This lecture explains the material to be covered in the course as a whole, its purpose, and its guiding thesis. We will examine the key innovations and insights of three important philosophers: Socrates, his student Plato, and Plato’s student Aristotle. Socrates was responsible for a fundamentally new way of philosophizing and, for all their originality, Plato and Aristotle were deeply indebted to Socrates. We will begin by examining two of Socrates’s contemporaries who wrote about him—Aristophanes and Xenophon—and then turn at greater length to consider Plato’s monumental portrait of his teacher. The final third of the course will be devoted to studying Aristotle’s Nicomachean Ethics and Politics, the two works of his in which the influence of Socrates is clearest. Studying Socrates, Plato, and Aristotle is worthwhile not only because they were among the architects of what we call “the West,” but also because we may still learn from them things of vital importance to us as human being