Papal infallibility

Papal infallibility is a dogma of the Catholic Church that states that, in virtue of the promise of Jesus to Peter, the Pope is preserved from the possibility of error "When, in the exercise of his office as shepherd and teacher of all Christians, in virtue of his supreme apostolic authority, he defines a doctrine concerning faith or morals to be held by the whole Church."

This doctrine was defined dogmatically in the First Vatican Council of 1869–1870, but had been defended before that, existing already in medieval theology and being the majority opinion at the time of the Counter-Reformation.

According to Catholic theology, there are several concepts important to the understanding of infallible, divine revelation: Sacred Scripture, Sacred Tradition, and the Sacred Magisterium. The infallible teachings of the Pope are part of the Sacred Magisterium, which also consists of ecumenical councils and the "...ordinary and universal magisterium." In Catholic theology, papal infallibility is one of the channels of the infallibility of the Church. The infallible teachings of the Pope must be based on, or at least not contradict, Sacred Tradition or Sacred Scripture.

First seven Ecumenical Councils

In the history of Christianity, the first seven ecumenical councils, from the First Council of Nicaea (325) to the Second Council of Nicaea (787), represented an attempt to reach an orthodox consensus and to restore, continue and develop a unified Christendom. The East–West Schism, formally dated to 1054, would become definitive almost three centuries after the last of these councils, but already by 787 the major western sees, although still in communion with the state church of the Byzantine Empire, were all politically outside the Empire, and the Pope was to crown Charlemagne as a western emperor 13 years later.

Eastern Orthodox, Oriental Orthodox, Nestorian, Roman Catholic, Anglican, and some Lutheran churches all claim to trace the legitimacy of their clergy by apostolic succession back to this period and beyond, to the earlier period referred to as Early Christianity. However, breaks of unity that still persist today had already occurred during this period.

Ecumenical council

An ecumenical council (or oecumenical council; also general council) is a conference of ecclesiastical dignitaries and theological experts convened to discuss and settle matters of Church doctrine and practice in which those entitled to vote are convoked from the whole world (oikoumene) and which secures the approbation of the whole Church.

The word "ecumenical" derives from the Greek language (ἡ) οἰκουμένη (γῆ), which literally means "the inhabited world", but which was also applied more narrowly to mean the Roman Empire. Bishops belonging to what became known as the Church of the East participated in none of the councils later than the second, and further noteworthy schisms led to non-participation by other members of what had previously been considered a single Christian Church. Later ecumenical councils thus included bishops of only parts of the Church as previously constituted and were rejected or ignored by Christians not belonging to those parts.

The first seven Ecumenical Councils, recognised by both the eastern and western branches of Chalcedonian Christianity, were convoked by Christian Roman Emperors, who also enforced the decisions of those councils within the state church of the Roman Empire.