The long period of helpless infancy through which the human being who is to survive in the struggle for existence must pass is proof conclusive that from the time when first men were men—and from an even earlier time—they must have lived together in groups. Whether those groups were, as in the case of the gorilla, patriarchal in kind, or matriarchal, as they are seen to be, or may be conjectured to have been, in the case of some tribes very low in the social scale, is still a disputed question. The tendency of those groups, however, was in the patriarchal direction; this tendency strengthens even in times when the tribe is still migratory, and is fully established by the time when the tribe settles down in a fixed habitation as a village-community. From the village-community the city-state develops; an amalgamation of city-states may produce a national state; a national state may become a world-power, and even seek to establish itself as a world-empire.