362 Darwinism and Other Essays. 



great as that needed for making the rule. Hence 

 when different people work independently at a 

 classified catalogue, they are sure to get into a 

 muddle. 



Suppose, for example, you have to classify a 

 book on the constitution of Massachusetts. I put 

 such books under the heading " LAW Mass. 

 Const.," but another person would prefer " LAW 



Const. Mass.," a third would rank them un- 

 der "LAW U. S. Const. Mass.," a fourth 

 under " LAW U.S. (Separate States) Mass. 



Const.," a fifth under "LAW Const. U. S. 



Mass.," and so on, through all the permutations 

 and combinations of which these terms are sus- 

 ceptible. Yet each of these arrangements would 

 bring the title into a different part of the cata- 

 logue, so that it would be quite impossible to dis- 

 cover, by simple inspection, what the library con- 

 tained on the subject of constitutional law in 

 Massachusetts ; and to this extent the catalogue 

 would become useless. Many such defects are 

 now to be found in our subject-catalogue, greatly 

 to the impairment of its usefulness ; and they 

 prove conclusively that the work of classifying 

 must always be left to a single superintendent 

 who knows well the idiosyncrasies of the catar 

 logue. This work consumes no little time. The 



