THEODORE, of Mopsuestia, a well-known writer of the Syrian church, and especially notable in connection with the controversy of "The Three Chapters," was born of a wealthy and distinguished family at Antioch, in the first half of the 4th century. He was the school-fellow and friend of St. John Chrysostom, and his fellow-pupil under the philosopher and rhetorician Libanius; and he was induced by the earnest exhorta tion of Chrysostom, to join with him in embracing the monastic life. His theological and scriptural studies were made under Flavian of Antioch and Diodorus of Tarsus; and having received priest's orders, he resided for a time at Antioch, where his learn ing and eloquence won the highest applause; and afterward at Tarsus, under his old teacher Diodorus. About the year 390, or a little later, he was chosen bishop of Mop suestia in Cilicia. In 394 he preached in the presence of the emperor Theodosius at Constantinople, on occasion of a synod held in that city. Of his further history little is
known; but his literary activity must have been prodigious, if we can judge by the con temporary accounts, and by the number of the works which are ascribed to him, hut of which only fragments now remain. The most important of these consisted of com mentaries on almost all the books of Scripture, and various polemical writings. A sup posed tendency to Pelagian and Nestorian errors was observable in Theodore, and was in part the occasion of the long controversy of the three chapters. This controversy, how ever, did not arise till long after the death of Theodore, which took place about 427. Considerable fragments of Theodore's commentaries have been published by cardinal 'Hai in his Spicilegium Romanum, and some of his works still exist in Syriac; but by far the greater proportion has been lost.