Theonas, or Theon
Theonas, or Theon (see the extract from Philostorgius given by Photius), was bishop of Marmarica, in Cyrenaica, n the 4th century, and one of the most devoted adherents of Arius. The synodal circular given in Athanasius, 1, 398 sq.
(ed. Montfaucon), from bishop Alexander, which mentions the earliest measures taken against Arius, contains the names of Theonas and his colleague and neighbor Secundus of Ptolemais. The circular referred to indicates that both Theonas and Secundus had been deposed; but it would seem that; the deposition was not enforced, since they appeared at the Council of Nice in the character of qualified members. They achieved notoriety in that synod by resisting the Homoousion more firmly even than did their leaders, Eusebius and others; and as they refused to unite in the condemnation of Arius, they were again deposed and banished. Philostorgius (1, 2, 1) states that Theonas was recalled by the emperor Constantine; but he would seem to have taken no further part in the ecclesiastical conflicts of the time. His name occurs no more in the lists of combatants. See Theodoret, Hist. Eccles. 1, 7 sq.; Socrates, Hist. Eccles. 1, 9 (Decrees of Nice); Epiphanius, Haer. 69. 8, and comp. 68, 6, and 69, 11; Tillemont, Memoires pour servir a l'Histoire Eccls. (Brussels, 8v-o ed.), 6:2; Hist. Abrgee des Ariens, art. 6:7; and History of the Council of Nice, art. 6:11. —Herzog, Real Encyklop. s.v.