MATTER 243 



If we turn to the perceptual sphere and ask what it is 

 that moves and why it moves, we are compelled to confess 

 ourselves utterly incapable of finding any answers what- 

 ever. Ignorabunus, we shall always be ignorant say some 

 scientists. That we are really ignorant will be the theme 

 of the present chapter, but I believe that this ignorance 

 does not arise from the limitation of our perceptive or 

 reasoning faculties. It is rather due to our having asked 

 unanswerable questions. We may legitimately ask why 

 the complex of our sense-impressions changes, but, accord- 

 ing to the views expressed above, motion is not a reality 

 of perception, and it is therefore, for the sphere of per- 

 ception, idle to ask what moves and why it moves. With 

 the growth of more accurate insight into the conceptual 

 nature of motion these questions will, I believe, be dis- 

 missed like the older questions as to the blue milk of the 

 witches and the influence of the s^dss (p. 22). With 

 their dismissal, however, physical science will be for ever 

 relieved of the metaphysical difficulties as to matter and 

 force which it has inherited from the old scholastic tradi- 

 tions. Ignorabimus, therefore, does not seem the true 

 answer to the first two questions ; it may be a true answer 

 to the problem of changes in sense-impression (see our 

 pp. 107 and 241). The third question — How do things 

 move ? — also wants restating to be of any real value, and 

 when restated it merges in the same question asked of 

 the conceptual sphere. What, we must ask, are the con- 

 ceptual types of motion best suited to describe the stages 

 of our perceptual experience ? The answer to this 

 question forms the subject-matter of our next chapter. 



Some of my readers may feel inclined to consider that 

 in this discussion we are entirely deserting the plane of 

 common sense. What moves ? Why, natural bodies 

 move, they will say, is the common-sense answer. But 

 common sense is often a name for intellectual apathy. 

 Being inquisitive, we naturally ask what these bodies 

 consist in, and probably shall be told that they are quan- 

 tities of matter. Still persisting with our questions we 

 ask : What, then, is matter ? It will not do to put us 



