Black Box World (X)

For example, when the foot is injured, if the nerve conduction pathway responsible for transmitting the tactile sensation of the body faculty at the back of the head is severed, the body consciousness will not feel the pain. Even if the foot is completely severed, the body consciousness will not sense it, nor feel any pain, and at this point, the body consciousness does not even exist. Because the nerve conduction pathway at the back of the head is severed, the external tactile objects cannot be transmitted through the nerve conduction pathway of the body faculty there. Consequently, the eighth consciousness (ālayavijñāna) cannot manifest the internal image-part of tactile objects within the black box of the indriya-rūpa (subtle material faculty), and thus cannot produce body consciousness or mental consciousness to discern any condition of the foot. Without body consciousness and mental consciousness, the tactile objects at that location cannot be discerned, therefore there is no pain sensation related to the foot.

One of the pathways for the tactile objects of the body faculty to reach the indriya-rūpa is located at the back of the neck. If this area is accidentally severed, the entire body becomes paralyzed, the head droops down, and cannot be held upright. If the indriya-rūpa in the back of the head is damaged, the pathways for the external five sense objects (rūpa, sound, smell, taste, touch) are cut off. The eighth consciousness then cannot produce the corresponding internal image-parts, the five consciousnesses cannot arise, and thus the five sense objects cannot be discerned. Consequently, bodily and verbal actions can no longer be produced. Only the faint awareness of the mental consciousness remains, sustaining the existence of the living being, but perhaps not for long. If the external eye faculty is damaged, it cannot receive external form objects (rūpa). If the internal eye faculty (i.e., the eye's indriya-rūpa) is damaged, it cannot form the internal image-part of form objects. Thus, eye consciousness will not arise to discern form objects, meaning one cannot see forms. The same principle applies to the other faculties. Therefore, what we discern are the internal image-part reflections within the black box.

As long as a person is alive, the damage to their indriya-rūpa cannot be complete; it can only be partial. If it were completely destroyed, all five internal faculties would become unusable, and the five sense objects could not arise. In that case, not only would the five consciousnesses fail to arise, but mental consciousness would also fail to arise, unable to discern the mental objects (dharmas) based on the five sense objects. The mental faculty (manas) would then know that the body's five aggregates (skandhas) are unusable, and it would certainly decide to leave the physical body to seek a new one for its use. Precisely because the indriya-rūpa is not completely destroyed and retains some functionality, a person becomes a vegetative state patient or a paralyzed patient.

If we carefully observe a person in a vegetative state, we will find that their body can still exhibit some movements and sensations. Because of this, the mental faculty considers that this body can still be made do with, and it will not leave the physical body. Since beginningless time, the mental faculty has always been attached to the physical body. Due to this attachment to the body, it is unwilling to abandon it and will only do so when absolutely necessary. These examples illustrate that the six sense objects we discern are images within the black box of the indriya-rūpa. They are internal image-parts formed by the external five sense objects transmitted through the nerve conduction pathways, and are not real. However, merely knowing they are unreal is insufficient; the habitual clinging tendency of the mental faculty is very difficult to change. It requires us to cultivate corresponding meditative concentration (samādhi) to gradually subdue the self-grasping nature of the mental faculty.