The scholastic teaching, then, on the subject was quite plain and unambiguous. Usury, or the payment of a price for the use of a sum lent in addition to the repayment of the sum itself, was in all cases prohibited. The fact that the payment demanded was moderate was irrelevant; there could be no question of the reasonableness of the amount of an essentially unjust payment.[1] Nor was the payment of usury rendered just because the loan was for a productive purpose--in other words, a commercial loan. Certain writers have maintained that in this case usury was tolerated;[2] but they can easily be refuted. As we have seen above, _mutuum_ was essentially a sale, and, therefore, no additional price could be charged because of some special individual advantage enjoyed by the buyer (or borrower). It was quite impossible to distinguish, according to the scholastic teaching, between taking an additional payment because the lender made a profit by using the loan wisely, and taking it because the borrower was in great distress, and therefore derived a greater advantage from the loan than a person in easier circumstances. The erroneous notion that loans for productive purposes were entitled to any special treatment was finally dispelled in 1745 by an encyclical of Benedict XIV.[3] [Footnote 1: Jourdain, _op. cit._, p. 35.] [Footnote 2: _E.g._ Périn, _Premiers Principes d'Économie politique_, p. 305; Claudio Jannet, _Capital Spéculation et Finance_, p. 83; De Metz-Noblat, _Lois économiques_, p. 293.] [Footnote 3: Rambaud, _op. cit._, p. 69.] § 5. _Extrinsic Titles_. Usury, therefore, was prohibited in all cases. Many people at the present day think that the prohibition of usury was the same thing as the prohibition of interest. There could not be a greater mistake. While usury was in all circumstances condemned, interest was in every case allowed. The justification of interest rested on precisely the same ground as the prohibition of usury, namely, the observance of the equality of commutative justice. It was unjust that a greater price should be paid for the loan of a sum of money than the amount lent; but it was no less unjust that the lender should find himself in a worse position because of his having made the loan. In other words, the consideration for the loan could not be increased because of any special benefit which it conferred on the borrower, but it could be increased on account of any special damage suffered by the lender--precisely the same rule as we have seen applied in the case of sales. The borrower must, in addition to the repayment of the loan, indemnify the lender for any damage he had suffered. The measure of the damage was the difference between the lender's condition before the loan was made and after it had been repaid--in other words, he was entitled to compensation for the difference in his condition occasioned by the transaction--_id quod interest_.