12 AN INTRODUCTION TO SCIENCE 



And not only is science limited to the world of sense, but 

 even this world expands into a nebulous zone of half-science 

 before the unknowable is reached. There is a limit beyond 

 which scientific thought cannot penetrate ; not because the 

 outer realm does not appertain to science, but because 

 experience which bears up thought with varying degrees of 

 firmness just as matter in its several conditions of aggrega- 

 tion, solid, liquid, gaseous, supports animals which stand, 

 swim, fly becomes too rarified a medium for human in- 

 telligence to mount in. 



Much painful mental effort may be saved by the honest 

 recognition of the limitations of science. A child, at the 

 age when errant curiosity compels it to ask questions, and 

 the simplicity of childhood believes that every question has 

 an answer, lies awake at night, beating its brains, in the 

 struggle to understand what happened before time began, 

 what space is like beyond the outside of infinity, and 

 whether, if there be no outside to space, the comet, which 

 travels fifty miles a second for a century', is not in the same 

 place all the time. An astronomer is compelled to use the 

 terms Time, Space, Movement ; yet he is as little able as a 

 child to form a mental picture of the absolute meaning of the 

 words. He uses them so often, and they serve his purpose 

 when explaining the sidereal system so well, that he forgets 

 the date at which he abandoned the attempt to realise Time, 

 Space and Movement as absolute what? things or the 

 attributes of things ? and settled down to speaking of them 

 henceforward as relations. 



The first step in chemistry or physics demands the recog- 

 nition of a distinction between Matter and Force. But what 

 is matter, and what force ? Matter is that upon which force 

 acts ; force is that which acts upon matter. Yet it is late, if 

 ever, that the physicist or chemist ceases his endeavour to 

 form a nearer conception of the meaning of that which in its 

 manifestations is the subject of his life-work. Time after 

 time he traces the chain of inductions back, and still further 



