A koan (known in Chinese as a gong an, and in Vietnamese as a cong an) is a meditation device, a special kind of Zen riddle. Koans are solved not with the intellect but with the practice of mindfulness, concentration and insight. A koan can be contemplated and practiced individually or collectively, but so long as it remains unsolved, a koan is unsettling. It is like an arrow piercing our body which we cannot take out; so long as it is lodged there we can neither be happy nor at peace.
Yet the koan's arrow has not really come from outside, nor is it a misfortune. A koan is an opportunity to look deeply and transcend our worries and confusion. A koan forces us to address the great questions of life, questions about our future, about the future of our country and about our own true happiness.
Some of the best known Zen koans include “The cypress in the courtyard”, “If everything returns to the one, where does the one return to?”, “Does a dog have Buddha nature?”, and “Who is invoking the Buddha’s name?” Vietnam's great leaders and statesmen have long practiced the art of contemplating koans, and contributed many famous ones of their own. Zen Master Tue Trung, whose brother General Tran Hung Dao repelled Genghis Khan's invasion, offered the powerful koan “All phenomena are impermanent. Everything that is born must finally die. What is born, and what dies?”
A koan cannot be solved by intellectual arguments, logic or reason, nor by debates such as whether there is only mind or matter. A koan can only be solved through the power of right mindfulness and right concentration. Once we have penetrated a koan, we feel a sense of relief, and have no more fears or questioning. We see our path and realize great peace.
“Does a dog have Buddha nature?” If you think that it's the dog's problem whether or not he has Buddha nature, or if you think that it's merely a philosophical conundrum, then it's not a koan. “Where does the one return to?” If you think this is a question about the movement of an external objective reality, then that is not a koan either. If you think Bat Nha is only a problem for 400 monks and nuns in Vietnam, a problem that simply needs a ‘reasonable and appropriate’ solution, then that too is not a koan. Bat Nha truly becomes a koan only when you understand it as your own problem, one that deeply concerns your own happiness, your own suffering, your own future and the future of your country and your people. If you cannot solve the koan, if you cannot sleep, eat or work at peace, then Bat Nha has become your koan.
'Mindfulness' means to recollect something, to hold it in our heart day and night. The koan must remain in our consciousness every second, every minute of the day, never leaving us even for a moment. Mindfulness must be continuous and uninterrupted; and continuous mindfulness brings concentration. While eating, getting dressed, urinating and defecating, the practitioner needs to bring the koan to mind and look deeply into it. The koan is always at the forefront of your mind. Who is the Buddha whose name we should invoke? Who is doing the invoking? Who am I? You must find out. So long as you haven’t found out you haven't made the breakthrough, you are not yet fully awake, you have not understood.
Thich Nhat Hanh continues to live in Plum Village in the meditation community he founded, where he teaches, writes, and gardens; and he leads retreats worldwide on "the art of mindful living." Plum Village website is www.plumvillage.org.