Anastasius (1) , a presbyter of Antioch, the confidential friend and counsellor of Nestorius, the archbp. of Constantinople. Theophanes styles him the "syncellus," or confidential secretary of Nestorius, who never took any step without consulting him and being guided by his opinions. Nestorius having commenced a persecution against the Quartodecimans of Asia in 428, two presbyters, Antonius and Jacobus, were dispatched to carry his designs into effect. They were furnished with letters commendatory from Anastasius and Photius, bearing witness to the soundness of their faith. The two emissaries of the archbp. of Constantinople did not restrict themselves to their ostensible object, to set the Asiatics right as to the keeping of Easter, but endeavoured to tamper with their faith. At Philadelphia they persuaded some simple-minded clergy to sign a creed of doubtful orthodoxy, attributed to Theodore of Mopsuestia. This was strongly opposed by Charisius, the oeconomus of the church, who charged Jacobus with unsoundness in the faith. His opposition aroused the indignation of Anastasius and Photius, who dispatched fresh letters, reasserting the orthodoxy of Jacobus, and requiring the deprivation of Charisius (Labbe, Conc. iii. 1202 seq.; Socr. vii. 29).
It was in a sermon preached by Anastasius at Constantinople that the fatal words were uttered that destroyed the peace of the church for so many years. "Let no one call Mary θεοτόκος . She was but a human being. It is impossible for God to be born of a human being." These words, eagerly caught up by the enemies of Nestorius, caused much excitement among clergy and laity, which was greatly increased when the archbishop by supporting and defending Anastasius adopted the language as his own (Socr. H. E. vii. 32; Evagr. H. E. i. 2). [See Nestorius.] In 430, when Cyril had sent a deputation to Constantinople with an address to the emperor, Anastasius seems to have attempted to bring about an accommodation between him and Nestorius (Cyril, Ep. viii.; Mercator, vol. ii. p. 49). We find him after the deposition of Nestorius still maintaining his cause and animating his party at Constantinople (Lupus, Ep. 144).
Tillemont identifies him with the Anastasius who in 434 wrote to Helladius, bp. of Tarsus, when he and the Oriental bishops were refusing to recognize Proclus as bp. of Constantinople, bearing witness to his orthodoxy, and urging them to receive him into communion (Baluz. Â§ 144).