PREFACE 



THE form of the present work needs a preliminary 

 word of explanation. Its subject is "Mind in Evolution," 

 but no one will expect that such a subject should be 

 treated with any pretence of adequacy within a single 

 volume or by a single writer. The contribution offered 

 in the following pages is of a double character. There 

 is, first, an attempt to sketch in outline what seem to the 

 writer to be the main phases of mental development. 

 There is, secondly, an attempt to fill in this outline so 

 far as the lower phases are concerned. To put the same 

 distinction in different words, a hypothesis is propounded 

 as to the general trend of mental evolution, and an attempt 

 is made to test this hypothesis so far as animal intelli- 

 gence and the generic distinction between animal and 

 human intelligence are concerned. For the rest, that is 

 to say in all that relates to the higher development of the 

 human mind in society, the outline is left to be filled in 

 upon a future occasion. The whole subject naturally falls 

 into the two main divisions of animal and human evolu- 

 tion, and the mass of matter to be dealt with is so great 

 that it is convenient to keep the two parts separate. At 

 the same time evolution is a single continuous process the 

 different phases of which are only seen in their true 



