20 MENTAL EVOLUTION IN MAN. 



CHAPTER II. 



IDEAS. * 



I NOW pass on to consider the only distinction which in my 

 opinion can be properly drawn between human and brute 

 psychology. This is the great distinction which furnishes a 

 full psychological explanation of all the many and immense 

 differences that unquestionably do obtain between the mind 

 of the highest ape and the mind of the lowest savage. It is, 

 moreover, the distinction which is now universally recognized 

 by psychologists of every school, from the Romanist to the 

 agnostic in Religion, and from the idealist to the materialist 

 in Philosophy. 



The distinction has been clearly enunciated by many 

 writers, from Aristotle downwards, but I may best render it in 

 the words of Locke : — 



" If it may be doubted, whether beasts compound and 

 enlarge their ideas that way to any degree ; this I think I 

 may be positive in, that the power of abstracting is not at all 

 in them ; and that the having of general ideas is that which 

 puts a perfect distinction betwixt man and brutes, and is an 

 excellency which the faculties of brutes do by no means attain 



* In my previous work I devoted a chapter to ** Imagination," in which I 

 created of the psychology of ideation so far as animals are concerned. It is now 

 needful to consider ideation with reference to man ; and, in order to do this, it is 

 further needful to revert in some measure to the ideation of animals. I will, how- 

 ever, try as far as possible to avoid repeating myself, and therefore in the three 

 following chapters I will assume that the reader is already acquainted with my 

 previous work. Indeed, the argument running through the three following 

 chapters cannot be fully appreciated unless their perusal is preceded by that of 

 chapters ix. and x. of Mental Evolution in Animals, 



