356 HEREDITY AND SELECTION IN SOCIOLOGY 



members of other species. The hare has to wage conflict within 

 his own species for his food ; he has to defend himself against the 

 wild cat, the fox, the weasel, man, and other enemies ; and he 

 has to wage a continual conflict in regard to climatic conditions 

 and in regard to his adaptations to these. And in all these 

 cases the smallest favourable variation counts ; the hare whom 

 accident has coloured more white than others will surAdve the 

 rigorous winter, during which the less white hares will be more 

 easily detected against the snow by their foes, and exterminated. 

 Progress is accomplished precisely by the accumulation, through- 

 out successive generations, of a vast number of small individual 

 variations. Certainly, mutation, or the sudden modification of 

 a large number of individuals simultaneously, under the in- 

 fluence of a condition aSecting all in an equal degree, does take 

 place, more especially in the plant world ; but progress in the 

 animal world, as a general rule, is due to the accumulation of 

 favourable individual variations, the ultimate cause of which is 

 to be found in the struggle for existence occasioned by excessive 

 reproduction. 



The nature and extent of the conflict always prevailing in the 

 stages of evolution below man have become so well known, as 

 the result of the studies of Darwin and his successors, of whom 

 Weismann is the most notable, that it is unnecessary to insist 

 upon them here. In human society conflict is not less keen than 

 it is elsewhere in the domain of life. Among primitive races, 

 among the savages of to-day, even among the most highly 

 civilised Western nations, this conflict assumes the same form 

 of brute force pitted against brute force, of healthy and strong 

 constitutions pitted against weak and enfeebled ones, the 

 available food and space falling to the former at the expense of 

 the latter. But social evolution brings other and ill-defined 

 forces into play in this eternal conflict. Intellectual develop- 

 ment, and also the vices which accompany it, play here a role 

 necessarily absent in the other spheres of evolution. The less 



