Manas Is a Formless Faculty, Not a Form Faculty

The eighteen realms include the six faculties, six sense objects, and six consciousnesses. The six faculties consist of the eye, ear, nose, tongue, body, and mental faculty. The first five faculties are composed of the four great elements (earth, water, fire, and wind). The gross sense organs are located on the body's surface, perceptible to the eyes and touchable by sentient beings, subject to decay and change, exhibiting birth and cessation phenomena visible to the physical eye. The subtle sense organs of the five faculties are situated in the posterior brain region, observable through surgery, and are also material dharmas that can be seen and touched, subject to destruction and alteration, being impermanent suffering dharmas characterized by birth and cessation. When these five faculties deteriorate, the functions of the material body become obstructed and cease, resulting in a vegetative state or even death.

The mental faculty, however, is not constituted by the four great elements but is formed from consciousness seeds. Therefore, it is not a material dharma but a mental dharma, possessing the functions and activities of consciousness. Material dharmas are phenomena produced by causes and conditions, lacking autonomy. They are passively born and manifested through the combined functions of the Tathagatagarbha and the mental faculty, relying entirely on the propelling force of the mental faculty. If the mental faculty ceases to propel, material dharmas vanish instantly. The mental faculty is not born at a later time; it has coexisted with the Tathagatagarbha since beginningless kalpas, sustained continuously by the consciousness seeds provided by the Tathagatagarbha, requiring no other causes or conditions. It is not a phenomenon produced by causes and conditions. As long as the mental faculty grasps objects, it will not perish but continue to exist, and the five aggregates world will consequently undergo continuous birth and cessation. Although the five aggregates and five faculties ceaselessly arise and cease, the mental faculty never perishes. No one can eliminate the mental faculty, except when Arhats and Pratyekabuddhas enter Nirvana.

The mental faculty, being a mental dharma without material form, differs vastly in function from the material five faculties. The five faculties lack discernment capability, mental factors, and the nature of defilement or purity. They can be influenced by the mental faculty; their function of receiving the five sense objects is directed by the mental faculty but cannot command the five sense objects or the five consciousnesses, much less the mental faculty itself. However, they can influence the mental faculty’s feelings and decision-making roles.

The functions and activities of the mental faculty, as a mental dharma, are immensely powerful. It exerts a dominant and decisive role over the body of five aggregates, governing the birth, transformation, and cessation of all worldly dharmas. It possesses the mental factors of consciousness, exhibiting both defiled and pure natures, discernment, judgment, decisiveness, the tendency to seek benefit and avoid harm, selfhood and selflessness, ignorance and wisdom, habits, afflictions, and universal clinging and attachment. It determines the cycle of birth and death for sentient beings, directs them toward Nirvana, accomplishes the Buddha Way, and governs all realms from heaven to earth. The material five faculties lack these characteristics; only the mental faculty, as a mental dharma, possesses them. Therefore, the mental faculty is a mental dharma, not a material dharma—it is a formless faculty.

The term "faculty" implies the birth of consciousness, but this "birth" is not direct causation. Rather, it enables the birth of the six consciousnesses, serving as their most immediate condition. What directly gives birth to the six consciousnesses is the Tathagatagarbha, which utilizes karmic conditions and the six faculties to produce them. However, if the mental faculty remains unattached to any dharma, the Tathagatagarbha cannot give rise to the six consciousnesses. Thus, the birth-condition of the five faculties is passive, while the birth-condition of the mental faculty is extremely proactive and vigorous. Its power to produce the six consciousnesses and all dharmas is formidable, and it also determines whether the five faculties are born or not. Such autonomous and potent initiative can only belong to the formless mental dharmas; the material five faculties cannot possess it. Therefore, the mental faculty is a mental dharma, not a material dharma—it is a formless faculty, not a material one.