Van Doren and philosopher Mortimer J. Smith coauthored the classic How to Read a Book. Adler is the author of A History of Knowledge (which sold 30,000 hardback copies and 150,000 paperback copies), as well as The Concept of Progress, Grand Treasury of Western Thought, The Annals of America, Second Chance: An American Tale, and other young-adult books and Webster's American biographies. He teaches at the University of Connecticut's Torrington Campus as an adjunct lecturer. Mark Van Doren, a Pulitzer Prize-winning poet and Columbia University professor, was his father.