166 THE UNIQUENESS OF LIFE 



8. Retrospect. 



How does the ' biological ' position differ from the theories 

 already illustrated? The first theory was that the activity 

 of living creatures stands apart from that of not-living things 

 only in being very much more complex. The ' biological ' 

 view recognises that many describable chemical and physi- 

 cal processes occur in the living body; and admits that many 

 more such processes and much more complicated ones 

 will be eventually sifted out, but insists that even if the 

 ledger of all the chemical and physical transactions were 

 complete, it would not furnish an account of the creature's 

 life from day to day, nor of its behaviour, nor of its individ- 

 ual development, nor of its racial evolution; and why not? 

 Because the concepts of chemistry and physics fail to grip. 

 This is what one of the acutest and best-informed of modern 

 methodologists, Professor Enriques, means by saying: 

 " The mechanical hypothesis does not appear to be incom- 

 patible with the phenomena of life, but it is unimportant 

 for the study of these phenomena" (1914, p. 385). And 

 again he speaks of " the irrelevancy of the mechanical ex- 

 planation in biology" (1914, p. 384). And why do the 

 chemico-physical formulae fail to grip the essential features 

 of the activity we call living ? Not because the processes in- 

 volved are too difficult or too complex but because they 

 demand a different order of scientific explanation. 



The second theory was that living creatures have exclu- 

 sive possession of a peculiar form of energy in a line with 

 the other forms of energy, like heat and electricity, and 

 not in any way mystical, but amenable to experimental 

 and mathematical treatment. The ' biological ' position dif- 

 fers from this in refraining (in the meantime) from any 



