an account of the relevant principles (archai). He does not tell us what he means by ‘nature’ – for that we have to wait until book II – and he does not tell us what he means by a ‘principle’ in this context, but as we read on we may come to think this omission unimportant. For straightway at the beginning of chapter 2 he appears to place himself in the tradition of a series of writers on nature (peri phuseōs) whose views on the ‘principles’ (archai) were perfectly well known. Thus Thales held that there was one ‘principle’, namely water, while Anaximenes selected air and Heraclitus fire; Empedocles again held that there were four principles (earth, water, air, fire), Anaxagoras that there were infinitely many, Leucippus and Democritus that there were just atoms and void, and so on. So Aristotle, it would seem, is preparing to offer us his answer to the question to which these answers had already been propounded by his predecessors: he is preparing to list the ultimate ingredients of the world, and to given an account of how the world is made up from those ingredients. Perhaps this characterization of what the older physicists were up to is rather oversimplified, but I think it is not worth elaborating their problem now.

In his published writings Gwil Owen has from time to time given us some characteristically stimulating comments on the Cratylus. Although he has not devoted an entire essay to the dialogue, it has often been among his favourite topics of discussion. I recall in particular a seminar which he conducted on it soon after his arrival in Cambridge in 1973. I hope he may enjoy this further contribution to the conversation.

The progress of the main argument of the Cratylus is clear enough, although not always well understood. Socrates in conversation with Hermogenes propounds a theory according to which a name (i.e. a noun, a verb, or an adjective – but not a word of primarily syntactic function) counts as a genuine or correct name if and only if its nominatum is a real thing and its constitution is naturally suited to its nominatum. The principal test of a name's suitability is its capacity to teach or disclose to us the nature or essence of its nominatum: simply by considering the constitution of a name we should be able to tell what it is the name of (386D–391A).

Socrates then attempts to explain just how a name could be so constituted as to disclose its nominatum. He does so by means of the hypothesis that his own language, Greek, consists of genuine names in the sense required by the theory.

The account he offers of the way in which Greek names can be construed as genuine names is developed in two stages.

In chapter 11 of his de Interpretatione Aristotle tries to explain why certain features of a thing go together to make up a unity, whereas others do not. ‘For example,’ he says, ‘a man is perhaps an animal and two-footed and tame, and from these there does come to be some one thing’ (2ob16–8). But ‘from white and man and walking,’ he adds, ‘there is not one thing’ (2ob18–19).

The reasoning in this chapter is intricate; but without tracing out the intricacies we can perhaps say that the unity Aristotle is seeking here is the oneness of an individual substance. In this passage he is unwilling to count as a unity the parasitic oneness that is enjoyed by features only accidentally compresent in a single substance. Though it may be true to say, he remarks later on in the chapter, ‘The white is musical’ (that is, presumably, ‘The white person, is musical’), still, he warns, musical white and white musical (contrast: two-footed animal) are not one thing (21a7–14).

Aristotle later softens his position. He allows, in Metaphysics v 6, for example, that there is such a thing as an accidental unity (hen kata sumbebēkos). The musical and the just, he says, make up an accidental unity because musicality and justice are accidents of one substance (1015b21–2).

These studies are offered to Gwil Owen on the occasion of his 60th birthday with respect, gratitude and affection. Their writers are all either pupils of his or younger scholars who, while not formally his pupils, would wish to acknowledge the stimulus of his talk and thought at a formative stage in their own philosophical histories. The volume contains fifteen chapters, all concerned in one way or another with aspects of the role played by reflection upon language in the thought of Plato, Aristotle, and other ancient Greek philosophers. It would have been as easy and as appropriate to persuade a quite different team of authors to write essays in Gwil Owen's honour on some quite different subject – say, Greek science and philosophy of science – no less close to his heart. So this book is dedicated to him with the good wishes, expressed by many to the editors, of a much greater number of pupils and others, on both sides of the Atlantic, than are assembled between these covers. Our thanks go to all who have helped us by their co-operation or advice, particularly our publisher Jeremy Mynott, who has made the project possible.

The second half of the Parmenides has been a source of puzzlement to generations of scholars, inspiring a wide variety of interpretations. Thanks to the groundbreaking work of Ryle and Owen, one can see this material today as offering serious reflections of conceptual and metaphysical nature. In this chapter I wish to locate the key conceptual problems that Plato addresses in this passage, and argue that Plato is here also defending and revising his theory of Forms.

General remarks

All attempts at interpretation have to come to grips with the strange structure of the passage. On the surface at least, it seems that the material is arranged into eight arguments; the arguments taken pair-wise contradict each other. This organisation is, however, not very tight. Thus it suggests that it might serve for Plato more as a frame of exposition rather than as the logical back-bone of content. For one thing, after the second argument we find a longer passage on time which begins by stating that we are starting for ‘the third time’ (155E4); commentators, taking the surface structure too seriously, have been treating this as an ‘appendix’ to the second argument. Further evidence for the hypothesis that the over-all structure is not meant very deeply is provided by the fact that the arguments are not of equal length. The second one is the longest, and the last four take up much less space than the first four.