102 THE GRAMMAR OF SCIENCE 



diate action of a deity. Materialist and idealist are here 

 at one in casting the routine of sense-impression into the 

 unknowable. But the business of the scientist is to know, 

 and therefore he will not lightly assent to throwing any- 

 thing into the unknowable so long as known " causes " 

 have not been shown to be insufficient. The scientific 

 tendency would therefore be to consider the routine of 

 our perceptions as due in some way to the structure of 

 our perceptive faculty before we appeal to any super- 

 sensuous aid. Far, indeed, as science at present stands 

 from any definite solution of the problem, there are yet 

 one or two points which it may not be unprofitable to 

 consider. 



In the first place, have we any evidence that the 

 perceptive faculty is a selective machine ? We have 

 already seen that it is possible at times for us to be 

 unconscious of sensations which on other occasions we 

 may keenly appreciate (p. 43). We have seen that the 

 outside world constructed by an insect in all probability 

 differs widely from our own (p. 85). To assume, there- 

 fore, sensations which form no part of our consciousness, 

 perhaps no part of any consciousness, is not an illogical 

 inference, for we proceed only from the known to what is 

 like the known (p. 60), to an eject which might have been, 

 or may one day be, an object.^ No better way of realising 

 the different selective powers of diverse perceptive facul- 

 ties can be found than a walk with a dog. The man 

 looks out upon a broad landscape, and the signs of life 

 and activity he sees in the far distance may have deep 

 meaning for him. The dog surveys the same landscape 

 indifferently, but his whole attention is devoted to matters 

 in his more immediate neighbourhood, of which the man 

 is only indirectly conscious through the activity of the 

 dog. Many things may be going on in the distance, 

 which, if at hand, would have considerable interest for the 



1 "A feeling can exist by itself without forming part of a consciousness," 

 writes Clifford in a paper, the main conclusion of which seems to me, how- 

 ever, quite unproven. ("On the Nature of Things-in-themselves," Lectures 

 and Essays, vol. i. p. 84. ) 



