But the great cause of inequality is in the natural monopoly which is given by the possession of land. The first perceptions of men seem always to be that land is common property; but the rude devices by which this is at first recognized--such as annual partitions or cultivation in common--are consistent with only a low stage of development. The idea of property, which naturally arises with reference to things of human production, is easily transferred to land, and an institution which when population is sparse merely secures to the improver and user the due reward of his labor, finally, as population becomes dense and rent arises, operates to strip the producer of his wages. Not merely this, but the appropriation of rent for public purposes, which is the only way in which, with anything like a high development, land can be readily retained as common property, becomes, when political and religious power passes into the hands of a class, the ownership of the land by that class, and the rest of the community become merely tenants. And wars and conquests, which tend to the concentration of political power and to the institution of slavery, naturally result, where social growth has given land a value, in the appropriation of the soil. A dominant class, who concentrate power in their hands, will likewise soon concentrate ownership of the land. To them will fall large partitions of conquered land, which the former inhabitants will till as tenants or serfs, and the public domain, or common lands, which in the natural course of social growth are left for a while in every country, and in which state the primitive system of village culture leaves pasture and woodland, are readily acquired, as we see by modern instances. And inequality once established, the ownership of land tends to concentrate as development goes on.