[Japanese, lit. “public notice” or “public document”] An anecdote, question or statement containing a paradox, used in Zen Buddhism as a form of spiritual training to open the student’s intuitive mind or as a test of a student’s level of attainment. Koans are not solvable by the reasoning mind or intellect. In order to solve a koan the student must attain the same level of intuitive understanding as that from which the master spoke the words of the koan.
According to the teachings of Zen Buddhism there are about 1,700 koans, of which 500 to 600 are used by Zen masters today.
The following is an example of a koan: If you meet a man of Tao on the way, greet him neither with words nor with silence. Now tell me, how will you greet him?
Pearls of Wisdom, vol. 32, no. 59, December 6, 1989.