These enemies of divine revelation extol human progress to the skies, and with rash and sacrilegious daring would have it introduced into the Catholic religion as if this religion were not the work of God but of man, or some kind of philosophical discovery susceptible of perfection by human efforts.
Pope Pius IXIf 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.
Pope Pius IXThe most Blessed Virgin Mary, in the first instant of her conception, by a singular grace and privilege granted by almighty God, in view of the merits of Jesus Christ, the savior of the human race, was preserved free from all stain of original sin.
Pope Pius IXNow 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.
Pope Pius IX