Sleep is determined by the manas, yet the manas does not possess the mind to cause the six consciousnesses to cease. It has no concept of the six consciousnesses; it is merely that the mental factor of volition decides not to cognize the six dust realms. The Tathagatagarbha then complies, causing the seeds of consciousness to arise less and less frequently and more and more slowly. The cognition of the six consciousnesses grows increasingly faint until they finally cease, resulting in sleep, where body and mind attain tranquility. The brain's nervous system issues fewer and fewer commands, the body's various metabolic activities decrease, consumption diminishes, and the energy within the body becomes abundant and full. The manas perceives that it can smoothly direct the activities of body and mind with minimal hindrance, and thus it seeks to cognize the six dust realms and desires the activities of the five aggregates. The Tathagatagarbha complies, giving rise to the six consciousnesses, and so one awakens from sleep.
From this, it is evident that the manas cognizes the condition of the physical body with great precision and arranges the five aggregates of the physical body in an orderly manner. If rest is planned for the next day, it allows the physical body to sleep longer, not rushing to engage the five aggregates in activity; if there are matters to attend to the next day, it causes the physical body to rise earlier. The mental activities of the manas are remarkably complex, sensitive, and flexible; its wisdom is not shallow, nor does it rely on the conscious mind to carry out these tasks. It works entirely alone, requiring no assistant. How could anyone claim that the manas possesses inferior discernment? If it were entirely inferior, at all times and in all respects, what activities could the entire aggregate of the five ever accomplish?
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