INTRODUCTION. 9 



present century, the difference between the views of these 

 two joint originators of the theory has since been shared by 

 the ever-increasing host of their disciples. We all know 

 what that difference is. We all know that while Mr. Darwin 

 believed the facts of human psychology to admit of being 

 explained by the general laws of Evolution, Mr. Wallace does 

 not believe these facts to admit of being thus explained. 

 Therefore, while the followers of Mr. Darwin maintain that 

 all organisms whatsover are alike products of a natural 

 genesis, the followers of Mr. Wallace maintain that a distinct 

 exception must be made to this general statement in the case 

 of the human organism ; or at all events in the case of the 

 human mind. Thus it is that the great school of evolutionists 

 is divided into two sects ; according to one the mind of man 

 has been slowly evolved from lower types of psychical exist- 

 ence, and according to the other the mind of man, not having 

 been thus evolved, stands apart, sui generis, from all other 

 types of such existence. 



Now assuredly we have here a most important issue, and 

 as it is one the discussion of which will constitute a large 

 element of my work, it is perhaps desirable that I should 

 state at the outset the manner in which I propose to deal 

 with it. 



The question, then, as to whether or not human intelli- 

 gence has been evolved from animal intelligence can only be 

 dealt with scientifically by comparing the one with the other, 

 in order to ascertain the points wherein they agree and the 

 points wherein they differ. Now there can be no doubt that 

 when this is done, the difference between the mental faculties 

 of the most intelligent animal and the mental faculties of the 

 lowest savage is seen to be so vast, that the hypothesis of 

 their being so nearly allied as Mr. Darwin's teaching implies, 

 appears at first sight absurd. And, indeed, it is not until we 

 have become convinced that the theory of Evolution can 

 alone afford an explanation of the facts of human anatomy, 



