INTRODUCTION TO SOCIOLOGY 243
than social frontiers, whether it is a question of a military and absolute empire, or of a pacific and socialistic democracy.
Under these conditions, the forces called moral, but in reality at the same time material, conspired with all the others in the progressive extension of the frontiers of the Inca empire. As today in Turkey, Russia, Persia, etc., the Inca was the supreme head of the religion. The external mission of the empire repre- sented by the autocracy fortified itself by a mission of religious propaganda. By means of war, and even without war, and before the military occupation, the surrounding savage tribes were suc- cessively converted to the solar cult. Even the religion preceded the armies, just as the English missionaries have paved the way for military colonization. Finally, the conquered territories were incorporated and their populations annexed and subjected to a common regime. Thus the frontiers always advanced by the assimilation of the territory and peoples beyond rivers and moun- tains, and even beyond deserts. Indeed, a society can be limited only by the conditions of its own organization or by another society, or, to be more exact, by its own organization in correla- tion with that of the external societies.
Ancient Peru represented the summum of development attained by the primitive communal types under a despotic mili- tary and religious form. This type would naturally enlarge, so long as it did not meet on the outside a force equal or superior to its own. It would necessarily be broken up in contact with more powerful forms which were better militarily and industrially equipped. It would even, without doubt, have become dislocated spontaneously, like every one of the great despotic and autocratic empires, through the very extension of its domination, when at a certain moment it proved an insufficient organ of co-ordination between the several parts of the social body. The communal and despotic Peruvian type was violently broken up in the sixteenth century by coming in contact with Spain, but in ancient Mexico, where this communal type had degenerated into a feudal mon- archy, it was already profoundly altered. Ancient Egypt also presents to us almost the same viscissitudes, and the Spanish monarchy of the sixteenth century had, besides certain superior-
