9. St. Thomas speaks of sales, but the principle applies equally to loans. It is upon loans of money that interest is commonly taken, and of money-loans we speak. Clearly, according to the doctrine stated, the lender can claim the compensation of interest, if he has to pinch himself in order to lend, or lends at a notable risk. He is selling his own loss,--or risk, which is loss once removed. But supposing he has other monies in hand, and the security is good, and he has enough still left for all domestic needs, and for all luxuries that he cares to indulge in,--moreover he has nothing absolutely to do with his money, in the event of his not lending it, but to hoard it up in his strong box, and wait long months till he has occasion to use it: in that case, if he lends it he will be no worse off on the day that he gets it back, no worse off in the time while it is away, than if it had never left his coffers. Such is the contract of _mutuum_, shorn of all accidental attendant circumstances, a contract, which "of its own nature," as Benedict XIV. says, that is, apart from circumstances, "requires the amount returned exactly to balance the amount received." Not though the borrower has profited of the loan to gain kingdoms, is any further return in strict justice to be exacted of him on that precise account. 10. But now an altered case. Suppose land is purchaseable, and it is proposed to stock a farm with cattle, and rear them, and convey them to a large town where there is a brisk demand for meat--the supposition is not always verified, nor any supposition like it, but suppose it verified in some one case--then, though the lender has other monies in hand for the needs of his household, and the security is good, yet the money is not so lent as that he foregoes no occasion of lawful gain by lending it. He foregoes the purchase of land and farm stock, or at least delays it, and delay is loss where profit is perennial. On that score of gain forfeited he may exact interest on the money that he lends, which interest will be no usury. The title of interest here given is recognized by divines as _lucrum cessans_, "interruption of profit." The interest is taken, so far as it goes upon a lawful title, not upon the fact of the borrower's profit--that is irrelevant--but upon the profit that the lender might have made, had he kept the money in hand.