A question arises here, whether usury be in itself a crime, since God formerly permitted his people to take interest of strangers, and only forbade it among themselves. And there was the best reason for that law. For if its just proportion had been overthrown, there would have been no reciprocity, since the Gentiles could exact interest of the Jews; and unless that right had been mutual and reciprocal, as the phrase is, the condition of God’s people would have been worse than that of the Gentiles. God therefore permitted his people to take interest, but not among each other, as I have said: this was only allowable with strangers. Besides, the law itself was political: but in this case the Prophet seems to condemn all kinds of interest, and exaggerates the weight of the sentence, when he adds increase, that is, whatever gains the avaricious mutually strive for. So also in the 15th Psalm, where a just mode of living is proscribed for us, David mentions, among other things — who has not lent his money on usury, (Psalm 15:5.) It seems, then, from these two places, that usury is in itself unlawful. But because God’s law embraces complete and perfect justice, hence we must hold that interest, unless it is opposed to God’s law, is not altogether to be condemned, otherwise ignominy would clearly attach to the law of God if it did not prescribe to us a true and complete rule of living justly. But in the law there is that perfection to which nothing can be added. If then we wish to determine whether interest is unlawful we must come to the rule of the law, which cannot deceive us: but we shall not find all interest contrary to the law, and hence it follows that interest is not always to be condemned. Here, too, we must remember that we must regard the subject rather than the words, for men trifle by their own caviling, but God does not admit of such fallacies. Hence, as I said, the substance ought to be weighed, because the words alone will not enable us to decide whether interest be sometimes lawful or not. For example, among the Latin’s the word for interest is honorable in itself and has no disgrace attached to it, but that for usury is odious. What causes disgrace to be thus hidden under it, but they fancied that they abhorred usurers, hence the general term interest contains within it all kinds of usury, and there was nothing so cruel, so unjust, and so barbarous, which was not covered by that pretense.
Now since the name for interest was unknown to the French, that for usury became detestable: hence the French devised a new craftiness by which they could deceive God. For since no one could bear the name of usury, they used “interest” instead: but what does this mean but something which interests us, and thus it signifies all kinds of repayment for loans, for there was no kind of interest among the ancients which is not now comprehended in this word. Now since we have said that interest cannot be totally and without exception condemned, (for we must not play upon words, but treat the real point,) we must see how far it can be proved not to be reckoned a crime. First of all, in a well regulated state, no usurer is tolerated: even the profane see this: whoever therefore professedly adopts this occupation, he ought to be expelled from intercourse with his fellow-men. For if any illiberal pursuits load those who pursue them with censure, that of the usurer is certainly an illiberal trade, and unworthy of a pious and honorable man. Hence Cato said that to take usury was almost the same as murder. For when asked concerning agriculture, after he had given his opinion, he inquired, But what is usury? Is it not murder? says he. And surely the usurer will always be a robber; that is, he will make a profit by his trade, and will defraud, and his iniquity will increase just as if there were no laws, no equity, and no mutual regard among mankind.
This is one point: but there is another part of the occupation besides that of taking interest. When any one sets up his table he uses the same art as a farmer does in employing his labor in cultivating the fields. But any one may receive interest without being a professed usurer. For example, a person may have capital and put out a part of it on loan, and thus receive interest: and if he do that once, he will not be called a usurer; so that we must consider when and from whom a person exacts interest. But this sentiment ought to prevail here: “neither everywhere, nor always, nor all things, nor from all.” This indeed was said of offices, and that law was imposed upon the governors of provinces: but it agrees best with this subject. It is not suitable then to receive “all things,” because if the profit exceed moderation it must be rejected, since it is contrary to charity: we said also that the continual habit and custom is not without fault. Neither “everywhere,” since the usurer, as I have said, ought not to enter or be brought into the Church of God. Then again, not “from all,” because it is always wrong to exact usury from a poor man; but if a man is rich, and has money of his own, as the saying is, and has a very good estate and a large patrimony, and should borrow money of his neighbor, will that neighbor commit sin by receiving a profit from the loan of his money? Another borrower is the richer of the two, and might do without it and yet suffer no loss: but he wishes to buy a farm and enjoy its fruits: why should the creditor be deprived of his rights when his money brings profit to a neighbor richer than himself?
We see, then, that it may sometimes happen that the receiver of interest is not to be hastily condemned, since he is not acting contrary to God’s law. But we must always hold that the tendency of usury is to oppress one’s brother, and hence it is to be wished that the very names of usury and interest were buried and blotted out from the memory of men. But since men cannot otherwise transact their business, we must always observe what is lawful, and how far it is so. I know that the subject might be treated at greater length, but I have shortly expressed what is sufficient for our purpose.”