the type to develop from the original predatory form to the form which industrial activity generates.
Especially where the two races, contrasted in their natures, do not mix, social coöperation implies a compulsory regulating system; the military form of structure, which the dominant impose, ramifies throughout. Ancient Peru furnished an extreme case; and the Ottoman Empire may be instanced. Social constitutions of this kind, in which aptitudes for forming unlike structures coexist, are manifestly in states of unstable equilibrium. Any considerable shock dissolves the organization; and, in the absence of unity of tendency, reestablishment of it is difficult, if not impossible. In cases where the conquering and conquered, though widely unlike, intermarry extensively, a kindred effect is produced in another way. The conflicting tendencies toward different social types, instead of existing in separate individuals, now exist in the same individual. The half-caste, inheriting from one line of ancestry proclivities adapted to one set of institutions, and from the other line of ancestry proclivities adapted to another set of institutions, is not fitted for either. He is a unit whose nature has not been moulded by any social type, and therefore cannot, with others like himself, evolve any social type. Modern Mexico and the South American republics, with their perpetual revolutions, show us the result.
It is observable, too, that, where races of strongly-contrasted natures have mixed more or less, or, remaining but little mixed, occupy adjacent areas subject to the same government, the equilibrium maintained so long as that government keeps up the coercive form shows itself to be unstable when the coercion relaxes. Spain, with its diverse peoples, Basque, Celtic, Gothic, Moorish, Jewish, partially mingled and partially localized, shows us this result.
Small differences, however, seem advantageous. Sundry instances point to the conclusion that a society formed from nearly-allied peoples, of which the conquering eventually mingles with the conquered, is relatively well fitted for progress. From their fusion results a community which, determined in its leading traits by the character common to the two, is prevented by their differences of character from being determined in its minor traits—is left capable of taking on new arrangements determined by new influences: medium plasticity allows those changes of structure constituting advance in heterogeneity. One example is furnished us by the Hebrews, who, notwithstanding their boasted purity of blood, resulted from a mixing of many Semitic varieties in the country east of the Nile, and who, both in their wanderings and after the conquest of Palestine, went on amalgamating kindred tribes. Another is supplied by the Athenians, whose progress had for antecedent the mingling of numerous immigrants from other Greek states with the Greeks of the locality. The fusion by conquest of the Romans with other Aryan tribes, Sabini, Sabelli,
