The World Between Breaths: Mu and Buddha Nature
Note: This article appeared in the Fall 2023 issue of Buddhadharma: The Practitioner’s Journal.
It’s not night, yet it’s so dark down where she is, that if she was to hold up her hand in front of her face, only the light of her lamp would help her distinguish her palm, the line she has followed down, and not much else. It’s dark, and freezing, and though the light wetsuit she wears offers little protection against the cold, she doesn’t feel it. Rather, she’s not aware of the cold, nor of time or space. She doesn’t remember, she doesn’t think, she doesn’t anticipate. All she knows is the weight of water. All she feels is its vastness and the blessed respite it gives her from the life above.
As she descends, the pressure of the ocean squeezes her lungs, the corresponding lack of air in them making her body heavier. This is how the ocean pulls her into its depths. This is how she lets it, not moving a single muscle, yet flying through the water in a perfect free fall. It’s not until she turns to begin her ascent that she exerts effort. She begins a slow and graceful dolphin kick that undulates through her body all the way to the tips of her fingers stretched overhead until, just before she reaches the surface, she lowers one hand and lets the last bit of momentum propel her back into the world of air and light.
She takes a breath, her first in a while, looks around, then briefly closes her eyes, the silence below already calling to her again. Nowhere else does she know this depth of quiet. Nowhere else does she feel so irrevocably, so unquestionably right. It’s only in this world between two breaths where she knows herself as she really is: indivisible from water and everything that surrounds her. It’s only in this world where she knows, without question, she is perfect, and whole.
I do not free dive. Or rather, I don’t free dive in the ocean, although the concept fascinates me. It’s not the length of time that some of these athletes spend under water that impresses me most (over ten minutes in some cases), or the depth they reach (almost 370 ft). What draws me is the necessary focus and surrender and utter commitment to stillness. After all, these are the same qualities needed to execute a different kind of plunge: the dive into awakening or the realization of our true nature.
Both as a water lover and as a meditator, I well understand the allure of the depths—the place where there’s no sound, no self, no other, no thing; where there’s nothing but being, and that, only faintly. That’s why, for me, the figure of the free diver so perfectly captures the “immersion” we go through in deep meditation. At the same time, I believe the image becomes truly perfect in that instant when the diver breaks the surface of the water and is held suspended for a moment, in both worlds: absolute and relative, ocean and air—and by extension land and all it contains. In Buddhism, that’s the moment in which we realize our buddha nature.
Buddha nature (Skt. buddhadhatu), buddhanature, or true nature is a Mahayana teaching that encapsulates both the potential for buddhahood—our true or awakened nature—as well as its expression. It’s both who we are and what we’re trying to become; what is, indistinguishable from what can be. As Thirteenth Century Zen Master Dogen said, only a person of suchness (tathata; often used interchangeably with buddha nature) can realize suchness. It’s only because we have the potential to awaken that we can actually do so. This seems obvious until we start to practice and frustration, doubt, disappointment, boredom, all rear their heads and make us wonder why we ever decided to commit to a spiritual path. In our struggle, what is perfect appears flawed, what is whole seems broken, and what is not only enough but immeasurable appears small and woefully inadequate. With or without practice, all of us have looked in the mirror at some point and thought, “I can’t. I’m not.”
This kind of self-doubt is excruciating in the best of circumstances; in the worst, it can be crippling. In Zen, however, doubt can be harnessed into what is called “great doubt,” and this is exactly what “Mu,” arguably the most famous of all Zen koans, is meant to encourage: doubt so all encompassing, that it helps us to break through both conceptual thinking (in Sanskrit prapañca) and the emotional obstacles or kleshas that prevent us from seeing our buddha nature.
A monk once asked Master Zhaozhou, “Does a dog have buddha nature or not?”
Zhaozhou answered, “Mu!” (“No” or “nothingness.”)
Mu opens the Wumenguan or Gateless Gate, a record of forty-eight “public cases,” as koans are translated, that thirteenth century Chinese master Wumen Huikai used to teach his monks. Longer versions of this brief dialogue appear in other sources, but it’s this exchange that has come down to us through the ages as the “koan of koans,” the “gateless barrier of Zen,” and the “red hot iron ball” a student swallows but cannot cough up.
The monk, presumably a student of the great Master Zhaozhou, had to know that since the fifth century, the accepted teaching in all the various schools of Mahayana Buddhism was that buddha nature permeates all of reality. It is the essence of both sentient and insentient beings—their bright, luminous nature. His question was therefore a challenge to his teacher or a thinly veiled expression of his own doubt. (“Dogs and cats may have buddha nature, but do I? Why don’t I know it, if it’s universal?”) In response, Zhaozhou simply said, “Mu,” presenting him and generations of Zen students with one of the most powerful, potentially transformative questions (What is Mu?) they would ever face.
As is the case with other Buddhist teachings that have entered popular culture, koans are sometimes misunderstood. They’re neither riddles nor puzzles. They’re not nonsensical statements a teacher dangles before students to prod them to sit zazen. Koans are unique spiritual tools, and because Mu is usually the first case that a student takes up during their training, it has a potency that time and familiarity with a long series of koans can blunt. That first time, after spending months or years methodically developing concentration, a student is presented with a question that the intellect cannot meet—not in the way required to see through the heart of what Mu is pointing to, which is essentially the essence of our being.
