Papal Infallibility

Do Catholics believe that the pope is infallible?

Catholics do not believe that the pope's every word or action is infallible. However, in very limited (and, in practice, very rare) circumstances, the Catholic Church teaches that a pope can declare a doctrine to be infallible.

In order for such a papal declaration to be considered infallible, it must be spoken "ex cathedra" — that is, in the official capacity as pope; it must define a doctrine having to do with faith and morals; and the doctrine must be declared definitive and binding on the entire Church.

The Church teaches that ecumenical councils can also declare doctrines infallibly.

Two examples of doctrines that have declared infallible are Pope Pius IX's definition of the dogma of the Immaculate Conception of Mary in 1854 and Pope Pius XII's definition of the dogma of the Assumption of Mary in 1950.