Infallibility

This is the most misunderstood doctrine on the power of the Pope. The Pope is NOT infallible for every word that comes out of his mouth. 

He may invoke the power of being infallible ONLY if he speaks “ex cathedra” (when in the discharge of his office as shepherd and teacher of all Christians, and by virtue of his supreme apostolic authority) and ONLY on matters that define a doctrine concerning faith or morals.

When making an infallible teaching or statement, the Pope will in fact put on his vestments (mitre and papal cozier in hand), assemble the church community, declare from his throne at his Archbasilica of St John Lateran in his capacity of Bishop of Rome to pronounce his infallible teaching. Further, the pope will have to decree the infallible teaching through a formula such as "By the authority of Our Lord Jesus Christ and of the Blessed Apostles Peter and Paul, and by Our own authority, We declare, pronounce and define the doctrine . . . to be revealed by God and as such to be firmly and immutably held by all the faithful”.

The Catholic Church does not teach that the pope is infallible in everything he says. Official invocation of papal infallibility is extremely rare.

The last known infallible declaration was over 60 years ago by Pope Pius XII, 1950, defining the Assumption of Mary.

Pope John XXIII once remarked: "I am only infallible if I speak infallibly but I shall never do that, so I am not infallible".

Therefore unless the Pope decrees an infallible teaching from his throne, whatever he says or teaches in speeches, talks and homilies are not infallible.

The Doctrine

Papal infallibility is a dogma of the Catholic Church which states that, in virtue of the promise of Jesus to Peter, the Pope is preserved from the possibility of error "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". 

This doctrine was defined dogmatically in the First Vatican Council of 1869–1870, but had been defended before that, appearing already in medieval tradition and becoming the majority opinion at the time of the Counter-Reformation. 

According to Catholic theology, there are several concepts important to the understanding of infallible, divine revelation: Sacred Scripture, Sacred Tradition, and the Sacred Magisterium. 

The infallible teachings of the Pope are part of the Sacred Magisterium, which also consists of ecumenical councils and the "ordinary and universal magisterium". In Catholic theology, papal infallibility is one of the channels of the infallibility of the Church. The infallible teachings of the Pope must be based on, or at least not contradict, Sacred Tradition or Sacred Scripture.

The doctrine of infallibility relies on one of the cornerstones of Catholic dogma: that of petrine supremacy of the pope, and his authority to be the ruling agent in deciding what will be accepted as formal beliefs in the Roman Catholic Church.

The most recent example (though not the only one) of the use of this power, referred to as speaking ex cathedra expressed since the solemn declaration of papal infallibility by Vatican I on July 18, 1870, took place in 1950 when Pope Pius XII defined Munificentissimus Deus, the Assumption of Mary as being an article of faith for Roman Catholics. With the ex-cathedra decree there are attached these words: “Hence if anyone, which God forbid, should dare willfully to deny or to call into doubt that which We have defined, let him know that he has fallen away completely from the divine and Catholic Faith.”

Ex- Cathedra

In connection with papal infallibility, the Latin phrase ex cathedra (literally, "from the chair"). The pope may only do this whilst in office exercising his supreme apostolic authority as the Bishop of Rome and only in a doctrine concerning faith or morals to be held by the whole Church.

The "chair" referred to is not a literal chair, but refers metaphorically to the pope's position, or office, as the official teacher of Catholic doctrine. The chair was the symbol of the teacher in the ancient world. The post of university professor is still referred today as "the chair". Bishops to this day have a cathedra, a seat or throne, as a symbol of their teaching and governing authority. The pope is said to occupy the "chair of Peter". As Bishop of Rome where the primacy of Peter and from which the power of the pope derives, the pope’s “chair” is the Cathedra in St John Lateran’s Basilica in Rome. 

