Summa summae S. Thomae, Tomus III

[In general it is required and suffices that restitution be made in such a way that the violated justice is fully repaired, or restored to equality. This follows from the notion of restitution, which, as has been said, is the giving back of a thing received, or the compensation for damage inflicted. Therefore, in whatever way the injured party is restored to the state in which he was before the injury, the obligation of commutative justice arising from theft or damage done is satisfied. Hence

1° It is not necessary, of itself, that restitution be made openly; indeed often it cannot be done in that way, nor even ought it to be, so that regard be had for the reputation and honor of the one restituting.

2° It is not necessary that restitution be made by the debtor himself, but it can be made by anyone else, provided the thing be given back to its owner. Thus at times, and for grave cause, it is entrusted to a confessor. But then great caution is needed: both that the seal of confession remain inviolate, and that there be no doubt for the penitent that the creditor has received the thing owed to him, lest any suspicion against the probity of the confessor ever arise.

3° It is not necessary that restitution be made with the owner being aware; because it is only required that the injured party be made whole. Hence the debtor can restitute, for example, by increasing the weight or measure in selling, or the owed work in laboring, and in six hundred other ways. ¹

4° It is commonly taught that restitution made by means of a simulated donation is valid. If, however, the creditor, moved by gratitude, were to give back another gift, this again would have to be restituted to him, at least in equivalent value, if the thing itself could not prudently be given back; because an antidotal donation, in this case, would proceed from error, and consequently would not be valid. ²

You will ask 1° how damages inflicted on associations are to be repaired, for example, on an insurance society against fire.

Some have said it impossible to repair such damages toward all who suffered them; because ordinarily, at the time of restitution, very many, who are unknown, would have left the society. But this reasoning does not hold, for when members depart others succeed them, to whom their rights are transferred. Therefore the difficulty exists only in the case of dissolution, since very few could be found, and the share to be given to each would be most minute. And so

I answer: Restitution must be made to the administrators of the society, taking care that it benefit the society itself. If, however, the society has ceased to exist by dissolution or in some other way, the money must be restituted or refunded either to the poor or to pious causes; because it is not lawful to grow rich from a thing unjustly acquired.

You will ask 2° how damage inflicted on the state is to be repaired.

I answer: It must be repaired by using the means established by law, if any exist. Now such a law exists in Austria. Where no such means have been legally established, however, restitution must be made through the officials in charge of taxes, if it is certain that the money is to be laid up in the public treasury. In France, where such a law is lacking, restitutions are entered in the public records. If, however, there is danger that the officials will turn this money to their own uses, it must be distributed to the poor, or expended for the benefit of pious causes. ³]