xii PEEFACE 



to believe that what we call life is merely the action 

 of mind on protoplasm ; and that it has no distinct 

 existence in itself. 



The principle of psychogenesis, proposed in 

 Chapter VII., although new, is only a corollary from 

 Professor Bering's theory ; but it gives a new con- 

 ception to the old Lamarckian doctrine of use and 

 disuse, and explains what Darwin used to call the 

 " indirect action " of the environment on organisms. 

 The adoption of this theory led me on to an 

 examination of the old problems of free-will and 

 dualism, and the conclusions at which I have arrived 

 are so satisfactory to myself that I think they may be 

 of some use to others who are doubtful which view 

 to take. 



The subject is a large one, owing to the multi- 

 plicity of details which would have to be considered 

 if this book were the first on the subject. But it is 

 unnecessary to repeat what is well known, or what 

 can be easily ascertained elsewhere; and, although 

 the number of facts is large, the principles derived 

 from the facts can be condensed into a small 

 compass, and the argument gains much from this 

 being done. 



An apology may be due from me, who am not a 

 psychologist, for discussing mental evolution at all. 

 But the biological and psychological evolutions were 

 inseparably bound together until the former 

 culminated in Man. For it was not until then that 

 psychology branched off on its own account. 

 Biology, therefore, includes the early history of 

 psychology ; and I approach the subject altogether 



