The manas is a formless faculty, not a material faculty

The eighteen dhātus include the six faculties, six sense objects, and six consciousnesses. The six faculties include the eye, ear, nose, tongue, body, and mind faculties. Among these, the first five faculties are composed of the four great seeds of earth, water, fire, and wind. The gross physical sense organs are on the surface of the body; sentient beings can see, touch, and feel them with the naked eye, and they can be damaged and altered, with birth-and-death phenomena visible to the naked eye. The supreme faculties of the five faculties are located at the back of the brain; they can be seen through surgery, and are also material form that can be seen, touched, and felt, capable of being damaged and altered, and are suffering dharmas subject to birth and death, impermanent. When the five faculties are damaged, the functions of the physical body are obstructed and abandoned, resulting in a vegetative state, or even death.

The manas, however, is not composed of the four great seeds of earth, water, fire, and wind; it is formed from seeds of consciousness. Therefore it is not material form but mind dharma, possessing the functions of a conscious mind. Material form is a dharma produced by causes and conditions; it has no autonomy and is passively born and manifested through the conjunction of the tathāgatagarbha and the manas. It cannot do without the impelling function of the manas; if the manas does not impel it, material form vanishes immediately. The manas, however, was not born later; it has coexisted with the tathāgatagarbha since beginningless kalpas, sustained continuously by the tathāgatagarbha providing seeds of consciousness, requiring no other causes and conditions—it is not a dharma produced by causes and conditions. As long as the manas has anything to grasp at, it will not perish and will continue to exist, and the world of the five aggregates will likewise continue to arise and cease. Although the five aggregates and five faculties undergo ceaseless birth and death, the manas never perishes; no one can eliminate the manas—except when arhats and pratyekabuddhas enter nirvāṇa. The conscious mind and manas, which lack material form, differ enormously in function from the five faculties that possess material form. The five faculties have no capacity for recognition, no mental factors (caittas), no defiled or pure nature; they can be influenced by the manas, and their function of receiving the five sense objects is directed by the manas, yet they cannot direct the five sense objects or the five consciousnesses, much less direct the manas—though they can influence the manas's feeling and decision-making functions.

The functional power of the manas as mind dharma is extremely formidable. It has the role of governing and making decisions over the five-aggregate body, dominating the arising, alteration, and eventual perishing of all worldly dharmas. It has the mental-factor functions of a conscious mind; it has both defiled and pure natures; it has the capacities of recognition, discernment, judgment, and decision-making; it has the tendency to seek benefit and avoid harm; it has both self-nature and selfless-nature; it has both foolishness and wisdom; it has habitual tendencies, habits, and afflictions; it has the imputed nature (parikalpita-svabhāva); it can determine sentient beings' birth, death, and saṃsāra, and determine whether sentient beings turn toward nirvāṇa and accomplish the buddha path. Heaven above and earth below are governed by the manas. The five faculties of material form lack these characteristics; only the manas of mind dharma has them. Therefore the manas is mind dharma, not material form—it is a formless faculty. A "faculty" has the meaning of giving rise to a conscious mind, but this so-called giving rise is not direct generation; rather, it can lead to the arising of the six consciousnesses, being the most immediate condition for the arising of the six consciousnesses. What directly gives birth to the six consciousnesses is the tathāgatagarbha, which, borrowing karmic conditions and the six faculties, gives rise to the six consciousnesses. But if the manas has no mind toward any dharma, the tathāgatagarbha cannot give rise to the six consciousnesses. Therefore the arising condition of the five faculties is very passive, while the arising condition of the manas is extremely active and proactive; its motive force for generating the six consciousnesses and all dharmas is immensely powerful, and it also determines whether the five faculties arise or not. Such autonomous, powerful motive force can only be possessed by formless mind dharma, not by the five faculties that possess form. Therefore the manas is mind dharma, not material form; it is a formless faculty, not a faculty with form.