Infallible

The pope teaches infallibly when definitively teaching the whole Church on faith or morals.

Many papal teachings are fallible. We owe intellectual assent to all teachings by the pope as shepherd of his flock, because he is the Vicar of Christ. The distinction between infallible and fallible teachings of the magisterium is not so much whether we must believe them, but whether or not a future pope may someday change them. That is not something the lay Catholic need be concerned with.

Definitively

The pope speaks infallibly only ex cathedra, from the Chair of Peter. Jesus, who said, Jn 10:11 “I am the good shepherd,” told Peter, Jn 21:15 “Feed my lambs … Tend my sheep … Feed my sheep.”

It is always very clear when a pope is speaking definitively. For example, Pope Pius XII’s apostolic constitution defining the dogma of the Blessed Virgin Mary’s assumption body and soul into heaven, Munificentissimus Deus, # 44, states: “... 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.”

Another example is Pope John Paul II’s apostolic letter, Ordinatio Sacerdotalis, states: “I declare that the Church has no authority whatsoever to confer priestly ordination on women and that this judgment is to be definitively held by all the Church’s faithful.”

When such definitive language is present, the pope is clearly speaking infallibly. When it is not present, he may or may not be speaking infallibly. We look for evidence that he is speaking with the full weight of his apostolic authority.

Within the context of the magisterium, the pope can freely offer his personal views the same as any private theologian. In most cases, when speaking as a private theologian, the pope makes it clear that he is not speaking infallibly, such as by inviting alternate viewpoints. Of course, when a pope speaks as a private theologian and openly invites alternative views, he is speculating rather than teaching. In that case we owe him the great respect due his office but not necessarily the intellectual assent due to his teachings.

The Whole Church

The pope speaks infallibly only as shepherd of the whole flock.

When addressing only some of the faithful does not speak infallibly. For example, the Apostolic Letter of Pope John Paul II to the Catholic People of Hungary for the Conclusion of the “Hungarian Millennium” of July 25, 2001 would not contain any infallible teaching.

Faith and Morals

Faith

Our Father in heaven commanded, : Dt 6:4 “Hear, O Israel, the Lord our God is one Lord; and you shall love the Lord your God with all your heart, and with all your soul, and with all your might.” He explained: Dt 6:6 “These words which I command you this day shall be upon your heart; and you shall teach them diligently to your children, and shall talk of them when you sit in your house, and when you walk by the way, and when you lie down, and when you rise. And you shall bind them as a sign upon your hand, and they shall be as frontlets between your eyes. And you shall write them on the doorposts of your house and on your gates.”

Jesus repeated, Mt 22:37 “You shall love the Lord your God with all your heart, and with all your soul, and with all your mind. This is the great and first commandment.”

All that we do related to our love for God is faith.

Morals

Our Father in heaven commanded, Lev 19:18 “You shall love your neighbor as yourself.”

Jesus repeated, Mt 22:39 “You shall love your neighbor as yourself,” Jn 15:12 “as I have loved you,”

All that we do related to our love for one another is morals.

Some Additional Observations

When the pope teaches infallibly, he also teaches unchangeably. Jesus told us, Jn 16:12 “I have yet many things to say to you, but you cannot bear them now. When the Spirit of Truth comes, He will guide you into all the truth.” The source of the pope’s infallible teaching is supernatural assistance of the Holy Spirit, who protects the supreme teacher of the Church from error. Since God is eternal and therefore does not change, the Holy Spirit’s teaching is unchangeable.

The pope teaches infallibly only while he is pope. During the third century, St. Callistus, before becoming Pope, had been associated with Sabellius, the advocate of the monarchian heresy. However, after becoming Pope, St. Callistus condemned Sabellius and excommunicated him.

The pope teaches infallibly only when not under duress. During the fourth century, Emperor Constantius embraced the Arian heresy and forced all the bishops in the empire to proclaim it. St. Athanasius stood virtually alone. When Pope Liberius proclaimed the true faith, Constantius imprisoned and so cruelly mistreated him that Liberius finally agreed to condemn Athanasius. Under extreme pressure Liberius signed an ambiguous confession of faith which was capable of Arian interpretation subordinating the Son to the Father, but he added to it even in prison an anathema on all who said that the Son is not like the Father in substance and in all things.

Papal infallibility addresses only what a Pope teaches, not what he does not teach. During the seventh century Emperor Heraclius at Constantinople promoted the monothelite heresy. Patriarch Sergius of Constantinople accepted this “one will” heresy and wrote to Pope Honorius I asking his opinion. Honorius refused to dispute the issue as Sergius had framed it. Pope St. Agatho affirmed Honorius’ orthodoxy when he declared in a letter to the Emperor that he and all his predecessors “have never ceased to exhort and warn [the monothelites] with many prayers that they should, at least by silence, desist from the heretical error of the depraved dogma.” Honorius is often condemned for negligence in leaving the Lord’s flock exposed to heretical teachers but never for any doctrine attributable to him.

The pope teaches infallibly only on doctrine, not on discipline. Doctrine is divine law because it comes from divine revelation. Discipline is man-made law. For example Pope Paul VI’s Paenitemini, Apostolic Constitution on Penance, February 17, 1966, states in chapter III that by divine law all the faithful are required to do penance. However, the particular penance of abstinence from meat on all Fridays of the year is a discipline, or man-made law, and may be changed by a pope.

The pope alone teaches infallibly. The Curia or anyone else to whom the pope delegates authority cannot teach infallibly. Curia documents generally receive the approval of the pope before they are published. For example, the declaration Dominus Iesus, by the Congregation for the Doctrine of the Faith, August 6, 2000, states: “The Sovereign Pontiff John Paul II, at the Audience of June 16, 2000, granted to the undersigned Cardinal Prefect of the Congregation for the Doctrine of the Faith, with sure knowledge and by his apostolic authority, ratified and confirmed this Declaration, adopted in Plenary Session and ordered its publication.” This document had the pope’s approval, but not his signature, so the document cannot be considered infallible. When a Curia document repeats a papal teaching, the infallibility of course remains in force but is attached to the original document signed by the pope.

Church Documents

Pastor Aeternus, the Dogmatic Constitution of the Church of Christ, approved by Vatican I on July 18, 1870, defined the extent and limits of papal infallibility. Paragraph 9 states:

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.

Lumen Gentium, the Dogmatic Constitution on the Church, approved by Vatican II including Pope Paul VI on November 21, 1964, clarified the definition. Section 25 states:

And 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.

This doctrine is also found in the Catechism of the Catholic Church, # 891.