Qoheleth's determinism, its relationship to free will and its philosophical background evidence its authority by a third-cenury sage influenced by Stoic ideas. Is the author of Ecclesisastes a determinist? Many readers, from the Targumist and Ibn Ezra up to the present day, have thought so. But there has been no systematic investigations of Qoheleth's determinism, its nature and extent, its relationship to free will and its philosophical background. In separate chapters, Rudman discusses key terms and texts that express a deterministic worldview, then explores the sources for Qoheleth's thought. He concludes that he author was a sage writing in the third quarter of the third century BCE, who was profoundly influences by Stoic ideas.