RELATION OF PHYSIOLOGY TO PHYSICS. 17 



biological standpoint in biology involves a change in 

 what has in recent times become the ordinary attitude 

 towards organic evolution. Since our conception of an 

 organism is different in kind, and not merely in degree, 

 from our conception of a material aggregate, it is clear 

 that in tracing back life to primitive forms we are 

 getting no nearer to what is called abiogenesis. The 

 result of investigation in this direction can only be to 

 extend further the domain of biology and widen bio- 

 logical ideas. Our aim must be, in short, not to reduce 

 organic to inorganic phenomena, but to bring inorganic 

 phenomena into the domain of biology. 



I am well aware that it will be strongly maintained 

 that the change of front which I have urged as necessary 

 involves the giving up of all real attempt at scientific 

 explanation in biology. As already explained, this is a 

 philosophical question, and I shall not attempt to deal 

 further with it here. What immediately concerns us 

 as biologists is whether the change of front will further 

 or hinder biological advance, particularly in physiology. 

 Now the first requisite of a working hypothesis is that 

 it should work, and I have tried to point out that as 

 a matter of fact the physico-chemical theory of life has 

 not worked in the past and can never work. As soon 

 as we pass beyond the most superficial details of physio- 

 logical activity it becomes unsatisfactory ; and it breaks 

 down completely when applied to fundamental physio- 

 logical problems such as that of reproduction. Those 

 who aim at physico-chemical explanations of life are 

 simply running their heads at a stone wall, and can 

 only expect sore heads as a consequence. It seems to 



me that the proposed change of front is onlv the con- 



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