My understanding is that the Catholic Church teaches that when the Pope speaks ex cathedra, he is infallible, because what he says in such instances is divinely protected from error. There are a lot of questions that the Church considers open, e.g. the question of whether infants who die without being baptized are saved. It seems like it would be a great idea for the Pope to attempt to assert ex cathedra that they are saved. Either the pronouncement would succeed, in which case we would know with certainty that it is true, or else something would prevent the pronouncement from going through, in which case we would have a hint that it is false.

I assume that I am misunderstanding something about papal infallibility and there is a catch somewhere. What's the catch? Naturally, I'm interested in the teaching of the Catholic Church.

Here are a couple of possible answers:

  • Technically, the Pope could "exploit" infallibility in this way, but it would be immoral.
  • If the Pope decided to try this sort of thing, he would be divinely prevented from making the ex cathedra pronouncement regardless of whether the doctrine in question was true or false, so we wouldn't actually learn anything from the exercise.

In either case, I'm left wondering: What exactly differentiates "legitimate" ex cathedra pronouncements, like the pronouncement of the immaculate conception in Ineffabilis Deus, from the sort of "illegitimate" ex cathedra pronouncement that I suggested?

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    I think it was Jesus that quoted this when Satan tempted him: "Do not put the LORD your God to the test".
    – user3961
    Commented Feb 12, 2016 at 23:06
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    Is there really a question here? It sounds more like a hypothetical situation looking for discussion. Commented Feb 13, 2016 at 1:23
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    If I forget to come back to this question, or if it gets VTC'd, the short answer is: "The Holy Spirit." It's not at all unheard of for a Pope to be in office months or day before dying of "natural" causes. ... Christ promised that the Church would prevail against the powers of darkness. If that promise is to hold, and if people themselves are fallible, it stands to reason that God's gotta kill off a few Popes to keep the teachings pure. ... Just sayin'.
    – svidgen
    Commented Feb 13, 2016 at 3:48
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    @svidgen Are you saying that in your opinion, those Popes that weren't Pope for long may or likely did have some sort of ill-preparation for the job, therefore God "removed" them from the chair?
    – user3961
    Commented Feb 13, 2016 at 8:09
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    @fredsbend sure. If they weren't planning on removing themselves, why not?
    – svidgen
    Commented Feb 13, 2016 at 16:14

4 Answers 4


Pope Pius XII—in his apostolic constitution that defines the dogma of the Immaculate Conception, Munificentissimus Deus (1950)—describes the process in which he sought counsel from all the bishops of the world in the letter Deiparæ Virginis Mariæ (1946), where he asked them (§11):

Do you, venerable brethren, in your outstanding wisdom and prudence, judge that the bodily Assumption of the Blessed Virgin can be proposed and defined as a dogma of faith? Do you, with your clergy and people, desire it?

The response was almost unanimous.

Although a pope has the authority to define a dogma without asking for counsel regarding its "definability," it would be rash not to seek counsel.

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    (In case you want to add it to your answer) As the case of the Immaculate Conception illustrates, popes (and ecumenical councils) don’t define dogmas unless the entire Church already historically believes them, at least implicitly. Even during, say, the Arian crisis, when the majority of bishops fell into the Homoeian (the somewhat inaccurately called "Semi-Arian") camp, the historical position of the Church had always been at least implicitly Homoousian. Or said more simply, popes and councils don’t make things up; they just clarify existing doctrines and beliefs. Commented Sep 27, 2016 at 10:35
  • @AthanasiusOfAlex Yes, Popes are bound by tradition. And the irreformability of a Pope's defined dogma derives solely from his authority (Vatican I: "such definitions of the Roman Pontiff are irreformable of themselves, and not from the consent of the Church.").
    – Geremia
    Commented Sep 27, 2016 at 16:27

You massively misunderstand the process of promulgating doctrine. It's not a magic process where God causes true statements to be generated out of thin air. Doctrine is developed through prayer, research, consultation, discernment and much more, and involves the whole church, not just the Pope. The belief is that God guides this process to ensure it is correct. Shortcutting the means would be equivalent to cheating God.

  • Folding in the Holy Spirit's guidance to the church (and a reference or two) would improve this answer, which is built on a solid foundation. Commented Sep 27, 2016 at 12:56

Do not put the LORD your God to the test (Deuteronomy 6:16).

We know the Pope is infallible because God gave Peter specifically, and the Apostles generally, the Keys of the Kingdom. What the Apostles can do collectively (like in an Ecumenical Council), Peter can do as an individual. Same keys, but different ways to excerise them.

Furthermore, the Pope and the Bishops generally aren't creating new doctrine, but rather discovering or emphasizing or interpretating the Revelation the Christ already gave us.

Christi pax,


  • This answer would be improved if it addressed the doctrine of infallibility as pronounced in the Vatican I ecumenical council (1870s). Commented Sep 27, 2016 at 12:58

"it would be a great idea for the Pope to attempt to assert ex cathedra that they are saved"

Probably not. God would probably have to kill or otherwise divinely stop the mouth (or pen in this case) of said pope before he did so, as stated by another person here, else the Church would have been overcome by Satan (the true faith is anathematized and lost and error taught in its place) in which impossibility the infallibility of the Church (in an extraordinatary sense with regard to the successor of St. Peter—due to the fact that he overrides the authority of all bishops and has the authority to bind all Catholics to a certain interpretation of the deposit of Faith whereas individual bishops do not—and in an ordinary overall sense with regard to the world's bishops) exists.

Papal infallibility precludes that such a 'trial dogma definition' could ever happen, ever. It would breach the infallibility of the Pope (more a descriptive fact about the Church than a 'power').

That is, your question is like 'what if water wasn't H2O' and is meaningless to ask (sorry, in the logical sense, not that it has no value in being asked).

Papal infallibility is a necessary consequence of 1) the infallibility of the Church as a whole (that the gates of Hell will not prevail against it—which a new faith/false doctrine being taught would constitute) and 2) that the Pope has the authority to teach and bind all to his teaching, in a way other bishops cannot and therefore do not require, and are not protected by, this kind of infallibility. They possess an infallibility which basically means no amount of bishops teaching heresy x will result in the same overcoming of the Church by Hell—a much more descriptive 'infallibility' than even the Pope.

It isn't some magic power.

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