Chapter Fourteen: The Principle of the Interchangeability and Mutual Functioning of the Six Sense Faculties

1. When we perceive the objects of the six dusts (sensory fields), there is perception by the first five consciousnesses, perception by the sixth consciousness, perception by the seventh consciousness, and perception by the tathāgatagarbha (Buddha-nature). Prior to Buddhahood, all dharmas necessarily involve the participation of the seventh consciousness. Therefore, when the six consciousnesses perceive the objects of the six dusts, the perceiving nature of the seventh consciousness is invariably present. The tathāgatagarbha can manifest whatever dharmas it perceives, enabling the seventh consciousness to cognize based on the tathāgatagarbha and thereby perceive those dharmas. Because the seventh consciousness possesses the mental factor of wisdom (prajñā), it possesses a certain degree of cognitive capacity regarding all dharmas, including the objects of the six dusts. This cognitive capacity of the seventh consciousness can function directly, without relying on the six consciousnesses.

The seventh consciousness of ordinary people cannot subtly perceive the objects of the six dusts because it clings too broadly, needing to attend to many dharmas, and thus the mind-consciousness cannot concentrate sufficiently to discern details. Due to the scatteredness of the mental faculty (manas) and the lack of meditative concentration (dhyāna), along with heavy afflictions (kleśa), its functions are severely obstructed and cannot be fully or effectively utilized. However, after cultivating meditative concentration and eradicating all afflictions, the seventh consciousness is no longer obscured by afflictions, and its functions can be effectively utilized. Especially after subduing some or all of the habitual tendencies of afflictions, its wisdom and virtuous capabilities become increasingly vast and unobstructed, enabling it to replace the six consciousnesses in perceiving the objects of the six dusts and discerning all dharmas.

For example, an Arhat, because the afflictions and self-clinging of their seventh consciousness have been completely severed and they no longer cling to self, their functions are no longer obstructed. Their wisdom becomes vast, and their virtuous functions expand. If an Arhat completes the Four Dhyānas and Eight Samādhis and attains supernatural powers (abhijñā), the six sense faculties can then interchange and function mutually. The seventh consciousness, the mental faculty, can directly perceive the six dusts without relying on the six consciousnesses. An Arhat can perceive sound directly with the seventh consciousness without using the ear faculty or the arising of ear consciousness; perceive form directly without using the eye faculty or the arising of eye consciousness; and directly feel cold, heat, touch, or pain without using the body faculty or body consciousness. In the samādhi of cessation (nirodha-samāpatti), the seventh consciousness can directly perceive the object of mind-consciousness (dharmas). At the stage of Buddhahood, the Buddha's undefiled consciousness (amala-vijñāna) can directly perceive the six dusts without relying on the first seven consciousnesses.

Therefore, after studying Buddhism and cultivating practice, one should strive to subdue self-nature, subdue self-clinging (ātma-grāha) and dharma-clinging (dharma-grāha). The lighter the afflictions and the fainter the clinging, the more powerful the functions of the mind-consciousness become, and the more luminous and perfect the mind-consciousness becomes. Conversely, the heavier greed, hatred, and delusion are, the more obstructed the functions of the mind-consciousness become, and the narrower the vision, truly exemplifying short-sightedness. Practitioners should reflect daily on their own faults, diligently subdue their greed and attachment, subdue their hatred and anger, subdue their delusion, subdue their arrogance, and subdue their skeptical views. They should not constantly harbor a small self within, always expressing self, always putting self first, allowing all afflictions to manifest and obscure the birth of their own wisdom.

2. The interchangeability and mutual functioning of the six sense faculties also involve a secret: the five sense faculties and the objects of the six dusts are all material form (rūpa) of the same category. The seven consciousnesses are all formed by seeds of consciousness (vijñāna-bīja) and belong to the same category. Thus, functions within the same category can substitute for one another. For example, the six dusts are all composed of the four great elements (mahābhūta), all being material form of the same category. The five sense faculties are also composed of the four great elements, all being material form of the same category. Therefore, the six dusts can be discerned through one sense faculty by one consciousness. All material forms, including the five sense faculties, the five sense objects, and the form included in the mental base (dharmāyatana), constitute the five sense faculties and six dusts. These eleven material forms are all composed of the four great elements, differing only in their manifested properties, but their essence is the same. These material forms are all objects that can be seen and discerned by the mind-consciousness. The discerning mind-consciousness is all generated from seeds of consciousness, differing only in the objects discerned, but their essential function is the same. Since this is so, material forms share the same essence, and mental dharmas share the same essence. Then, through cultivation, it is entirely possible to use one consciousness to replace all consciousnesses to discern all material forms. This is achievable.

