But a question which necessarily presents itself here, is to know if, when one loans, it is a duty to deprive one's self of all remuneration; or if it is, on the contrary, permitted to exact a price over and beyond the sum loaned. This is what is called money _interest_; and when this interest is or appears excessive, it is called _usury_. This question, discussed during the whole middle ages, was, before its true principles were established, first resolved by practice and necessity. It is to-day evident to all sensible minds, that capital, like work, has a right to remuneration. Why? Because without the expectation of this remuneration, the possessor of the capital would forthwith consume it himself or allow it to waste away without use. This will be better understood in considering the two principal forms of remuneration for capital: _interest_ and _rent_. Interest and rent are both the product of a capital loaned, but with this difference, that rent is the product of a _fixed_ capital (house, field, workshop); while interest is the product of a _circulating_ capital (money or paper). The interest of capital represents two things: 1, the deprivation of him who loans, and who might consume his capital; 2, the risk he incurs, for capital is never loaned except to be invested, and consequently it may be lost. These are the two fundamental reasons which establish the legitimacy of interest, despite the prejudices which have long condemned it as _usury_, and the utopias which would establish the _gratuity_ of _credit_.[24] The principal reason against the legitimacy of interest is deduced from the _sterility of money_. "Interest," says Aristotle, "is _money bred from money_; and nothing is more contrary to nature." But, as Bentham remarks (_Defense of Usury_, letter 10), "if it be true that a sum of money is of itself incapable to breed, it is not the less true that with this same borrowed sum, a man can buy a ram and a sheep, which, at the end of a year, will have produced two or three lambs." In other terms, as Calvin says, "it is not from the money itself that the benefit comes, it is from the use that is made of it." It has been said that he who _loans_ does not _deprive_ himself of his money, since he can do without it. (Proudhon, _Letters to Bastiat_, 3d letter.) But he does deprive himself of it, since he might have consumed it himself. The proof that a loan is a privation, is the pain men have in economizing and in investing their money. How many men are there who, in possession of a sum of one hundred francs, would not rather spend it than place it on interest?