Why Do We Not Realize It Is a Dream While Dreaming?

Who is it that knows within a dream? Who is it that knows the dust realms upon awakening? Both the sixth and seventh consciousnesses possess knowing within and outside dreams. The knowing of all dharmas is primarily governed by the knowing of the sixth and seventh consciousnesses. The five consciousnesses can only perceive the five dust realms in reality and cannot perceive dream realms, for dream realms lack the five dust realms. The knowing of the mental consciousness is greatly related to the material body. When the material body encounters obstructions, the knowing of the mental consciousness becomes weak or ceases. Those who attain the four dhyānas and eight samāpattis have no obstructions in their material body; the knowing of their mental consciousness is clear, vast, and luminous. Whether asleep or awake, they can know with clarity and luminosity. Even after consuming many bottles of wine, they will not become intoxicated, for the wine can no longer paralyze the central nervous system of the brain, and thus the mental consciousness remains unaffected.

The knowing of the mental consciousness is also greatly related to the knowing of the mental faculty (manas). Generally speaking, the mental faculty knows all dharmas, though this involves the question of whether it can know them as they truly are. How the portion that the mental faculty knows as it truly is can influence the mental consciousness, enabling the mental consciousness to also know, and to process what is known in a timely manner, involves the communication capacity between these two consciousnesses. This so-called communication capacity is wisdom. How what the mental consciousness knows can effectively influence and guide the mental faculty also involves communication capacity, which is a matter of wisdom. Wisdom, in turn, is closely related to meditative concentration (dhyāna). Meditative concentration can calm, pacify, and stabilize the mind, enhance thinking capacity, and increase the power of wisdom. Thus, the mutual influence between these two consciousnesses becomes great. Meditative concentration can also render the material body unobstructed. When the material body is unobstructed, the mental consciousness encounters no hindrances; its knowing becomes sensitive, penetrating, and effective in influencing the mental faculty. Conversely, the mental faculty can also effectively influence the mental consciousness. When the two mutually communicate and share, the knowing of all dharmas becomes smooth and encounters little obstruction.

The state of unity between waking and dreaming is a realm of wisdom cultivated through practice. Knowing it is a dream and not being bound by the dream state is wisdom. This cultivation primarily refers to the practice of meditative concentration. Meditative concentration is an indispensable part of cultivation. Only with meditative concentration can wisdom be developed, enabling the knowing of the sixth and seventh consciousnesses to become more true to reality and principle, knowing more truly, subtly, and vastly. Only by removing the hindrance of sleep can profound meditative concentration arise. Those with deeper meditative concentration think clearly while awake and experience no confusion in dreams, knowing the state without obstruction just as they do when awake.

The knowing of ordinary people is obstructed, which is commonly said to be lacking psychic powers (abhijñā). Those with psychic powers have unobstructed knowing, possessing powers such as mind-reading (cetopariya-ñāṇa) and divine eye (dibba-cakkhu). This is the meritorious fruit of meditative concentration and wisdom. Knowing within a dream is the fruit attained by those whose minds are purified through excellent meditative concentration. The monk Chi Kung (Jigong) attained the four dhyānas and eight samāpattis and possessed psychic powers. No matter how much wine he drank, his nervous system was unaffected and remained unanesthetized. His mental consciousness was forever clear, able to observe and know all states as they truly are. When ordinary people fall asleep, their mental consciousness ceases. The function of the mental faculty relying on the mental consciousness to know states becomes inoperative. Thus, during dreams, the mental faculty's discernment is weak, and it does not know it is dreaming. The isolated mental consciousness within the dream also has very weak discernment and likewise does not know it is dreaming. Cultivated individuals, however, possess strong power of meditative concentration, an unobstructed material body, and clear, luminous sixth and seventh consciousnesses; their discernment is strong. While dreaming, they know it is a dream and are not deluded.

The great master K'uei Chi (Kuiji) attained the four dhyānas and eight samāpattis and possessed psychic powers. At night while sleeping, he was extremely clear and luminous, even more so than ordinary people when awake. His sixth and seventh consciousnesses were sharp. After falling asleep, if a louse's leg fell off causing it to cry out in pain, Master K'uei Chi could hear it. This is the meritorious fruit of the power of meditative concentration and psychic powers. If he could hear the louse's cry while asleep, does this mean he was not asleep? For ordinary people, sleep is a hindrance (āvaraṇa) that obscures their mind, causing them not to see or hear, like a dead person. Those who have eliminated the hindrance of sleep require very little sleep to nourish the material body. Their meditative concentration reaches at least the first dhyāna; their mind is clear and luminous, with slight or no obscurations at all. While sleeping, they may not completely sever the mental consciousness, yet they obtain sufficient sleep, which differs from ordinary people.

Especially those with psychic powers: their sleep is like being awake, even clearer and more luminous than ordinary people when conscious. In ancient times, martial artists also slept lightly, possessing high alertness. This alertness can be said to belong to the mental consciousness, but the mental faculty indeed also possesses alertness. Its alertness is even stronger in function than that of the mental consciousness. Therefore, without the mental faculty, the functional role of the mental consciousness cannot be fully explained. Sleep and torpor (styāna) are of the same category; both belong to hindrances that obscure the luminosity of the conscious mind. Only after the hindrance of sleep is eliminated does the first dhyāna arise. The more torpid one is while sleeping, the worse their meditative concentration skill, or the absence of meditative concentration altogether, indicating heavy hindrances. The more confused one is in dreams, the less meditative concentration they possess. The more easily one becomes intoxicated by wine, the greater the obstructions of the material body, and the less meditative concentration they have. Those with deep meditative concentration skill can regulate the material body well, unaffected by environmental factors, and unobstructed in the functioning of the six consciousnesses. Therefore, the power of concentration (samādhi-bala) is extremely important. Even without practicing Buddhism, cultivating meditative concentration well yields immense benefits.