The Difference Between Sleep and Meditative Concentration

The Difference Between Sleep and Meditative Concentration (Samādhi)  So-called meditative concentration means that the mind's thoughts are concentrated and not scattered, gathering in the six faculties and resting on a single object, without scattered grasping at various objects. The eye consciousness and mind consciousness focus on one material sense-object, shutting out other sense-objects; or the ear consciousness and mind consciousness focus on one sound sense-object, shutting out other sense-objects; or the mind consciousness focuses on one mental sense-object, shutting out other sense-objects. In these states of focus of the six consciousnesses, the mind consciousness takes the lead; the manas governs all dharmas. If the manas does not scatter its grasping and only rests on a few mental sense-objects, the six consciousnesses can focus on a single object. Because the manas is the consciousness that takes charge, and the six consciousnesses must all obey the manas's directives, only by subduing the manas can meditation practice be effective.

So-called sleep means that all six consciousnesses temporarily cease and do not manifest; only thus can the body and mind eliminate fatigue. If the six consciousnesses do not cease, the consciousness-mind has active functioning, just as when awake, and this is not sleep. In that case, the body and mind cannot get true rest, and the body still feels just as tired as before.

Sleep is divided into two kinds: with dreams and without dreams. When asleep without dreams, the six consciousnesses do not arise; only the eighth consciousness and the seventh consciousness remain at their posts, sustaining the life activities of the physical body. When dreaming, the mind consciousness participates in slight discriminating activity within the dream; thus the sleep is not deep, the body cannot get sufficient rest, and the next day one will feel fatigued.

In both meditative concentration and sleep, the seventh and eighth consciousnesses are running. In meditative concentration, the seventh consciousness has already been effectively subdued, and its grasping has decreased; the less and lighter the grasping, the deeper the mind consciousness enters meditative concentration. In sleep, the seventh consciousness still grasps at the body faculty and mental sense-objects; it merely knows that the body needs rest and does not let the six consciousnesses come out to discriminate.

In the meditative concentration before the first dhyāna, there are six consciousnesses discriminating the six sense-objects, but the degree of discrimination of the six sense-objects differs, the degree of single-mindedness of the consciousness-mind differs, and the feelings of body and mind also differ. In the first dhyāna, the nose consciousness and tongue consciousness do not arise. In the dhyānas of the second dhyāna and above, the first five consciousnesses disappear, leaving only the sixth, seventh, and eighth consciousnesses; the mind consciousness abides in a relatively deep and subtle state of meditative concentration, discerning the mental sense-objects of that meditative state. In the samādhi of no perception (asaṃjñi-samāpatti) and the cessation attainment (nirodha-samāpatti), the mind consciousness also completely ceases, leaving only the seventh and eighth consciousnesses.