Introduction The Christological controversies of the early Church are simultaneously some of the most fascinating and frustrating events of Christian history. At the third of the four great ecumenical councils—Ephesus, in 431 AD—the theologies of Cyril of Alexandria and Nestorius of Constantinople squared off concerning the makeup of the person of Christ. The heart of this debate was whether there were two distinct persons (divine logos and human) within the incarnate Jesus Christ, or if