CO-ORDINATING MECHANISMS 9 



has been taken as strong evidence for the 

 presence in living organisms of some co 

 ordinating influence apart from blind physical 

 and chemical forces. 



The reply to this argument is that many 

 of the mechanisms by which co-ordination is 

 brought about have already been discovered, 

 and that every year more is being discovered 

 about them. Descartes, in his writings about 

 the nervous system, was the first to point the 

 way in this line of discovery. He suggested 

 nervous mechanisms, by means of which 

 afferent stimuli and muscular responses are 

 co-ordinated; and since his time the theory 

 that the nervous system is at bottom nothing 

 more than a complex system of reflex mechan 

 isms has been experimentally verified in many 

 directions, and has now become a generally 

 accepted physiological doctrine. The reflex 

 actions associated with consciousness are evi 

 dently so complex that their gradual analysis 

 may take generations of research work. We 

 have also to bear in mind that many forms of 

 nervous activity are excited or influenced by 

 chemical stimuli acting, not on peripheral 

 afferent nerves, but on the central nervous 



