706 COMPARATIVE AND GENETIC PSYCHOLOGY 



then held to form an impassable gulf between the brute beasts 

 and man with his spiritual capacities. This tendency, which was 

 inevitable as a stage in the progress of thought, led to the utmost 

 widening of the limits within which psychological terms, such as 

 "inference," "abstraction," "generalization," and "reasoning" were 

 used; the extension being designed so as to render these terms as 

 comprehensive as possible and to enable them to cover not only 

 fully differentiated processes but the earlier even the embryonic 

 stages of their development. But when the conception of evo- 

 lution had won its way to acceptance, when the principle of con- 

 tinuity had taken its place as part of the recognized scheme of 

 scientific interpretation, the emphasis of thought changed from 

 the evolutional curve as a whole, now freely and fully accepted 

 as continuous, to the differentiated stages which could analytically 

 be distinguished therein. They were applied again in more re- 

 stricted senses; the restriction being designed to render them 

 distinctively applicable to certain higher phases of differentiation 

 within an admittedly continuous process. 



In any case it is necessary to bear in mind the fact (of which 

 I have suggested the probable cause) that the same terms are 

 applied by different authors with wide differences of limitation - 

 by some in a more extended and by others in a more restricted 

 sense. From this it follows that some at least of the divergences 

 of interpretation in the comparative psychology of animals are 

 more apparent than real. 



The influence of the terms we employ, closely connected as it is 

 with our early training, is often deep and abiding. It has been 

 a special merit of Dr. Stout's treatment of psychological topics that 

 he has emphasized, so clearly and in so many ways, the funda- 

 mental distinction, as I conceive it to be, between perceptual and 

 ideational process. As he himself has pointed out, one of the great 

 difficulties in the way of its general acceptance, is due to the fact 

 that the existing terminology grew up at a time previous to any 

 serious attempt to render clear the distinction. Some of my hearers 

 may remember the almost pathetic words in which Dr. Stout la- 

 ments the misleading influence of the terms we are at present almost 

 forced to employ. If I may be allowed slightly to modify his state- 

 ment without, as I believe, introducing anything foreign to his 

 thought, his contention is that "human language is especially 

 constructed to describe the mental processes of human beings [in 

 ideational terms], and this means that it is especially constructed 

 so as to mislead us when we attempt to describe the workings of 

 minds which differ in any great degree from the human," and even 

 the workings of our own minds on the perceptual plane. "A horse, 

 having had a feed at a certain place one day, stops of his own accord 



