Summa Theologiae Moralis, vol. I: De Principiis

S. Th. I-II, q. 21, a. 3 and 4 ; q. 114, a. 1, 2, 5-10.

190. Merit etymologically is derived from the word merces (reward), and therefore designates a service or laborious work done for the benefit of another, which is wont to be done only by hirelings for a stipend or reward. In the broadest sense it signifies whatever is sufficient, suitable, worthy for obtaining something, or that which demands something, and so it is also said of inanimate things, e. g., of a painting; — more properly it is a human work to which retribution is due from some justice strictly or broadly so called, and so it is also said of an evil work (Mt. XVI, 26 ; Iob. VI, 2 ; Hebr. X, 29 ; Eccli. XVI, 14, 15); — in the strict sense however it is a good work done in service or benefit of another and therefore worthy of reward and retribution.

It can be considered in the abstract and in the concrete: in the concrete it is the work of virtue to which a reward is due, a work worthy of retribution; in the abstract it is the property of a human act, namely the moral value of a work by virtue of which it is worthy that something be given back to the one working, the goodness existing in the human act because of which it is worthy of praise and reward, or the dignity of the work and therefore the right or title in the one working for retribution.

191. The philosophical foundation of merit is in the exigence of the order of nature, or in the natural law by virtue of which an active being's own proper good is its own and therefore ought to accrue to it, since it has the very perfection of the entity as its end. Whence, when a free person has chosen an act in service or for the benefit of another person, that person has provided something which is his own; whence it is equitable and just that the other should give back something good, compensating the good provided (II-II, q. 106, a. 3; I, q. 65, a. 2). But if equality is required and rendered, merit is from justice properly so called; otherwise from equity and fitness, friendship, and liberality, which in some way pertain to justice.

On the contrary, since each man in relation to his ultimate end is of the same dignity, as being of his own right, and therefore is not a mere means subordinated to others, but exists for his own good, he cannot be deprived of his order to his own good without justice demanding recompense of punishment. Whence S. Thomas (q. 21, a. 3): he who « acts to the profit (emolumentum) or harm (damnum, detrimentum) of another », « acquires merit or demerit in relation to retribution which is made according to justice ».

192. Division of merit. — A. By reason of the one rewarding, merit is civil when the work is done for the benefit or service either of an individual or of society; — and moral when it is done in service of God.

a) As to civil merit:

1. An act directed toward the good (or evil) of an individual person has merit (or demerit) directly with the person, indirectly with the society on which the good of the person, who is in some way its part and member, redounds.

2. An act directed toward the good (or evil) of society has merit primarily with the society, secondarily with the individual members insofar as they are members.

3. An act directed toward the good (or evil) of the agent himself has no merit with the agent himself (because justice is toward another), but can indirectly have the notion of merit with society (q. 21, a. 3).

b) Every human act has moral merit (or demerit) with God, inasmuch as it tends toward the profit (or detriment) not of God himself but of his honor and of the order established by him; — and indeed: 1) By reason of God himself: for God is the ultimate end of man. But to the ultimate end is due that all acts be referred to it. Therefore he who does an evil act not referrible to God does not preserve the honor which is due to the ultimate end, and vice versa.

2. By reason of society, whose God is ruler and guardian: God is the governor and ruler of the whole universe. But he who rules a community has care of the common good and must give retribution for those things which are done well or ill in society. Therefore human acts have merit or demerit with God; otherwise it would have to be said that he does not care about human acts (a. 4).

B. By reason of the reward, merit is natural, which proceeds from the powers of nature, and expects only a natural reward; whence if it is in service of God, it is done in relation to God as the natural end; — another is supernatural, which is done by the powers of grace in relation to God as the supernatural end, and merits a supernatural reward, namely the good of eternal life. It is also called theological.

They differ in that the first follows upon every good act by reason of its goodness, the second by some relation of justice to God from whom, at least from fittingness, it merits at least a temporal good, and therefore it imports a reward from the very notion of the act; — the other imports a reward to be given back not only from the very notion of the act but also from the state of the person working, and therefore it belongs only to supernatural acts and indeed of the just man alone, to whom eternal life itself or some other good in relation to eternal life is due as a reward¹. Here we treat only of supernatural merit.

C. By reason of dignity, merit is: Either simply so called or of condignity, to which the reward is due from justice, to which it has equal value and equal dignity or condignity. It is a work whose value equals the value of the reward because there is equality between merit and reward according to right estimation: equality therefore not always material or quantitative, but moral, which is called of virtue and proportion, just as between seed and the fruit that is born from it (q. 114, a. 3, ad 3). — Or it is merit of congruity and in a certain respect, to which in no way is retribution made from justice, but only from a certain fitness and equity and friendship or liberality of the giver the gift is bestowed which befits the giver; and therefore it does not infallibly obtain the reward, unless the one rewarding has promised, and then not from justice but from fidelity. It is a work whose value does not equal the value of the reward because equality between reward and merit is lacking.

In the former merit there is an exigence for the reward, in the other only a fittingness. The former can be compared to the stipend that is owed to a soldier and the wage that is owed to a servant; the latter to an honorary distinction (e. g., an equestrian order) which the prince not from justice nor altogether gratuitously bestows on a soldier for deeds bravely done, a gratification or gift that inferiors or servants have received for more or less supererogatory services. This division is not univocal but analogous.

193. What can man merit? — Of condignity the just man can merit for himself the increase of habitual grace, the remission of venial sin, heavenly glory and its increase. Of congruity he can merit for himself infallibly actual graces, the first excepted.

Christ alone could merit for others of condignity, as head of all men. Of congruity a man can merit for others but not infallibly: actual graces including the first, habitual grace and its increase, the remission of sin, and eternal life.

These are proved in the treatise on grace. Cf. S. Thomas I-II, q. 114.