The doctrines of the Hellenistic Schools—Epicureans, Stoics, and Skeptics—are known to have had a formative influence on later thought, but because the primary sources are lost, they have to be reconstructed from later reports. This important collection of essays by one of the foremost interpreters of Hellenistic philosophy focuses on key questions in epistemology and ethics debated by Greek and Roman philosophers of the Hellenistic period.