Published online by Cambridge University Press: 23 December 2013
My purpose is not to give a full interpretation of this difficult and important passage, but to discuss one particular problem, taking up some remarks made by F. M. Cornford (in Plato's Theory of Knowledge) and by Mr. R. Robinson (in his paper on Plato's Parmenides, Classical Philology, 1942). First it may be useful to give a very brief and unargued outline of the passage. Plato seeks to prove that concepts are related in certain definite ways, that there is a συμπλοκὴ εἰδῶν (251d–252e). Next (253) he assigns to philosophy the task of discovering what these relations are: the philosopher must try to get a clear view of the whole range of concepts and of how they are interconnected, whether in genus-species pyramids or in other ways. Plato now gives a sample of such philosophising. Choosing some concepts highly relevant to problems already broached in the Sophist he first (254–5) establishes that they are all different one from the other, and then (255e–258) elicits the relationships in which they stand to one another. The attempt to discover and state these relationships throws light on the puzzling notions ὄν and μὴ ὄν and enables Plato to set aside with contempt certain puzzles and paradoxes propounded by superficial thinkers (259). He refers finally (259e) to the absolute necessity there is for concepts to be in definite relations to one another if there is to be discourse at all: διὰ γὰρ τήν ἀλλήλων τῶν εἰδῶν συμπλοκὴν ὁ λόγος γέγονεν ἡμῖν So the section ends with a reassertion of the point with which it began (251d–252e): that there is and must be a συμπλοκὴ εἰδῶν.
The question I wish to discuss is this. Is it true to say that one of Plato's achievements in this passage is ‘the discovery of the copula’ or ‘the recognition of the ambiguity of ἔστιν’ as used on the one hand in statements of identity and on the other hand in attributive statements? The question is whether Plato made a philosophical advance which we might describe in such phrases as those just quoted, but no great stress is to be laid on these particular phrases. Thus it is no doubt odd to say that Plato (or anyone else) discovered the copula. But did he draw attention to it? Did he expound or expose the various roles of the verb ἔστιν? Many of his predecessors and contemporaries reached bizarre conclusions by confusing different usesof the word; did Plato respond by elucidating these different uses? These are the real questions.
1 I shall refer to these two works by page numbers, without repeating their titles.
2 The use of this term may seem provocative. But whether or not the εἴδη and γένη of the Sophist are something more than ‘mere’ concepts, a good deal of interpretation of 251–9 can satisfactorily proceed on the assumption that they are at least concepts.
3 I quote Geach's, Mr. translation, in Translations from the Philosophical Writings of Gottlob Frege, edited by Geach, Peter and Black, Max, pp. 43–4.Google Scholar
4 One is reminded of Aristotle, Physics 185b28:
5 I have discussed these arguments, in another connection, in a short paper in the Bulletin of the Institute of Classical Studies of the University of London, No. 2, 1955 pp. 31–35.
6 In Museum Helveticum, 1945, especially pp. 171–5.
7 In Plato's Theory of Ideas, p. 111, n. 6.
8 This is rather a cavalier dismissal of the passage on which Cornford relies so heavily. But it is not possible in the space available to attempt a full study of the perplexing argument of 255c12–e1, and without such a study no statement as to the exact force of μετέχειν in 255d4 is worth much. My own conviction is that even in this passage μετέχειν does not stand for the symmetrical relation ‘blending’ but it is certainly not used in quite the same way as in the other places where it occurs in 251–9.