Who declared papal infallibility?
Score: 4.4/5 (68 votes) In 1854, Pius IX decreed the doctrine of the Immaculate Conception to be infallible in his bull, Ineffabilis Deus. The First Vatican Council in 1869-70, in its Pastor Aeternus decree, declared that the pope was infallible when he spoke “ex Cathedra” – or from the papal throne...