Papal infallibility

Papal infallibility is a dogma of the Catholic Church which states that, in virtue of the promise of Jesus to Peter, the Pope when he speaks ex cathedra is preserved from the possibility of error on doctrine "initially given to the apostolic Church and handed down in Scripture and tradition". It does not mean that the pope cannot sin or otherwise err in most situations. This doctrine, defined dogmatically at the First Vatican Council of 1869–1870 in the document Pastor aeternus, is claimed to have existed in medieval theology and to have been the majority opinion at the time of the Counter-Reformation. The doctrine of infallibility relies on one of the cornerstones of Catholic dogma, that of papal supremacy, whereby the authority of the pope is the ruling agent as to what are accepted as formal beliefs in the Catholic Church. The use of this power is referred to as speaking ex cathedra. "Any doctrine 'of faith or morals' issued by the pope in his capacity as successor to St. Peter, speaking as pastor and teacher of the Church Universal [Ecclesia Catolica], from the seat of his episcopal authority in Rome, and meant to be believed 'by the universal church,' has the special status of an ex cathedra statement. Vatican Council I in 1870 declared that any such ex cathedra doctrines have the character of infallibility (session 4, Constitution on the Church 4)." The church teaches that infallibility is a charism entrusted by Christ to the whole church, whereby the Pope, as "head of the college of bishops", enjoys papal infallibility. This charism is the supreme degree of participating in Christ's divine authority, which, in the New Covenant, so as to safeguard the faithful from defection and guarantee the profession of faith, ensures the faithful abide in the truth. The church further teaches that divine assistance is also given to the Pope when he exercises his ordinary Magisterium.