Zen ‘Koans’: What Is the Sound of One Hand?

Busy Busy Beggar (Aizu Museum, Waseda University)

Posted by Keith Tidman

‘Two hands clap and there is a sound; what is the sound of one hand?’

The puzzle above long ago entered popular culture, and is familiar to many: The question’s origins date back to one of the most influential Zen Buddhists, Hakuin Ekaku, whose life straddled the 17th and 18th centuries.

The Zen name for such a puzzle is koan — a paradoxical anecdote, dialog, or question. The idea is that koans permit thinking to escape the bounds of rationality and instead embrace intuition-like ways to awaken enlightenment and arouse spiritual development. It’s a realm where logical reasoning is shown inadequate, to be suspended. By pondering the mystery of koans, contemplative monks absorb Buddhist teachings — letting go of the strictly analytic method to understanding, and instead learning to accept ambiguity and paradox and the absence of just one truth.

There are more than 1,700 classical koans, amassed over many centuries in China, Japan, and elsewhere (Thomas Cleary, Secrets of the Blue Cliff Record, 2002). Each one is a meditative device aimed at prompting the deep awareness that comes only from an open, freed-up mind. The interpretations of koans are often not obvious or clear-cut, their ambiguity making multiple alternative insights possible. In turn, these insights might lead to additional questions, inviting further reflection.

As far as the pursuit of open-mindedness and intuition goes, the following aphorism was offered in the Diamond Sutra:

‘Out of nowhere, the mind comes forth’. 

The observation originated in a 9th-century Sanskrit document, translated into Chinese, which was among thousands of scrolls hidden in ‘The Cave of a Thousand Buddhas’, evidently a library concealed to protect its contents.

Here’s another koan, perhaps less well-known outside of Zen circles:

Two monks were arguing about the temple flag waving in the wind. One insisted, ‘The flag moves’. The other equally insisted, ‘No, it is the wind that moves’. They argued back and forth but couldn’t agree. The Zen master Huineng was passing by and, having overheard the two monks, said, ‘It is not the flag moving. It is not the wind moving. It is your mind moving’. 

In this koan, the minds of the first two monks were riveted on the flapping flag, becoming increasingly obsessed with the issue of whether the flag was moving (the observable world) or whether it was in reality the wind that moved  (an invisible force acting on the observable world). Huineng’s point is that the two monks’ minds had become agitated over a minor distraction, consumed by binary, either-or thinking, instead of being in the restful state fostered by Zen Buddhism. Huineng reminded them to move beyond the diversionary tug of who was right or wrong — as both were seeing only partial truth — and instead calm their needlessly restless minds, caught up in the argument.

This anecdotal koan is less enigmatic, but likewise offers a valuable insight into human behaviour:

Tanzan and Ekido were once traveling together down a muddy road. A heavy rain was still falling. Coming around a bend, they met a woman in a silk kimono and sash, unable to cross the intersection. ‘Come on’, said Tanzan, at once lifting the woman and carrying her over the mud.

Ekido did not speak again until that night, when they reached a lodging temple. Then he no longer could restrain himself. ‘We monks don’t go near females’, he told Tanzan, ‘especially not young and attractive ones. It is dangerous. Why did you do that?’

‘I left the woman there’, said Tanzan. ‘Are you still carrying her?’

The account has various interpretations. One version is not to let the past consume you, such that an out-of-control preoccupation crowds out of the mind all else of greater value, including the present — forfeiting immediate experiences. Ekido was plagued by the niggling urge to judge and conform, unable to let go of re-litigating over and over whether Tanzan had violated the literal monastic code of conduct.

In doing so, Ekido succumbs to stepping outside of mindfulness, sacrificing what’s transpiring in the here and now. Meanwhile, Tanzan had moved on. Sometimes, moral codes are cloudy, even appropriately flexible in interpretation and application in order to bend to circumstances. As in this case, the right ‘moral’ choice may have been to break momentarily with convention in order to do a kindness — a higher good.

Another ‘paradoxical anecdote’ offers a different insight: 

Nan-in, a Zen master during the Meiji era, received a university professor who had arrived to inquire about Zen. Nan-in served tea. He poured his visitor’s cup full, and then kept on pouring.

The professor watched the overflow until he no longer could restrain himself. ‘It is overfull. No more will go in!’ ‘Like this cup’, Nan-in said, ‘you are full of your own opinions and speculations. How can I show you Zen unless you first empty your cup?’

Here, the need to let go of — to unlearn — long-held, unaccommodating beliefs, preconceptions, biases, expectations, knowledge, and presumed wisdom is a prerequisite to opening the mind to learn new and different things. The paradox is that arguably the professor might not be able, no matter how sincere his intentions, to disassociate from a lifetime of learning — unable to empty his metaphorical cup.

This is another classic koan:

A man traveling across a field encountered a tiger. He fled, the tiger racing after him. Coming to a precipice, the man caught hold of the root of a wild vine and swung himself down over the edge. The tiger sniffed at him from above. Trembling, the man looked down to where, far below, another tiger was waiting to eat him. Only the vine sustained him.

Two mice, one white and one black, little by little started to gnaw away at the vine. Just then, the man saw a luscious strawberry near him. Grasping the vine with one hand, he plucked the strawberry with the other. How sweet it tasted!

The man faces inevitable death on all sides, trapped by a hungry tiger above and one below. He also faces the two mice, whose gnawing on the vine bodes increasingly dire outcomes. The man chooses to live in the moment, enjoying the luscious strawberry. It is a moment of sublime happiness. Seeing the tigers on each side, the man sees his life similarly bracketed: Before life he had nonexistence and after life he will return to nonexistence, for eternity. He is left with the present. We might similarly conclude the best option in life is to grasp that singular moment in which we relish the ‘strawberry’.

So, what to make of the koan, at the start of this essay, asking about the sound of one hand? The point is that a koan is dynamic and transformational, in the sense that it is, to recall the words of philosopher and Zen monk G. Victor Sogen Hori (in Zen Sand, 2003):

‘…both the object being sought and the relentless seeking itself. In a koan, the self sees the self not directly, but under the guise of the koan. . . . When one realizes (‘makes real’) this identity, then two hands have become one. The practitioner becomes the koan that he or she is trying to understand. That is the sound of one hand.’

In today’s world, heavily influenced by the ubiquity of the scientific method, analysis, quantification, and logic, people are heavily swayed by this way of thinking in which society seeks insight, knowledge, understanding, and even wisdom. But despite the significant contributions such approaches make available, they overlook and even obscure key aspects of the world and life. Perspectives on what motivates our thinking, our relationships, our values, our connections to the planet, our happiness, our fundamental nature, our intent, our enlightenment, and our potential.

In this way, the ancient koans — with their emphasis on intuitiveness, open-mindedness, and spirituality — are still able in the modern era to inform, inspire, and guide these vital human interests.