“The Shorter Discourse on Emptiness concludes with this insight: to dwell in emptiness means to inhabit fully the embodied space of one’s sensory experience, but in a way that is no longer determined by one’s habitual reactivity. To dwell in such emptiness does not mean that one will no longer suffer. As long as one has a body and senses, one will be “prone to the anxiety” that comes with being a conscious, feeling creature made of flesh, bones, and blood. And this would have been just as true for Gotama as it is for us today.

Here, emptiness is not a truth—let alone an ultimate truth—that is to be understood correctly as a means to dispel ignorance and thereby attain enlightenment. For Gotama, the point is not to understand emptiness but to dwell in it. To dwell in emptiness brings us firmly down to earth and back to our bodies. It is a way of enabling us to open our eyes and see ordinary things as though for the first time. As the Buddha instructed his student Bahiya, to live in such a way means that “in the seen, there will be only the seen; in the heard, only the heard; in the sensed, only the sensed; in that of which I am conscious, only that of which I am conscious.

[…]

From the age of twenty-seven to the age of thirty-one, I continued my Buddhist monastic training in a Son (Zen) monastery in South Korea, where the sole meditation practice was to sit facing a wall for ten to twelve hours a day asking oneself: “What is this?” I have been guided by this impossible question ever since. It has led me away from a religious quest for ultimate truth and brought me back to a perplexed encounter with this contingent, poignant, and ambiguous world here and now. The Son tradition originated in seventh-century Tang China as a reaction against the overly metaphysical concerns of the established Buddhist schools. It sought to recover the simplicity of early Buddhism by following Gotama’s example of sitting still beneath a tree in an uncompromising engagement with the primordial questions of what it means to be born, get sick, grow old, and die. The Son masters realized that the very way in which you posed these questions would determine the kind of “enlightenment” you might gain. A famous aphorism encapsulates this realization:

Great doubt—great awakening;

Little doubt—little awakening;

No doubt—no awakening.

The quality of your “doubt”—of the questions you ask—is directly correlated to the quality of your insight. To ask such questions viscerally will engender a correspondingly visceral awakening. To pose them intellectually, with “little doubt,” will lead only to intellectual understanding. For those who are not stirred by existential questions at all, awakening is not even conceivable. Son practitioners rejected the metaphysical learning of scholar-monks not because they disagreed with their conclusions but because they disagreed with the way the scholars posed the questions in the first place. To practice Son means to ask these questions with the whole body, with “its 360 bones and joints and the 84,000 pores of one’s skin,” so that it becomes a “solid lump of doubt.” Moreover, the doubt needs to reach a critical mass, “like a red hot iron ball, which you have gulped down and which you try to vomit but cannot.

To sustain this kind of urgent perplexity entails learning how to remain in a balanced, focused, and inquiring frame of mind without succumbing to the seductive lure of “it is this” and “it is not that.” To pose a question with sincerity, you need to suspend all expectations as to what the answer might be. You need to rest in a condition of unknowing, vitally alert to the sheer mystery of being alive rather than dead. In this way, you cultivate a middle way between “it is” and “it is not,” affirmation and negation, being and nothingness. To tread this middle way in practice is like walking a tightrope: the path is constantly wobbling and shifting. We inhabit a linguistic realm where we cannot avoid using terms like “is” and “is not,” and a moral realm where we are bound to express preferences and make choices. The polarities embedded in human consciousness are useful, if not indispensable, in providing a framework to guide our course through life. They are like the pole carried by the tightrope walker that provides the crucial stability to take the next step. The point, therefore, is not to reject dualities in favor of a hypothetical “non-duality” but to learn to live with them more lightly, fluidly, and ironically. The danger of duality, against which the Buddha warned his followers, does not lie in oppositional thinking itself. Rather, it lies in how we use such thinking to reinforce and justify our egoism, cravings, fears, and hatreds.”