What are koans?
Koans are records of actual exchanges between teachers and their students. They are not invented paradoxical statements,as is often thought. The best known koan is probably Joshu’s Mu,which goes as follows:
A monk goes up to Joshu.
Monk: Does a dog have buddha nature?
Joshu: Mu (mu variously means no,not or different from)
Monk: Everything has buddha nature. How can a dog not have buddha nature?
Joshu: Karmic nature
This koan is frequently misinterpreted, both in translating mu 無 simply as not (which is how the Monk hears it) and in giving the final line as because it (the dog) has karmic nature. One is then confusedly juggling buddha nature and karmic nature, what they are and how they relate. It is easy to misinterpret these koans, as classical chinese is very terse, and frequently plays on words.
A re-working of the koan would go like this:
A monk goes up to Joshu.
Monk: Does a dog have buddha nature?
Joshu: JThe dog is real. Reality different from your concept of it
Monk (mishearing mu as not): But everything has buddha nature. How can a dog not have buddha nature?
Joshu: It is your nature to think like this
The Monk comes to Joshu in an unbalancedly idealistic state, and Joshu attempts to bring him back into balance.
Another famous koan goes like this:
A monk seeing Yasutan practicing zazen.
Monk: What are you thinking in the still-still state?
Yasutan: I’m thinking (shiryo) not thinking (fushiryo).
Monk: But how can you think not thinking?
Yasutan: Hishiryo
Shiryo means thinking. The prefix fu- is the negation;not thinking.The prefix hi- again has a wide meaning, but in this exchange hishiryo is frequently translated as beyond thinking, so one then might acquire the peculiar notion that in zazen you should reach some special state where there is no thought, where thinking is transcended. This is a source of difficulty for practitioners, who, frustrated by the persistence of their thoughts, believe they can’t do zazen, and so give up. The tone of the koan then is often lofty and mysterious, but in fact a more accurate rendering of hishiryo is simply different from. In other words, although in zazen thoughts do not cease altogether, we aren’t pre-occupied with them. We aren’t intentionally thinking, and the state in zazen isn’t voiding the mind in the normal sense, but making real its vastness.
A good collection of koans with modern interpretations, like this one, is Gudo Nishijima’s Master Dogen’s Shinji Shobogenzo.
More detailed teachings on Koans