When the monks assembled before the noon meal to hear his lecture, the Master Fa-yen [885-958] pointed at the bamboo blinds. Two monks simultaneously went and rolled them up. Fa-yen said, "One gain, one loss."5
Don't think! Respond instantly! Don't say a word unless it's right, Don't make a move that isn't intuitive. And above all, don't analyze.
Yun-men [862/4-949] asked a monk, "Where have you come here from?" The monk said, "From Hsi-ch'an." Yun-men said, "What words are being offered at Hsi-ch'an these days?" The monk stretched out his hands. Yun-men struck him. The monk said, "I haven't finished talking." Yun-men then extended his own hands. The monk was silent, so Yun-men struck him.6
You weren't there. You're not the monk. But now you've got to do something to show the master you grasp what went on in that exchange. What was spontaneous to the older masters you must grasp in a secondhand, systematized situation. And if you can't answer the koan right (it should be stressed, incidentally, there is not necessarily a fixed answer), you had best go and meditate, try to grasp it nonintellectually, and return tomorrow to try again.
Off you go to meditate on "Mu" or "One gain, one loss," and the mental tension starts building. Even though you know you aren't supposed to, you analyze it intellectually from every angle. But that just heightens your exasperation. Then suddenly one day something dawns on you. Elated, you go to the master. You yell at him, or bark like a dog, or kick his staff, or stand on your hands, or recite a poem, or declare, "The cypress tree in the courtyard," or perhaps you just remain silent. He will know (intuitively) if you have broken through the bonds of reason, if you have transcended the intellect.
There's nothing quite like the koan in the literature of the world: historical episodes that have to be relived intuitively and responded to. As Ruth F. Sasaki notes, "Collections of 'old cases,' as the koans were sometimes called, as well as attempts to put the koans into a fixed form and to systematize them to some extent, were already being made by the middle of the tenth century. We also find a few masters giving their own alternate answers to some of the old koans and occasionally appending verses to them. In many cases these alternate answers and verses ultimately became attached to the original koans and were handled as koans supplementary to them."7 Ironically, koans became so useful, indeed essential, in the perpetuation of Ch'an that they soon were revered as texts. Collections of the better koans appeared, and next came accretions of supporting commentaries—when the whole point was supposed to be circumventing reliance on words! But commentaries always seemed to develop spontaneously out of Ch'an.
Today two major collections of koans are generally used by students of Zen. These are the Mumonkan (to use the more familiar Japanese name) and the Hekiganroku (again the Japanese name) or Blue Cliff Record.8 Masters may work a student through both these collections as he travels the road to enlightenment, with a new koan being assigned after each previous one has been successfully resolved.
The Blue Cliff Record was the first of the two collections. It began as a grouping of one hundred kung-an by a master named Hsueh-tou Ch'ung-hsien (980-1052) of the school of Yun-men. This master also attached a small poem to each koan, intended to direct the student toward its meaning. The book enjoyed sizable circulation throughout the latter part of the eleventh century, and sometime thereafter a Lin-chi master named Yuan-wu K'o-ch'in (1063-1135) decided to embellish it by adding an introduction to each koan and a long-winded commentary on both the koan and the poem supplied by the previous collector. (In the case of the poem we now have commentary on commentary—the ultimate achievement of the theologian's art! However, masters today often omit Yuan-wu's commentaries, giving their own interpretation instead.9) The commentator, Yuan-wu, was the teacher of Ta-hui, the dynamic master of the Lin-chi lineage whom we will meet here.
The Mumonkan, a shorter work, was assembled in 1228 by the Ch'an monk Wu-men Hui-k'ai (1183-1260) and consists of forty-eight koans, together with an explanatory comment and a verse. Some of the koans in the Mumonkan also appear in the Blue Cliff Record. The Mumonkan is usually preferred in the Japanese summer, since its koans are briefer and less fatiguing.10