Protagoras

One of Plato’s liveliest dialogues, the Protagoras stages a crowded encounter in which Socrates debates the great Sophist Protagoras on whether virtue (aretē) can be taught.

The argument turns on the unity of the virtues and ends in a striking reversal — Socrates, who began by doubting that virtue is knowledge, comes to defend it, while Protagoras, who sold its teaching, is left in difficulty.