Zen is a matter of life and death:

'Kyogen said, "It (Zen) is like a man (monk) hanging by his teeth in a tree over a precipice. His hands grasp no branch, his feet rest on no limb, and under the tree another man asks him, 'Why did Bodhidharma come to China from the West?' If the man in the tree does not answer, he misses the question, and if he answers, he falls and loses his life. Now what shall he do?" '