io6 ESSAYS OF A BIOLOGIST 



series of automatisms, the more we see it rigorously 

 determined by combination of inner constitution and 

 outer circumstance, the more we have cause to deny 

 to animals the possession of anything deserving the 

 name of reason, ideals, or abstract thought. The 

 more, in fact, do they appear to us as mechanisms 

 (which is a much better word than machines, since 

 this latter carries with it definite connotations of metal 

 or wood, electricity or steam). They are mechanisms, 

 because their mode of operation is regular ; but they 

 differ from any other type of mechanism known to 

 us in that their working is — to put it in the most 

 non-committal way — ^accompanied by emotion. It 

 is, to be sure, a combination of emotion with reason 

 that we attribute to a soul ; but none the less, in 

 popular parlance at least, the emotional side is pre- 

 dominant, and pure reason is set over against the 

 emotional content which gives soul its essence. And 

 this emotional content we most definitely find running 

 through the lives of higher animals. 



The objection is easily and often raised that we 

 have no direct knowledge of emotion in an animal, 

 no direct proof of the existence of any purely mental 

 process in its life. But this is as easily laid as raised. 

 We have no direct knowledge of emotion or any 

 other conscious process in the life of any human being 

 save our individual selves ; and yet we feel no hesita- 

 tion in deducing it from others' behaviour. Although 

 it is an arguable point whether biological science may 



