THE NATURE OF THE SOUL. 109 



reason in the highest. It contains also a number 

 of extracts from a manuscript which Darwin left " on 

 instinct," and a complete collection of all that he 

 wrote in the province of psychology. 



The second and more important volume of Romanes's 

 work treats of ' ' Mental evolution in man and the origin 

 of human faculties." The distinguished psychologist 

 gives a convincing proof in it " that the psychological 

 barrier between man and the brute has been over- 

 come." Man's power of conceptual thought and of 

 abstraction has been gradually evolved from the non- 

 conceptual stages of thought and ideation in the 

 nearest related mammals. Man's highest mental 

 powers — reason, speech, and conscience — have arisen 

 from the lower stages of the same faculties in our 

 primate ancestors (the simiae and prosimise). Man 

 has no single mental faculty which is his exclusive 

 prerogative. His whole psychic life differs from that 

 of the nearest related mammals only in degree, and 

 not in kind ; quantitatively, not qualitatively. 



I recommend those of my readers who are interested 

 in these momentous questions of psychology to study 

 the profound work of Romanes. I am completely at 

 one with him and Darwin in almost all their views 

 and convictions. Wherever an apparent discrepancy 

 is found between these authors and my earlier produc- 

 tions, it is either a case of imperfect expression on my 

 part or an unimportant difference in application of prin- 

 ciple. For the rest, it is characteristic of this " science 

 of ideas " that the most eminent philosophers hold 

 entirely antagonistic views on its fundamental notions. 



