73 o THE POPULAR SCIENCE MONTHLY. 



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, dj 

 not mix, social cooperation implies a compulsory regulating system ; 

 the military form of structure, which the dominant impose, ramifies 

 throughout. Ancient Peru furnished an extreme case ; and the Otto- 

 man 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, reestab- 

 lishment of it is difficult, if not impossible. In cases where the con- 

 quering and conquered, though widely unlike, intermarry extensively, 

 a kindred effect is produced in another way. The conflicting tenden- 

 cies toward different social types, instead of existing in separate 

 individuals, now exist in the same individual. The half-caste, inher- 

 iting from one line of ancestry proclivities adapted to one set of insti- 

 tutions, 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 na- 

 tures have mixed more or less, or, remaining but little mixed, occupy 

 adjacent areas subject to the same government, the equilibrium main- 

 tained so long as that government keeps up the coercive form shows 

 itself to be unstable when the coercion relaxes. Spain, with its di- 

 verse peoples, Basque, Celtic, Gothic, Moorish, Jewish, partially min- 

 gled 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 peo- 

 ples, of which the conquering eventually mingles with the conquered, 

 is relatively well fitted for progress. From their fusion results a com- 

 munity which, determined in its leading traits by the character com- 

 mon 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 Semit- 

 ic varieties in the country east of the Nile, and who, both in their 

 wanderings and after the conquest of Palestine, went on amalgamat- 

 ing 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, 



