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.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.