Undoubtedly--and I am the first to recognize it--the rent of land, like that of money and all personal and real property, is a spontaneous and universal fact, which has its source in the depths of our nature, and which soon becomes, by its natural development, one of the most potent means of organization. I shall prove even that interest on capital is but the materialization of the aphorism, ALL LABOR SHOULD LEAVE AN EXCESS. But in the face of this theory, or rather this fiction, of the productivity of capital, arises another thesis no less certain, which in these latter days has struck the ablest economists: it is that all value is born of labor, and is composed essentially of wages; in other words, that no wealth has its origin in privilege, or acquires any value except through work; and that, consequently, labor alone is the source of revenue among men. How, then, reconcile the theory of farm-rent or productivity of capital--a theory confirmed by universal custom, which conservative political economy is forced to accept but cannot justify--with this other theory which shows that value is normally composed of wages, and which inevitably ends, as we shall demonstrate, in an equality in society between net product and raw product? The socialists have not wasted the opportunity. Starting with the principle that labor is the source of all income, they began to call the holders of capital to account for their farm-rents and emoluments; and, as the economists won the first victory by generalizing under a common expression farm-rent and usury, so the socialists have taken their revenge by causing the seignorial rights of capital to vanish before the still more general principle of labor. Property has been demolished from top to bottom: the economists could only keep silent; but, powerless to arrest itself in this new descent, socialism has slipped clear to the farthest boundaries of communistic utopia, and, for want of a practical solution, society is reduced to a position where it can neither justify its tradition, nor commit itself to experiments in which the least mistake would drive it backward several thousand years. In such a situation what is the mandate of science?