224 MENTAL EVOLUTION IN MAN. 



locrical index of the development of human ideation of the 

 receptual order, which by accident admits of closer comparison 

 with that of the higher mammalia than is possible in the case 

 of a child who begins to talk at the usual age. But, as 

 regards the former case, we have already seen that the 

 gestures begin by being much less expressive than those of 

 a dog, then gradually improve until they become psycho- 

 logically identical, and, lastly, continue in the same gradual 

 manner along the same line of advance. Therefore, if in this 

 case no difference of kind can be alleged ttntil the speaking 

 age is reached, neither can it be alleged after the speaking age 

 is reached in the case where this happens to be earlier. Or, 

 in the words previously used, if a dog like a parrot were able 

 to use verbal signs, or if a parrot were equal in intelligence 

 to a dog, the connotative powers of a child would continue 

 parallel with those of a brute through a somewhat longer 

 reach of psychological development than we now find to be 

 the case. 



Remembering, then, that brutes so low in the psycho- 

 logical scale as talking birds reach the level of denotating 

 objects, qualities, &c. ; remembering that some of these birds 

 will extend their denotative names to objects and qualities 

 conspicuously belonging to the same class ; remembering, 

 further, that all children before they begin to speak have 

 greatly distanced the talking birds in respect of indicative 

 language or gesture-signs, while some children (or those late 

 in beginning to speak) will raise this form of language to the 

 level of pantomime, thus proving that the receptual ideation of 

 infants just before they begin to speak is invariably above 

 that of talking birds, and often far above that of any other 

 animal ; — remembering all these things, I say it would indeed 

 be a most unaccountable fact if children, soon after they do 

 begin to speak, did not display a great advance upon the 

 talking birds in their use of denotative signs, and also in their 

 extension of such signs into connotative words. As we 

 have seen, it must be conceded by all prudent adversaries 

 that, before he is able to use any of these signs, an infant is 



