For the serious student, posture is the first step in zazen or sitting in meditation. It is a peculiar fact that for spiritual practice, first of all the posture of the body must be made just right, whereas in physical training we always have to make sure that it is approached in the proper “sporting” spirit, getting that right first. In zazen, then, we have to see that the body is in the posture laid down as correct. Zen master Dogen, in the Fukan Zazen-gi classic on meditation, gives full details.
As to place, a thick mat is spread, the small round meditation cushion put on it, and the seat taken on that. If there is no meditation cushion, an ordinary cushion doubled over may be used. The rear half of the buttocks is placed on the cushion, and the seat made firm. There are two main postures, the fully locked and the half-locked positions. The names refer to the placing of the legs. In the first the legs are locked together by first setting the right foot on the left thigh and then bringing the left foot over onto the right thigh The right hand, palm upward, is laid on the left foot, and the left hand, also palm upward, on the right hand. The tips of the thumbnails are to be touching. The spine is quite straight and erect, neither inclined to the left nor leaning to the right, neither bending forward nor falling back, but with ears in line with the shoulders and the nose above the navel . Such is the correct meditation posture. The tongue touches the upper jaw, the mouth is closed, and the eyes slightly opened. The breathing should be natural, but so that the breath as it passes through the nostrils is barely audible. In this way the body is settled for meditation.
The half-locked position is putting just the left foot on the right thigh . However, as a change, the left foot can be taken down and the right foot put on the left thigh. The Zazen-gi only mentions the position with the left foot on the right thigh, but for students either position, namely with just one foot on the opposite thigh, can be taken as the half-locked position. The other points are the same as in the fully locked posture.
Beginners may use the half-locked position first and slowly progress to the fully locked. Those who always wear Western clothes and sit in chairs find the fully locked position difficult, and they may sit on their feet in the Japanese way, or it is also permissible to sit for meditation on a chair. People should select the position they can manage.
The ancient classification of human posture is into four: walking, standing, sitting, and lying. It may be asked why the Zen rule prescribes only sitting. On this the Patriarch Dogen says: “Of the four, why is the sitting posture alone given as appropriate for meditation and realization? Know then that from ancient times all the Buddhas have followed this practice as the path to enter satori. To the request for a reason, let it merely be known that the reason is that this is the way of the Buddhas, and one should not ask further. The patriarchs praise it as the gateway to peace and bliss. This is not the way of practice of only one Buddha or two Buddhas, but the path of all the Buddhas and all the patriarchs.”
For one who has realized and is in the Samadhi of Buddha-in-his-own-glory, there is no necessity to stick to going or standing or sitting or lying exclusively, but in general the correct sitting posture, the fully locked position, is the right way—so we are told by generations of patriarchs and teachers of the past who followed the example of Shakyamuni Buddha and have left a record of their own experience.