Koan

A paradoxical riddle or puzzle used in Zen to shock the mind into awareness.

The kanji for "koan" (公案) is an abbreviation for "ko-fu no an-toku". In ancient China, this was a signpost on which new laws were announced to the public. In much the same sense, a koan states a realized principle, or law of reality.

Koans are used almost exclusively in Ch'an (Chinese) and Zen (Japanese) schools of Buddhism, and specifically by the Rinzai or "Sudden Enlightenment" school. The other main branch of Zen, called Soto or "Gradual Enlightenment", does not normally use koans.

There are compilations and commentary written with respect to koan. Two notable collections of koan are the Gateless Gate (http://www.ibiblio.org/zen/cgi-bin/koan-index.pl) and the Blue Cliff Record.

In Sudden Enlightenment training, koans are given to students, according to their ability, to break through and directly perceive reality with the wisdom eye.

Not all koans actually have an answer or explanation, which can be frustrating to people who are used to expecting answers. Instead, they sometimes are intended only to prompt you to ask the right questions, or to question your previous assumptions.

List of koans

Show me the face you had before you were born.
What is the sound of one hand clapping?
The mind is like a dog. His master points at the moon, but he barks at the hand.

List of koans

Not to be confused with random nonsense or "cleverness".