WIST

He who is not angry when there is just cause for anger is immoral. Why? Because anger looks to the good of justice. And if you can live amid injustice without anger, you are immoral as well as unjust.

Thomas Aquinas (1225-1274) Italian saint, religious, philosopher
(Attributed)

The truth of our faith becomes a matter of ridicule among the infidels if any Catholic, not gifted with the necessary scientific learning, presents as dogma what scientific scrutiny shows to be false.

Thomas Aquinas (1225-1274) Italian saint, religious, philosopher
De potentia Dei [On the Power of God], 4.1

It is better to die excommunicated than to live and violate the conscience.

Thomas Aquinas (1225-1274) Italian saint, religious, philosopher
Disputed Questions on Truth [Questiones disputatae de veritate]

Every judgement of conscience, be it right or wrong, be it about things evil in themselves or morally indifferent, is obligatory, in such wise that he who acts against his conscience always sins.

Thomas Aquinas (1225-1274) Italian saint, religious, philosopher
Quodlibet III, q.27 (1270)

Distinctions drawn by the mind are not necessarily equivalent to distinctions in reality.

Thomas Aquinas (1225-1274) Italian saint, religious, philosopher
Summa Theologica, I, q.50 (1265-1274)

To disparage the dictate of reason is equivalent to contemning the command of God.

Thomas Aquinas (1225-1274) Italian saint, religious, philosopher
Summa Theologica 1a-2ae, xix. 5, ad 2 (1265-1274)

As it is better to give than to receive, so it is better to share the fruit of one’s contemplation than merely to contemplate.

Thomas Aquinas (1225-1274) Italian saint, religious, philosopher
Summa Theologica, “Treatise on the States of Life,” Q.188 “Of the Different Kinds of Religious Life” (1265-1274)
Alt trans.: "For even as it is better to enlighten than merely to shine, so it is better to give to others the fruits of one's contemplation than merely to contemplate." Text.

Future contingents cannot be certain to us, because we know them as such. They can be certain only to God whose understanding is in eternity above time. Just as a man going along a road does not see those who come after him; but the man who sees the whole road from a height sees all those who are going along the road at the same time.

Thomas Aquinas (1225-1274) Italian saint, religious, philosopher
Summa Theologica, I, q. 14, art. 13, ad 3 (1265-1274)

Man should not strive after that which is beyond his reason.

Thomas Aquinas (1225-1274) Italian saint, religious, philosopher
Summa Theologica, Q.1, art. 1 (1265-1274)
Aquinas proceeds with disproof for this proposition.