ORGANIC REGULATION 109 



though the assumption is false it must be borne in mind 

 that working hypotheses applicable to the available 

 sense data are indispensable to the advance of knowl- 

 edge and practice. With limited data crude and simple 

 working hypotheses, sufficient to cover the data with- 

 out further complication, are alone of practical use; 

 and both knowledge and practice, in dealing with iso- 

 lated and imperfect data, naturally proceed on crude 

 hypotheses. Where we can as yet see no organic 

 determination in isolated observations relating to life 

 the best available description of them is in mechanis- 

 tic terms such as we apply to the inorganic world. 

 Such descriptions supply an indispensable basis for 

 more adequate description and interpretation; but to 

 give a general application to the crude working hypothe- 

 ses on which these descriptions are based implies a 

 disregard of the wider biological observations which 

 indicate that further investigation would reveal organic 

 determination. This disregard is a very marked fea- 

 ture in current text-books of physiology. Each part 

 of physiology, and even each subdivision of a part, 

 is apt to be treated in isolation from the rest, with the 

 necessary consequence that not only is no place left 

 for the facts relating to organic determination, but 

 the isolated details are very imperfectly described, as 

 has been illustrated again and again in the course of 

 these lectures. 



The real reason of this defect is that physiologists 

 have been endeavouring to fit their descriptions to the 

 imperfect current working hypotheses of physics and 



