The dharma of the manas is deeper and subtler than that of the mind consciousness

When asleep, because one feels the quilt is heavy, one turns over automatically, yet at that moment one is not aware of it. Are there body consciousness and mind consciousness present then? Turning over is also a function of consciousness. The sense faculties are themselves passive receivers and transmitters; without consciousness, the faculties would be mere wood and stone. When the manas wants to turn over, the six consciousnesses emerge and set the body in motion; at that time there is faint body consciousness and mind consciousness. Why does the manas decide to turn over? Because it discerns that the quilt is heavy. The manas makes contact with this mental sense-object and knows it affects the body, so it lets the body consciousness and mind consciousness come out to discern it. When the body consciousness and mind consciousness feel the heaviness, the manas decides to turn over, and then the body consciousness and mind consciousness together turn the body over. If one turns over a bit too many times, sleep becomes poor, and the next day one feels physically exhausted, because the six consciousnesses keep appearing and the body has not rested well. If turning over in sleep were not the function of the six consciousnesses, then during a coma, when the manas wants to move the body, it should be able to move it. Yet in a coma the body cannot move; although the manas constantly wants the body to become active and to bring oneself back to consciousness, it cannot be done.

When turning over in the middle of the night, because the body is fatigued and the mind consciousness is weak, one may not necessarily be able to introspect on one's own operation. Depending on the degree of strength or weakness of the mind consciousness, the power of introspection also differs. Therefore, some people know what state they were in during the night and what they did; others do not know. When they do not know, the sleep is deep and the quality of sleep is good. Nevertheless, there is still a rapid yet faint discernment by the mind consciousness. When the mind consciousness is faint, one can hardly perceive the mind consciousness's own existence and operation, and the function of the manas stands out. What the manas directly discerns, in many cases, the mind consciousness does not necessarily know; and since the manas has no names and words, it cannot express it.

The manas silently encompasses all dharmas, whereas the mind consciousness does not; therefore, what the manas discerns must forever exceed what the mind consciousness discerns, and it is far deeper and subtler than the mind consciousness. Hence the dharmas of the manas are deeper, subtler, and more important than those of the mind consciousness; whether one becomes a Buddha or not depends entirely on the manas. The operation of the manas itself cannot be called simple or complex, because the manas's discerning wisdom is poor; the manas cannot introspect and analyze its own operation of contacting mental sense-objects and discerning mental sense-objects. Mental sense-objects are so important that when the manas cannot discern them clearly itself, it summons the mind consciousness to come out and discern them.