Antiochene theology emphasizes Christ's humanity and the reality of the moral choices he faced. In order to preserve the impassibility of Christ's Divine Nature, the unity of His person is defined in a looser fashion than in the Alexandrian tradition. The normative Christology of the Assyrian church was written by Babai the Great (d. 628) during the controversy that followed the 431 Council of Ephesus. Babai held that within Christ there exist two "qnome" (Syriac: ܩܢܘܡܐ / "qnômâ", a complex term, equivalent for Greek term hypostasis), unmingled, but everlastingly united in the one prosopon (person) of Christ.