Dhyana Reduces the Energy Consumption of the Four Great Elements

When one attains meditative concentration (dhyāna), the need for sleep diminishes, as the body requires less rest. This is because meditative concentration itself reduces the activity of the six consciousnesses, thereby consuming less of the nourishment provided by the four great elements. It also causes the mind-base (manas) to grasp less, reducing the physical body's activity and decreasing its influence and control over the entire nervous system. Consequently, the brain's nervous system, internal organs, and the entire body engage in less activity and expend less of the four great elements. The body thus does not become fatigued, and the mind-base no longer feels compelled to decide on sleep.

The deeper the meditative concentration, the less sleep is required, to the extent that sleep may become entirely unnecessary. At this stage, the mind-base becomes very tranquil, no longer inclined toward any deliberate action, and thus ceases to excessively engage the brain's nervous system. There is minimal activity of the body faculty and mental consciousness. The more settled the mind-base, the less it grasps, the fewer regulatory activities occur, the less the four great elements are consumed, and the less need there is for sleep and food.

Some individuals, in their daily work, accomplish a significant amount of tasks yet harbor very few mental thoughts. They consume less, do not need to eat as much food, nor require as much sleep, yet remain full of energy. This demonstrates that it is the mental activity of the mind-base that most heavily consumes the energy of the four great elements; the six consciousnesses themselves do not consume very much. Therefore, even when the workload handled by the six consciousnesses is substantial, if the mental thoughts of the mind-base are few, the overall activity level decreases, and the work does not feel tiring.

It is evident that the mind-base is capable of understanding and mastering the condition of the physical body at all times and in all places. It can regulate and direct it anytime, anywhere. He discerns with great acuity and precision; it is not coarse at all. The mental consciousness (mano-vijñāna) is unaware of the body's various states and still requires the mind-base to provide hints and alerts.