Thomas Aquinas

To bear with patience wrongs done to oneself is a mark of perfection, but to bear with patience wrongs done to someone else is a mark of imperfection and even of actual sin.

Law is nothing other than a certain ordinance of reason for the common good, promulgated by the person who has the care of the community.

Now this relaxation of the mind from work consists on playful words or deeds. Therefore it becomes a wise and virtuous man to have recourse to such things at times.

A song is the exultation of the mind dwelling on eternal things, bursting forth in the voice.

We are like children, who stand in need of masters to enlighten us and direct us; God has provided for this, by appointing his angels to be our teachers and guides.

To one who has faith, no explanation is necessary. To one without faith, no explanation is possible.

Man cannot live without joy; therefore when he is deprived of true spiritual joys it is necessary that he become addicted to carnal pleasures.

If forgers and malefactors are put to death by the secular power, there is much more reason for excommunicating and even putting to death one convicted of heresy.

Man can sin against nature in two ways. First, when he sins against his specific rational nature, acting contrary to reason. In this sense, we can say that every sin is a sin against man's nature, because it is against man's right reason.

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.

A man does not always choose what his guardian angel intends.

The magnitude of the punishment matches the magnitude of the sin. Now a sin that is against God is infinite; the higher the person against whom it is committed, the graver the sin-it is more criminal to strike a head of state than a private citizen-and God is of infinite greatness. Therefore an infinite punishment is deserved for a sin committed against Him.

Give us, O Lord, a steadfast heart, which no unworthy affection may drag downwards; give us an unconquered heart, which no tribulation can wear out; give us an upright heart, which no unworthy purpose may tempt aside. Bestow upon us also, O Lord our God, understanding to know you, diligence to seek you, wisdom to find you, and a faithfulness that may finally embrace you; through Jesus Christ our Lord.

We can't have full knowledge all at once. We must start by believing; then afterwards we may be led on to master the evidence for ourselves.

Three conditions are necessary for Penance: contrition, which is sorrow for sin, together with a purpose of amendment; confession of sins without any omission; and satisfaction by means of good works.

All the efforts of the human mind cannot exhaust the essence of a single fly.

It is altogether unlawful to kill oneself... Wherefore suicide is contrary to the inclination of nature, and to charity whereby every man should love himself... Life is God's gift to man, and is subject to His power, Who kills and makes to live. Hence whoever takes his own life, sins against God... for it belongs to God alone to pronounce sentence of death and life.

To live well is to work well, to show a good activity.

Temperance is simply a disposition of the mind which binds the passion.

There is but one Church in which men find salvation, just as outside the ark of Noah it was not possible for anyone to be saved.

Pray thee, spare, thyself at times: for it becomes a wise man sometimes to relax the high pressure of his attention to work.