160 THE MECHANISM OF LIFE 



So much for the main ideas and methods which have been 

 introduced into biology from the chemical and physical side.1 

 Nothing at all has been said here about the impetus which these] 

 ideas have given to what we*may call utilitarian biology; to! 

 processes of further preparation of foodstuffs; to the breeding 

 and rearing of useful organisms; and above all to methods for 

 the prevention and curative treatment of disease. Even now,] 

 and much more in the future, the relative freedom from disease 

 that may be enjoyed by every sane man and woman is to bel 

 traced back to the investigations made by a few chemists and 

 physicists and biologists and medical men during tile last two! 

 centuries. To many people all this work is very disagreeable,! 

 and they do not like to think about it or even to enquire how itj 

 is carried on. Like Tennyson's Princess, they shudder at 



" Those monstrous males that carve the living hound, 

 And cram him with the fragments of the grave, 

 Or, in the dark dissolving human heart, 

 And holy secrets of this microcosm, 

 Dabbling a shameless hand with shameful jest, 

 Encarnalise their spirits." 



Throughout their lives they live upstairs, so to speak, knowing 

 that most of the things that make living tolerable are the work 

 of those that labour in the kitchen ; and one likes to think that j 

 some time or other science takes its revenge, and that in the j 

 end they have to go down into the basement and found a pathetic j 

 reliance on the rather sordid toil that goes on there. 



It has been said by Michael Foster, and the statement can 

 easily be verified, that the periods when mechanistic conceptions 

 of life have dominated biology have also been those when the 

 greatest advances in our knowledge of the activities of the 

 organism were made; while the periods during which vital istic 

 views were generally current were sterile ones from the same 

 point of view. 



Modern Mechanisms of Lite. Now one may ask what is the 

 difference between the Cartesian mechanism and that which is 

 represented in, say, the writings of Jacques Loeb, or is there 

 really any difference ? To Descartes there was nothing in the 

 activities of the animal body but matter, the configurations of 

 matter, and the motions of matter. Everything was mechanical. 

 There is no doubt at all as to what he meant. " I wish it to be 

 considered," he says in the Discourse on Method, " that the 

 motion which I have now explained " (that of the circulation of 



