Antilogikē

Abstract

Plato’s dialogue Theaetetus examines the nature of knowledge. It starts with the thesis that knowledge is perception. Socrates articulates the view, quotes authorities (Homer, Heraclitus and Protagoras among them) and describes how, following these authorities, perception must be defined: neither the object nor the perception can exist by itself: act, object and perception must form an indivisible block. The unperceived world contains motions, some swift, some slow, but without definite properties. The motions interact and produce the block with its well defined ingredients. This is a striking anticipation of some features of quantum mechanics (Einstein-Podolsky-Rosen correlations), for here, too, it makes no sense to speak of objects and their properties except as parts of a particular interaction. Finally, Socrates raises various difficulties. For example, he says that if knowledge really were the same as perception then we would cease to know when we close our eyes — but we still know because we remember what we have seen. Or he says that closing one eye we both know and don’t know. Or he says that perception is certain, it is possessed by everybody, and relative to them so that teachers, such as Protagoras turn out to be superfluous. ‘We must say, then’, Socrates concludes his diatribe (which contains further counter examples) ‘that each of the two [viz. knowledge and perception] are different from each other’. ‘Obviously’, mumbles Theaetetus, his fall guy.