The Roman Pontiffs have always...held that all those rites should be preserved which deviate neither from accuracy in matters of faith, nor from what is fitting.

Give me an army saying the Rosary and I will conquer the world.

If anyone says that it is possible that at some time, given the advancement of knowledge, a sense may be assigned to the dogmas propounded by the Church which is different from that which the Church has understood and understands: let him be anathema.

Now you know well that the most deadly foes of the Catholic religion have always waged a fierce war, but without success, against this Chair [of St. Peter]; they are by no means ignorant of the fact that religion itself can never totter and fall while this Chair remains intact, the Chair which rests on the rock which the proud gates of hell cannot overthrow and in which there is the whole and perfect solidity of the Christian religion.

If a future Pope teaches anything contrary to the Catholic Faith, do not follow him.

Nothing can ever pass away from the words of Christ, nor can anything be changed in the doctrine which the Catholic Church received from Christ to guard, protect, and preach.

Atheism in legislation, indifference in matters of religion, and the pernicious maxims which go under the name of Liberal Catholicism are the true causes of the destruction of states; they have been the ruin of France. Believe me, the evil I denounce is more terrible than the Revolution, more terrible even than The Commune. I have always condemned Liberal Catholicism, and I will condemn it again forty times over if it be necessary.