Plato and the Copula: Sophist 251–259

Abstract

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.