koan

A puzzling, often paradoxical statement, anecdote, question, or verbal exchange, used in Zen Buddhism as an aid to meditation and a means of gaining spiritual awakening.

A story about a Zen master and his student, sometimes like a riddle, other times like a fable, which has become an object of Zen study, and which, when meditated upon, may unlock mechanisms in the Zen student’s mind leading to satori.

A riddle with no solution, used to provoke reflection on the inadequacy of logical reasoning, and to lead to enlightenment.

a paradoxical anecdote or a riddle that has no solution; used in Zen Buddhism to show the inadequacy of logical reasoning