Question Two: Concerning the Roots of Restitution

S. Th. II-II, q. 62, a. 4 and 6.

288. The root or title from which the obligation of restoring arises is twofold: another's thing received, and unjust taking; these titles of themselves exist separately, yet sometimes they are joined.

1. From the sole title of a thing received, or by reason of simple detention, he is bound to restore who has another's thing with himself even without fault, whether the other is willing, as in a commodatum or deposit, and then the detention becomes unjust if the thing is not rendered at its time; — or whether the other is unwilling, as if by chance accident or by the act of a third party it is with me and I do not know that it belongs to another, and then the detention becomes unjust if the thing is not immediately rendered when it appears to belong to another. For a thing cries out for its owner, and no one can voluntarily be deprived by another of his own thing against his will; and therefore when someone "has beyond that which is his, it ought to be taken away from him and given to him who lacks it" (a. 6).

2. From the sole title of unjust taking he is bound to restore who by an unjust way has taken away another's thing, even if the thing does not remain with him, or even has been destroyed, and he has nothing from it; in one word, he who inflicted unjust damage on another and thus unjustly deprived him of a thing: "for he who damages someone seems to take away from him that in which he damages him" (a. 4). — The reason is that, although he himself does not have more than he ought to have, the other nevertheless, from his unjust action, has less than he ought to have; whence he violated justice concerning the thing of another, which he is bound to remove by restitution (a. 6, ad 1).

3. By both titles at once he is bound to restore who unjustly has taken away another's thing and has it with himself, in itself or in an equivalent.

Among these titles a great difference is to be noted for practice; for:

a) He who is bound to restore by reason of unjust taking remains obligated to restitution, even if the thing owed perishes without his fault (unless perhaps it would certainly have perished with the owner at the same time), because the title of obligation always remains, namely, the violation of justice, until it is repaired by restitution; — on the contrary, he who is bound to restore by reason only of the thing received does not, because if some thing perishes without his fault, the title of obligation ceases, which is to have another's thing.

b) He who is bound by reason of unjust taking must restore not only the thing or its value, but also all fruits even consumed and all damages and detriments caused, because he is their voluntary and culpable cause; — on the contrary, he who is bound by reason only of the thing received is not bound to repair damages of which he is not the voluntary cause, nor to restore fruits, if they were consumed in good faith and he was not made richer from them.

c) Hence the measure of restitution for unjust taking is the quantity of damage inflicted (benadeeling); for a thing received, the quantity of possession, or how much from another's thing someone possesses or has been made richer (bezitting).