The concept of emptiness—shūnyatā—in Mahayana Buddhism is perhaps a subject best avoided in casual conversation. It so vexes everyone not least because of issues of translation: "emptiness," many scholars think, hardly suffices as a substitute. In English it has a more distinctly nihilist flavor than was intended. Yet emptiness is so indispensable that it can hardly go unmentioned when the practice and purpose of meditation come up in Buddhist thought.
Leave it to Zen to put things in such succinct and down-to-earth ways: the practice of meditation is to develop “’no mind,’” says Suzuki Roshi. It is to have “no gaining idea.” The reason is to have no reason. But from the same point of view, there is a point: “the point we should make clear in our practice,” the Zen master tells us: we should "put more emphasis on big mind rather than small mind.”
If you need more clarification, you might turn to another Zen popularizer who also began to draw audiences in California in the 50s: Alan Watts. Watts came to San Francisco not with a lifetime of monastic training in Japan, but through his training as an academic, Episcopal priest, and Zen enthusiast in Britain. He is wordier, less poetic, and more essayistic in his delivery, but in discussing the purpose of meditation, you will find him saying the very same things as the Zen masters:
Meditation is the discovery that the point of life is always arrived at in the immediate moment. And therefore, if you meditate for an ulterior motive — that is to say, to improve your mind, to improve your character, to be more efficient in life — you've got your eye on the future and you are not meditating!
As for Suzuki's “big mind," Watts has his own version: “The art of meditation is a way of getting into touch with reality… our basic inseparability from the whole universe.” These are not necessarily synonyms for “emptiness,” but the idea of having no idea maybe comes close to summarizing the concept. “Not knowing,” as the koan says, “is most intimate.”
Maybe it’s hair-splitting and belabors the comparison, but Suzuki Roshi did not talk about meditation as a way to stop all thinking. This is futile, he would argue. Watts seems to suggest otherwise when he says that “we become interiorally silent and cease from the interminable chatter that goes on inside our skulls. Because you see, most of us think compulsively all the time." Most honest people will tell you they think compulsively during meditation as well. But in his guided meditation above, Watts acknowledges just this fact.
Indeed, his matter-of-fact way of recognizing the ever-presence of thought is what makes the instructions he gives so useful, even if they are also, ultimately, pointless. Hear the original fifteen minute guided meditation at the top of the post and an edit, with some, maybe distracting, background music, just above. To let thinking recede into the background, we must engage our other senses, letting every sound and sensation come and go and the autonomous nervous system take over.
How to let go of thinking about thinking? Let Watts guide you in an exercise and see what happens. Then listen to Suzuki Roshi describe the Buddhist philosophy of emptiness. As far as meditation, or "zazen practice," goes, he says, our zazen practice is based on... the teaching of shūnyatā or emptiness," which is not an idea but an experience of "letting go of fixed ideas," writes another Zen master who brought his practice to the U.S., "in order to go beyond them."