PHOTINUS, fo'ti-nus: Bishop of Sirmium; b. in Ancyra in Galatia; d. in Galatia 376. He was a pupil of Marcellus of Ancyra and bishop of Sirmium in Pannonia, near the modern Mitrovicza. He first appears at the Synod of Antioch in 344, where the Eastern Church condemned him and Marcellus. This judgment was approved by a Synod at Milan in 345, and Photinus was deprived of his bishopric by a Synod of Sirmium in 351. According to Epiphanius he appealed to the Emperor Constantius, was granted a hearing, and disputed with Basil of Ancyra before his judges. Socrates and Sozomen correctly refer this disputation to the Synod of Sirmium in 351, and state that he was exiled. The Synod of Milan, 355, renewed the anathema. That he returned for a season appears from the friendly letter of Emperor Julian to him and from the fact that Jerome knows him to have been banished by Valentinian (364-375). His heresy obtained little influence in the East; but in the West, especially on the Balkan peninsula, Photinians continued for a longer period. They were known at Sirmium in 381, and at the beginning of the fifth century a Photinian Marcus, driven from Rome, found refuge in the diocese of Senia, Dalmatia. Augustine refers to them frequently not as a sect but as persons in general who think after the Photinian manner; i.e., persons who regard Christ as a mere man.

Photinus was a dynamic monarchian (see MONARCHIANISM) who, without denying the virgin birth, regarded the person of Christ as essentially human; and denied a hypostatic distinction of the Logos from the Father and a hypostasis of the Spirit. He attached himself to the Marcellian doctrine and argumentation: "the Son is known simply according to his appearance in the flesh" and Daniel (vii. 13) speaks "prophetically, not as of the Son existing." His most significant writings, according to Jerome, were Contra gentes and Libri ad Valentinianum. Socrates knows of a book "Against All Heresies" and Rufinus of a tract on the symbol (MPL, xxi. 336).