CHAP. XII.] AND PERCEPTION. 193 



can be realized without an accompanying Intellectual 

 Activity, and that though such activity is simple and rudi- 

 mentary, in the case of simple Sensations, it becomes 

 more definite and complex with the increasing many- 

 sidedness of the multiplying Perceptions of higher 

 animals. He will then dimly see how an increase of 

 Sensorial Activity in successive generations of animals 

 necessarily involves a corresponding increase in Instinc- 

 tive and Intellectual Activity, associated, as we shall find, 

 with a growing wealth of Emotion and more than the 

 germs of Volition. He will then, too, be able better to 

 realize the full significance of the increasing development 

 and the knitting together of the sensory ganglia which at 

 first compose the Brain, and the subsequent appearance 

 of separate organs, the Cerebral Lobes, in connection 

 with each and all of them, in which the various substrata 

 for Sensory Impressions may come into relation with one 

 another, and in which, more especially, there may develop 

 the structural correlatives whose activity is associated 

 with such Perceptions, Intellectual Acts, Emotions, and 

 Volitions, as the several creatures are accustomed to 

 experience or manifest. 



If we look, therefore, to the principles of 'heredity' 

 generally, and to such facts as have been disclosed by the 

 observations of D. A. Spalding, it becomes manifest that 

 the dogma of the schoolmen, already quoted, supported as 

 it was by Gassendi, Hobbes, and later still by Condillac, 

 is no more true for individual animals above the lower 

 grades than it is for man himself. Each organism does 

 not acquire all its Knowledge by ' experience ' through the 

 avenues of Sense each inherits a complex mechanism, 

 already attuned during the lives of a long line of progeni- 

 tors to be affected in certain ways and to act in certain 

 modes. When, therefore, the phrase or dogma ' nihil est 



o 



