Dyophysite Christology of the Church of the East

The Antiochene school of biblical interpretation, associated with teachers such as Theodore of Mopsuestia, emphasized the full reality and integrity of Christ's human nature against what it saw as an Alexandrian tendency to merge the human and divine natures so closely that Christ's humanity risked being absorbed or overshadowed. Nestorius, Patriarch of Constantinople and a student of this Antiochene tradition, was condemned at the Council of Ephesus in 431 on the charge of dividing Christ into two separate persons, a reading of his preaching that the Church of the East's own later theologians disputed as a distortion.

The Persian church, already administratively distinct from the church inside the Roman Empire because of its position under Sassanid rule, sided with the condemned Antiochene line rather than its Alexandrian opponents, and at the Synod of Seleucia-Ctesiphon in 486 formally affirmed that Christological direction as its own.

The tradition received its lasting technical formulation from Babai the Great, abbot of the monastery on Mount Izla around 600 CE, who taught two qnome, concrete individual natures, divine and human, united in one parsopa, a single manifest person, a formula built to affirm both the full reality of each nature and the genuine unity of Christ's person without collapsing either the Alexandrian or the Antiochene concern.

Nestorian was always an outsider's polemical term, never a name the church used for itself; it called itself simply the Church of the East, or, in the language of its own liturgy, the Assyrian Church of the East. Modern historical scholarship on Syriac Christianity, notably the work of Sebastian Brock, has argued that the church's mature Christology as fixed by Babai the Great is considerably more careful and more clearly dyophysite in a defensible, orthodox sense than what Nestorius himself was actually condemned for at Ephesus, and that continuing to use the label obscures the tradition's own theological development more than it explains it.

The church nonetheless suffered under the weight of that label for over a millennium, surviving the Mongol conquests of the thirteenth and fourteenth centuries, near destruction under Timur, and catastrophic massacres in the late nineteenth and early twentieth centuries that scattered its remaining communities from their historic heartland in northern Mesopotamia across the world. Throughout, the church maintained a claimed apostolic succession tracing to Saint Thomas and to Saints Addai and Mari, and its Christology remains today formally unreconciled both with the Chalcedonian churches it never joined at Chalcedon in 451 and with the Oriental Orthodox churches, whose miaphysite Christology it has historically regarded as the opposite theological error from its own.