IS MAN THE ONLY RE AS ONER? 515 



and only slowly disentangle themselves from tlie lower forms 

 wliicli constitute their matrix. Thus the image little by little 

 lifts itself butterfly-like out of its chrysalis, the percept. Simi- 

 larly, what we call thinking, with its conscious comparing and 

 relating of the products of sense-perception, emerges in the most 

 gradual way out of lower forms of psychosis. 



But this is not all, or the main thing. While the higher and 

 lower forms of intellection undoubtedly exhibit qualitative differ- 

 ences, it may be possible to transcend these differences by going 

 deeper, and detecting the veritable elements of the intellective 

 process. This deej^er analysis is emphatically the work of modern 

 psychology, and, as every reader of Mr. Herbert Spencer knows, 

 is of vast assistance to the evolutionist in following the psychical 

 process from its rudest conceivable form in the lower grades of 

 animal life up to the highest achievements of human thought. 

 The luminous idea that all intelligence is at bottom a combination 

 of two elementary processes, differentiation and integration, seems 

 to lift one at once high above the perplexities with which our 

 author so laboriously deals. It enables us to say that animal in- 

 telligence, just because it is intelligence, must be identical in sub- 

 stance with our own. The qualitative differences between percep- 

 tion and conception, or, to take Dr. Romanes's example, " the logic 

 of recepts " and the logic of concepts, which obstinately persist so 

 long as we look at the process ah extra, now appear as mere results 

 of different degrees of complexity, of unlike modes of combina- 

 tion of the ultimate elements ; just as to the physiologist the mani- 

 fold variety of color resolves itself into different modes of combi- 

 nation of two or three elementary sentient processes. 



When once this fundamental identity of all intellective pro- 

 cesses is clearly apprehended, the question where exactly in the 

 evolutionist's tree the twig of thought proper, or better, perhaps, 

 of conscious generalization, branches off, sinks to its proper place 

 as a question of quite secondary importance. At the same time 

 we^may agree with Dr. Romanes that the point has its real his- 

 torical or genealogical interest, and that he has not done amiss to 

 devote a volume to its discussion. 



The question turns mainly on the point how much the animal 

 can do by means of pure imagining and the aid of association. 

 Our author clearly recognizes that this will carry animals some 

 way, and may give to their mental operations the appearance of 

 a true generalizing process. But he has not fixed the limits of 

 this pictorial or suggestive inference with the precision one looks 

 for, partly, no doubt, because his whole view of the generic image 

 as somehow involving a generalizing process tended to obscure 

 from him the real point. One might safely, perhaps, hazard the 

 assertion that the diving-bird can get on very well without any- 



