The following is the list of the general councils recognized by Roman Catholics (the numbering is the customary one, and the opening year is given): (1) 1 Nicaea, 325; (2) 1 Constantinople, 381; (3) Ephesus, 431; (4) Chalcedon, 451; (5) 2 Constantinople, 553; (6) 3 Constantinople, 680; (7) 2 Nicaea, 787; (8) 4 Constantinople, 869; (9) 1 Lateran, 1123; (10) 2 Lateran, 1139; (11) 3 Lateran, 1179; (12) 4 Lateran, 1215; (13) 1 Lyons, 1245; (14) 2 Lyons, 1274; (15) Vienne, 1311; (16) Constance, 1414; (17) Basel and Ferrara-Florence, 1431, 1438; (18) 5 Lateran, 1512; (19) Trent, 1545; (20) 1 Vatican, 1869; (21) 2 Vatican, 1962 (see separate articles on each council; e.g., Nicaea, First Council of). The Orthodox Eastern Church recognizes the first seven and counts the Trullan Synod of 692 as an ecumenical extension of the Third Council of Constantinople. The first council was the model for the rest.
The common purpose of the first eight councils was to determine whether specific theological novelties were orthodox or heretical (not orthodox). The rest of the councils, all held in Western Europe, have dealt chiefly with church discipline and morals. Two of them, the Second Council of Lyons and the Council of Ferrara-Florence, were occupied with abortive attempts at reconciliation between East and West. Conciliar theory, which held that an ecumenical council is superior to the pope, played a central role in attempts to heal the Great Schism. Conciliar theory was in its heyday at the Council of Constance (see Schism, Great). The Council of Trent, convened to deal with the Protestant Reformation, was probably the most far-reaching in its effects. Pope John XXIII established as one of the principal themes of the Second Vatican Council the reunion of all Christians with the Church of Rome.
The traditional opinion is that when the bishops of the world unite to define belief in the light of what they have received from their predecessors, God will protect them from error. This is a manifestation of the infallibility of the teaching church, and papal infallibility is compared to it in the definition published by the First Vatican Council (see infallibility). Two famous councils that claimed in vain to be ecumenical are the Robber Council of Ephesus (see Eutyches) and the Council of Pisa during the Great Schism.
Protestants recognize the authority of the first four ecumenical councils, but, as first expressed by Martin Luther, do not regard ecumenical councils and their canons as binding on the conscience. Only when council decisions follow scripture do Protestants consider them authoritative. Nevertheless Protestant observers have officially attended the last two councils. The ecumenical movement among Protestants is not to be confused with an ecumenical council, although they share a similar aim.
See studies by L. Jaeger (tr. 1961), P. Hughes (1961), F. Dvornik (1961), and E. F. Jacobs (rev. ed. 1963).
An ecumenical council (or oecumenical council; also general council) is a conference of the bishops of the whole Church convened to discuss and settle matters of Church doctrine and practice. The word derives from the Greek language "Οικουμένη", which literally means "the inhabited world", which first referred to the Roman Empire and later was extended to apply to the world in general.
Due to schisms, the acceptance of these councils varies widely between different branches of Christianity. The Roman Catholic and Eastern Orthodox Churches jointly held the first eight Ecumenical councils (meeting from the 4th to the 9th century). They accept as Ecumenical the first seven but differ on the identity of the eighth. While the Eastern Orthodox Church has not generally accepted any later synod as Ecumenical, the Roman Catholic Church continues to hold Ecumenical Councils of those bishops in full communion with the Pope.
Those churches that parted ways with the other over christological matters, only accept the first few councils, the Oriental Orthodoxy churches the first three, the Assyrian church the first two as Ecumenical.
Some Protestants, most commonly Lutherans and Anglicans, accept either the first seven or the first four as Ecumenical councils.
Most councils dealt not only with doctrinal but also with disciplinary matters, which were decided in canons ("rules"). In some cases other documentation survives as well. Study of the canons of church councils is the foundation of the development of canon law, especially the reconciling of seemingly contradictory canons or the determination of priority between them. Canons consist of doctrinal statements and disciplinary measures — most Church councils and local synods dealt with immediate disciplinary concerns as well as major difficulties of doctrine. Eastern Orthodoxy typically views the purely doctrinal canons as dogmatic and applicable to the entire church at all times, while the disciplinary canons apply to a particular time and place and may or may not be applicable in other situations.
