The Cross to me is certain salvation. The Cross is that which I ever adore. The Cross of the Lord is with me. The Cross is my refuge.

Moral science is better occupied when treating of friendship than of justice.

The soul, which is the first principle of life, is not a body, but the act of a body; just as heat, which is the principle of calefaction, is not a body, but an act of a body.

Reason in man is rather like God in the world.

Obedience unites us so closely to God that it in a way transforms us into Him, so that we have no other will but His. If obedience is lacking, even prayer cannot be pleasing to God.

Given the sin of impiety through which they [the Romans] sinned against the divine nature [by idolatry], the punishment that led them to sin against their own nature followed.... I say, therefore, that since they changed into lies [by idolatry] the truth about God, He brought them to ignominious passions, that is, to sins against nature; not that God led them to evil, but only that he abandoned them to evil.

Secondly, man sins against nature when he goes against his generic nature, that is to say, his animal nature. Now, it is evident that, in accord with natural order, the union of the sexes among animals is ordered towards conception. From this it follows that every sexual intercourse that cannot lead to conception is opposed to man's animal nature.