Plato’s long and astonishing career produced not only a large and arguably the most influential output of intellectual writing in Western, if not human, history but also the establishment of a research and educational institution that maintained its identity for more than nine hundred years. But the general features of these events have been written about and celebrated through many centuries of adulation, polemic, and relatively neutral scholarship. It is not the intent of this book, however, to comment on or celebrate these general features but rather to concentrate on the interrelations of some of Plato’s later writings and to...

Cephalos After we came to Athens from our home in Clazomenae, we happened upon Adeimantus and Glaucon in the market-place. Seizing my hand, Adeimantus said, ‘Welcome, Cephalos, if we can do anything for you while you are here, you have only to say it.’

‘How very timely,’ said I. ‘I am here for just that purpose – to ask a favour of you.’

‘Tell us the favour,’ he said.

[126B] And I said, ‘What was the name of your half-brother on your mother’s side? For I don’t remember it. He was just a boy when I came here from Clazomenae...

Parmenides [135C] What then will you do about philosophy? Where will you turn while these things remain unknown?

Socrates At the moment I do not see that at all clearly.

P The reason is that you have, Socrates, undertaken too soon, before being exercised, to define Beautiful, Just, Good, and each one of the forms. I noticed that yesterday when I heard you in conversation with Aristotle here. Believe me, the zeal that you have for arguments is noble, even divine. But you must bring yourself to exercise in what is seemingly unprofitable and what most people callmere talk...

It would be a mistake to think that the upshot of going through the procedure for the Parmenidean Version of the affirmative one supposition is utterly negative and barren. There are at least two important results. First, what Parmenides has shown in going through Zeno’s procedure is precisely what one would expect from what Plato took to be the doctrine of the historical Parmenides. Second, the form of the great exercise has been given the shape and arrangement that Plato wants us to understand before we move to the other versions of the one supposition. Let me discuss these in...

Parmenides [142B] Would you have us then take up the supposition again from the beginning to see if something of a different sort might appear to us in going through it again? We say then, if one is, the consequences concerning this, whatever they happen to be, must be conceded, do we not? Attend now from the beginning. If one is, can it be and yet not have a share of being (ousia) ? Then there must also be the being (ousia) of the one that is not the same as the one. For, unless that being were of it...

Parmenides Now what of this? Consider how it goes in the matter of the one’s touching and not touching itself and the others. The one was shown, I believe, to be in itself as a whole. And the one was also shown to be in the others. Then in so far as it is in the others [148E] it would touch the others. In so far as it is in itself it would be precluded from touching the others; but, being in itself, it would touch itself. So the one would both touch itself and the others.

But what of...

Parmenides Once more and for a third time let us proceed with the account. If the one is such as we have described it, being both one and many, neither one nor many, and having a share of time, is it not necessary that it, because it is, then have a share of being, because it is not, then not have a share of being? Well then, when it has a share, can it then not have a share, or, when it does not have a share, can it then have a share?

Thus it has a share at one...

The major effort of this supposition is to show how negative predication is possible, thus doing away with the claim that negative predication destroys the possibility of sayinganything. The effort is parallel to the effort of theSophistto show how false belief is possible. Both the present effort and that of theSophistrequire construing negative predication as a special form of positive predication, a form having the liability of treating negative predicates asindefinites(aorista).

Parmenides Well then, must we not, after this, consider what must go along with the supposition that the one is not? What...

As I announced in the introductory chapter, this book has two aims: first, to provide a detailed interpretation of theParmenides; second and related (with much already noted), to exhibit a remarkable set of intellectual interrelations between theParmenidesand several other dialogues commonly thought to be late. These are theTimaeus, theTheaetetus, theSophist, and thePhilebus. Attention also is paid to Books VI and VII of theRepublicbecause of their obvious concerns with the nature of mathematics and their promise of dialectic’s making ultimate principles known.

There has been little disagreement about the relative order of...

The relevance of theTheaetetusfor the present work is its place in the late philosophy of Plato and, of course, what it reveals of that late philosophy. Interestingly, of the four dialogues made up of theTheaetetusand the three explicitly contemplated early in theSophist(Sophist,Statesman, andPhilosopher) only theTheaetetushas (or was to have had) Socrates as protagonist. The setting of theSophistis the day following that of theTheaetetus, and it has the same dramatis personae with the addition of an Eleatic Stranger (an about-to-be-reformed disciple of Parmenides) who carries the intellectual burden...

I have argued earlier that it is plausible to think that Plato’s choice of protagonist for theParmenides, theSophist, and theStatesmansignalizes a marked change in his thought, and that change has by now been appropriately explained. We come now, however, to what has been commonly taken to be an even later dialogue, and once again Socrates is the protagonist. Does this signalize a return to an earlier pattern of thought? I don’t think so. I do think that the subject matter of thePhilebus, namely, the choiceworthy life for a human being, is so appropriate for Plato’s...

The eleven interpretative chapters of this book are at once an effort to explain the text of theParmenidesand an effort to provide plausible linkage of that explanation with the texts of other important late dialogues. It is difficult not to believe that Plato himself intended the linkage. First, the start of theParmenidesis clearly linked with theRepublicin that Glaucon and Adeimantus are given the role of greeters of the party from Clazomenae. And, of course, the setting of theTimaeusjust as clearly links that dialogue with theRepublic. Second, the favourable references to Parmenides...