The Triumph of Pro-nicene Theology over Anti-Monarchian Exegesis: Cyril of Alexandria and Theodore of Heraclea on John 14.10-11

This article begins by identifying a previously unknown quotation in Cyril of Alexandria’s Commentary on the Gospel of John as an extract from the Johannine commentary of Theodore of Heraclea, a leading member of the fourth-century Eusebian alliance. I argue that the relevant fragment from Theodore’s commentary dealing with John 14.10–11 reveals his attempt to oppose Marcellus’s Monarchian exegesis of John 10.38. In order to do so he drew upon third-century anti-Monarchian authors, most notably Origen. Cyril responded to Theodore’s exegesis in a thoroughly pro-Nicene fashion, demonstrating that his exegesis fell short of the pro-Nicene consensus that developed in the latter half of the fourth century. Cyril’s chief criticisms of Theodore’s exegesis are that he applied corporeal categories to the Son, that he implied that the Son does not share the Father’s infinity, and that he failed to adequately distinguish the Father/Son relationship from the Creator/creation relationship. This small episode highlights the shifting doctrinal concerns from the fourth to the fifth centuries, as well as the centrality of biblical exegesis to theological formulation during these years.