MATTER 241 



metrical point nor a body bounded by continuous surfaces; 

 the mind absolutely rebels against the notion of anything 

 moving but these conceptual creations, which are limits, 

 unrealisable, as we have seen, in the field of perception. 

 If the world of phenomena be, as the materialists would 

 have us to believe, a world of moving bodies like the con- 

 ceptual world by which science symbolises it, if we are to 

 assert the perceptual existence of atom and ether, then 

 in both cases we are incapable of considering the ultimate 

 element which moves as anything but a perceptual 

 realisation of geometrical ideals. Yet, so far as our 

 sensible experience goes, these geometrical ideals have no 

 phenomenal existence ! We have clearly, then, no right 

 to infer as a basis of perception things which our whole 

 experience up to the present shows us exist solely in the 

 field of conception. It is absolutely illogical to fill up a 

 void in our perceptual experience by projecting into it a 

 load of conceptions utterly unlike the adjacent perceptual 

 strata. It is " a profound psychological mistake," says 

 George Henry Lewes, " to assert that whenever we can 

 form clear ideas, not in themselves contradictory, these 

 ideas must of necessity represent truths of nature." ^ The 

 reader will, we feel certain, find it impossible to conceive 

 anything other than geometrical ideals as the moving 

 element at the basis of phenomena. The attempt, how- 

 ever, to conceive something else is worth the making for 

 it inevitably leads us to the conclusion that the term 

 " moving body " is not scientific when applied to per- 

 ceptual experience. In external perception (p. 183) we 

 have sense-impressions and more or less permanent group- 

 ings of sense-impressions. These sense-impressions vary, 

 dissolve, form new groups — that is, they change. Of the 

 universe as contained in messages received at the brain 

 telephonic exchange, or of groups of sense-impressions, 

 we cannot assert motion — objects appear, disappear, and 

 reappear ; sense-impressions alter and modify their group- 

 ing. Change is the right word to apply to them rather 



1 See especially §§ 69, 69a, and 108 of his Aristotle : a Chapter from 

 the History of Science. London, 1864. 



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