i8o THE GRAMMAR OF SCIENCE 



ground to the metaphysician and the materialist. There 

 these gymnasts, released from the dreary bondage of 

 space and time, can play all sorts of tricks with the un- 

 knowable, and explain to the few who can comprehend 

 them how the universe is " created " out of will, or out of 

 atom and ether, and how a knowledge of things beyond 

 perception, i.e. beyond the knowable, may be attained by 

 the favoured few. The scientist bravely asserts that it is 

 impossible to know what there is behind sense-impression, 

 if indeed there can " be " anything ; ^ he therefore refuses 

 to project his conceptions, atom and ether, into the real 

 world of perception until he has perceived them there. 

 They remain for him valid ideals so long as they continue 

 to economise his thought. 



That the conceptions of geometry and physics im- 

 mensely economise thought is an instance of that wonder- 

 ful power to which I have previously referred in this work 

 (p. 1 04), namely, the power the reasoning faculty possesses 

 of resuming in conceptions and brief formulse the relation- 

 ships and sequences it finds in the material presented to 

 it by the perceptive faculty. As our knowledge grows, 

 as our sense becomes keener under the action of evolution 

 and with the guidance of science, so we are compelled 

 to widen our concepts, or to add additional ones. This 

 process does not as a rule signify that the original con- 

 cepts are invalid, but merely that they form a basis, which 

 is only sufficient for classifying and describing certain 

 phases of sense-impression, certain sides of phenomena. 

 As we grow cognisant of other phases and sides, we are 

 forced to adopt new concepts, or to modify and extend 

 the old. We may ultimately reach perceptions of space 

 which cannot be described by the geometry of Euclid, but 

 none the less that geometry will remain perfectly valid as 

 an analysis and classification of the wide range of per- 

 ceptions to which it at present applies. (See p. 97 and 

 footnote.) If the reader will bear in mind the views here 



1 Our notion of " being " is essentially associated with space and time, and 

 it may well be questioned whether it is intelligible to use the word except in 

 association with these modes of perception. 



