Abstract

Plato's Theaetetus investigates the nature of knowledge. Socrates converses with two mathematicians, Theaetetus and Theodorus, who cannot arrive at the necessary and sufficient conditions of knowledge. Theaetetus offers three definitions, none of which can withstand scrutiny. Most commentators on the Theaetetus examine the arguments put forward and, by constructing a definition of knowledge, attempt to complete what Plato began. But analysis of the various definitions offered is incomplete as an investigation of the dialogue. ;Before Socrates elicits from Theaetetus the first definition of knowledge as perception, he characterizes himself as a midwife. And before readers are introduced to Socrates, we encounter Euclides as the alleged "author" of the dialogue. It is incumbent upon the reader to notice all the elements that Plato offers and to examine whether the dramatic setting of the arguments sheds light on their outcome. The inner frame of the dialogue reveals that the nature of Theaetetus's soul is under investigation as much as the nature of knowledge. The nature of writing and memory, discussed in the outer frame, are incorporated in the second definition of knowledge as opinion, and in the third definition as true opinion with logos. Logos is the unifying principle of the dialogue, in that Socrates' dissection of the three meanings of logos recapitulates the three definitions of knowledge. ;A rigorous reading, incorporating both the action and the speeches of the dialogue, shows that the Theaetetus exhibits the essential ingredients of knowledge. The lengthy examination of perception shows it as model for knowledge, in that an account is needed of both the knower and the known, before a complete definition is possible. Thus the Theaetetus is a guide on the way to knowledge. By the end we have a thorough understanding of both the need for a structure of soul and for the structure of that which is to be known, as well as the tool, logos, which would enable us to put the two together in a definition of knowledge