RAYMOND SMULLYAN, well-known mathematician and logician, is Oscar Ewing Professor of Philosophy at Indiana University and Professor Emeritus of The City University of New York-Lehman College and Graduate Center. His many writings include four previous volumes of recreational logic and math problems, What Is The Name of This Book?, The Lady or the Tiger?, Alice in Puzzleland, and To Mock a Mockingbird; two studies of deductive logic in chess, The Chess Mysteries of Sherlock Holmes and The Chess Mysteries of the Arabian Knights; and three collections of philosophical essays and aphorisms, The Tao Is Silent, This Book Needs No Title, and 5000 B.C.