We have seen that the family assumes a new status within political society. It comes to be a compact unit, contrasting markedly with the groups composed of the same sex--in particular, the men's clubs--that dominated the preceding period. The _differentiation of classes_ was a no less potent factor in the development of political society. Its beginnings, no doubt, go back to the declining period of totemic tribal institutions, but only in the political age does it become an important influence in social organization. This is due to _two_ conditions, which are themselves the direct result of the folk migrations that mark the beginning of the political age. The first of these conditions consists in changes affecting property rights; the other, in the subjection of the native populations by the more energetic immigrants. The origin of property, as is well known, is even to-day generally traced, from an abstract juristic point of view, to the occupancy of an ownerless piece of land. This theory, however, is too abstract to be generally true. Above all, it presupposes the existence of ownerless land. But this is seldom to be found. Even when a migrating people occupies new lands, it, as a rule, conquers a territory that was previously in the possession of other tribes. If, therefore, we have in mind the sort of property that was most significant for the development of political culture, we should trace its origin to an _expropriation of earlier owners_ rather than to an occupation of ownerless land. Contradicting the abstract theory, moreover, is the fact that it is not the individual who becomes the owner of property through such occupation, but the _entire tribe_, the people that has immigrated and has dispossessed the original inhabitants. Property, therefore, was originally _common property_. True, even in early times, it was no longer all of the land that was held in common ownership. Nevertheless, the conditions of ownership that have emerged in the course of the development of political society give unmistakable evidence of having originated in common ownership. Even up to fairly recent times, woodland and meadow have remained, either entirely or in part, common property; usually there is also a special temple-property set apart for purposes of cult. Everything goes to show that these cases are to be regarded as remnants of a common property that was at one time more comprehensive, and not as the result of joining pieces of property that were at one time owned by individuals. The latter hypothesis is contradicted by the whole direction of development of private property. Interacting with changes in property rights are racial differences. The conquering immigrant peoples subjugate the native races or crowd them back. All the cultural peoples that possess a political organization are the product of folk mixtures. The subjugation of an original population may lead to varying results, depending on the