340 THE PHILOSOPHY OF BIOLOGY 



particular case of this irreversible physical tendency. 

 Now the mechanism of Weismann 'must base itself on 

 the concepts of physics and chemistry, and it must 

 postulate the origin of life from non-living substances. 

 Why ? Because life is a reversible process, that is, it 

 exhibits a tendency which does not exist in inorganic 

 processes. Clearly the logic is faulty ! And must we 

 conclude that life has an end ? Weismann himself 

 suggests that nothing in the results of biology indicates 

 that physical death is a necessity : it is rather an 

 adaptation. The soma, or body, is the envelope of 

 the germ-plasm, and exposed as it is to the vicissitudes 

 of an environment which is always hostile, it becomes 

 at length an unfit envelope. But with the reproductive 

 act the germ-plasm acquires a new soma, and it is no 

 longer necessary that the former one should continue 

 to exist as an unfit envelope. Physical death therefore 

 occurs as an adaptation serving for the best inter- 

 ests of the race. The organism need not die, for the 

 germ-plasm may be a physical continuum throughout 

 innumerable generations. Somatic death is only a 

 destructive metabolism : it is a catastrophic meta- 

 bolism, if we like. 



We may legitimately discuss such problems as the 

 origin of the protoplasm of the prototrophic organism, 

 or that of the chlorophyll-containing cell, or that of 

 the nerve-cell. On the mechanistic view each of these 

 conditions is a phase of a transforming physico-chemical 

 system, and it is within the scope of the methods of 

 physical science to investigate the nature of these 

 transformations. But if the argument of this book is 

 sound, then the problem of the origin of life, as it is 

 usually stated, is only a pseudo-problem ; we may as 

 usefully discuss the origin of the second law of thermo- 

 dynamics ! If life is not only energy but also the 



