CLASSIFICATION 47 



not make the sciences which deal with them concrete or 

 abstract. 



We doubt whether anything is to be gained by classify- 

 ing the sciences. They are mutually dependent, and pass 

 without definition one into the other. The study of the 

 formation of starch in a plant belongs equally to chemis- 

 try, botany and solar physics. But while, philosophically 

 speaking, there is but one Science, the cultivation of Science 

 has led to the allocation of particular parts of its field to 

 particular classes of men. The students of Science can 

 be classified with more success than the subdivisions of 

 knowledge which they severally endeavour to make their 

 own. 



If we attempted to picture the tree of Knowledge we 

 should sketch it somewhat as follows : At the base, where 

 it rests upon the ground, ( i ) the observation of the physi- 

 cal properties of familiar objects. The description of these 

 objects and the comparison of their properties require the 

 exercise of thought. The endeavour to think clearly and 

 to express consistently gave rise, long before any such 

 science was formulated, to (2) the twin trunk Logic. 

 Among the properties of the objects examined were cer- 

 tain relations in number and extension. As soon as mere 

 counting and measurement were accomplished, and num- 

 bers and extensions were imagined apart from things 

 numbered or measured, a thick stem branched off from 

 the tree of knowledge, as (3) Mathematics. The bole then 

 divided according to the kinds of phenomena observed 

 into (A ) the study of the movements of the heavenly 

 bodies, Astronomy, and (B ) the study of the earth. The 

 force which holds the heavenly bodies in their place was 

 subsequently investigated by the physicists, and their con- 

 stitution, as shown by the spectroscope, by the chemists. 

 The earth may be looked at as a whole, (a) Geology, or 

 in its constituent parts. The parts are non-living and liv- 

 ing. In the consideration of non-living things attention 



