Section B: On Justice and Injustice in Involuntary Exchanges

S. Th. II-II, q. 61, a. 3.

343. Involuntary exchanges are those by which harm is inflicted on another against his will. This happens when someone uses the thing or person or work of another, while he is unwilling, whether secretly by fraud, or manifestly by violence: each is exercised either against one's own person, or against a connected person, or against any things whatever of another, both by deeds and by words.

Moreover there are four kinds of goods about which commutative justice can be concerned, and the injury which is opposed to it: the internal goods of life and body as to one's own person or that of one's neighbor, the goods of marriage, namely, the internal goods of a connected person, the external goods of fortune, the mixed goods of reputation and honor.

Hence one must speak of injuries which are done:

A. by deed, 1) in the internal goods of life and body as to one's own person: both in the spiritual goods of the soul, and in the goods of the body by the killing of oneself or one's neighbor and by other harms in the bodily members;

2. in the goods of marriage, as to a connected person, by adultery and seduction;

3. in exterior goods, secretly by theft, manifestly by robbery;

B. by words, namely, 4) in reputation and honor, secretly by detraction, manifestly by contumely and by other things of this kind.