“In Zen training we seek to extinguish the self-centered, individual ego, but we do not try to do this merely by thinking about it. It is with our own body and mind that we actually experience what we call ‘pure existence.’
The basic kind of Zen practice is called zazen (sitting Zen), and in zazen we attain samadhi. In this state the activity of consciousness is stopped and we cease to be aware of time, space, and causation. The mode of existence which thus makes its appearance may at first sight seem to be nothing more than mere being, or existence. However, if you really attain this state you will find it to be a remarkable thing. At the extremity of having denied all and having nothing left to deny, we reach a state in which absolute silence and stillness reign, bathed in a pure, serene light. Buddhists of former times called this state annihilation, or Nirvana...
In ordinary daily life our consciousness works ceaselessly to protect and maintain our interests. It has acquired the habit of utilitarian thinking, looking upon the things of the world as so many tools – in Heidegger’s phrase, it treats them ‘in the context of equipment.’ It looks at objects in the light of how they can be made use of. We call this attitude the habitual way of consciousness. This way of looking at things is the origin of man’s distorted view of the world… Zen aims at overthrowing this distorted view of the world, and zazen is the means of doing it.

On coming out of samadhi it can happen that one becomes fully aware of one’s being in its pure form; that is, one experiences pure existence. This experience of the pure existence of one’s being, associated with the recovery of pure consciousness in samadhi, leads us to the recognition of pure existence in the external world too. Discussion of these topics inevitably leads us into epistemological tangles, but let us proceed for the moment, granting that such recognition of pure existence is possible. To look at oneself and the objects of the external world in the context of pure existence is kensho, or realization.
This experience, as we have stressed, is attained by the training of body and mind. Reason comes later and illuminates the experience, and thus the two wheels of the cart of cognition are completed.”