70 ESSAYS OF A BIOLOGIST 



of evolutionary biology and of modern psychology 

 have not only changed our outlook on specially 

 human problems, but have altered the vv^hole balance, 

 if I may so put it, of science. There was a time 

 when the basic studies of physics and chemistry 

 seemed not only basic but somehow more essentially 

 scientific than the sciences dealing with life. Dis- 

 tinctions were drawn between the experimental and 

 the observational sciences — often half-consciously 

 implying a distinction between accurate, scientific, 

 self-respecting sciences and blundering, hit-or-miss, 

 tolerated bodies of knowledge. Biological phenomena 

 are now, however, seen to be every whit as susceptible 

 of accurate and experimental analysis ; and indeed 

 ^•to present so many problems to the physicist and 

 chemist that in fifty years or so, I venture to prophesy, 

 the wise virgins in those basic sciences will be those 

 who have laid in a store of biological oil. 



But the main point is this — the study of evolution, 

 of animal behaviour and of human psychology makes 

 it clear that in the higher forms of animals at least 

 we are dealing with a category not touched on at all 

 by the physicist and chemist — the category of mind 

 and mental process. Sir Charles Sherrington, with 

 admirable lucidity, drew for us, in his recent address 

 to the British Association, the problem of the re- 

 lation between mind and matter as it presents itself 

 to the biologist. 



The great change that has come over science in 



