What do Lewis Carroll, George Sand, Mark Twain, and Dr. Seuss have in common? They are all pseudonyms for some of the most celebrated writers in history. Whether for reasons of gender discrimination, insecurity, shyness, fear of social repercussions, or simply to have more freedom to write, many authors have chosen to sign their work under different names. Read on to discover 10 writers who, by hiding their identity, changed the course of literature.