Not to oppose erroneous doctrine is to approve of it, and not to defend at all true doctrine is to suppress it.

The mysteries of the faith are not to [be] explained rashly to anyone. Usually in fact, they cannot be understood by everyone but only by those who are qualified to understand them with informed intelligence. The depth of the divine Scriptures is such that not only the illiterate and uninitiated have difficulty understanding them, but also the educated and the gifted.

By heart we believe and by mouth confess the one Church, not of heretics but the Holy Roman, Catholic, and Apostolic Church outside which we believe that no one is saved.

Not to oppose erroneous doctrine is to approve of it, and not to defend at all true doctrine is to suppress it.

It is necessary to obey a Pope in all things as long as he does not go against the universal customs of the Church, but should he go against the universal customs of the Church, he need not be followed.

Every cleric must obey the Pope, even if he commands what is evil; for no one may judge the Pope.

So much must I live for others, that almost I am a stranger to myself.