When Paul Reps put together the little book, Zen Flesh, Zen bones, that came out in 1957, it gained a certain amount of well deserved attention. Based on older material done back in the 1930s, for example, John Murray’s The Gateless Gate (1934), Reps’ book, at least for me, provided one of my first doors into the mysterious subject of the Zen koan. (Yes, I still have the little book in its original slipcase which was printed in Japan.)

Conspicuously absent from the book which I came to learn many, many years later, is the way koans were actually intended to work. An aside, we need to keep in mind that neither Bodhidharma nor the Sixth Patriarch knew of the koan. The koan is pretty much of a Sung Dynasty development.

Let me say, that the way koans work was earlier explained by Charles Luk in his book, Ch’an and Zen Teaching (Series One) through the discourses by Master Hsu-yun. The following, I hope, will help the reader get a better understanding of what is going on with koans; that they are intuitive devices and stern judges of our insight into pure Mind. Key to such an insight is the hua-t’ou. Master Hsu-yun says the following:

“In ancient times, the Patriarchs and Ancestors directly pointed at the mind for realization of self-nature and attainment of Buddhahood. Like Bodhidharma who ‘quietened the mind’ and the Sixth Patriarch who only talked about ‘perception of self-nature’, all of them just advocated the outright cognizance (of it) without any more ado. They did not advocate looking into a hua t’ou, but later they discovered that men were becoming unreliable, were not of dogged determination, indulged in playing tricks and boasted of their possession of precious gems which really belonged to others. For this reason, these ancestors were compelled to set up their own sects, each with its own devices; hence, the hua t’ou technique” (37).

Pausing here, permit me to give a concise definition of the hua-t’ou which comes from The Blue Cliff Records (trans. Shaw, p. 45):

“The real substance of the Universe, the ‘First Principle,’ that which is behind or beyond the Voice [hua] or expression of ultimate Truth, this ‘Pre-Voice’ [hua-t’ou] is transmitted only from heart [mind] to heart [mind], and no matter how great or holy or advanced in Enlightenment a man may be he cannot transmit it by means of words and phrases” (brackets are mine).

We should keep in mind that the hua-t’ou is immediate with us. It is not out there but in here. It opens us up to pure Mind, but because we are so attached to our mortal flesh and words, we never come in contact with it—not even close.

Skipping a paragraph, Master Hsu-yun continues.

“What is hua t’ou? (lit. word-head). Word is the spoken word and head is that which precedes word. For instance, when one says ‘Amitâbha-Buddha’, this is a word. Before it is said it is a hua t’ou (or ante-word). That which is called a hua t’ou is the moment before a thought arises. As soon as a though arises, it become a hua wei (lit. word-tail). The moment before a thought arises is called ‘the un-born’. That void which is neither disturbed nor dull, and neither still nor (one-sided) is called ‘the unending’. The unremitting turning of the light inwards on oneself, instant after instant, and exclusive of all other things, is called ‘looking into the hua t’ou or ‘taking care of the hua t’ou’ (37)

The hua-t’ou is meant to get us to stop engaging with internal words and images, and the outside world. All of this can be summed up as being hua-wei. We are not interested in interfacing with hua-wei reality. Using the koan, Joshu’s Dog from Zen Flesh, Zen Bones, it will now be easy to understand how the koan works.

“A MONK ASKED Joshu, a Chinese Zen master: “Has a dog Buddha-nature or not?” Joshu answered: “Mu.” [Mu is the negative symbol in Chinese, meaning “No thing” or “Nay.”]” (p. 115).

Mu is really twofold, it is hua-wei and hua-t’ou. If you subvocalize Mu or say it out loud, you are engaged with hua-wei and birth and death. You’re clueless as to what Buddha-nature really is which is immortal. If, on the other hand, you can catch a glimpse of what is most primordial, unborn, the first principle, ultimate reality as that which is beyond space, time and phenomena, you have a good idea of the role of hua-t’ou in koans—and Buddha-nature.