tinguished as political integration, we find that this has the following traits:
While the aggregates are small, the incorporation of materials for growth is carried on at one another's expense in feeble ways—by taking one another's game, by robbing one another of women, and, occasionally, by adopting one another's men. As larger aggregates are formed, incorporations proceed in more wholesale ways: first, by enslaving the separate members of conquered tribes, and presently by the bodily annexation of such tribes. And, as compound aggregates pass into doubly and trebly compound ones, there arise increasing desires to absorb adjacent smaller societies, and so to form still larger aggregates.
Conditions of several kinds further or hinder social growth and consolidation. The habitat may be fitted or unfitted for supporting a large population; or it may, by great or small facilities for intercourse within its area, favor or impede coöperation; or it may, by presence or absence of natural barriers, make easy or difficult the keeping together of the individuals under that coercion which is at first needful. And, as the antecedents of the race determine, the individuals may have in greater or less degrees the physical, the emotional, and the intellectual natures fitting them for combined action.
While the extent to which social integration can in each case be carried depends in part on these conditions, it also depends in part upon the degree of likeness among the units. At first, while the nature is so little molded to social life that cohesion is small, aggregation is largely dependent on ties of blood, implying great degrees of likeness. Groups in which such ties, and the resulting congruity, are most marked, and which, having family traditions in common, a common male ancestor, and a joint worship of him, are in these further ways made alike in ideas and sentiments, are groups in which the greatest social cohesion and power of coöperation arise. For a long time the clans and tribes descending from such primitive patriarchal groups have their political concert facilitated by this bond of relationship and the likeness it involves. Only after adaptation to social life has made considerable progress does harmonious coöperation among those who are not of the same stock become practicable; and even then their unlikenesses of nature must fall within moderate limits. Where the unlikenesses of nature are great, the society, held together only by force, tends to disintegrate when the force fails.
Likeness in the units forming a social group being one condition of their integration, a further condition is their joint reaction against external action; coöperation in war is the active cause of social integration. The temporary unions of savages for offense and defense show us the initiatory step. When many tribes unite against a common enemy, long continuance of their combined action makes them
