Arianism

Arianism, a Christian heresy of the 4th century ad that denied the full divinity of Jesus Christ. It was named after its author, Arius. A native of Libya, Arius studied at the theological school of Lucian of Antioch, where other supporters of the Arian heresy were also trained. After he was ordained a priest in Alexandria, Arius became involved (319) in a controversy with his bishop concerning the divinity of Christ. Arius was finally exiled (325) to Illyria because of his beliefs, but debate over his doctrine soon engulfed the whole Church and agitated it for more than half a century. Although his doctrine was eventually outlawed (379) throughout the Roman Empire by Emperor Theodosius I, it survived for two centuries longer among the barbarian tribes that had been converted to Christianity by Arian bishops.

Arius taught that God is unbegotten and without beginning. The Son, the Second Person of the Trinity, therefore, because he is begotten, cannot be God in the same sense that the Father is. The Son was not generated from the divine substance of the Father; he did not exist from all eternity, but was created out of nothing like all other creatures, and exists by the will of the Father. In other words, the relationship of the Son to the Father is not natural, but adoptive.

The teaching of Arius was condemned in 325 at the first ecumenical council at Nicaea. The 318 bishops assembled there drafted a creed which stated that the Son of God was “begotten not made”, and consubstantial (Greek homoousios, “of the same substance”) with the Father; that is, the Son was part of the Trinity, not of creation. Previously, no creed had been universally accepted by all Churches. The status of the new creed as dogma was confirmed by bans against the teaching of Arius.

Despite its condemnation, the teaching of Arius did not die. In part this was due to the interference of imperial politics. Under the influence of the Greek Church historian Eusebius of Caesarea, whose orthodoxy had also been questioned, Emperor Constantine I recalled Arius from exile in about 334. Soon after, two influential people came to the support of Arianism: the next emperor, Constantius II, was attracted to the Arian doctrine; the bishop and theologian Eusebius of Nicomedia, later patriarch of Constantinople, also became an Arian leader.

By 359 Arianism had prevailed and was the official faith of the empire. Quarrelling among themselves, however, the Arians divided into two parties. The semi-Arians consisted mostly of conservative eastern bishops, who basically agreed with the Nicene Creed but were hesitant about the unscriptural term homoousios (consubstantial) used in the creed. The neo-Arians said that the Son was of a different essence (Greek heteroousios) from, or unlike (Greek anomoios), the Father. This group also included the Pneumatomachi (combatants against the Spirit), who said that the Holy Spirit is a creature like the Son. With the death of Constantius II in 361, and the reign of Valens, who persecuted the semi-Arians, the way was opened for the final victory of Nicene orthodoxy, recognized by Emperor Theodosius in 379 and reaffirmed at the second ecumenical council (Constantinople I) held in 381.