The Question of the Self-Refuting Character of Protagorean Relativism in teh Theaetetus

The Theaetetus is the first sustained philosophical inquiry into knowledge. The dialogue is presented through the conversations of five characters—Euclides, Terpsion, Socrates, Theodorus, and Theaetetus—the last three of which carry the burden of the dialogue. Early in the dialogue, Socrates, Theodorus, and Theaetetus consider the question "What is knowledge?" and spend the rest of the dialogue entertaining three theories of knowledge. The first theory is that knowledge is perception, the second that knowledge is true judgment, and the third that knowledge is true judgment with an account. Through the method of question and answer, Socrates shows that each account fails to properly capture what knowledge is in some way or another. The dialogue concludes without a positive answer to the question, though the three main interlocutors agree to meet the following day to continue their conversation. This paper will investigate the first of the three theories of knowledge offered by Theaetetus, namely, that knowledge is perception. In particular, this paper will address the claim that the Protagorean relativism employed as a defense of the first theory is self-refuting. Many fine Plato scholars and other philosophers argue that Protagorean relativism is self-refuting, among them Myles Burnyeat, Ronald M. Polansky, and John Passmore. However, in her article "Protagoras and Inconsistency," Sarah Waterlow offers a rival interpretation of Protagoras' relativism under which relativism doesn't so much refute itself as show itself to be, in her words, a "dialectical nothing."1 aim to make clear in this paper Waterlow's interpretation of Protagoras' relativism and her criticism of the Burnyeat/Polansky/Passmore position [hereafter BPP]. I will also defend Waterlow's interpretion against the BPP position. First, though, a significant amount of background on the dialogue is required.