VITALISM 389 



physical basis ; at present the only safe course is to confess 

 ignorance. 



A more fundamental objection to vitalism, however, remains. 

 It appears to contradict the principle, on which all science is 

 really founded, that not more ultimate causes must be postulated 

 than are absolutely necessary. Science has proceeded far in 

 recent years in the unification of all the phenomena associated 

 with matter ; it appears a retrograde step to assume some- 

 thing fundamentally different in the living from what exists in 

 the non-living. Of course if, with Driesch, we regard it as 

 demonstrable that physico-chemical factors are insufficient to 

 account for the phenomena of life, this objection falls ; but it 

 may be worth while for those who do not go so far and who 

 think that he has only made out a good case rather than adduced 

 conclusive proof, to consider whether his hypothesis does con- 

 tradict the fundamental principle referred to. For this purpose 

 we must consider his idea rather more closely. He finds two 

 characteristics displayed in common by an organism which is 

 developing from less differentiated to a more complex bodily 

 form on the one hand or which is acting more or less con- 

 sciously on the other. 



In each case the process appears to be purposeful, i.e. when 

 it is completed we can see that it had an object ; and in each 

 case it makes use of matter and of physical and chemical 

 energy in such a way as to promote the apparent " purpose " 

 without in any way contradicting the ordinary laws of matter 

 and energy. Hence he suggests that the controlling principle 

 is similar in each case ; his names, " entelechy " for the principle 

 which controls development or regeneration and " psychoid " 

 for that controlling action, are unimportant ; the essential thing 

 is that in each case matter and energies are used in such a way 

 that the result is different from what it would have been in the 

 absence of the controlling principle and that to the onlooker 

 the process appears purposeful. The controlling principle is 

 not energy and the energies which it directs are simply those 

 known to chemistry or physics ; it is merely assumed that just 

 as a man, when he lifts a weight, converts into kinetic form 

 energies which would have remained potential if he had willed 

 to remain at rest, so an organism developing from an egg or 

 regenerating a - limb, sets free or controls energies which in the 

 absence of life would have taken a different course. It has 



