to another individual, there is a twofold measure of merit or demerit in his action:  first, in respect of the retribution owed to him by the individual to whom he has done good or harm; secondly, in respect of the retribution owed to him by the whole of society.  Now when a man ordains his action directly for the good or evil of the whole society, retribution is owed to him, before and above all, by the whole society; secondarily, by all the parts of society.  Whereas when a man does that which conduces to his own benefit or disadvantage, then again is retribution owed to him, in so far as this too affects the community, forasmuch as he is a part of society:  although retribution is not due to him, in so far as it conduces to the good or harm of an individual, who is identical with the agent:  unless, perchance, he owe retribution to himself, by a sort of resemblance, in so far as man is said to be just to himself.

It is therefore evident that a good or evil action deserves praise or blame, in so far as it is in the power of the will:  that it is right or sinful, according as it is ordained to the end; and that its merit or demerit depends on the recompense for justice or injustice towards another.

Reply Obj. 1:  A man’s good or evil actions, although not ordained to the good or evil of another individual, are nevertheless ordained to the good or evil of another, i.e. the community.

Reply Obj. 2:  Man is master of his actions; and yet, in so far as he belongs to another, i.e. the community, of which he forms part, he merits or demerits, inasmuch as he disposes his actions well or ill:  just as if he were to dispense well or ill other belongings of his, in respect of which he is bound to serve the community.

Reply Obj. 3:  This very good or evil, which a man does to himself by his action, redounds to the community, as stated above. ________________________

FOURTH ARTICLE [I-II, Q. 21, Art. 4]

Whether a Human Action Is Meritorious or Demeritorious Before God,
According As It Is Good or Evil?

Objection 1:  It would seem that man’s actions, good or evil, are not meritorious or demeritorious in the sight of God.  Because, as stated above (A. 3), merit and demerit imply relation to retribution for good or harm done to another.  But a man’s action, good or evil, does no good or harm to God; for it is written (Job 35:6, 7):  “If thou sin, what shalt thou hurt Him? . . .  And if thou do justly, what shalt thou give Him?” Therefore a human action, good or evil, is not meritorious or demeritorious in the sight of God.

Obj. 2:  Further, an instrument acquires no merit or demerit in the sight of him that uses it; because the entire action of the instrument belongs to the user.  Now when man acts he is the instrument of the Divine power which is the principal cause of his action; hence it is written (Isa. 10:15):  “Shall the axe boast itself against him that cutteth with it?  Or shall the saw exalt itself against him by whom it is drawn?” where man while acting is evidently compared to an instrument.  Therefore man merits or demerits nothing in God’s sight, by good or evil deeds.