This Book Needs No Title brings the delight and fascination with self-reference and paradox that distinguish Raymond Smullyan's popular books on logic to bear on philosophical and spiritual themes. Progressing organically from brief anecdotes, paradoxes, jokes, and epigrams to dialogues, essays, and finally the marvelous novella-length parable, "Planet Without Laughter", Smullyan uses reason to illuminate its own limits in playfully serious treatments of subjects such as egoism, pessimism, anxiety, mysticism, free will and determinism, dualism, Zen, spontaneity, and humor. No thinker has ever banished grimness more fully from his philosophy than Smullyan, nor made profundity more cheerfully contagious, as the uninhibited pleasure in inquiry in these pages joyfully testifies.