The next two are regarded as ecumenical by some in the Eastern Orthodox Church but not by others, who instead consider them to be important local councils. They have nevertheless received universal acceptance by all Eastern Orthodox Churches even where their ecumenicity is not recognized.
Others, including 20th century theologians Metropolitan Hierotheos (Vlachos) of Naupactus, Fr. John S. Romanides, and Fr. George Metallinos (all of whom refer repeatedly to the "Eighth and Ninth Ecumenical Councils"), Fr. George Dragas, and the 1848 Encyclical of the Eastern Patriarchs (which refers explicitly to the "Eighth Ecumenical Council" and was signed by the patriarchs of Constantinople, Jerusalem, Antioch, and Alexandria as well as the Holy Synods of the first three), regard other synods beyond the Seventh Ecumenical Council as being ecumenical. Those who regard these councils as ecumenical often characterize the limitation of Ecumenical Councils to only seven to be the result of Jesuit influence in Russia, part of the so-called "Western captivity of Orthodoxy."
Before the 20th century, the council of 879 AD was recognized as the 8th ecumenical council by people like the famous expert on Canon Law, Theodore Valsamon (11th century), St. Neilos of Rodes, St. Mark Evgenicus (15th century), St. Symeon of Thessaloniki (15th century), and the Patriarch of Jerusalem Dositheus, in his Tome of Joy (17th century).
The first seven councils were called by the Emperor. Most historians agree that the emperors called the councils to force the Christian bishops to resolve divisive issues and reach consensus. One motivation for convening councils was the hope that maintaining unity in the Church would help maintain unity in the Empire. The relationship of the Papacy to the validity of these councils is the ground of much controversy between Roman Catholicism and Eastern Orthodox Churches and to historians.
The Roman Catholic Church holds that these ecumenical councils are infallible.

Some Protestants, including some fundamentalist and nontrinitarian churches, condemn the ecumenical councils for other reasons. Independency or congregationalist polity among Protestants involves the rejection of any governmental structure or binding authority above local congregations; conformity to the decisions of these councils is therefore considered purely voluntary and the councils are to be considered binding only insofar as those doctrines are derived from the Scriptures. Many of these churches reject the idea that anyone other than the authors of Scripture can directly lead other Christians by original divine authority; after the New Testament, they assert, the doors of revelation were closed and councils can only give advice or guidance, but have no authority. They consider new doctrines not derived from the sealed canon of Scripture to be both impossible and unnecessary, whether proposed by church councils or by more recent prophets.
Supporters of the councils contend that the councils did not create new doctrines but merely elucidated doctrines already in Scripture that had gone unrecognized. Proponents often argue that the early councils serve as a good benchmark or tool for scriptural interpretation to guard against the individualistic or idiosyncratic interpretations of Bible that ultimately leads to schism. The thinking is that an ecumenical council representing the whole church is much less likely to misunderstand the voice of the Holy Spirit in expounding the Scriptures than is a handful of zealous believers.
Moreover, Pope John Paul II, in his encyclical Ut Unum Sint ("That they may be one"), invited other Christians to discuss how the primacy of the Bishop of Rome should be appropriately exercised from now on; he says that the future may be a better guide than the past. In this way, the Bishop of Rome is allowing for the development of an ecclesiology that would be acceptable to both East and West, would allow for reconciliation of Roman Catholic and Eastern Orthodox Churches, and would provide a common understanding of the authority of councils called ecumenical.
Similarly, on November 11, 1994 at meeting of Mar Dinkha IV, Patriarch of Babylon, Selucia-Ctesiphon and all of the East, leader of the Assyrian and Pope John Paul II at the Vatican, a Common Christological Declaration was signed, bridging a schism dating from the Third Ecumenical Council at Ephesus. The separation of the Oriental believers from the one holy catholic and apostolic Church after the Fourth Ecumenical Council at Chalcedon was addressed in a "Common Declaration of Pope Paul VI and of Pope Shenouda III of Alexandria" at the Vatican on May 10, 1973 and in an "Agreed Statement" prepared by the "Joint Commission of the Theological Dialogue between the Orthodox Church and the Oriental Orthodox Churches" at the Monastery of Saint Pishoy in Wadi El Natrun, Egypt on June 24, 1989.