In Roman Catholicism, papal infallibility is the doctrine that, under certain conditions, the pope cannot err when teaching in matters of faith or morals. It is a centuries-old idea based on the belief that the church, entrusted with the mission of Jesus, will be guided by the Holy Spirit. It has been a matter of controversy, even among Catholic theologians, ever since 1870, when the First Vatican Council first listed the conditions under which popes are infallible. What are they? Discuss (http://forum.thefreedictionary.com/postst27417_The-First-Vatican-Council-Declares-Papal-Infallibility--1870-.aspx)
Free Dictionary Encyclopedia