346 THE PRINCIPLES OF SCIENCE. 



one or other of the elementary circumstances out of which 

 it was produced. We restore nature, as it were, to the 

 simple conditions out of which its endless variety was 

 developed. As Professor Bowen has excellently said a , 

 ' The first necessity which is imposed upon us by the 

 constitution of the mind itself, is to break up the infinite 

 wealth of Nature into groups and classes of things, with 

 reference to their resemblances and affinities, and thus to 

 enlarge the grasp of our mental faculties, even at the 

 expense of sacrificing the minuteness of information which 

 can be acquired only by studying objects in detail. The 

 first efforts in the pursuit of knowledge, then, must be 

 directed to the business of Classification. Perhaps it will 

 be found in the sequel, that Classification is not only the 

 beginning, but the culmination and the end, of human 

 knowledge.' 



Classification Involving Induction. 



The purpose of classification must always be the detec- 

 tion of resemblances and laws of nature. However much 

 the process may in some cases be disguised, classification 

 is not really distinct from the process of perfect induction, 

 whereby we endeavour to ascertain the connexions which 

 exist between the several properties of the objects under 

 treatment. There can be no use in placing an object in a 

 class unless something more than the fact of being in that 

 class is thereby implied. If we arbitrarily formed a class 

 of metals and placed therein a selection from the list of 

 known metals made by the ballot we should have no 

 reason to expect that the metals in question would re- 

 semble each other in any points except that they are 



a ' A Treatise on Logic, or, the Laws of Pure Thought,' by Francis 

 Bowen, Professor of Moral Philosophy in Harvard College, Cambridge, 

 United States, 1866, p. 315. 



