No. The First Vatican Council infallibly taught that each valid Roman Pontiff has the gift of truth and a never failing faith. Therefore, each and every valid Pope is preserved from all grave failures of faith, including apostasy, heresy, and schism, idolatry, sacrilege, and blasphemy. Since the question has been closed by the Council, faithful Catholics may not opine that any Pope from Peter to the present Pope has failed in faith.

Can we say that a Pope considered to have failed in faith was never valid? If we judge validity in this way, we might err and accuse a valid Pope of invalidity, as whether or not a person fails in faith is a matter of prudential judgment. Some accuse Honorius I of heresy, but Saint Robert Bellarmine and Cardinal Manning (father of Vatican I) exonerate him. Since the Church depends upon Peter as upon a Rock, we cannot have the determination as to who is Roman Pontiff depend upon varying prudential judgments.

The Church is indefectible. Therefore, the body of Bishops cannot go astray by following a false head. Any claimed Pontiff accepted by the body of Bishops must be valid. Pope Francis has been accepted by the body of Bishops as the Roman Pontiff; therefore, it is a dogmatic fact that he is a valid Roman Pontiff. And every valid Pope has the gift of truth and never failing faith, so he cannot lose his validity. He remains the valid Roman Pontiff until death or resignation.

Did the Sixth Ecumenical Council condemn Pope Honorius for heresy? Some Council fathers attempted to condemn Honorius for heresy, which proves how difficult this type of prudential judgment is. Then Pope Saint Agatho wrote to the Council:

“For Peter himself received from the Redeemer of all, by three commendations, the duty of feeding the spiritual sheep of the Church. Under his protecting shield, this Apostolic Church of his has never turned away from the path of truth in any direction of error.”
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“And his authority, as that of the Prince of all the Apostles, the whole Catholic Church and the Ecumenical Synods have faithfully embraced and followed in all things.”
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“but from the beginning she has received the Christian faith from her founders, the princes of the Apostles of Christ, and remains undefiled unto the end….”
“…the evangelical and apostolic uprightness of the orthodox faith, which has been established upon the firm rock of this Church of blessed Peter, the Prince of the Apostles, which by his grace and guardianship remains free from all error….”

The letter was accepted into the acts of the Council, so it is an infallible teaching of a Council. Every teaching on faith and morals of every Ecumenical Council is infallible, as it is the teaching of all the successors to the Apostles, the teaching of all the Teachers of the Church, and therefore the teaching of Christ. The indefectibility of the Church guarantees the indefectibility of every Pope, of the body of Bishops, and of every Ecumenical Council.

Bellarmine: “A general Council represents the universal Church, and hence has the consensus of the universal Church; wherefore if the Church cannot err, neither can a legitimate and approved ecumenical Council err.” [On Councils, book 2, chapter 2]

Bellarmine: “we hold by Catholic faith that legitimate councils confirmed by the Supreme Pontiff cannot err” [On Councils, book 2, chapter 9]

So the teaching of the 20th Ecumenical Council (Vatican I) is the teaching of the Sixth Ecumenical Council. Popes cannot lead the Church astray. Therefore, all such accusations against Pope Francis are false, heretical, and schismatic. But the papal accusers seem to possess no fear of God and no love for the Pope.

Then after Pope Saint Agatho died, some Council fathers again attempted to accuse Honorius. The near-final text of one document condemned him along with certain heretics. But Pope Saint Leo II, in the very document approving of the Council’s acts, changed the accusation from heresy to negligence. Nothing is truly of a Council, unless approved by the Roman Pontiff. Thus, the infamous document asserting that Ecumenical Councils are above the Roman Pontiff is not of that Council, as it was never approved by the Pope.

Martin V (1417-1431) never confirmed Haec Sancta Synodus (April 6, 1415) from the Council of Constance, session 5. The document was written while a group of Bishops were following an antipope, so that cannot be considered an Ecumenical Council. And successive Popes refused to approve the document. Then subsequent Councils infallibly rejected its teachings (Florence, Vatican I).

Most commentators, when considering the question of whether a Pope can commit heresy, simply pick some Popes to accuse, and then propose that since those Popes committed heresy, then it is possible. They fail to consider that their own opinions might err. And this is the same error made by the accusers of Pope Francis. The accusers think themselves to have the gift of truth and a never failing faith, while they think the Pope to be like the seed planted in shallow soil, who fails in faith when tested by the heat of the sun. Since prudential judgments can fail as to whether a person has committed heresy, we have to look to the teaching of the Church.

See this list of teachings: The Roman Pontiff: Immunity from Error and Never-failing Faith

Pope Marcellinus was accused of apostasy and idolatry. However, Saint Robert Bellarmine exonerates him along with many other accused Popes. The Saint and Doctor’s conclusion is that Popes cannot fail in faith. The opposing opinion, that Popes can fail in faith is refuted by the teaching of so many Popes, Saints, and gatherings of Bishops and absolutely condemned as an heretical opinion by Vatican I.

