It is very telling that some religions refer to death as “eternal life,” and that in the Mahaparinibbana Sutta the Buddha doesn’t die. He enters parinirvana, full extinction, which is something other than death. In Buddhism generally, death isn’t death—it’s a staging area for further life. So there are many respectable and less respectable reasons to wonder about the question of death.

There are a lot of older people in the Buddhist communities in which I practice. Some are in their seventies and eighties, others in their sixties, like me. Because of this, the theme of death and impermanence is always on our minds and seems to come up again and again in the teachings we study. All conditioned things pass away. Nothing remains as it was. The body changes and weakens as it ages. In response to this, and to a lifetime’s experience, the mind changes as well. The way one thinks of, views, and feels about life and the world is different. Even the same thoughts one had in youth or midlife take on a different flavor when held in older age. The other day a friend about my age, who in her youth studied Zen with the great master Song Sa Nim, told me, “He always said, ‘Soon dead!’ I understood the words then as being true: very Zen, and almost funny. Now they seem personal and poignant.”

“All conditioned things have the nature of vanishing.” What is impermanence after all? When we’re young we know that death is coming, but it will probably come later, so we don’t have to be so concerned with it now. And even if we are concerned with it in youth, as I was, the concern is philosophical. When we are older we know death is coming sooner rather than later, so we take it more personally. But do we really know what we are talking about?

Death may be the ultimate loss, the ultimate impermanence, but even on a lesser, everyday scale, impermanence and the loss it entails still happens more or less “later.” Something is here now in a particular way; later it will not be. I am or have something now; later I will not. But “later” is the safest of all time frames. It can be safely ignored because it’s not now—it’s later, and later never comes. And even if it does, we don’t have to worry about it now. We can worry about it later. For most of us most of the time, impermanence seems irrelevant.

But in truth, impermanence isn’t later; it’s now. “All conditioned things have the nature of vanishing.” Right now, as they appear before us, they have that nature. It’s not that something vanishes later. Right now, everything is in some way—though we don’t understand in what way—vanishing before our very eyes. Squeezing uncomfortably through the narrow doorway of now, we don’t know whether we are coming or going. Impermanence may be a deeper thought than we at first appreciate.

Impermanence is not only loss; it is also change, and change can be refreshing, renewing. In fact, change is always both good and bad, because change, even when it is refreshing, always entails loss. Nothing new appears unless something old ceases. As they say on New Year’s Eve, “Out with the old, in with the new,” a happy and a sad occasion. As with the scene in the Mahaparinibbana Sutta, there’s despair and equanimity at the same time. Impermanence is both.

In one of his most important essays, the great twelfth-century Japanese Zen master Dogen writes, “Impermanence is itself Buddha Nature.” This seems quite different from the classical Buddhist notion of impermanence, which emphasizes the loss side of the loss/ change/renewal equation. For Dogen, impermanence isn’t a problem to be overcome with diligent effort on the path. Impermanence is the path. Practice isn’t the way to cope with or overcome impermanence. It is the way to fully appreciate and live it.

“If you want to understand Buddha Nature,” Dogen writes, “you should intimately observe cause and effect over time. When the time is ripe, Buddha Nature manifests.” In explaining this teaching, Dogen, in his usual inside-out, upside-down way (Dogen is unique among Zen Masters in his intricately detailed literary style, which usually involves very counterconceptual ways of understanding typical concepts), writes that practice isn’t so much a matter of changing or improving the conditions of your inner or outer life, as a way of fully embracing and appreciating those conditions, especially the condition of impermanence and loss. When you practice, “the time becomes ripe.” While this phrase naturally implies a “later” (something unripe ripens in time), Dogen understands it is the opposite way: Time is always ripe. Buddha Nature always manifests in time, because time is always impermanence.

Of course time is impermanence and impermanence is time! Time is change, development, loss. Present time is ungraspable: as soon as it occurs it immediately falls into the past. As soon as I am here, I am gone. If this were not so, how could the me of this moment ever give way to the me of the following moment? Unless the first me disappears, clearing the way, the second me cannot appear. So my being here is thanks to my not being here. If I were not not here I couldn’t be here!

In words, this becomes very quickly paradoxical and absurd, but in living, it seems to be exactly the case. Logically it must be so, and once in a while (especially in a long meditation retreat) you can actually, viscerally, feel it. Nothing appears unless it appears in time. And whatever appears in time appears and vanishes at once, just as the Buddha said on his deathbed. Time is existence, impermanence, change, loss, growth, development—the best and the worst news at once. Dogen calls this strange immense process Buddha Nature. “Buddha Nature is no other than all are, because all are is Buddha Nature,” he writes. The phrase all are is telling. Are: existence, being, time, impermanence, change. All are: existence, being, time, impermanence, change is never lonely; it is always all-inclusive. We’re all always in this together.

The other day I was talking to an old friend, an experienced Zen practitioner, about her practice. She told me she was beginning to notice that the persistent feeling of dissatisfaction she always felt in relation to others, to the world, and to the circumstances of her inner and outer life, was probably not about others, the world, or inner and outer circumstances, but instead was about her deepest inmost self itself. Dissatisfaction, she said, seems in some way to be herself, to be fundamentally engrained in her. Before realizing this, she went on, she’d assumed her dissatisfaction was due in some way to a personal failing on her part—a failing that she had hoped to correct with her Zen practice. But now she could see that it was far worse than that! The dissatisfaction was not about her, and therefore correctable; it was built into her, it was essential to her self!