a) As every evil deed implies demerit and is deserving of punishment, so the notion of merit supposes a morally good work (_opus honestum_). Cfr. Eph. VI, 8: “Knowing that whatsoever good thing any man shall do, the same shall he receive from the Lord.”(1276) 2 Cor. V, 10: “We must all be manifested before the judgment-seat of Christ, that every one may receive the proper things of the body, according as he hath done, whether it be good or evil.”(1277) There are no morally indifferent works _in individuo_, _i.e._ practically; and if there were, they could be neither meritorious nor demeritorious, but would become meritorious in proportion as they are made morally good by means of a “good intention.” It would be absolutely wrong to ascribe merit only to the more perfect works of supererogation (_opera supererogatoria_), such as the vow of perpetual chastity, excluding all works of mere obligation, such as the faithful observance of the commandments. Being morally good, the works of obligation are also meritorious, because goodness and meritoriousness are correlative terms.(1278) Whether the mere omission of an evil act is in itself meritorious, is doubtful.(1279) But most theologians are agreed in holding that the external work, as such, adds no merit to the internal act, except in so far as it reacts on the will and sustains and intensifies its operation. This and similar questions properly belong to moral theology. b) The second requisite of merit is moral liberty (_libertas indifferens ad actum_), that is to say, freedom from both external and internal compulsion. This has been dogmatically defined against Jansenius.(1280) That there can be no merit without liberty is clearly inculcated by Sacred Scripture. Cfr. 1 Cor. IX, 17: “For if I do this willingly, I have a reward.”(1281) Matth. XIX, 17: “If thou wilt enter into life, keep the commandments.”(1282) “Where there is compulsion,” says St. Jerome, “there is neither a crown nor damnation.”(1283) The morality of an act depends entirely on its being an _actus humanus_. Now no act is truly “human” unless it be freely performed. Consequently, freedom of choice is an indispensable condition of moral goodness and therefore also of merit.