A Zen roshi or master, carrying a flailing stick in his hand, approaches one of his students with the following problem. “Observe what I am holding in my hand,” begins the master. “If you tell me it is a stick I will strike you with it. If you tell me it is not a stick I will strike you with it. If you fail to respond promptly with an answer, I will strike you with it. Now I ask you, what is this that I am holding in my hand?”

The solution is not to respond verbally but rather to seize the flailing stick from the master. The story illustrates the method of koan. A koan is a statement or question which seems to, and often does, defy all the laws of logic, the solution of which requires an unusual response or fresh way of viewing the world and responding to challenges.