We are not conscious of our breathing. I don’t think there is anyone here who is consciously exhaling and inhaling. However, in Zen practice, you are asked to be aware of your breathing. This is something that is unavoidable, even though it would be better not to have to do such an inconvenient thing as to be conscious of breathing. In any case, I would like you to concentrate on your breathing: inhaling, exhaling, inhaling, exhaling—one breath at a time, gently, carefully, sincerely. By concentrating on the breath you can gradually enter asamadhi (concentration) of breathing, a samadhi of awareness.
However, as long as you are conscious of samadhi, the “you” who is conscious of it is still outside of samadhi. If you are truly in samadhi, it is not possible to be conscious or perceive that you are in samadhi. What I would like you to do is “grind up” consciousness by means of that awareness—grind it up like sesame seeds in a mortar. It may take some time to “grind up” consciousness by means of consciousness, but if you persevere in being conscious of the breath, it is certainly possible to enter samadhi. When you enter samadhi, you will return to the condition when you were unaware of your breathing.
This may seem troublesome and complicated. Nevertheless, Zen practice is the process of first knowing something and then, by means of “grinding up” that awareness, returning full circle to the beginning. If two people are in the same state or condition and are leading the same kind of life, one person can, while being conscious of his or her breathing, walk the Way. It is certainly possible for such a person to attain liberation. In contrast, the other person is doing nothing except simply sitting. For this person there is no liberation. Consequently, there is the difference of heaven and earth between them.