Saint Thomas Aquinas
Just as a man cannot live in the flesh unless he is born in the flesh, even so a man cannot have the spiritual life of grace unless he is born again spiritually. This regeneration is effected by Baptism: "Unless a man is born again of water and the Holy Spirit, he cannot enter into the kingdom of God.
It is requisite for the relaxation of the mind that we make use, from time to time, of playful deeds and jokes.
It is possible to demonstrate God's existence, although not a priori, yet a posteriori from some work of His more surely known to us.
It is clear that he does not pray, who, far from uplifting himself to God, requires that God shall lower Himself to him, and who resorts to prayer not to stir the man in us to will what God wills, but only to persuade God to will what the man in us wills.
In the life of the body a man is sometimes sick, and unless he takes medicine, he will die. Even so in the spiritual life a man is sick on account of sin. For that reason he needs medicine so that he may be restored to health; and this grace is bestowed in the Sacrament of Penance.
In order for a war to be just, three things are necessary. First, the authority of the sovereign. Secondly, a just cause. Thirdly, a rightful intention.
If, then, you are looking for the way by which you should go, take Christ, because He Himself is the way.
If the highest aim of a captain were to preserve his ship, he would keep it in port forever.
If someone knows from experience that daily Communion increases fervor without lessening reverence, then let him go every day. But if someone finds that reverence is lessened and devotion not much increased, then let him sometimes abstain, so as to draw near afterwards with better dispositions.
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.
Human salvation demands the divine disclosure of truths surpassing reason.
How is it they live in such harmony the billions of stars - when most men can barely go a minute without declaring war in their minds about someone they know.
How can we live in harmony? First we need to know we are all madly in love with the same God.
Hold firmly that our faith is identical with that of the ancients. Deny this, and you dissolve the unity of the Church.
Happiness is secured through virtue; it is a good attained by man's own will.
Good can exist without evil, whereas evil cannot exist without good.
Friendship is the source of the greatest pleasures, and without friends even the most agreeable pursuits become tedious.
For loving draws us more to things than knowing does, since good is found by going to the thing, whereas the true is found when the thing comes to us.
Final and perfect happiness can consist in nothing else than the vision of the Divine Essence... For perfect happiness the intellect needs to reach the very Essence of the First Cause. And thus it will have its perfection through union with God... in which alone man's happiness consists, as stated above.
Faith has to do with things that are not seen and hope with things that are not at hand.