INTRODUCTION xvii 



necessarily followed that the object of biological 

 evolution was the development of man. The reason 

 for the inference was, not that man is the highest 

 product of evolution, for other animals have in their 

 turn been in that position ; but that the advent of 

 man had made a complete change in the course of 

 evolution, and has added a new form psychological 

 evolution to the older forms. This has culminated 

 in free-will in man, by means of which he has, to 

 some extent, the power of altering the course of 

 evolution. The changes brought about are as 

 follows : 



1. The process of natural selection is over, so far 

 as man's bodily structure is concerned. No impor- 

 tant change has taken place in his body since the 

 middle of the Pleistocene period ; and none can take 

 place in the future, because his hand is quite capable 

 of carrying out the ideas evolved in his brain ; and 

 it is by these that he lives and competes with his 

 neighbours. 



2. The diversity of animal and plant life on the 

 earth seems to have reached its maximum. Man is 

 a destructive force in nature, and already he has 

 exterminated several of the larger animals. As 

 time goes on we may expect that all animals and 

 plants that are hurtful to him will be destroyed, 

 and that the whole earth will become a garden, the 

 sea alone being able to resist his encroachments. 



3. There are a number of elementary substances 

 in the world which appear to be of no use except to 

 man : for example, gold, silver, lead, zinc, etc. 

 These must have been intended for his use, for they 



