The Arian Controversy
In Alexandria, around the year 318, a tall and ascetic priest named Arius posed a question that would split the church for sixty years. If the Father is unbegotten and eternal, and the Son is…
Biblical Narrative
In Alexandria, around the year 318, a tall and ascetic priest named Arius posed a question that would split the church for sixty years. If the Father is unbegotten and eternal, and the Son is begotten — was there not a time when the Son was not? Arius preached his answer in songs, in dockside hymns the Alexandrian sailors learned to whistle, and the city took sides on the wharves and in the bath-houses.
His bishop Alexander, with the young deacon Athanasius at his elbow, answered no. The Son is co-eternal with the Father, of one substance, begotten and not made. To make Christ less than fully divine, they said, is to fall back into a pagan ladder of demigods. The argument grew until letters flew from Egypt to Antioch, from Antioch to Rome, and the new Christian emperor convened the bishops in council at Nicaea.
There the bishops chose a strange and difficult Greek word — homoousios, of one essence — and pressed it into a creed. We believe in one Lord Jesus Christ, the only-begotten Son of God, begotten of the Father before all worlds, true God of true God, of one substance with the Father. Two hundred and fifty bishops signed; Arius and two of his supporters did not, and were exiled.
But the controversy did not end. For two generations the Arian, semi-Arian, and Nicene parties contended in synods, in courts, in the patronage of competing emperors. Constantine's son Constantius II favored the Arians; Julian the Apostate let all of them quarrel; Theodosius the Great finally settled the matter at the Council of Constantinople in 381. The Trinity received its enduring formulation through the labors of bishops and the favor of emperors, in the long-disputed conversation about how the One God could be three.
There was when the Son was not.Arius (Thalia, fragment quoted in Athanasius)
Archaeology · History · Genetics
The Arian controversy (c. 318–381 CE) was the most consequential theological dispute of late antiquity. Arius (c. 256–336), an Alexandrian presbyter, taught that the Son of God was a created being, the first and highest of creatures, but not co-eternal with the Father. His bishop Alexander excommunicated him around 318; Arius's appeals to bishops in Asia Minor (Eusebius of Nicomedia, Eusebius of Caesarea) drew imperial attention.
Constantine convened the Council of Nicaea in May–June 325, the first ecumenical council. Of roughly 250–318 bishops attending (sources vary), nearly all signed a creed declaring the Son homoousios — 'of the same substance' — with the Father. Only Arius and two Libyan bishops refused; they were exiled to Illyria. The Nicene Creed and a list of canons survive in multiple recensions; the modern liturgical 'Nicene Creed' is actually the expanded Niceno-Constantinopolitan creed of 381.
The post-Nicene period saw repeated political reversals. Athanasius, who succeeded Alexander as bishop of Alexandria in 328, was exiled five times under successive emperors. The middle decades produced numerous credal compromises (Sirmium 357, the 'Dated Creed' of 359), and the historian R. P. C. Hanson catalogued more than a dozen rival creeds in The Search for the Christian Doctrine of God (1988). The Cappadocian Fathers — Basil, Gregory of Nazianzus, Gregory of Nyssa — refined the trinitarian vocabulary in the 360s–370s.
The Council of Constantinople (381), summoned by Theodosius I, reaffirmed Nicaea and condemned Arianism, semi-Arianism, and the Pneumatomachoi (those who denied the divinity of the Spirit). The settlement was decisive in the empire but Arianism survived among the Germanic peoples — Goths, Vandals, Lombards — through Ulfilas's fourth-century Arian mission, and persisted in some kingdoms into the seventh century. The dispute's afterlife shaped the Christological controversies of the fifth century at Ephesus and Chalcedon.
Few episodes in the history of doctrine display so vividly the difficulty of formulating a Christian theology adequate to its own scriptural foundations.R. P. C. Hanson, The Search for the Christian Doctrine of God (1988)