Synesius, a philosopher of the 5th century, born in Cyrene, Africa, about 379, died at Ptolemais about 430. He was of an ancient Greek family, studied at Alexandria under Hypatia, and at Athens, and on his return to Cyrene devoted himself to literary pursuits. Famine having come upon Cyrene about 397, Synesius was sent to Constantinople to solicit aid, and was successful. After three years' stay in the Byzantine capital, he returned to Cyrene, and soon afterward, under the influence of a Christian wife, renounced paganism. In 410, on the death of the bishop of Ptolemais (now Tolmeta in Barca), Synesius was chosen to the see, although he had not been baptized, was married, and held opinions not regarded in the church as orthodox. He accepted the post with reluctance, was baptized, and after seven months of preparation entered upon his episcopal duties. He was a Neo-Platonist before he became a Christian, and during his episcopate explained Christian dogmas in the light of his philosophy, inclined to the preex-istence of the human soul, believed in its immortality, held the resurrection to be a myth, and conceived the Trinity as a triple-headed energy displaying the innate nature of the "unity of unities." His works consist of epistles, treatises, and hymns.

The best complete collection of them is that of Petau, in Greek with a Latin translation, editions of which appeared at Paris in 1012, 1633, and 1640. A new and more critical edition was published by Krabinger (2 vols. 8vo, Berlin, 1851). Many editions of the hymns have been published with translations into various tongues. A French version first appeared in 1581, and new ones in 1836 and 1839. See also Migne's Patrologie grecque, vol. lxvi.; and Kolbe, Der Bischof Synesius von Gyrene (Berlin, 1870).