As Steven Heine points out, the koan is “Zen’s main religious symbol” and John Tarrant calls them “ancient technologies for transforming the mind.” Dale Wright observes that “koan meditation may be the most condensed and self-conscious linguistic practice ever devised in any culture.”
“The use of koan in Zen Buddhism is a unique phenomenon in the history of religion; nothing like it exists in other religious traditions. Developed in China, koan testify to an authentically Chinese mentality, particularly in the way they are rooted in real life. If Zen can be called the Chinese expression of Buddhism, then koan are the most Chinese dimension of Zen.”
Here are a sampling of these Zen stories with the English translation before the original Chinese version:
A monk asked Joshu in all earnestness, “Has a dog Buddha nature or not?”
Joshu said, “Mu!”
Tozan’s Three Pounds of Flax
A Monk asked Master Tozan, “What is Buddha?”
Tozan said, “Three pounds of flax.”
A monk asked Unmon in all earnestness, “What is Buddha?”
Unmon said, “A dried up shit-stick!”
Not the Wind, Not the Flag
The wind was flapping a temple flag, and two monks were having an argument about it. One said, “The flag is moving.” The other said, “The wind is moving.” They argued back and forth but could not reach the truth. The sixth patriarch said. “It is not the wind that moves. It is not the flag that moves. It is your mind that moves.” The two monks were struck with awe.
No Mind, No Buddha
A monk asked Baso in all earnestness, “What is Buddha?”
Baso replied, “No mind, no Buddha”
The Oak Tree in the Front of the Garden
A monk asked Joshu in all earnestness, “What is the meaning of the patriarch’s coming from the West?”
Joshu said, “The oak tree in the front of the garden.”
Every Day Is a Good Day
Yunmen said, “I don’t ask you about before the fifteenth day; try to say something about after the fifteenth day.” Yunmen himself answered for everyone, “Every day is a good day.”
Ryutan’s Name Echoes On and On
(a.k.a. Ryutan Blows Out the Candle)
One night Tokusan persisted in asking Ryutan for instruction.
Ryutan finally said, “The night is late. Why don’t you go to bed?”
Tokusan thanked him, made his bows, raised the door curtain and left. Seeing how dark the night was, he turned back and said, “It’s pitch black outside.”
Ryutan lit a candle and handed it to Tokusan.
Just as Tokusan reached for it, Ryutan blew out the candle.
At that Tokusan came to sudden realization and made a deep bow.
Think Neither Good Nor Evil
The sixth patriarch was once pursued by the monk Myo as far as Mount Daiyu.
The patriarch, seeing Myo coming, laid the robe and bowl on a rock and said,
“This robe represents the faith. How can it be competed for by force? I will allow you to take it away.”
Myo tried to lift it up, but it was as immovable as a mountain.
Terrified and trembling with awe, he said, “I came for the Dharma, not the robe. I beg you, please reveal it to me.”
The patriarch said, “Think neither good nor evil. At that very moment, what is the original face of Monk Myo?”
In that instant, Myo suddenly attained deep realization, and his whole body was covered with sweat.
Who Is That One?
Patriarch En of Tozan said, “Even Shakyamuni and Maitreya are servants of that one. Just tell me, who is that one?”