This classic Zen Buddhist collection of 49 koans with commentary by Mumon was originally published in 1934, and later included in Paul Reps and Nyogen Senzaki’s popular anthology Zen Flesh, Zen Bones. Koans are a Zen Buddhist spiritual technique which use word-play to achieve enlightenment. They frequently involve absurd or contradictory statements, which are intended to create extreme cognitive dissonance in the mind of the pupil. As such, their actual content or structure is not as important as the mental state which they induce.