Volume one of S. Ephraim’s Prose Refutations contains the English translation of St. Ephraim’s five discourses against false teachings. In the first discourse, Ephraim directs his main attack against the teachings of Manichaeism, a major Gnostic religion that was challenging Christianity. The other four refutations are directed at Bardaisan, Mani, and Marcion. This volume also contains discourses 2–5 in the original Syriac.