"The day when efficacy would prevail over truth will never come for the Church, for then the gates of hell would have prevailed against her."

“When one's function is to teach the loftiest wisdom, it is difficult to resist the temptation to believe that until you have spoken, nothing has been said.”

“What we need is not truths that serve us but a truth we may serve.”

“To be free is of the essence of every intellectual being.”

“It is not possible to escape from the results of the irruption of faith into the structures of our knowledge.”

“In so far as we are individuals, each of us is a fragment of a species, a part of this universe, a single dot in the immense network of forces and influences, cosmic, ethnic, historic, whose laws we obey. We are subject to the determination of the physical world. But each man is also a person, he is not subject to the stars and atoms; for he subsists entirely with the very subsistence of his spiritual soul, and the latter is in him a principle of creative unity, of independence and of freedom.”

“In each of us there dwells a mystery, and that mystery is the human personality.”