Sex is beyond reason, and yet we constantly reason about it. So, too, did the peoples of ancient Greece and Rome. But until recently there has been little discussion of their views on erotic experience and sexual ethics. The Sleep of Reason brings together an international group of philosophers, philologists, literary critics, and historians to consider two questions normally kept separate: how is erotic experience understood in classical texts of various kinds, and what ethical judgments and philosophical arguments are made about sex? From same-sex desire to conjugal love, and from Plato and Aristotle to the Roman Stoic Musonius Rufus, the contributors demonstrate the complexity and diversity of classical sexuality. They also show that the ethics of eros, in both Greece and Rome, shared a number of commonalities: a focus not only on self-mastery, but also on reciprocity; a concern among men not just for penetration and display of their power, but also for being gentle and kind, and for being loved for themselves; and that women and even younger men felt not only gratitude and acceptance, but also joy and sexual desire.