Seven Councils, and Nothing Added Since

Eastern Orthodoxy holds that seven councils, meeting between 325 and 787, settled the essential doctrine of the Christian faith once and for all, and that no later council carries the same binding, universal authority. The seven are Nicaea I in 325, which confronted Arianism and produced the earliest form of the Nicene Creed; Constantinople I in 381, which completed that creed and affirmed the divinity of the Holy Spirit; Ephesus in 431, which defended Mary's title as Theotokos, God bearer, against Nestorius; Chalcedon in 451, which defined Christ as one person in two natures; Constantinople II in 553, which clarified points left open by Chalcedon; Constantinople III in 680 to 681, which affirmed that Christ has two wills, divine and human, against monothelitism; and Nicaea II in 787, which restored the veneration of icons after a period of imperial iconoclasm. Orthodox theology treats these seven as a single, complete dogmatic deposit rather than as the first installment of an open series. Later Orthodox gatherings, which some Orthodox writers call the eighth and ninth councils, are honored as important but are not given the same universal, binding rank as the original seven, and Orthodoxy has held to this closed list for well over a thousand years.