Objection 1:  It would seem that virtues can not be caused in us by habituation.  Because a gloss of Augustine [Cf.  Lib.  Sentent.  Prosperi cvi.] commenting on Rom. 14:23, “All that is not of faith is sin,” says:  “The whole life of an unbeliever is a sin:  and there is no good without the Sovereign Good.  Where knowledge of the truth is lacking, virtue is a mockery even in the best behaved people.”  Now faith cannot be acquired by means of works, but is caused in us by God, according to Eph. 2:8:  “By grace you are saved through faith.”  Therefore no acquired virtue can be in us by habituation.

Obj. 2:  Further, sin and virtue are contraries, so that they are incompatible.  Now man cannot avoid sin except by the grace of God, according to Wis. 8:21:  “I knew that I could not otherwise be continent, except God gave it.”  Therefore neither can any virtues be caused in us by habituation, but only by the gift of God.

Obj. 3:  Further, actions which lead toward virtue, lack the perfection of virtue.  But an effect cannot be more perfect than its cause.  Therefore a virtue cannot be caused by actions that precede it.

On the contrary, Dionysius says (Div.  Nom. iv) that good is more efficacious than evil.  But vicious habits are caused by evil acts.  Much more, therefore, can virtuous habits be caused by good acts.

I answer that, We have spoken above (Q. 51, AA. 2, 3) in a general way about the production of habits from acts; and speaking now in a special way of this matter in relation to virtue, we must take note that, as stated above (Q. 55, AA. 3, 4), man’s virtue perfects him in relation to good.  Now since the notion of good consists in “mode, species, and order,” as Augustine states (De Nat.  Boni. iii) or in “number, weight, and measure,” as expressed in Wis. 11:21, man’s good must needs be appraised with respect to some rule.  Now this rule is twofold, as stated above (Q. 19, AA. 3, 4), viz. human reason and Divine Law.  And since Divine Law is the higher rule, it extends to more things, so that whatever is ruled by human reason, is ruled by the Divine Law too; but the converse does not hold.

It follows that human virtue directed to the good which is defined according to the rule of human reason can be caused by human acts:  inasmuch as such acts proceed from reason, by whose power and rule the aforesaid good is established.  On the other hand, virtue which directs man to good as defined by the Divine Law, and not by human reason, cannot be caused by human acts, the principle of which is reason, but is produced in us by the Divine operation alone.  Hence Augustine in giving the definition of the latter virtue inserts the words, “which God works in us without us” (Super Ps. 118, Serm. xxvi).  It is also of these virtues that the First Objection holds good.