Article 2
Now, second, you asked, if a Jew should sin, should this person be punished with the financial penalty, since he seems to have nothing aside from usurious money.
To which question it seems the response should be, in line with what has been said before, that it is expeditious that he be punished with a financial penalty, in order that he might not accrue some benefit from his iniquity; it also seems to me that the Jew should be punished with a greater fine (or anyone else who practices usury) than anyone else in a similar case, to make the point that the money taken from him be known to be less his entitlement. Another punishment can be added to this financial punishment, lest this seem to suffice for a penalty, that he cease to possess the money that is owed to others. Nonetheless, money taken from usurers in the name of punishment cannot be kept but should be expended for the aforementioned uses, if they do not have anything other than usurious money.
But if it be said that the princes of countries suffer loss from this, this loss should be imputed to them as coming from their own negligence; for it would be better if they compelled Jews to work for their own living, as they do in parts of Italy, than that, living without occupation they grow rich by usury, and thus their rulers be defrauded of revenue. In the same way, and through their own fault, princes are defrauded of their proper revenues if they permit their subjects to enrich themselves by theft and robbery alone; for they would be bound to restore [to the real owner] whatever they had exacted from them [the thieves].
Chapter 2 of 8