All dharmas possess the discerning and choosing function of manas

Our bodily activities are carried out by the manas through its regulation of the brain, with the cooperation of the six consciousnesses. For example, when we open our eyes in the morning, the eyes do not open by themselves; it is the manas that issues the command and regulates the six consciousnesses to open the eyes. For example, when eating, once the manas perceives the signal of being full and decides to stop eating, it commands the six consciousnesses to cease eating, and the six consciousnesses obey the command and stop. This also proves that the manas, through the brain, can control the activities of the whole body, and all the activities of the body are the activities of the six consciousnesses. For example, blushing with a thick neck, leaping up in fury, being exasperated and flustered, coming to blows, beaming with joy, being elated with delight, and so on—all of these are manifested because of the afflictive emotions of the manas; they are the result of the manas's manipulation.

Upon what basis does the manas issue commands? Why does the manas grasp the condition of the physical body so accurately and so promptly? All dharmas within the physical body are manifested and appropriated (upātta) by the tathāgatagarbha. As to how far the eating has progressed, the tathāgatagarbha will reflect it moment by moment just as it is; relying on the tathāgatagarbha, the manas knows everything without exception. After the manas knows, it will give rise to a mind of decision, make a determination, and then issue the command. Of course, the manas's knowledge of the six sense objects and its knowledge of the detailed condition of the body are obtained through the discernment of the six consciousnesses. The condition of the body during a coma or while asleep is also reflected moment by moment by the tathāgatagarbha just as it is, and the manas will come to know it in a timely manner. At these times there is no mind consciousness at all; it is entirely the manas knowing on its own, relying on the tathāgatagarbha.

Take another example: when suddenly meeting an acquaintance, the mind consciousness cannot recall the person's name no matter how it tries, yet one still feels that one knows the name, feels very familiar with it, as if it were on the tip of the tongue and could be spoken at any moment. In this situation, it is merely that the mind consciousness cannot recall it; it does not mean that the manas does not recognize the person or the name. After the person leaves, the mind consciousness will suddenly remember it. Why can the mind consciousness remember it? It is because the manas has given the mind consciousness a certain amount of information, and the mind consciousness suddenly remembers. In the operation of all dharmas, the function of the manas is necessarily present, but the function of the mind consciousness is not necessarily present. If there are some functions and operations for which we cannot distinguish whether the manas is involved or how great its role is, then we should think about the several states in which the six consciousnesses are absent, and consider how the manas works in them.