When we talk about zazen, we need to be careful that our instructions do not casually reinforce the habitual dualities of body/mind and self/world. Yet, the most common instruction that newcomers are given does exactly this, the injunction to allow thoughts to come and go freely.
Perhaps we give this instruction because newcomers are always surprised and distressed at the unrelenting cascade of drivel that appears to be surging through them the moment they start sitting. But zazen is the practice of all of us, not just the mind.
After a while, what becomes more apparent is the persistent colouring of experience in a way that is often very disagreeable: agitation, fear, torpor, boredom, despair. How do we advise the student then? If we call these emotions, we somehow allocate them to the mind. If we call them disturbances of the nervous system, we somehow allocate them to the body. Either way, the duality is enforced.
We need to find a way to talk about practice which doesn’t take these familiar dualities for granted, only to try to dissolve them later.
One way is through the actual experience of breathing. If we pay careful attention, it is not that our breath is the movement of air in and out of our lungs, in and out of our mouth and nose. Our actual experience is that our breath goes everywhere. It goes up, into our head, it goes down, into our pelvis. It extends everywhere.
And, experiencing the breath in this way, it is possible to see a different duality: the dynamic movement of this spacious breath, like an expanding and contracting pillar of emptiness at our core. And around this pillar, likewise alive, likewise moving, the fabric of form; a fabric which is sometimes the body, sometimes the mind, sometimes the heart, sometimes the world.