Socrates believed that the search for truth was the highest aspiration of human learning. And by truth he meant something more inclusive than the factual accuracy of propositions about the natural world. Much closer to his heart, and to his ever-renewed practical efforts, was the venturesome question of the truth about the right way to live. Yet, in the course of his encounters with the most accomplished intellects of his age, he came to see, as Plato showed him declaring frankly in the Apology, that there was something enigmatic about this question, something that resisted resolution in conclusive terms.1 This is not to deny that there are notable advances made in the lively debates of the early dialogues of Plato, which show Socrates at his philosophical and educational best. But those advances are of a curious and frequently chastening kind. Characteristically, they reveal to participants in the dialogues some undetected biases, often crucial ones, in their own starting points. In doing this, however, they also gradually disclose to the participant (or indeed the reader) who remains alert to the tenor of Socrates’ thinking something that is both sobering and challenging.