Rooms, corridors, bookcases, shelves, filing cards, and computerized catalogues assume that the subjects on which our thoughts dwell are actual entities, and through this assumption a certain book may be lent a particular tone and value. Filed under Fiction, Jonathon Swift's is a humorous novel of adventure; under Sociology, a satirical study of England in the eighteenth century; under Children's Literature, an entertaining fable about dwarfs and giants and talking horses; under Fantasy, a precursor of science fiction; under Travel, an imaginary voyage; under Classics, a part of the Western literary canon. Categories are exclusive; reading is not--or should not be. Whatever classifications have been chosen, every library tyrannizes the act of reading, and forces the reader--the curious reader, the alert reader--to rescue the book from the category to which it has been condemned.