Qoheleth's determinism, its relationship to free will and its philosophical background evidence its authorship by a third-century sage influenced by Stoic ideas. Is the author of Ecclesisastes a determinist? Many readers, from the Targumist and lbn Ezra up to the present day, have thought so. But there has been no systematic investigation 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 the author was a sage writing in the third quarter of the third century BCE, who was profoundly influenced by Stoic ideas.