Ask a Catholic

[Metis]

So how do we know when they are declaring infallibly? That they're not contradicting each other?

There is a special formulation in the language they use. Here is the paragraph from Munificentissimus Deus:

44. For which reason, after we have poured forth prayers of supplication again and again to God, and have invoked the light of the Spirit of Truth, for the glory of Almighty God who has lavished his special affection upon the Virgin Mary, for the honor of her Son, the immortal King of the Ages and the Victor over sin and death, for the increase of the glory of that same august Mother, and for the joy and exultation of the entire Church; by the authority of our Lord Jesus Christ, of the Blessed Apostles Peter and Paul, and by our own authority, 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.

HOWEVER - this is where it gets a little bit tricky: the popes in more ancient times used different wording, so there is some disagreement over exactly which dogmas were declared infallibly. As I said before, the list ranges from about 6-10 generally recognized examples.

Pope Eugene IV: “We decree and order that from now on, and for all time […] All and every single Jew, of whatever sex and age, must everywhere wear the distinctive dress and known marks by which they can be evidently distinguished from Christians.”

Pope Eugene IV: “We decree and order that from now on, and for all time, Christians shall not eat or drink with the Jews, nor admit them to feasts, nor cohabit with them, nor bathe with them. […]  They cannot live among Christians, but in a certain street, separated and segregated from Christians, and outside which they cannot under any pretext have houses.”

Both from his decree of 1442
Guess my boyfreind was never a very good Catholic then, he lived next door to a Jew that dresses like everyone else. He even went to her barbaques!

We decree for now and all time....That sounds like a pretty specific pronouncement Randy, one that dear old Eugene put in such strong terms it was evidently rather important to him. I can pull out several others ranging from calling for the execution of non-Catholics to Innocent III proclaiming himself king of the universe. How come these proclamations aren't infalliable but are worded if not just as strongly than even stronger than the ones Catholic take as Gospel?

Edit: The pun was unintended -_-;