In my years of engaging apologetics topics with Protestants, and even sometimes fellow Catholics, I have found that the Church teaching on infallibility is one of the most difficult for people to grasp. It is more often necessary to explain what infallibility does not mean than what it does, and so root out the errors in people’s understanding.
Infallibility was dogmatically defined by Vatican I in Pastor Aeternus.
We teach and define that it is a divinely-revealed dogma: that the Roman Pontiff, when he speaks ex Cathedra, that is, when in discharge of the office of Pastor and Teacher of all Christians, by virtue of his supreme Apostolic authority, he defines a doctrine regarding faith or morals to be held by the Universal Church, by the divine assistance promised to him in blessed Peter, is possessed of that infallibility with which the divine Redeemer willed that His Church should be endowed for defining doctrine regarding faith or morals: and that therefore such definitions of the Roman Pontiff are irreformable.
This is a very specific, and limited, definition.
The pope must be speaking ex cathedra as teacher of the whole Church.
He must define a doctrine concerning faith or morals.
He must specify that this doctrine is to be held as true by the whole Church.
Yet there are four things that it is always necessary to remind people, even Catholics, that all this does not mean.
It does not mean that the pope is without sin.
This is a common mistake among Protestants and secularists. In a series of anti-Catholic sermons ten or so years ago, Dr. John MacArthur took note of the fact that John Paul II had apologized for the sins of the Church during the Crusades and the Inquisition. He seemed to think it incongruous that a Church that claimed infallibility could admit to having been in error.
But the pope did not apologize for what the Church taught, but only for what some Catholics had done. There is a difference. Infallibility does not mean impeccability. The confessional exists for a reason, and even the pope goes to Confession.
It does not mean that everything a pope says, or every opinion of the pope, is infallible.
The pope must be speaking ex cathedra. A Wednesday audience, or a papal interview, are not infallible.
The pope must be speaking on a question of faith or morals. The pope’s opinion about a scientific theory is not infallible. The pope’s opinion of the Red Sox is not infallible.
It does not mean that the pope can answer every question about the faith, or the scriptures, that could possibly come up.
Protestant apologists are fond of asking, for example, why the Church does not just give us an infallible interpretation of every verse of Scripture.
The reason is because infallibility has a very limited purpose, and that is to ensure the unity of the faith and to answer pressing moral questions that could not have been anticipated by the authors of the Bible. Embryonic stem cell research is one such question.
The pope was never meant to replace a person’s thinking and reading ability, only to keep them within boundaries set by divine revelation.
It does not mean that that Catholics have a license to ignore things that are not technically infallible.
Some Catholics, I am afraid to say, have a very difficult time with this last one. But Lumen Gentium 25 has settled the question for us.
This reliÂgious subÂmisÂsion of mind and will must be shown in a speÂcial way to the authenÂtic magÂisÂterium of the Roman PonÂtiff, even when he is not speakÂing ex catheÂdra, that is, it must be shown in such a way that his supreme magÂisÂterium is acknowlÂedged with revÂerÂence, the judgÂments made by him are sinÂcerely adhered to, accordÂing to his manÂiÂfest mind and will.
Vatican I does not define this dogma narrowly so that Catholics have an escape hatch by which to flee teachings they don’t like. (“Unless the pope says the magic words, I can poo-poo that, buddy.”) It does so because the Church is very careful to distinguish between levels of epistemological certainty and between what is divine revelation and what is not.
But God did not give us a teaching Church so that we would pay attention only to the very narrow category of divine revelation. That is why quibbling too specifically about whether such and such a document is infallible is often a mask for a desire to ignore what is nevertheless authoritative.
It may be more important for Catholics to consider what is authoritative than what is infallible.