The koan is a device that may allow a disciple to attain enlightenment. A koan has to be pondered on, and it is largely used in Ch'an Buddhism, and, later on, in Japanese Zen as well. A koan presents itself as a kind of enigma, in such terms: "I can't understand!" It is a challenge to the mind, rather than to intellect. Various sentences have furnished the material to a koan, in Ch'an and Zen. It might regard masters' phrases, a verbal intercourse between a teacher and his disciples, passages from the Sutras, and so on. In certain circumstances, someone has been enlightened. A koan is a "case", that attests the entering in another plan of reality. He who meditates on the koan can re-live the same experiences of its protagonists. A disciple has to give the koan a central relevance all of his life: he has to constantly concentrate on it, avoiding letting thought from wandering elsewhere. As it is easy to comprehend, this task is very hard to perform.
There are three important collections of koan in Ch'an and Zen: "The Barrier Without a Door" (Chinese: Wu-men kuan), "The Blue Cliff Record" (Pi-yen lu), and "The Book of Serenity" (Ts'ung-jung lu). Two koans are particularly relevant, and are given to novices in Rinzai School. "A disciple asked the patriarch (that is, a Ch'an/Zen master): "Has a dog the Buddha-nature?" The patriarch answered: "Wu" (No). This koan constitutes a problem. The Buddha-nature is a component that all living beings possess. How can a dog be excluded from it? Some say that the answer "wu" (Japanese: mu) has to be phonetically meant, that is, as an imitation of dog's barking. However it may be, there is nothing to do with it: any key of reading a koan shows itself inadequate. Nevertheless, a disciple must ponder on the koan all the same, examining thoroughly all possible interpretations: one by one, he will suppress all of them, so that he can understand that all are insignificant and unsatisfactory. Another koan is, if anything, still more puzzling: "Listen to the sound of the one hand" (it was elaborated by Zen master Hakuin). The same discourse is valid regarding the dog's koan.
Such technique can also be used in psychotherapy with good results. The important thing is to make the client understand that his symptoms have no meaning and no consistence. In that way, he will get rid of them. An example from clinical practice may be stimulating. From time to time, a client insists on the same thing: his altophobia, the fear of heights. He perfectly describes the anguish and the symptoms which catch him on certain occasions. He is waiting for an answer from his therapist. After a long pause, his therapist's only answer is as follows: "Then, I seem to understand that you are afraid of heights, and that you are caught by anguish on certain occasions." That's all. At this point, two alternatives present themselves to the client: he may go away, in search of another therapist, but he has to admit his provisional failure; or, on the other hand, he might understand that the therapist's words have a deep meaning to be pondered on. In this case, he may concentrate his attention on the answer, as it were a koan. Who knows...after some time he might even be able to understand that there is another plan of reality, which logical reason and language cannot reach!
(I have developed these issues in a paper; see "La pratica del Buddhismo Zen nella psicoterapia", - "The Practice of Zen Buddhism in Psychotherapy" - "Studi Urbinati", B/2, 1983).
