Abstract

The present essay inquires cornford’s view about Plato’s accusation. According to this accusation, Plato in Theaetetuswrongly introduces Protagoras as a thinker who believes in “impossibility of being contradictory qualities in the same thing” and finally interprets Protagoras’ doctrine as a kind of subjectivism or relativism. On the contrary, Cornford declares that historical Protagoras believes in “co-existent theory of contraries in the same thing”. Cornford thinks this false interpretation depends upon Plato’s wrong explanation of homo mensura. Thus on Conford’s view, introduced Protagoras in Theaetetus has a gross difference from historical and real Protagoras. Conford’s view rests upon two points: text of Theaetetus and report of sextus Empiricus. Reconsidering both points, we criticize Cornford’s view via two reasons: logical reasoning and historical reference.