CHAPTER XL 

 CLASSIFICATION. 



98. THAT orderly arrangement of objects called Classi 

 fication, has two purposes ; which, though not absolutely dis 

 tinct, are distinct in great part. It may be employed to 

 facilitate identification ; or it may be employed to organize 

 our knowledge. If a librarian places his books in the alpha 

 betical succession of the author s names, he places them in 

 such way that any particular book may easily be found ; but 

 not in such way that books of a given nature stand together. 

 When, conversely, he makes a distribution of books accord 

 ing to their subjects, he neglects various superficial similari 

 ties and distinctions, and groups them according to certain 

 primaiy and secondary and tertiary attributes, which sever 

 ally imply many other attributes groups them so that any 

 one volume being inspected, the general characters of all the 

 neighbouring volumes may be inferred. He puts together 

 in one great division, all works on History ; in another all 

 Biographical works ; in another all works that treat of 

 Science ; in another Voyages and Travels ; and so on. Each 

 of his great groups he separates into sub-groups ; as when 

 hr, puts different kinds of pure Literature, under the heads 

 of Fiction, Poetry, and the Drama. In some cases he 

 makes sub-sub-groups ; as when, having divided his Scientific 

 treatises into abstract and concrete, putting in the one Logic 

 and Mathematics, and in the other Physics, Astronomy, Ge- 



