Section I: On the Preambles to the Decalogue Or On the Theological Virtues

419. "Preambles to law," says St. Thomas (2.2, q. 22, a. 1), "are those things without whose existence law cannot have place. But of this kind are the precepts concerning the act of faith and the act of hope: because through the act of faith, the mind of man is inclined so that it recognizes the author of the law as such, to whom it ought to subject itself; but through hope of reward, man is induced to the observance of the precepts." But charity is the very end of the law, according to that saying (1 Tim. 1:5): The end of the precept is charity from a pure heart, and a good conscience, and faith not feigned. For it moves to observing the whole law, according to that saying (1 John 5:3): For this is the charity of God, that we keep his commandments; and finally all the precepts tend together toward love of God and neighbor, according to that saying of St. Augustine: "Whatever we are prohibited by God's law, and whatever we are commanded to do, we are prohibited and commanded for this, that we may fulfill these two" (tr. 87, toward the end).

Those three preamble virtues are called theological, because they have God himself for their object; the Apostle commemorates them, writing to the Corinthians (13:13): And now there remain faith, hope, charity. Through FAITH we know God, who has revealed and proposed himself to us as the end to be attained; through HOPE we are raised up into him, so that with confidence we expect beatific possession of him; finally through CHARITY we adhere to him, loving him for his own sake, and our neighbors on account of him.

Therefore there will be three treatises:

TREATISE I. On Faith.

TREATISE II. On Hope.

TREATISE III. On Charity.