Obj. 3: Further, no one can be unjustly deprived of what he is not bound to give. Now a judge justly deprives a thief of more than the amount of his theft, under the head of damages. Therefore a man is bound to pay it, and consequently it is not sufficient to restore the exact amount.
On the contrary, Restitution re-establishes equality where an unjust taking has caused inequality. Now equality is restored by repaying the exact amount taken. Therefore there is no obligation to restore more than the exact amount taken.
I answer that, When a man takes another's thing unjustly, two things must be considered. One is the inequality on the part of the thing, which inequality is sometimes void of injustice, as is the case in loans. The other is the sin of injustice, which is consistent with equality on the part of the thing, as when a person intends to use violence but fails.
As regards the first, the remedy is applied by making restitution, since thereby equality is re-established; and for this it is enough that a man restore just so much as he has belonging to another. But as regards the sin, the remedy is applied by punishment, the infliction of which belongs to the judge: and so, until a man is condemned by the judge, he is not bound to restore more than he took, but when once he is condemned, he is bound to pay the penalty.
Hence it is clear how to answer the First Objection: because this law fixes the punishment to be inflicted by the judge. Nor is this commandment to be kept now, because since the coming of Christ no man is bound to keep the judicial precepts, as stated above (I-II, Q. 104, A. 3). Nevertheless the same might be determined by human law, and then the same answer would apply.
Reply Obj. 2: Zachaeus said this being willing to do more than he was bound to do; hence he had said already: "Behold . . . the half of my goods I give to the poor."
Reply Obj. 3: By condemning the man justly, the judge can exact more by way of damages; and yet this was not due before the sentence. _______________________
FOURTH ARTICLE [II-II, Q. 62, Art. 4]
Whether a Man Is Bound to Restore What He Has Not Taken?
Objection 1: It would seem that a man is bound to restore what he has not taken. For he that has inflicted a loss on a man is bound to remove that loss. Now it happens sometimes that the loss sustained is greater than the thing taken: for instance, if you dig up a man's seeds, you inflict on the sower a loss equal to the coming harvest, and thus you would seem to be bound to make restitution accordingly. Therefore a man is bound to restore what he has not taken.