Whether a Catholic doctrine is infallibly defined, or merely a certain teaching of the magisterium, we owe our religious assent. So, whether a doctrine is understood as infallible or not is irrelevent, and is only a matter of practical importance to dogmatic theologians and dissidents. Faithful Catholics are to submit to their superiors whether they speak infallibly or not.
Nonetheless, if we want to know if a doctrine is infallible, just ask the Pope.
The charism of papal infallibility is not merely to be equated to those instances where the pope pronounces *ex cathedra *that a dogma is de fide definita.
The pope certainly acts infallibility on those occassions when he proclaims material dogma is to be assented to definitively as a formal dogma of the Catholic faith, as in the case of the doctrine of the Assumption and Immaculate Conception. Yet, the pope also acts infallibly when he defends against erroneous understandings of Catholic doctrines which are already formal dogma, that is, already matters of faith and morals. Pointing just to two material dogmas expounded upon and made formal dogmas (Assumption and Immaculate Conception), while not appreciating the countless formal dogmas defended by papal judgment is to only grasp part of the concept of papal infallibility, in my opinion.
Vatican II’s, Lumen Gentium 25*, *clarifies this by speaking of the charism of infallibility which the Roman Pontiff enjoys when he acts as supreme teacher of the universal Church and is “expounding or defending a doctrine of Catholic faith.”
So, when a pope defends a doctrine of faith that is already a formal dogma, by proclaiming a proposition to be erroneous or heretical for example, he is also acting with the charism of infallibility.
Furthermore, the pope can defend a dogma that has never been pronounced as *de fide definita, *but is infallible by virtue of the ordinary universal magisterium. For example, *Providentissimus Deus, *while not an *ex cathedra *statement on the inerrancy of Scripture, is certainly a defense of the formal dogma of the inerrancy of Scripture, and as such, is an exercise of the charism of papal infallibility.
Thus, there have been countless occasions in the past 2000 years when the pope has definitively passed judgment on some matter of faith and morals. A “list” of these occasions is impractical as it would be too volumous. And since we are to submit to all Catholic doctrines, infallible or not, such a list has little value to practicing Catholics. It is more practical to have a compendium of all Catholic doctrines. This we have in the documents of ecumencial councils, papal encyclicals published in the *Acta Apostolica Sedis, *and the Catechism of the Catholic Church.