A young physician in Tokyo named Kusuda met a college friend who had
been studying Zen. The young doctor asked him what Zen was.
"I cannot tell you what it is," the friend replied, "but one thing is
certain. If you understand Zen, you will not be afraid to die."
"That's fine," said Kusuda. "I will try it. Where can I find a teacher?"
"Go to the master Nan-in," the friend told him.
So Kusuda went to call on Nan-in. He carried a dagger nine and a half
inches long to determine whether or not the teacher was afraid to die.
When Nan-in saw Kusuda he exclaimed: "Hello, friend. How are you? We
haven't seen each other for a long time!"
This perplexed Kusuda, who replied: "We have never met before."
"That's right," answered Nan-in. "I mistook you for another physician
who is receiving instruction here."
With such a begining, Kusuda lost his chance to test the master, so
reluctantly he asked if he might receive instruction.
Nan-in said: "Zen is not a difficult task. If you are a physician,
treat your patients with kindness. That is Zen."
Kusuda visited Nan-in three times. Each time Nan-in told him the same
thing. "A phsisician should not waste time around here. Go home and take
care of your patients."
It was not clear to Kusuda how such teaching could remove the fear of
death. So on the forth visit he complained: "My friend told me that when
one learns Zen one loses his fear of death. Each time I come here you
tell me to take care of my patients. I know that much. If that is your
so-called Zen, I am not going to visit you anymore."
Nan-in smiled and patted the doctor. "I have been too strict with
you. Let me give you a koan." He presented Kusuda with Joshu's Mu to work
over, which is the first mind-enlightening problem in the book called
The Gateless Gate.
Kusuda pondered this problem of Mu (No-Thing) for two years. At length he
thought he had reached certainty of mind. But his teacher commented: "You
are not in yet."
Kusuda continued in concentration for another yet and a half. His
mind became placid. Problems dissolved. No-Thing became the truth. He
served his patients well and, without even knowing it, he was free from
concern of life and death.
Then he visited Nan-in, his old teacher just smiled.