250 THE GRAMMAR OF SCIENCE 



still smaller atoms — (and there are certain phenomena 

 presented by the spectrum analysis of the gaseous elements 

 that might well induce us to believe that the atom cannot 

 be conceived as the ultimate or " prime element of 

 matter ") — but what about these smaller atoms, are they 

 geometrical ideals or are they built up of tinier atoms 

 still, and if so where are we to stop ? The process 

 reminds us of the lines of Swift : — 



" So naturalists observe, a flea 

 Has smaller fleas that on him prey ; 

 And these have smaller still to bite 'em, 

 And so proceed ad infinitum" 



I am unable to verify Swift's statement as to the fleas, but 

 I feel quite sure that to assert the real existence in the 

 world of phenomena of all the concepts by aid of which 

 we scientifically describe phenomena — -molecule, atom, 

 prime-atom — even if it be ad infinitum^ will not save us 

 from having ultimately to consider the moving thing to 

 be a geometrical ideal, from having to postulate the 

 phenomenal existence of what is contrary to our per- 

 ceptual experience. This point brings out very clearly 

 what the present writer holds to be a fundamental canon 

 of scientific method, namely : To no concept, however 

 invaluable it may be as a means of describing the routine 

 of perceptions, ougJit phenomenal existence to be ascribed until 

 its perceptual equivalent lias been actually disclosed. 



Whenever we disregard this canon, when, for example, 

 we assert reality for the mechanisms by aid of which we 

 describe our physical experience, then we are more likely 

 than not to conclude with an antinomy, or a conflict of 

 rules. For such mechanisms are constructs largely based 

 on conceptual limits, which are unattainable in the field 

 of perception. When we consider space as objective and 

 matter as that which occupies it, we are forming a con- 

 struct largely based on the geometrical symbols by aid of 

 which we analyse motion conceptually. We are pro- 

 jecting the form and volume of conception into perception, 

 and so accustomed have we got to this conceptual element 

 in the construct that we confuse it with a reality of per- 



