 Foucault never published any of the material developed in these two lecture series, and in the lectures in the 1980s he turned to examine texts from ancient philosophy. Many of the ideas developed there were later published as The Use of Pleasure and Care of the Self. His studies of ancient sexuality, and, particularly, the idea of an aesthetics of existence also led him to the ancient idea of philosophy as a way of life rather than a search for theoretical truth. Although The Use of Pleasure has some discussion of Plato’s conception of philosophy, Foucault’s treatments of the topic are primarily in lectures that he had no time to develop for publication. Some of these lectures discuss Socrates (in the Apology and in Alcibiades I) as both a model and an exponent of a philosophical life focused on “care of the self” and follow the subsequent ancient discussions of this topic in, for example, Epictetus, Seneca, and Plutarch. Other lectures deal with the ancient ideal of “truthful speaking” (parrhesia), regarded as a central political and moral virtue. Here Foucault discusses earlier formulations of the notion, in Euripides and Socrates, as well as its later transformations by the Epicureans, Stoics, and Cynics. This research project might have been one of the most fruitful of all Foucault’s engagements with traditional philosophy. But his early death in 1984 prevented him from completing it.