Library of Congress  

"In the Library of Congress the classification was originally based upon Lord Bacon's scheme for the division of knowledge into three great classes, according to the faculty of the mind employed in each. 1. History (based upon memory); 2. Philosophy (based upon reason); 3. Poetry (based upon imagination). This scheme was much better adapted to a classification of ideas than of books. Its failure to answer the ends of a practical classification of the library led to radical modifications of the plan, as applied to the books on the shelves, for reasons of logical arrangement, as well as of convenience. A more thorough and systematic re-arrangement is now in progress."--A Book for All Readers (1900) by Ainsworth Rand Spofford