NESTORIUS (381?–451?), Christian bishop after whom was named one of the major heresies concerning the doctrine of Christ. The figure of Nestorius is much less significant than the teachings associated with his name and the theological developments after his deposition. He was born in Germanicia in Cilicia, a Roman province in southeastern Asia Minor (modern-day Turkey). In the Syrian city of Antioch, he distinguished himself by his asceticism and skill in preaching. When the clergy of the capital city of Constantinople could not agree on a replacement for the patriarch Sisinnius, the emperor invited Nestorius to accept the post. As bishop he was zealous in stamping out heresy, particularly Arianism and Novatianism. He soon became embroiled in controversy, however, initially because of the preaching of his assistant Anastasius, a presbyter he had brought with him from Syria, but later through his own lack of judgment.

Nestorius criticized the term...