By the side of net product, the natural reward of the laborer, I have pointed out as one of the happiest effects of monopoly the CAPITALIZATION of values, from which is born another sort of profit,--namely, INTEREST, or the hire of capital. As for RENT, although it is often confounded with interest, and although, in ordinary language, it is included with profit and interest under the common expression REVENUE, it is a different thing from interest; it is a consequence, not of monopoly, but of property; it depends on a special theory., of which we will speak in its place. What, then, is this reality, known to all peoples, and nevertheless still so badly defined, which is called interest or the price of a loan, and which gives rise to the fiction of the productivity of capital? Everybody knows that a contractor, when he calculates his costs of production, generally divides them into three classes: 1, the values consumed and services paid for; 2, his personal salary; 3, recovery of his capital with interest. From this last class of costs is born the distinction between contractor and capitalist, although these two titles always express but one faculty, monopoly. Thus an industrial enterprise which yields only interest on capital and nothing for net product, is an insignificant enterprise, which results only in a transformation of values without adding anything to wealth,-- an enterprise, in short, which has no further reason for existence and is immediately abandoned. Why is it, then, that this interest on capital is not regarded as a sufficient supplement of net product? Why is it not itself the net product? Here again the philosophy of the economists is wanting. To defend usury they have pretended that capital was productive, and they have changed a metaphor into a reality. The anti-proprietary socialists have had no difficulty in overturning their sophistry; and through this controversy the theory of capital has fallen into such disfavor that today, in the minds of the people, CAPITALIST and IDLER are synonymous terms. Certainly it is not my intention to retract what I myself have maintained after so many others, or to rehabilitate a class of citizens which so strangely misconceives its duties: but the interests of science and of the proletariat itself oblige me to complete my first assertions and maintain true principles.