Protagoras, Homo Mensura, and Self Refutation

Is Homo Mensura Self-Refuting? Plato’s Theaetetus involves a famous exchange between Socrates, an old mathematician named Theodorus, and his brilliant young pupil named Theaetetus, in which they attempt to answer the question of what is knowledge. The common denominator in this exchange, is that Protagoras is an old friend of Theodorus, and Theaetetus has adopted Protagorean relativism as his own doctrine. The exchange between Socrates and the two men is at least in part (in addition to attempting to discover a theory of knowledge in general) intended to demonstrate that the doctrine of Protagoras is self-refuting.