Does Relativism Refute Itself?

In this third session on Plato's Theaetetus, Richard Polt guides students through one of the dialogue's richest stretches. The lecture begins by revisiting the equation of knowledge with perception and the Protagorean claim that each person is the measure of truth. Can Protagoras consistently claim special wisdom if everyone's perceptions are equally valid? The famous argument suggests relativism may refute itself. Polt then examines how experts and their power of prediction challenge relativist assumptions, especially in politics. The lecture takes a dramatic turn with Socrates's famous digression comparing the philosopher and the lawyer, raising questions about freedom, ignorance, and nobility of character. The story of Thales falling into a well introduces the archetype of the absent-minded thinker. Polt asks whether Socrates is really describing himself. The session closes by tracing the radical Heraclitean doctrine of universal flux to its logical extreme, where constant change destroys the very possibility of language, setting up the final refutation of knowledge as perception.