Black Box World (X)

For example, when a foot is injured, if the section of the sensory nerve at the back of the head responsible for transmitting tactile sensations from the body's sensory faculties is severed, the body consciousness will no longer perceive pain. Even if the foot is completely severed, the body consciousness will not sense it, feel no pain, and at that moment, the body consciousness itself ceases to exist. This is because the severed sensory nerve at the back of the head prevents external tactile sensations from being transmitted through the body's sensory nerve pathways. Consequently, the eighth consciousness (ālaya-vijñāna) cannot manifest the internal aspect (internal manifestation) of tactile sensations within the subtle sense faculty (adhipati-indriya) "black box." This prevents the arising of body consciousness and mental consciousness (mano-vijñāna), leaving no capacity to perceive or discriminate any condition related to the foot. Without body consciousness and mental consciousness, the tactile sensations in that area cannot be discriminated, resulting in the absence of any pain sensation related to the foot.

One of the channels through which tactile sensations from the body's sensory faculties reach the subtle sense faculty is located at the nape of the neck. If this area is accidentally severed, the entire body becomes paralyzed, the head will droop and cannot be straightened. If the subtle sense faculty in the hindbrain is damaged, the pathways for the external five sense objects (forms, sounds, smells, tastes, and touches) are cut off. The eighth consciousness then cannot produce the corresponding internal manifestations (internal aspects), preventing the five sense consciousnesses from arising. Consequently, the five sense objects cannot be discriminated, and actions of body and speech can no longer be produced. Only a faint awareness from the mental consciousness remains, sustaining the existence of the life form, though this might not last long. If the external eye faculty is damaged, it cannot receive external visual forms. If the internal eye faculty (i.e., the subtle sense faculty of the eye) is damaged, it cannot form the internal aspect of visual forms, preventing the eye consciousness from arising to discriminate visual forms, resulting in the inability to see. Similarly, the same principle applies to the other sense faculties. Therefore, what we discriminate are the internal manifestations—the shadows—within the "black box" of the subtle sense faculties.

As long as a person can stay alive, the damage to their subtle sense faculties cannot be complete; it can only be partial. If the damage were complete, all the internal five sense faculties would become unusable, and the five sense objects could not arise. In that case, not only would the five sense consciousnesses fail to arise, but the mental consciousness would also fail to arise, unable to discriminate the mental objects (dharmas) based on the five sense objects. The mental faculty (manas) would then recognize that the body's five aggregates (form, feeling, perception, mental formations, and consciousness) are no longer functional. It would inevitably decide to leave the physical body and seek a new one for its use. Precisely because the damage to the subtle sense faculties is not complete and some functionality remains, a person can become a vegetative state patient or a paralyzed patient.

If we carefully observe a person in a vegetative state, we will notice that their body can still exhibit some movements and sensations. Because of this, the mental faculty (manas) considers this body to be still marginally functional and thus does not abandon the physical body. Since beginningless time, the mental faculty has been attached to and cherishes the physical body. Due to this attachment, it is unwilling to relinquish it and will only do so when absolutely forced to. These examples illustrate that the six sense objects we perceive are merely images within the "black box" of the subtle sense faculties. They are internal manifestations formed when external five sense objects are transmitted via sensory nerves; they are not real. However, merely knowing they are unreal is insufficient. The deeply ingrained habitual clinging of the mental faculty is extremely difficult to change. It requires us to cultivate corresponding meditative concentration (samādhi) to gradually subdue the self-attachment nature of the mental faculty.