Therefore, Pope Francis is innocent, and his accusers are the ones who are guilty.

The claim is made that Vatican I did not confirm the teaching of Saint Robert Bellarmine that a Pope cannot commit heresy. And the relatio of Bishop Vincent Gasser is presented as evidence of this interpretation. However, the claim is easily refuted. {See also this article on Gasser’s relatio.}

First, the teaching of a Council is what it states, and the Council states that each Pope has the gift of “truth and never failing faith”. So it is impossible to reconcile accusations of heresy and idolatry with a faith that does not fail. These sins are grave failings of faith. Neither can the gift be limited to the office or to the teachings, as it is Peter himself who is the Rock, not his office only, not his teachings only. Peter was given the threefold commission to feed the sheep because he loved Christ more than these others (Jn 21:15). Since the commission is to the person, so are the gifts. An office or a teaching does not have the infused virtue of faith, but only a person.

Second, Cardinal Manning, a father of Vatican I, in his book: “The Vatican Council and Its Definitions: A Pastoral Letter to the Clergy”, p. 83-84., confirms that this is the meaning intended by the Council.

Manning: “The application of the promise ‘Ego rogavi pro te,’ [“I have prayed for you”] etc. to the infallible faith of Peter and his successors, is made by St. Ambrose, St. Augustine, St. Leo, St. Gelasius, Pelagius II., St. Gregory the Great, Stephen Bishop of Dori in a Lateran Council, St. Vitalian, the Bishops of the IV Ecumenical Council AD 451, St. Agatho in the VI. AD 680, St. Bernard AD 1153, St. Thomas Aquinas AD 1274, St. Bonaventure AD 1274: that is, this interpretation is given by three out of the four Doctors of the Church, by six Pontiffs down to the seventh century. It was recognized in two Ecumenical Councils. It is expressly declared by the Angelic Doctor, who may be taken as the exponent of the Dominican school, and by the Seraphic Doctor, who is likewise the witness of the Franciscan; and by a multitude of Saints.”

“The interpretation by the Fathers of the words ‘On this rock,’ etc. is fourfold, but all four interpretations are not more than four aspects of one and the same truth, and all are necessary to complete its full meaning. They all implicitly or explicitly contain the perpetual stability of Peter’s faith….”

“In these two promises [i.e. Lk 22:32, Mt 16:18] a divine assistance is pledged to Peter and to his successors, and that divine assistance is promised to secure the stability and indefectibility of the Faith in the supreme Doctor and Head of the Church, for the general good of the Church itself.”

Third, we have the historical example of Pope Vigilius, to answer the question as to what would happen if a heretic were elected Pope. Vigilius was a manifest heretic and an antipope. He also was of low character, being willing to teach heresy and put a heretic on the See of Constantinople, if only the Emperor would declare him Pope. The emperor and empress did so, and he became an antipope. But when the true Pope, Silverius died, Vigilius was installed as the Bishop of Rome, accepted by the clergy and people, and accepted subsequently by the body of Bishops. And from the time that his true papacy began, all heresy was vanquished in him by the grace of God. He refused to keep his promises to the emperor and empress. He remained faithful to the true teachings of the Faith.

What happens when a heretic is elected Pope? Does he become an invalid Pope, due to his heresy? No, the grace of God destroys all heresy within his heart and mind, and he becomes not only a valid Pope but a Rock whose faith cannot fail.

Finally, the name of Saint Robert Bellarmine is invoked to support the claim that a Pope can commit heresy. First of all, the actual opinion of Bellarmine (later turned into dogma by Vatican I) was that the Pope “cannot in any way be heretical, or publicly teach heresy”, regardless of whether he is teaching alone or with an Ecumenical Council. He later considers the hypothetical as to what would happen if a Pope committed heresy, but this was an intellectual exercise, not his belief.

Bellarmine discusses four opinions. He calls the opinion, that a Pope may be a heretic himself and teach heresy, even though he is defining a doctrine with an Ecumenical Council, heretical. He calls the second opinion, that the Pope may be a heretic and may teach heresy apart from an Ecumenical Council, “altogether erroneous and proximate to heresy”. Bellarmine calls the third opinion, that “the Pontiff cannot in any way be heretical or publicly teach heresy”, probable, but not certain. [However, it is certain now, having been defined by a Council.] And then the fourth opinion, called “most certain” is that a Pope can never “define anything heretical to be believed by the whole Church.

Therefore, a Pope can never be a heretic, and Pope Francis is innocent of all accusations which propose that he has failed in faith, by apostasy, by heresy, by idolatry or any other grave sins against faith.

Ronald L. Conte Jr.