THE COMPOSITION OF MIND 



certain relations as like or unlike certain other 

 relations. Certain correlated groups of colours 

 are automatically classified with other correlated 

 groups of colours previously received upon the 

 retina, and also with certain correlated groups 

 of muscular and tactual impressions, previously 

 received simultaneously with the groups of col- 

 ours in question. Thus our visual perception 

 of objects consists of a group of sensations ^///i 

 a complicated series of inferences which does 

 not differ fundamentally from a course of scien- 

 tific demonstration. And the same truth may 

 be, with equal justice, though less vividly, illus- 

 trated in the case of any other sense than sight. 

 A much simpler case than that of visual per- 

 ception is that of a spoon, containing some un- 

 known liquid, thrust into the mouth by another 

 person in the dark. Here the only clew to the 

 character of the liquid is its taste ; and when, 

 by its peculiar mild pungency, the Hquid is re- 

 cognized as bromide of potassium, the psychical 

 process consists of a gustatory sensation plus an 

 act of classification by which the sensation is 

 grouped, with other like sensations previously 

 received. The example is a good one, as show- 

 ing us also the obverse case. If bromide of 

 potassium has not been previously tasted, the 

 result is simply gustatory sensation unattended 

 by perception ; or rather, it is gustatory sen- 

 sation generically classified as mildly pungent, 

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