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).