Exploring the world of sixth-century Miaphysitism, Torrance here provides translations of the letters between two Miaphysites of differing outlooks. Severus of Antioch was the Patriarch of Antioch and a moderate Miaphysite whose doctrine differed from Catholic teaching primarily in terminological divergences. Sergius the Grammarian is a lesser-known figure, but the content of his letters demonstrates that he was a more extreme Miaphysite. The correspondence between the two consists of three letters of Sergius and the three replies by Severus. An additional apology by Sergius rounds out the collection. Made available in the original Syriac along with Torrances translation, these letters are an important part of the working out of concerns associated with the context of the Council of Chalecedon. Presented here with a new introduction by the translator, the letters are available to readers interested in this fascinating and involved period of church history. Iain R. Torrance earned his D. Phil. at Oxford University and is the President of Princeton Theological Seminary. He has written widely on many current issues in theology and is a respected scholar of Eastern Christianity.