The most original, most profound, and most humorous collection of recreational logic and math problems ever written. -- Martin Gardner, Scientific American The value of the book lies in the wealth of ingenious puzzles. They afford amusement, vigorous exercise, and instruction. -- Willard Van Orman Quine, The New York Times Book Review If you're intrigued by puzzles and paradoxes, these 200 mind-bending logic puzzles, riddles, and diversions will thrill you with challenges to your powers of reason and common sense. Raymond M. Smullyan -- a celebrated mathematician, logician, magician, and author -- presents a logical labyrinth of more than 200 increasingly complex problems. The puzzles delve into G del's undecidability theorem and other examples of the deepest paradoxes of logic and set theory. Detailed solutions follow each puzzle.