Speaking ex-cathedra is a big event and an extremely serious matter concerning doctrine on faith or morals. Therefore the Pope is unlikely to deviate from the tradition to be fully vested in pontifical dress, mitre and papal staff (crozier) in hand when he pronounces the infallible statement and will do so from his throne or cathedra at the Archbasilica of St John Lateran. 

Whilst it is not technically necessary to do so, since it is from this authority that the pope will speak ex-cathedra to be infallible, the Pope will not likely simply utter the infallible words in a homily on a weekday mass or announce it from his study window at the Apostolic Palace to the crowd in St Peter’s square.

Being a a decree which is to be held by the whole Church, it will take the form of a formal document proclaiming the infallible statement or teaching using the necessary formulas and proclaimed by the pope himself from his throne. 

The response demanded from believers has been characterized as "assent" in the case of ex cathedra declarations of the popes and "due respect" with regard to their other declarations.

Statements by a pope which exercise papal infallibility are referred to as "solemn papal definitions" or ex cathedra teachings. Also considered infallible are the teachings of the whole body of bishops of the Church, especially but not only in an ecumenical council.

This authority is considered by Catholics to be apostolic and of divine origin. 

The response demanded from believers has been characterized as "assent" in the case of ex cathedra declarations of the popes and "due respect" with regard to their other declarations.

Conditions for teachings being declared infallible:

According to the teaching of the First Vatican Council and Catholic tradition, the conditions required for ex cathedra papal teaching are as follows:

1. "the Roman Pontiff"

2. "speaks ex cathedra" ("that is, when in the discharge of his office as shepherd and teacher of all Christians, and by virtue of his supreme apostolic authority"....)

3. "he defines"

4. "that a doctrine concerning faith or morals"

5. "must be held by the whole Church"  

For a teaching by a pope or ecumenical council to be recognized as infallible, the teaching must be a decision of the supreme teaching authority of the Church (pope or College of Bishops):

1. it must concern a doctrine of faith or morals
2. it must bind the universal Church
3. it must be proposed as something to be held firmly and immutably. 

In July 2005 Pope Benedict XVI stated during an impromptu address to priests in Aosta that: "The Pope is not an oracle; he is infallible in very rare situations, as we know".

A doctrine proposed by a pope as his own opinion, not solemnly proclaimed as a doctrine of the Church, may be rejected as false, even if it is on a matter of faith and morals, and even more any view he expresses on other matters. 

A well-known example of a personal opinion on a matter of faith and morals that was taught by a pope but rejected by the Church is the view that Pope John XXII expressed on when the dead can reach the beatific vision. 

Catholic theologians in general hold that the canonization of a saint by a pope is infallible teaching that the person canonized is definitely in heaven with God. A decree of canonization commands that the person be venerated by the whole Church as a saint, while beatification merely permits it.

In connection with papal infallibility, the Latin phrase ex cathedra (literally, "from the chair") has been defined as meaning "when, in the exercise of his office as shepherd and teacher of all Christians, in virtue of his supreme apostolic authority, (the Bishop of Rome) defines a doctrine concerning faith or morals to be held by the whole Church".[2]

The "chair" referred to is not a literal chair, but refers metaphorically to the pope's position, or office, as the official teacher of Catholic doctrine: the chair was the symbol of the teacher in the ancient world—the post of university professor is still referred to as "the chair"—and bishops to this day have a cathedra, a seat or throne, as a symbol of their teaching and governing authority. The pope is said to occupy the "chair of Peter", as Catholics hold that among the apostles Peter had a special role as the preserver of unity, so the pope as successor of Peter holds the role of spokesman for the whole church among the bishops, the successors as a group of the apostles. (Also see Holy See and sede vacante: both terms evoke this seat or throne.)

