DEFECTS OF VITALISM 27 



their mutual arrangement may be completely 

 altered by mechanical means, and yet one of 

 the separated cells, or the disarranged collec 

 tion of cells, may develop in a perfectly 

 normal manner. Here we have presumably 

 disarranged the normal mechanism for de 

 velopment, and yet normal development 

 occurs. From this Driesch concludes that 

 a factor is present which acts independently 

 of physical and chemical stimuli, and which 

 he calls * entelechy/ and identifies with the 

 old * vital force.' 



Now there is no evidence at all that each 

 cell, in growing and dividing in the one 

 particular manner which constitutes normal 

 development, is not determined by special 

 physical and chemical stimuli peculiar to its 

 position relatively to the other cells, and to 

 the external environment. We do not yet 

 know what these stimuli are ; but probably 

 no physiologist would doubt that they exist, 

 and will be discovered when our methods 

 are fine enough. Hence Driesch's argument 

 for an independent vital force breaks down 

 entirely. 



A further objection to vitalism is that it 



