100 ESSAYS OF A BIOLOGIST 



even though warfare is still resorted to, yet it does not 

 operate in the same way as in earlier stages of human 

 evolution. A salient example of this is afforded by 

 the result of the recent war to Germany; although an 

 equally good instance can be seen, for example, in 

 the Boer War. In primitive wars, the defeated tribe 

 was wherever possible exterminated or enslaved: it 

 ceased to exist as an independent unit, and the great 

 majority of its male members were killed. This is 

 impossible under present conditions: and all those 

 who preserve, or have ever possessed, any political 

 sanity aim, for instance, neither at the physical nor 

 the economic destruction or subordination of Ger- 

 many, but — to use one of those attractive catchwords 

 that sounded so well in war-time — at her ''change of 

 heart" — in other words, the extermination, not of a 

 nation, but of a national tradition. 



To what extent this substitution of mental for 

 physical will continue it is hard to say; already, to 

 take another field, the multiplication of cheap books 

 has led to an ever increasing number of men and 

 women fmding most of their adventure and romance 

 in books instead of in the life that we are accustomed 

 to call real. But that would lead us away from our 

 main point — enough to have indicated another great 

 difference between processes above and below the 

 human level. 



There are numerous important questions concern- 

 ing our right to apply biological ideas of heredity 

 directly to human beings which I would have liked 