Infallible Authority defined in Vatican Councils

The power of the pope’s infallibility was dogmatically defined in the First Vatican Council’s declaration in 1870. The council declared:  “We, adhering faithfully to the tradition received from the beginning of the Christian faith, to the glory of God, our Saviour, the elevation of the Catholic religion and the salvation of Christian peoples, with the approbation of the sacred Council, teach and explain that the dogma has been divinely revealed: that the Roman Pontiff, when he speaks ex cathedra, that is, when carrying out the duty of the pastor and teacher of all Christians by his supreme apostolic authority he defines a doctrine of faith or morals to be held by the universal Church, through the divine assistance promised him in blessed Peter, operates with that infallibility with which the divine Redeemer wished that His church be instructed in defining doctrine on faith and morals; and so such definitions of the Roman Pontiff from himself, but not from the consensus of the Church, are unalterable. But if anyone presumes to contradict this definition of Ours, which may God forbid: let him be anathema.”

The Second Vatican Council in 1964 declared: “... this infallibility with which the Divine Redeemer willed His Church to be endowed in defining doctrine of faith and morals, extends as far as the deposit of Revelation extends, which must be religiously guarded and faithfully expounded. And this is the infallibility which the Roman Pontiff, the head of the college of bishops, enjoys in virtue of his office, when, as the supreme shepherd and teacher of all the faithful, who confirms his brethren in their faith, by a definitive act he proclaims a doctrine of faith or morals. And therefore his definitions, of themselves, and not from the consent of the Church, are justly styled irreformable, since they are pronounced with the assistance of the Holy Spirit, promised to him in blessed Peter, and therefore they need no approval of others, nor do they allow an appeal to any other judgment. For then the Roman Pontiff is not pronouncing judgment as a private person, but as the supreme teacher of the universal Church, in whom the charism of infallibility of the Church itself is individually present, he is expounding or defending a doctrine of Catholic faith. The infallibility promised to the Church resides also in the body of Bishops, when that body exercises the supreme magisterium with the successor of Peter. To these definitions the assent of the Church can never be wanting, on account of the activity of that same Holy Spirit, by which the whole flock of Christ is preserved and progresses in unity of faith."

Instances of infallible declarations

1. "Tome to Flavian", Pope Leo I, 449, on the two natures in Christ, received by the Council of Chalcedon;

2. Letter of Pope Agatho, 680, on the two wills of Christ, received by the Third Council of Constantinople;

3.    Benedictus Deus, Pope Benedict XII, 1336, on the beatific vision of the just after death rather than only just prior to final judgment[73];

4. Cum occasione, Pope Innocent X, 1653, condemning five propositions of Jansen as heretical;

5. Auctorem fidei, Pope Pius VI, 1794, condemning seven Jansenist propositions of the Synod of Pistoia as heretical;

6. Ineffabilis Deus, Pope Pius IX, 1854, defining the Immaculate Conception;

7.   Munificentissimus Deus, Pope Pius XII, 1950, defining the Assumption of Mary.

Catholic theologians agree that both Pope Pius IX's 1854 definition of the dogma of the Immaculate Conception of Mary and Pope Pius XII's 1950 definition of the dogma of the Assumption of Mary are instances of papal infallibility, a fact which has been confirmed by the Church's magisterium. However, theologians disagree about what other documents qualify.

The Holy See has given no complete list of papal statements considered to be infallible. A 1998 commentary on Ad Tuendam Fidem issued by the Congregation for the Doctrine of the Faith published on L'Osservatore Romano in July 1998 listed a number of instances of infallible pronouncements by popes and by ecumenical councils, but explicitly stated (at no. 11) that this was not meant to be a complete list.

One of the documents mentioned is Pope John Paul II's apostolic letter Ordinatio Sacerdotalis on reserving priestly ordination to men alone, which the Congregation earlier stated to be infallible, although not taught ex cathedra (i.e., although not a teaching of the extraordinary magisterium), clarifying that the content of this letter has been taught infallibly by the ordinary and universal magisterium. This was confirmed in a commentary by the same Congregation and in commentaries by Cardinals Joseph Ratzinger and Tarcisio Bertone.

As well as popes, ecumenical councils have made pronouncements that the Church considers infallible.