There is nearly universal agreement that Plato's Apology of Socrates is a seminal work in philosophy and political theory, as interesting to lay readers as to scholars, and new books on it appear every few years. But why another? What justification can there be for offering yet one more commentary on this dialogue that has been commentaried almost to death? My defense is that by paying unusually close attention to what Socrates indicates about the meaning and extent of his irony, I have arrived at unconventional conclusions about his teaching on virtue, politics, and the gods, the significance of his famous turn from natural philosophy to political philosophy, and the purpose of his insolent “defense speech.” My primary intention is to show that Plato's Socrates is not just a colorful and quirky figure from the distant past, but an unrivaled guide to the good life – the thoughtful life – who is as relevant today as he was in ancient Athens. On the basis of my understanding of the dialogue as a whole, and of the Delphic oracle story in particular, I also attempt to show that the Apology is the key to the Platonic corpus, indicating how many of the disparate themes and apparently contradictory conclusions of the other dialogues fit together.