SCIENCE AND SOCIETY 7 



stances which may be advanced in the defence of 

 botanists. The progress of the science of animal 

 physiology can be explained by causes lying outside the 

 province of science, by considerations of a practical kind. 

 To develop and prosper, every science requires the 

 moral and material support of society ; but, on the 

 other hand, society takes practical interest only in 

 things which it considers useful. Society has already 

 been convinced of the usefulness of animal physiology, 

 while the idea of the usefulness of the physiology of 

 plants has only just dawned. Almost every science 

 owes its origin to an art of some sort, just as every art in 

 its turn is the outcome of some need in man. This 

 appears to be the inevitable course of the development 

 of human knowledge. To begin with, man appreciates 

 knowledge merely as a means towards obtaining the 

 fullest possible amount of material enjoyment ; only in 

 a later stage does knowledge become to him in itself a 

 source of enjoyment. Intellectual aspirations are then 

 as exacting as material wants. Knowledge considered 

 as a means to an end is art ; knowledge considered as an 

 end in itself is science. Medicine is the art under whose 

 wing the physiology of animals developed. After many 

 unsuccessful efforts to solve its own problems by means 

 of rough empiricism or abstract thought medicine came 

 to the conclusion that it must go further back to study 

 the laws of animal life and join hands with science ; 

 thus it was that the science of animal physiology arose 

 and developed in the medical schools. But, together 

 with the necessity for preserving physical health to 

 which medicine answers, man has other needs ; he 

 requires food, clothing, a roof over his head, and means 

 of locomotion. He obtains the majority of these 

 commodities directly or indirectly from plants which 

 he cultivates and tends. It is only after studying the 

 laws of their existence, after learning by observation or 

 experiment from the plant itself the means by which it 



