Eunomius a bishop and founder of a sect of Arians. He was born in the village of Dacora, in Cappadocia, and is described by his admirer, Philostorgius, as ugly in appearance, and somewhat stammering. He was educated by his father until, under the advice of the Arian bishop Secundus, of Antioch, he went to Alexandria, where he became the disciple, associate, and notary of Aitius (q.v.), the head of the Anomacmans. On a journey which he undertook to visit the emperor, he was seized by the Semiarians and sent to Phrygia; but in 360, his friend Eudoxius, formerly bishop of Antioch, but who had recently been called to Constantinople, procured for him the see of Cyzicum. There he proclaimed his views, first cautiously and moderately, but soon openly and unreservedly. The people of Cyzicum loudly complained of him, and, though he defended himself at Constantinople with great eloquence, he was abandoned by Eudoxius, who prevailed upon him to resign, since he was unwilling to subscribe the formula of Ariminum, or approve the deposition of Aftius. After this time Eunomius acted as the acknowledged head of the party. Under Julian, who recalled all the exiled bishop's, Eunomius was with Aritius in Constantinople, disseminating their views, collecting adherents, and consecrating bishops, who settled in many regions of Asia Minor, Syria, and Egypt. Being suspected of intimate relations with Procopius, a rebel against the authority of emperor Valens, he was twice exiled, but each time soon recalled. In 383 the emperor Theodosius demanded from all the prominent men of the several religious parties an explanation of their theological views, rejected the profession of faith made by Ennomius, had him arrested at Chalcedon and exiled to Halmnyris, in Mcesia, and from there to Caesarea, in Cappadocia. From there, when his longer stay was not tolerated, he returned to his native place, where he died about 396.
Eunomius wrote a commentary on the Epistle to the Romans, and a number of letters, which were known to Photius. Both the commentary and the letters are lost. His first defense (ἀπολογητικός), which was written either in 360 or (according to Rettberg) in 365, called forth a long reply from Basil. From several manuscripts of the latter, the text of this work of Eunomius has been restored. It is partly given by Cave (Hist. Liter. Genev. 1720, 1:139), and completely by Fabricius (Biblith. Graeca, 8), Canisius (Lect. Antiq. 1), and Thilo (Biblioth. dogmat. 2). A second defense (ὑπὲρ ἀπολογίας ἀπολογία, as Gregory calls it) elicited in reply the twelve orations of Gregory of Nyssa. The fragments of Eunomius contained in the work of Gregory have been collected by Rettberg (Marcelliana, page 125). His profession of faith (ἔκθεσις τῆς πίστεως), which Eunomrius in 383 presented to the emperor Theodosius, has been published by Valesius (notes to Socrates, 5:10), Fabricius (1.c.), Cave (1.c.), and Rettberg (Marcelliana, page 149).
Eunomius was one of the prominent leaders of the Arians. He was capable, keen, undaunted, and full of contempt for his opponents. He had a keener dialectic faculty than Arius, and anticipated Des Cartes in making clearness the test of truth. "An opponent of whatever was inconceivable and transcendental, he pursued knowledge in a one-sided direction, not deeply speculative, but proceeding from an empirical understanding to make everything clear, which was his principal aim. In short, he advocated an intelligent supranaturalism, in which a rationalistic tendency was concealed, similar to what we find in Socinus" (Neander, Hist. of Dogmas, ed. Ryland, 1:264). The following account of the confession of faith of the Eunomians is given biny Cave (volume 1, page 140), from a manuscript in archbishop Tennison's library: "There is one God, uncreated and without beginning, who has nothing existing before him, for nothing can exist before what is uncreate; nor with him, for what is uncreate must be one; nor in him, for God is a simple and uncompounded Being. This one simple and eternal Being is God, the Creator and Ordainer of all things. For God created, begot, and made the Son only, by his direct operation and power, before all things, and every other creature; not producing, however, any being like himself, or imparting any of his own proper substance to his Son; for God is immortal, uniform, and indivisible, and therefore cannot communicate any part of his own proper substance to another. He alone is unbegotten, and it is impossible that any other being should be formed of an unbegotten substance. He did not use his own substance in begetting his Son, but his will only; nor did he beget him in the likeness of his substance, but according to his own good pleasure. He then created the Holy Spirit, the first and greatest of all spirits, by his own power and operation mediately, yet by the immediate power and operation of the Son. After the Holy Spirit, he created all other things in heaven and in earth, visible and invisible, corporeal and incorporeal, mediately by himself, by the power and operation of his Son." The adherents of Eunomnius, who were very numerous, were, together with those of Ahtius, condemned as heretics by the second (Ecumenical Council. After the death of Eunomius, the Eunomians fully separated from the communion of the predominant Church. Some factions called themselves after prominent teachers, as Eutychius, Theophronius. The Church gave them a number of nicknames, as ὀνοβόσται, spadones. They baptized, not upon the Trinity, but upon the death of Christ. They did not exist long as a sect, but soon died out, in consequence of internal dissensions and numerous secessions to the dominant Church. — Herzog, Real-Encyklop. 4:220; Mosheim, Ch. Hist. 1:248, 301, Tillemont; Dorner, Lehre Christi, 1:819 (Edinb. transl., div. 1, volume 2, page 243); Neander, Church Hist. 2:319-425; Clarke, Sacred Liter. 1:318; Schaff, Church History, 3, § 121. (A.J.S.)