Article I. On the Nature and Division of Commutative Justice

I. Nature. Although the nature of commutative justice and its difference from distributive and legal justice have been explained above (n. 380 ff.), nevertheless it is useful to recall to memory or to add these things:

1. The conditions required for justice, namely alterity, debt, and equality, are present in commutative justice in a more perfect way than in distributive and legal justice. For in it there is:

a) The perfect character of alterity, as between part and part; not so in distributive justice, which is between the whole and the parts, nor in legal justice, which is between the part and the whole.

b) The perfect character of debt, because it regards a strict right, while the other kinds of justice regard a less strict right (n. 757).

c) The perfect character of equality, because it requires equality taken simply, or arithmetic equality, of thing to thing; while the other kinds of justice require equality, proportionately taken, of thing to thing. I say proportionately taken, that is, if there is question of distributive justice, corresponding to the capacity, merit, and so forth of the part; if there is question of legal justice, corresponding to the requirements of the whole, or the common good.

2. Commutative justice, and it alone, if it has been violated, brings with it the obligation of restitution. It is said:

a) Commutative justice brings with it the obligation of restitution. The reason is that commutative justice regards those things which, by force of a special connection, are peculiarly destined to someone's advantage and are proper or quasi-proper¹ to him; and therefore, if they have been taken away and still exist, they must be rendered in themselves; if they have been destroyed or consumed, they must be rendered in an equivalent (St. Thomas, II-II, q. 62, a. 1; St. Alphonsus, III, 547).

b) Commutative justice alone brings with it the obligation of restitution. For legal justice regards things which are not proper or quasi-proper to society, in other words, things which are owed to society not by strict right but only by broad right, at least if the thing to be rendered is determinate. But a broad right, if it has been neglected, must indeed be rendered as long as the law persists, yet not by way of restitution, but as if the obligation were now beginning for the first time. Distributive justice likewise regards things which are not proper or quasi-proper to a member of society, but are owed only by broad right. But if that broad right has been neglected, restitution can no longer be made: not from common goods already distributed in a disorderly way, because they have become his to whom they were distributed; not from common goods yet to be distributed, because these also must be distributed according to an equal proportion; and not from proper goods, because distributive justice regards common goods only (St. Alphonsus, III, 547).

¹ By quasi-proper things I understand those things in which someone has a strict right (ius ad rem, n. 757).

II. Division. Commutative justice is divided into various species. The reason is that the objects of commutative justice, that is, the rights which it commands to be rendered, are of different orders, for example a right to material goods, to reputation, to honor. Hence also the sins which violate those different rights, for example theft, detraction, insult, are specifically different.