Ecumenical Council - Infallibility of Ecumenical Councils

The doctrine of the infallibility of ecumenical councils states that solemn definitions of ecumenical councils, approved by the Pope, which concern faith or morals, and to which the whole Church must adhere are infallible. Such decrees are often labeled as 'Canons' and they often have an attached anathema, a penalty of excommunication, against those who refuse to believe the teaching. The doctrine does not claim that every aspect of every ecumenical council is infallible.

The Roman Catholic Church holds this doctrine, as do most or all Eastern Orthodox theologians. However, the Orthodox churches accept only the first seven general councils as genuinely ecumenical, while Roman Catholics accept twenty-one. Only a very few Protestants believe in the infallibility of ecumenical councils, but they usually restrict this infallibility to the Christological statements of the first seven councils. Lutheran Christians recognize the first four councils, whereas most High Church Anglicans accept all seven as persuasive but not infallible.

While the Russian Orthodox Church does recognize the first seven ecumenical councils as valid, some Russian Orthodox theologians believe that the infallibility of these councils' statements derived from their acceptance by the faithful (and thus from the infallibility of all believers), and not from the acts of the councils themselves. This differs from the Greek Orthodox view, which accepts that an ecumenical council is itself infallible when pronouncing on a specific matter. However this is not inflexible as the iconoclasm controversy was instigated by order of an ecumenical council (Council of Hieria), which took another ecumenical council (Second Council of Nicaea 787) to reverse.