CONDITIONS OF PROGRESS 



portions of the tribally organized population 

 of Central Asia. Their invasion of Europe was 

 in this respect like the subsequent invasion of 

 England by the miscellaneous hordes roughly 

 described as Angles and Saxons, Danes and 

 Normans, and like the still later colonization of 

 North America by the most mobile and adven- 

 turous elements of West European society. We 

 may fairly suppose that the Aryan invaders of 

 Europe were the most supple minded of their 

 race, — the " come-outers," perhaps, for whom 

 the cake of custom at home was getting too 

 firmly cemented, but who had undergone suffi- 

 cient social discipline to enable them to get along 

 with a less solid cake in future. However this 

 may be, the main point is that they were not 

 aborigines but colonizers, and as such were 

 subjected to a great heterogeneity of environ- 

 ing circumstances from the time when we first 

 catch sight of them. They were the pioneers 

 or Yankees of prehistoric antiquity, in whom 

 unusual flexibleness of mind was the natural re- 

 sult of continual change in the sets of relations 

 to which they were obliged to make their theo- 

 ries and actions conform. Prehistoric antiquity 

 presents no other case like this. The great im- 

 mobile civilizations appear to have grown up 

 in comparatively well-protected regions, where 

 competition with outlying communities was 

 checked at an early date. Screened in this way 



VOL. IV 33 



