The Difference Between Manas Activity and Mind Consciousness Activity

If the manas is stirred, there will be various reactions in the physical body, such as blushing, a racing heart, shyness, bulging veins, trembling all over, and so on. When the mind consciousness alone is stirred, the body has little reaction and remains relatively calm. The activity of the manas consumes a certain amount of energy, whereas the activity of the mind consciousness does not necessarily consume energy, or consumes relatively little. Those who only talk but do not act are operating with the mind consciousness alone while the manas is unmoved; those who say one thing and do another speak with the mind consciousness while the manas has no intention to act, and so they do not act; those with a habit of deception perform with the mind consciousness while the manas is not stirred at all. Therefore, to observe a person's character, look at how they act, not merely at how they speak—doing is more real than saying. 

If the activity of the mind consciousness consumes energy, it also involves the whole body, because energy flows throughout the entire body; the whole body uses the same stream of energy, and energy is not divided into separate parts. It is merely that people who like to use their brains to think and deliberate first consume the energy in the brain; when the brain's energy runs low, the energy of the whole body is then consumed. The brain drives the whole body along with it; when the brain is tired, the whole body also feels fatigued and needs rest. Within the activity of the mind consciousness, the activity of the manas is not entirely absent—the manas is involved to some degree, so energy is consumed; the greater the involvement, the more energy is consumed. If I do not ponder problems attentively and just quietly engage in superficial activity of the mind consciousness all day, I do not feel tired even after a whole day and night, nor do I feel very hungry. If I ponder problems attentively, I feel tired after a short while and get hungry easily. That is why I am entirely unwilling to deal with people and affairs, unwilling to stir my thoughts, unwilling to consider unimportant matters—unless they are meaningful and relatively important. 

When investigating Chan (canchan) attentively, a great deal of energy is also consumed; when cultivating meditative concentration (samādhi) without thinking, energy consumption is low, and the body instead feels very comfortable and relaxed. Cultivating concentration without thinking is relatively effortless, while contemplative practice (vipaśyanā-caryā) and deliberation are brain-burning. When thinking with the mind consciousness, because the attention is shallow and slight, it is relatively fast and easy—one can speak in generalities, fluently and eloquently, with a stream of clever words—but the content is shallow and superficial, reflecting one's level of knowledge and memory rather than one's level of wisdom. When thinking with the manas, because the attention is very deep, the conscious mind runs slowly and laboriously, but the content is deep and far-reaching in significance, reflecting a person's deep-level wisdom. 

Let me use an analogy to illustrate the difference between using the mind consciousness and using the manas. Suppose a person is walking in mud: if the mud is shallow, only covering the soles of the shoes, walking is still fairly fast and effortless; if the mud reaches the ankles, the calves, or the knees, it is not easy to pull the feet out, and every step takes great effort, making walking very slow. Thinking with the mind consciousness is like walking on a surface with shallow mud; thinking with the manas is like walking on a surface with deep mud. Therefore, for a person who thinks with the manas, if they remain at the deep level of the manas and are highly focused, whenever they shift a thought or switch to a new problem, the flow of thought is very slow, requiring the consumption of much energy and feeling somewhat tiring. Such a person therefore likes quietude and does not want people or affairs from outside to disturb them.