Which popes made infallible statements?

Answer 1

Other answers from our community:

By definition, all of them.

There are no infallible popes. However the Sacred Magisterium a special teaching body of the Catholic Church is kept infallible in its doctrinal pronouncations through the power of the Holy Spirit. Note that the Ordinary Magisterium is fallible.

Answer 2

Two popes have made ex cathedra statements regarded by the Catholic Church as infallible. In 1870, the First Vatican Council , taught and declared the infallibility of the pope, in Pastor Aeternalis (chapter 6):
"9. Therefore, faithfully adhering to the tradition received from the beginning of the christian faith, to the glory of God our savior, for the exaltation of the Catholic religion and for the salvation of the christian people, with the approval of the Sacred Council, we teach and define as a divinely revealed dogma that when the Roman Pontiff speaks EX CATHEDRA, that is, 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, he possesses, by the divine assistance promised to him in blessed Peter, that infallibility which the divine Redeemer willed his Church to enjoy in defining doctrine concerning faith or morals. Therefore, such definitions of the Roman Pontiff are of themselves, and not by the consent of the Church, irreformable."

Some years earlier, in anticipation of the declaration of the infallibility of the pope and after consultation with Catholic bishops, Pius IX defined the dogma of the Immaculate Conception of Mary (Ineffabilis Deus, 1854): "We declare, pronounce and define that the doctrine which holds that the Blessed Virgin Mary, at the first instant of her conception, by a singular privilege and grace of the Omnipotent God, in virtue of the merits of Jesus Christ, the Saviour of mankind, was preserved immaculate from all stain of original sin, has been revealed by God, and therefore should firmly and constantly be believed by all the faithful."

In chapter 4 of Pastor Aeternalis the council appears to have limited the infallibility of the pope to jealously guarding and explaining what was handed down through the apostles, and not the ability to disclose a new doctrine by revelation:

"6. For the Holy Spirit was promised to the successors of Peter not so that they might, by his revelation, make known some new doctrine, but that, by his assistance, they might religiously guard and faithfully expound the revelation or deposit of faith transmitted by the apostles."

The pope's pronouncement on the Immaculate Conception of the Virgin Mary was certainly not handed down through the apostles, so even if the pope is indeed infallible on certain matters Bishop Geoffrey Robinson (Confronting Power and Sex in the Catholic Church) believes this clause means that the pope was assuming an infallibility he did not have in this case.

The only ex cathedra use of infallibility, at least since 1870, took place nearly a century later in 1950, when Pope Pius XII defined the Assumption of the Virgin Mary (Munificentissimus Deus): "By the authority of our Lord Jesus Christ, of the Blessed Apostles Peter and Paul, and by our own authority, we pronounce, declare, and define it to be a divinely revealed dogma: that the Immaculate Mother of God, the ever Virgin Mary, having completed the course of her earthly life, was assumed body and soul into heavenly glory." Although the Assumption of Mary has been the subject of speculations since at least the fourth century, there is no suggestion that this dogma was transmitted by the apostles, so once again Bishop Robinson doubts its infallibility.