Let us examine the material forms of the six dusts. The external form dust is composed of the four great elements. The tathāgatagarbha takes up the external form dust, transforming it into extremely subtle particles of the four great elements. These particles, ceaselessly arising and perishing, are transmitted through the eye faculty to the subtle sense organs (adhyātma-indriya), forming the image of form dust, called internal form dust. The external sound dust is composed of the four great elements. The tathāgatagarbha takes it up into very subtle particles of the four great elements. These particles, ceaselessly arising and perishing, are transmitted through the ear faculty to the subtle sense organs, forming the image of sound dust, called internal sound dust. The external smell dust is composed of the four great elements. The tathāgatagarbha takes it up into extremely subtle particles of the four great elements. These particles, ceaselessly arising and perishing, are transmitted through the nose faculty to the subtle sense organs, forming the image of smell dust, called internal smell dust. The external taste dust is composed of the four great elements. The tathāgatagarbha takes it up into extremely subtle particles of the four great elements. These particles, ceaselessly arising and perishing, are transmitted through the tongue faculty to the subtle sense organs, forming the image of taste dust, called internal taste dust. The external touch dust is composed of the four great elements. The tathāgatagarbha takes it up into extremely subtle particles of the four great elements. These particles, ceaselessly arising and perishing, are transmitted through various parts of the body faculty to the subtle sense organs, forming the image of touch dust, called internal touch dust. The form included in the mental base is further manifested by the tathāgatagarbha based on the previous internal five dusts and is also composed of particles of the four great elements.

The five sense faculties, which serve a transmitting function, are composed of the four great elements, being material form, born of and sustained by the tathāgatagarbha. The five sense faculties share the same nature. Therefore, the five dusts can be entirely transmitted through one sense faculty to the subtle sense organs. The tathāgatagarbha then manifests the object of mind-consciousness (dharmas). Subsequently, the sense faculty and its object make contact, and the tathāgatagarbha produces one consciousness to discern all the appearances of the six dusts. That is to say, the eye faculty can transmit sound dust, smell dust, taste dust, and touch dust to the subtle sense organs. The tathāgatagarbha then manifests the form included in the mental base and produces one consciousness to discern them all. Similarly, the ear faculty can transmit the other five dusts, the nose faculty can transmit the other five dusts, the tongue faculty can transmit the other five dusts, and the body faculty can transmit the other five dusts. The tathāgatagarbha produces one consciousness, and one unified consciousness discerns the six dusts. Of course, regarding which sense faculty transmits the five dusts and which consciousness unifies the discernment, it is directed by the mental faculty (manas). The mental faculty decides; even the tathāgatagarbha follows its direction. Such a mental faculty is no ordinary mental faculty; it has already attained the undefiled state (anāsrava).

Then, which consciousness should this be? The answer is that any of the eight consciousnesses can serve this function, depending on the individual's level of cultivation. At the highest level is the Buddha, who uses the undefiled consciousness (amala-vijñāna) to perceive the six dusts without needing the seven consciousnesses—something other great bodhisattvas and ordinary beings cannot achieve. Next are the Bodhisattvas on the Bhūmis (stages) and Arhats, who can use the seventh consciousness or the sixth consciousness to discern, or use one of the five sense consciousnesses to discern. If a bodhisattva lacks a physical body, then the first four sense faculties also do not exist, and among the six sense faculties, only the mental faculty remains. In such a case, can this bodhisattva perceive the first five dusts? Certainly, they can. Because the first five dusts are taken up and manifested by the tathāgatagarbha, the seventh consciousness can cognize them. A bodhisattva with perfect concentration and wisdom can use the seventh consciousness to directly perceive the first five dusts and the six dusts, without needing the subtle sense organs, the sixth consciousness, or the first five consciousnesses. At the stage of Buddhahood, the World-Honored One does not even need the seventh consciousness, being even more direct and efficient.

This is the supremely wondrous merit achieved by undefiled wondrous concentration (samādhi) and undefiled wondrous wisdom (prajñā). How supremely wondrous and exquisite is undefiled merit! Ignorance, habitual tendencies of afflictions, and the afflictions of greed, hatred, and delusion truly severely obscure beings' own inherently supreme merit, leaving them with only the nominal title of "original Buddha" without the actual function, which is truly regrettable and lamentable! What should be done? We should strive to eradicate afflictions, eradicate all ignorance and defilements. The eradication of afflictions and defilements can only be achieved through the path of severing the view of self (satkāya-dṛṣṭi) and realizing the mind and seeing the nature (enlightenment), becoming a great-hearted bodhisattva who benefits self and others. In this way, we can restore the originally pure face of the mind-ground, fully manifesting all the luminosity of the mind-ground. Then we will attain the most supreme and perfect fruition—the fruition of Buddhahood!

3. Beings in the desire realm all possess eight consciousnesses, and the Buddha also possesses eight consciousnesses. The intermediate state (antarābhava) also fully possesses all eight consciousnesses; it is not only the seventh consciousness. However, in the intermediate state, the habitual tendencies of the seventh consciousness can manifest completely without concealment, while the controlling power of the sixth consciousness is relatively weak and cannot fully or effectively control the seventh consciousness. The seventh consciousness then acts according to its habitual inertia, hence the saying, "the dead speak frankly." In the intermediate state, the thinking and discriminating functions arising from the sixth consciousness are somewhat weaker than when alive. The seventh consciousness's discernment of the six dusts lacks much dependency and thus acts and makes decisions according to its own habitual tendencies. If the afflictions of the seventh consciousness have not been subdued, they can fully manifest at this time, leading to rebirth according to afflictive habitual tendencies. After rebirth, one must then undergo the suffering of birth and death. The intermediate state also has a body, including eyes, ears, nose, tongue, and body, but the body is relatively ethereal and subtle, not a substantial physical body. It is composed of subtle four-element matter, so the body encounters little obstruction and possesses some weak supernatural powers, such as the divine eye, divine ear, knowledge of others' minds, supernormal mobility, and knowledge of past lives, enabling it to know many things unknown to humans.