OF THE QUASI-INTEGRAL PARTS OF JUSTICE (FOUR ARTICLES)
We must now consider the quasi-integral parts of justice, which are "to do good," and "to decline from evil," and the opposite vices. Under this head there are four points of inquiry:
(1) Whether these two are parts of justice?
(2) Whether transgression is a special sin?
(3) Whether omission is a special sin?
(4) Of the comparison between omission and transgression.
Whether to decline from evil and to do good are parts of justice?
Objection 1: It would seem that to decline from evil and to do good are not parts of justice. For it belongs to every virtue to perform a good deed and to avoid an evil one. But parts do not exceed the whole. Therefore to decline from evil and to do good should not be reckoned parts of justice, which is a special kind of virtue.
Objection 2: Further, a gloss on Ps. 33:15, "Turn away from evil and do good," says: "The former," i.e. to turn away from evil, "avoids sin, the latter," i.e. to do good, "deserves the life and the palm." But any part of a virtue deserves the life and the palm. Therefore to decline from evil is not a part of justice.
Objection 3: Further, things that are so related that one implies the other, are not mutually distinct as parts of a whole. Now declining from evil is implied in doing good: since no one does evil and good at the same time. Therefore declining from evil and doing good are not parts of justice.
On the contrary, Augustine (De Correp. et Grat. i) declares that "declining from evil and doing good" belong to the justice of the law.
I answer that, If we speak of good and evil in general, it belongs to every virtue to do good and to avoid evil: and in this sense they cannot be reckoned parts of justice, except justice be taken in the sense of "all virtue" [*Cf. Q[58], A[5]]. And yet even if justice be taken in this sense it regards a certain special aspect of good; namely, the good as due in respect of Divine or human law.
On the other hand justice considered as a special virtue regards good as due to one's neighbor. And in this sense it belongs to special justice to do good considered as due to one's neighbor, and to avoid the opposite evil, that, namely, which is hurtful to one's neighbor; while it belongs to general justice to do good in relation to the community or in relation to God, and to avoid the opposite evil.
Now these two are said to be quasi-integral parts of general or of special justice, because each is required for the perfect act of justice. For it belongs to justice to establish equality in our relations with others, as shown above (Q[58], A[2]): and it pertains to the same cause to establish and to preserve that which it has established. Now a person establishes the equality of justice by doing good, i.e. by rendering to another his due: and he preserves the already established equality of justice by declining from evil, that is by inflicting no injury on his neighbor.
Reply to Objection 1: Good and evil are here considered under a special aspect, by which they are appropriated to justice. The reason why these two are reckoned parts of justice under a special aspect of good and evil, while they are not reckoned parts of any other moral virtue, is that the other moral virtues are concerned with the passions wherein to do good is to observe the mean, which is the same as to avoid the extremes as evils: so that doing good and avoiding evil come to the same, with regard to the other virtues. On the other hand justice is concerned with operations and external things, wherein to establish equality is one thing, and not to disturb the equality established is another.
Reply to Objection 2: To decline from evil, considered as a part of justice, does not denote a pure negation, viz."not to do evil"; for this does not deserve the palm, but only avoids the punishment. But it implies a movement of the will in repudiating evil, as the very term "decline" shows. This is meritorious; especially when a person resists against an instigation to do evil.
Reply to Objection 3: Doing good is the completive act of justice, and the principal part, so to speak, thereof. Declining from evil is a more imperfect act, and a secondary part of that virtue. Hence it is a. material part, so to speak, thereof, and a necessary condition of the formal and completive part.
Whether transgression is a special sin?
Objection 1: It would seem that transgression is not a special sin. For no species is included in the definition of its genus. Now transgression is included in the definition of sin; because Ambrose says (De Parad. viii) that sin is "a transgression of the Divine law." Therefore transgression is not a species of sin.
Objection 2: Further, no species is more comprehensive than its genus. But transgression is more comprehensive than sin, because sin is a "word, deed or desire against the law of God," according to Augustine (Contra Faust. xxii, 27), while transgression is also against nature, or custom. Therefore transgression is not a species of sin.
Objection 3: Further, no species contains all the parts into which its genus is divided. Now the sin of transgression extends to all the capital vices, as well as to sins of thought, word and deed. Therefore transgression is not a special sin.
On the contrary, It is opposed to a special virtue, namely justice.
I answer that, The term transgression is derived from bodily movement and applied to moral actions. Now a person is said to transgress in bodily movement, when he steps [graditur] beyond [trans] a fixed boundary---and it is a negative precept that fixes the boundary that man must not exceed in his moral actions. Wherefore to transgress, properly speaking, is to act against a negative precept.
Now materially considered this may be common to all the species of sin, because man transgresses a Divine precept by any species of mortal sin. But if we consider it formally, namely under its special aspect of an act against a negative precept, it is a special sin in two ways. First, in so far as it is opposed to those kinds of sin that are opposed to the other virtues: for just as it belongs properly to legal justice to consider a precept as binding, so it belongs properly to a transgression to consider a precept as an object of contempt. Secondly, in so far as it is distinct from omission which is opposed to an affirmative precept.
Reply to Objection 1: Even as legal justice is "all virtue" (Q[58], A[5]) as regards its subject and matter, so legal injustice is materially "all sin." It is in this way that Ambrose defined sin, considering it from the point of view of legal injustice.