28 MENTAL EVOLUTION IN MAN. 



as I myself am led by a similar impulse to visit a restaurant. 

 Similarly, if I say to my dog the word " Cat," I arouse in his 

 mind an idea, not of any cat in particular — for he sees so 

 many cats, — but of a Cat in general. Or when this same dog 

 accidentally crosses the track of a strange dog, the scent of 

 this strange dog makes him stiffen his tail and erect the hair 

 on his back in preparation for a fight ; yet the scent of an 

 unknown dog must arouse in his mind, not the idea of any 

 dog in particular, but an idea of the animal Dog in general. 



Thus far, it will be remembered, I have been presenting 

 evidence in favour of the view that both infants and animals 

 show themselves capable of forming general ideas of a simple 

 order, and, therefore, that to the formation of such ideas the 

 use of language is not essential. I will next consider what 

 has to be said on the other side of the question ; for, as pre- 

 viously remarked, many — I may say most — psychologists 

 repudiate this kind of evidence in toto, as not germain to the 

 subject of debate. First, therefore, I will consider their ob- 

 jections to this kind of evidence ; next I will sum up the whole 

 question ; and, lastly, I will suggest a classification of ideas 

 which in my opinion ought to be accepted by both sides as 

 constituting a common ground of reconciliation. 



To begin with another quotation from Locke, " How far 

 brutes partake in this faculty [i.e. that of comparing ideas] is 

 not easy to determine ; I imagine they have it not in any 

 great degree : for though they probably have several ideas 

 distinct enough, yet it seems to me to be the prerogative of 

 human understanding, when it has sufficiently distinguished 

 any ideas, so as to perceive them to be perfectly different, and 

 so consequently two, to cast about and consider in what cir- 

 cumstances they are capable to be compared : and therefore 

 I think beasts compare not their ideas further than some 

 sensible circumstances annexed to the objects themselves. 

 The other power of comparing, which may be observed in 

 men, belonging to general ideas, and useful only to abstract 

 reasonings, we may probably conjecture beasts have not. 



"The next operation we may observe in the mind about 



