Phenomena and differentiation reappear with the light. Differentiation is where we begin our practice. We come into training steeped in the world of duality, tossed by this and that event or object. After years of practice, after taking the backward step and turning deep into ourselves, we discover the unity of all things. Then, like a fly on fly-paper we begin to stick to emptiness, just like many Buddhist practitioners have stuck to it through the centuries. The absolute basis of reality is an easy place to get stuck. But if you study with a teacher who is alive and kicking, he or she will expend effort to loosen the bonds so that you can again see the world of differentiation, but from a totally different perspective. We must see that the truth is in neither the absolute nor the relative.

In the second of his Five Ranks, Dongshan says, “The old grandmother, having just awakened, comes upon an ancient mirror. That which is clearly reflected in front of her face is none other than her whole likeness. Don’t lose sight of your face again and go chasing your shadow.” The second rank is the emergence out of the absolute basis of reality. In the absolute realm there is no knowing. There is no consciousness. The moment you realize it, consciousness has already moved. It’s after the fact. It is on the cusp of that awakening that everywhere you go you meet yourself. You return into the world of differentiation, back to the other side of darkness. Most of koan study is dedicated to investigating these two realms in order to appreciate the third rank of Dongshan, which goes beyond the absolute and relative.

In the second rank we deal with phenomena of the relative world. In the “Mountains and Rivers Sutra,” this is referred to as mountains walking. It’s the continual flux of all things. Nothing is fixed. Everything is in a constant state of becoming. You, me, everything we see, think, feel, experience, everything in the whole universe is in a ceasless state of flux. Nothing is static. This impermanence is the cause of much of our suffering because we tend to cling to things. When we grasp, the thing we’re holding on to changes and we change. Yesterday already happened—it doesn’t exist. Tomorrow hasn’t happened yet—it doesn’t exist. This moment and the next moment are different, so what is the use of clinging?

Dogen says, “Because the blue mountains are walking they are constant. Their walk is swifter than the wind; yet those in the mountains do not sense this, do not know it. To be ‘in the mountains’ is a flower opening ‘within the world.’ Those outside the mountains do not sense this, do not know it. Those without eyes to see the mountains do not sense, do not know, do not see, do not hear this truth.”

“Because the blue mountains are walking they are constant.” They are constant or endless, a continuum that encompasses the whole universe, past, present and future. It’s not just now. Or rather, it is just now, but this now contains past, present and future.

“To be ‘in the mountains’ is a flower opening ‘within the world.’” Another way of saying this is “opening within the world flower.” Isn’t that interdependent origination? “Opening within the world flower” means that mountains and the world are the same. Nothing exists outside the mountains. In fact, we say “in the mountains” or “outside the mountains,” but “in the mountains” doesn’t mean there is someone in them literally. It’s not like going for a hike in the mountains. It’s speaking of the mountains themselves as those in the mountains. “Those outside the mountains” means that the mountains themselves are called “outside the mountains.” It reaches everywhere. Everywhere I go, I meet it.