Series Foreword I. Introduction Early Christology Initial Problems Justin Martyr, Melito of Sardis, Irenaeus of Lyon, Tertullian of Carthage, Origen of Alexandria Further Problems The Arians and Athanasius; Apollinaris of Laodicea; Theodore of Mopsuestia; Cyril, Nestorius, and Eutyches; Leo and Chalcedon II. Melito of Sardis A Homily on the Passover III. Irenaeus of Lyon Against Heresies IV. Tertullian Against Praxeas On the Flesh of Christ V. Origen On First Principles VI. Athanasius Orations against the Arians VII. Apollinaris of Laodicea On the Union in Christ of the Body with the Godhead Fragments VIII. Theodore of Mopsuestia Fragments of the Doctrinal Works IX. The Controversies Leading Up to the Council of Chalcedon Nestorius's First Sermon against the Theotokos Cyril of Alexandria's Second Letter to Nestorius Nestorius's Second Letter to Cyril Cyril's Letter to John of Antioch Pope Leo I's Letter to Flavian of Constantinople The Council of Chalcedon's "Definition of the Faith" Bibliography