The great feature in the theology of the fourth and fifth centuries was the opposition between the school of Alexandria, allegorical, mystical, Oriental, and the school of Antioch, matter-of-fact, literal, accurate, Western-minded. There were Saints and Doctors of both schools, and heretics in both, the latter carrying the tendencies of their respective schools to excess. From Alexandria came Origen, Athanasius, Cyril, Arius, Apollinaris, Dioscorus. From Antioch, John Chrysostom, Theodoret, Theodore of Mopsuestia, Nestorius. Theodore in his early career was a friend of St John Chrysostom, who addressed to him the still extant treatise, Ad Theodorum lapsum, against the forsaking of monastic life. He was a priest with Chrysostom at Antioch, then in 392 bishop of Mopsuestia (Mopsou hestia) in Cilicia, and died in his bishopric in 428, three years before the Council of Ephesus. Theodore was a voluminous writer and biblical commentator, fond of the literal sense, hating allegories. He was a vigorous opponent of Arius, and especially of Apollinaris. On the other hand, he countenanced the Pelagians, and wrote against St Jerome and St Augustine. Theodore, like Bishop Jansenius of Ypres, enjoyed the reputation of orthodoxy all his life, and died in the peace of the Church. As the Jansenists took up the book of Jansenius, drew their heresy from it, and involved themselves and it in a final condemnation; so the Nestorians fell back upon Theodore, the protagonist of the Antiochene school. Thus Theodore and his works came to be condemned in the fifth General Council, the second of Constantinople in 553. Since their condemnation, the greater part of them have perished.

Nestorius, a Syrian, educated at Antioch, became bishop of Constantinople in 428, the year of Theodore's death. He was condemned and deposed in the Council of Ephesus in 431. Nestorianism is the most rationalistic, and in that way the acutest, of all heretical perversions of the Incarnation. At this day, east and west, beyond the visible pale of the Catholic Church, thousands of professing Christians are, consciously or unconsciously, Nestorians.

Of God and His Creatures: 4.34