“Begin by following Mu,” my teacher said when he first gave me the koan to work with during zazen. “With each exhalation, silently recite Mu, letting that one word fill all of your body and mind. Don’t worry about what it means—this isn’t about meaning. Your job is to see Mu itself. And the only way to see Mu,” he said, leaning forward in his seat, “is to be Mu!” Then he rang his bell, sending me out of the dokusan room.
I diligently did what he told me, and after a while, he asked me to start questioning Mu. He repeated that the task was not to figure it out, but to realize it directly. At the time, I had no idea what he meant—I simply had no frame of reference for this kind of knowing. I’d trusted my intellect for far too long to let go of it easily and was used to working hard for anything I wanted to achieve. I didn’t know how to do less, know less, and let go of control. Predictably, it was a long ride.
It’s difficult to explain how Mu works to bring about the first glimpse into our buddha nature. You sit on your cushion going, “Mu, Mu, Mu,” periodically asking yourself what it is, and one day, seemingly out of the blue, you get an insight into the very fabric of the self and reality. It seems almost magical. But one simple way to think about how Mu works is in terms of a common metaphor for buddha nature: that of the sun obscured by clouds. The sun is ever present in the sky, always shining, always radiating heat, although sometimes we can’t see its light or feel its warmth. When our mind sky is filled with clouds—our endless internal dialogue, our conflicting emotions, the many thoughts and beliefs that keep us firmly entrenched in a limited view of who we are—the sun is hidden and inaccessible. But when those clouds part through the practice of calming the mind (shamatha), insight (vipasyana) into our ever present, bright, luminous nature has a chance to arise. The only point where this metaphor fails is that it seems to discount the clouds as obstacles—as hindrances that get in the way of our seeing clearly into who we are. And although on one level this is true, when the clouds do eventually part, we realize they were never a problem. Neither sun nor sky nor clouds obscure each other. How could they, when they are of the same nature? They are all perfectly, inarguably Mu—not obstacle but gate.
Because I spent a bit of time working on this koan myself, I had the opportunity to watch, and sometimes struggle through, all sorts of mind states in the process of questioning Mu. First I was gung-ho, then doubting, then indifferent. I went through a period where I was intensely afraid, but I couldn’t tell you why. I went through a bitchy period, where I could barely stand myself or others. And at one point, I realized I was gay—which wasn’t much of a realization since everyone seemed to know long before I did. But it did shift my life fundamentally for the better, and I have Mu to thank for that. It’s of course possible I would have seen it eventually without ever working on a koan, but I think the opposite is less likely: it's hard to remain in a closet (of any kind) when you’re spending day after day questioning who you are. It still didn’t help me to see Mu, but when I finally did, it was not surprisingly the image of water that helped me.
“Zuisei, do you realize you’re leaning?” one of the seniors at the monastery where I trained said to me after yet one more sesshin where I’d failed to see Mu.
“Leaning?”
“Yes, like this,” he said, holding his hand up in front of his face at a forty-five-degree angle.
No, I hadn’t realized it, but the moment he said it, I flashed on something my teacher had said to me recently, “Sometimes it’s your very effort that stops you.”
That was the moment when I realized I was trying too hard. I had to relax into Mu, but how? I thought of those times when my body felt most relaxed, most at ease with itself, and immediately thought, Water. Then I proceeded to create a little ritual for myself. Every time I took my seat for zazen, I imagined that with each consecutive hit of the timekeeper’s bell, I was slowly immersing myself in a clear pool filled with warm water. Ching! And I was in water up to my knees. Ching! Now it covered my chest. Ching! I was fully immersed, sitting at the bottom of the pool, and every molecule of water was Mu and every molecule in my body was also Mu. After a month of this, on the first full day of our next monthly sesshin, I saw it.
It took a while, but eventually it occurred to me that if I could only trust that the bright, luminous nature of my mind was there, and shining, then all I had to do was get out of the way and let it.
In 1963, the physiologist Per Scholander discovered what he called the “Master Switch of Life,” a series of reflexive changes in the body that get triggered the moment a vertebrate animal dives. Also known as the “mammalian diving reflex,” it causes the redistribution of blood away from the extremities and toward the two organs that need the oxygenated blood the most: the brain and the heart. As a bonus, it also protects the lungs from collapsing under the water’s intense pressure, and it happens automatically the moment the animal dives. The trick—for free divers, at least—is to not give into the panic of non-breathing and relax into a different way of being, at least for a little while.
I’d like to propose that the koan Mu is also like this Master Switch of Life: it shifts our way of perceiving from our “normal” cognitive processing to the direct apprehension of an object as it is. In other words, if, while working on Mu we can resist the impulse to think our way through the problem of not knowing who we are, and instead relax profoundly into a different, yet-to-be-discovered kind of knowing, then the answer will eventually reveal itself, because it was always there. The answer to Mu is therefore not new or even transcendental, but simply the extra-ordinary experience of who we are. And to get there, what’s needed is trust in stillness and silence as deep and vast as the ocean. What’s needed is the faith that between one breath and the next, an entire world exists—that realm where we realize that what we’ve so long been looking for, we have always been.
*Photo by Jeremy Bishop