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First Ecumenical CouncilDocumented

First Ecumenical Council (Nicaea I)

Α΄ Οἰκουμενικὴ Σύνοδος

Date
325
Location
Nicaea

Condemned Arianism and confessed the Son as homoousios, of one essence, with the Father; gave the Church her Creed.

Historical background

  • Arius, a presbyter of Alexandria, taught that the Son is a creature, “there was when He was not.” St Alexander of Alexandria convicted him; the emperor Constantine convened the bishops (traditionally 318) at Nicaea.

Principal dispute

  • Whether the Son of God is true God of true God, or the first and highest of creatures.

Dogmatic result

  • The Creed of Nicaea: the Son is “God of God, Light of Light, true God of true God, begotten not made, of one essence (ὁμοούσιος) with the Father.”

Heresies and persons condemned

  • Arius and Arianism, that the Son is a creature and “there was when He was not.”
  • Those who say the Son is of another hypostasis or essence, or mutable, anathematized in the Creed's appendix.

Key canons

  • 20 canons

    On order, jurisdiction and discipline, including the standing prohibition of kneeling on Sundays and in Pentecost.

Later reception

  • Received by the whole Church as the First Ecumenical Council; its faith reconfessed by every council after it.

Bibliography

  • The Creed and canons of Nicaea (ΡΠΣ 2; Pedalion).
  • Socrates & Sozomen, Ecclesiastical Histories (NPNF 2nd ser., vol. 2).