INTRODUCTION TO SOCIOLOGY 241
zation, which, through conquest, tended to effect the fusion of the old genetic tribes by subordinating them to a more extensive group. The old frontiers determined by the mountains, deserts, and water courses gave way to new boundaries. Populations of different origin could inhabit the same city and the same district. The costume alone distinguished those in each district, as in the city they were distinguished by the obligation of dwelling in different quarters. The empire was divided, in the same way as the capital, into four circumscriptions, with four vice-kings. The circumscriptions were divided into departments, the latter into ten, fifty, one hundred, and so on, up to ten thousand inhabitants, with chiefs of tens, fifties, hundreds, etc., as administrators, over- seers, and responsible protectors.
In Peru centralization was stronger than in ancient Mexico, whose regime was feudal. In Peru there was a chief for every ten men, whereas in Mexico there was one chief for each group of twenty families only. The old genetic relations were therefore partly preserved in the great feudal empire of North America.
The so-called natural or geographical frontiers are thus in reality always social frontiers variable according to the conditions of the internal or external equilibrium of each society. Natural barriers are not the cause of group boundaries, but the effect of the organization of the group in correlation with the surrounding social environments. This is why, at a certain stage of evolution in Asia and Europe, as well as in America and elsewhere, we see divisions appearing analogous to those observed in Peru. There must be some reason for this similarity of development in the different countries. A general law suffices to explain it. This law is that the same social phenomena tend to be produced wher- ever the social conditions are analogous and in proportion as they are analogous.
In Peru the primitive community of each tribe had fused with all the other communities and ended in a vast communal state, but authoritatively differentiated. The Inca had absorbed all the chiefs of the tribes, just as the empire had absorbed within its limits all the prior and separate territories. The Inca incar- nated the state, and it was he who became the proprietor and
