Eunomius, born at Dacora in Cappadocia early in the fourth century, had studied theology at Alexandria under Aetius, and afterwards had come under the influence of Eudoxius of Antioch, who had ordained him deacon, and on whose recommendation he had been appointed bishop of Cyzicus in 360, where his free utterance of extreme Arian views had led to popular complaints.
By command of the emperor, Constantius II, Eudoxius was compelled to depose Eunomius from the bishopric within a year of his elevation to it.
During the reigns of Julian and Jovian, Eunomius had resided in Constantinople in close intercourse with Aetius, developing what will come to be known as the anomoean party and helping to consecrate schismatical bishops.
The teaching of the Anomoean school, led by Aetius and Eunomius, starting from the conception of God as Creator, argued that between the Creator and created there could be no essential, but at best only a moral, resemblance.
"As the Unbegotten, God is an absolutely simple being; an act of generation.
would involve a contradiction of His essence by introducing duality into the Godhead."
He had then gone to live at Chalcedon, from whence in 367 he was banished to Mauretania for harboring the rebel Procopius.
He was recalled, however, before he reached his destination.
According to Socrates of Constantinople (v. 24), Eunomius carried his views to a practical issue by altering the baptismal formula.
Instead of baptizing in the name of the Trinity, he baptized in the name of the Creator and into the death of Christ.
This alteration was regarded by the orthodox as so serious that Eunomians on returning to the church were rebaptized, though the Arians were not.
The Eunomian heresy was formally condemned by the Council of Constantinople in 381.
In 383 the emperor Theodosius, who had demanded a declaration of faith from all party leaders, punished Eunomius for continuing to teach his distinctive doctrines, by banishing him to Halmyris in Scythia Minor.
He afterwards resided at Chalcedon and at Caesarea in Cappadocia, from which he had been expelled by the inhabitants for writing against their bishop Basil.
His last days are spent at his birthplace Dacora, where he dies about 393, after which Eutropius orders that Eunomius' body be moved to Tyana and his books be burned.
The sect will maintain a separate existence for some time, but will gradually fall away owing to internal divisions.
