Why Can Closing the Eyes Nourish the Spirit?

"Shen" (spirit) refers to the mind consciousness. First, it refers to the eye consciousness; second, the mind consciousness; third, the manas. The eighth consciousness does not need nourishment; it consumes no energy and is never tired.

Can the manas get tired? Since beginningless kalpas, the manas, like the eighth consciousness, has never rested. Although it does not always bear its burdens without complaint, it grasps at all dharmas and worries about everything. When does it finally become unwilling to worry?

The manas also has times of weariness, boredom, and fatigue. It cannot be consistent from beginning to end. So the manas also needs rest, shifting its attention to relatively relaxed and pleasant things, and no longer clinging to troubling matters. When there is too much clinging and it can no longer carry the load, it also knows to set things down temporarily.

What most needs nourishment is the mind consciousness, because whenever the mind consciousness moves, it consumes some nutrients, especially brain cells. When material energy is insufficient, the mind consciousness feels fatigued. When there is a great deal of thinking, the mind consciousness's train of thought can no longer keep up; at this time it needs rest, no longer discriminating, distinguishing, discerning, or deliberating.

Does the eye consciousness need nourishment? When the eyes look at things for a long time, the eyes will ache, vision will decline, things will appear unclear, and there will be dizziness and a swollen head, and so on. However, this is not a problem of the eye consciousness, but rather that the eye faculty, fixed on one object for a long time without moving, causes neural fatigue. The material form of the eye faculty belongs to a part of the body faculty; when a problem arises in the eye faculty, it is a problem of the body faculty. The sensation of fatigue and soreness is tactile sensation, which is what the body consciousness discerns.

Because the eye faculty spends a long time viewing objects, it consumes more energy. The attention of both the manas and the mind consciousness is directed onto one object, which requires consuming brain cells and can also cause fatigue and weariness. If the optic nerves being constantly taut were not a problem, then it would not matter how long the eye consciousness views objects.

The optic nerves connect to the liver meridian. Viewing objects over a long period causes fatigue and damage to the liver meridian, and the liver will develop problems. When the liver has problems, it affects the thinking and discrimination of the mind consciousness. The physical body influences the conscious mind, and the conscious mind also influences the physical body; body and mind are mutually dependent.

In fact, the conscious mind never has problems; the issue lies in whether the body's material energy can be supplied sufficiently. The normal functioning of the conscious mind requires the six sense objects to appear normally and the brain cells to function normally. If material form is consumed excessively, or the supply is insufficient, the operation of the conscious mind will be affected, and it can no longer perform its function of discrimination normally.

Closing the eyes to rest the spirit can also be described as regulating the activity of the nervous system, not letting the nervous system become overly or excessively active—especially rigid, unidirectional, relentless activity—so that the body is not damaged.