Koans are questions or statements (often paradoxes) that provoke spiritual understanding and thought. Often used by masters as a way of teaching pupils Koans are also used to test enlightenment.

However, it would be wrong to think that a koan and its solution add up to wisdom and truth. In fact, they are more like tools that help in bringing about an understanding of the true nature of the self and everything around.

A well-known koan: "In clapping both hands a sound is heard; what is the sound of one hand?"

A koan cannot be solved by study or analytical thought. In fact, the pupil must leave all thoughts and ideas behind and respond intuitively in order to solve it.

Koans don't have a right answer. Everything is open to different interpretations. It is often seen that Western pupils find this very frustrating as they are used to trying to get the right (and only) answer to a problem. The best way to work on koans is with a teacher's able guidance.

The first collection of koans was made in the 11th century CE and is a favorite teaching tool of the Rinzai school of Buddhism.