SPACE AND TIME 169 



that is in intensity, but also qualitatively? If we could 

 magnify the sense-impressions due to the infinitesimal 

 fraction of a drop of water up to a sensible intensity, 

 would they so differ from those characteristic of the con- 

 tents of the original vessel that we should not give them 

 the name water ? Now we cannot test the effects of an 

 indefinitely continued division in the phenomenal world, 

 for we soon reach a stage at which we fail to get, by the 

 means at our disposal, any sense-impressions at all from 

 the divided substances. Our magnifiers of sense-impres- 

 sion have but a limited range.^ But although in the 

 sphere of perceptions there is no possibility of carrying 

 division to its ultimate limit, we can yet in conception 

 repeat the process indefinitely. If after an infinite number 

 of divisions we conceive that the same group of sense- 

 impressions would be found, then we are said to conceive 

 the substance as contimioits. We have then to ask how 

 far the conception of continuity applies to the real bodies 

 of our perceptual experience. From the finite process of 

 division which is possible in perception, we might easily 

 conclude that continuity was a property of real substances ; 

 and there is small doubt that a slight amount of obser- 

 vation is favourable to the notion that many real sub- 

 stances are continuous, although the infinite division 

 necessary to the conception of continuity fails as a 

 perceptual equivalent. Further observation and wider 

 insight, however, contradict this notion. The physicist 

 and the chemist bring many arguments to show us that 

 the finite process of division which suggests continuity 

 would, if carried to an infinite limit, show bodies to be 

 discontinuous. On a first and untrained inspection we 

 find a continuity and a sameness in perceptions which 

 disappear on closer and more critical examination. The 

 ideas conveyed in these words are found to be no real 

 limits to the actual, but ideal limits to processes which 

 can only be carried out in tlie field of conception. Bcar- 



^ E.g. the microscope, the microphone, the spectroscope, etc. From the 

 spectroscope we obtain, perhaps, positive indications of a qualitative change 

 in many substances as the quantity is diminished. 



