Is the Perpetual Deliberation of Manas Within the Brain or in the External Void?

If the manas (mind faculty) were constantly examining and pondering outside the brain, it would have no relation to oneself. If the manas could exist in empty space, whose manas would it be? Who would execute the results of its pondering? How could the six consciousnesses arise from the contact between sense faculties and objects to provide feedback to the manas's pondering? Therefore, it is said that the manas cannot exist in the empty space outside the brain. What is the nature of that which is outside the brain? Is it necessarily empty space? The Śūraṅgama Sūtra states: "Empty space arises within your mind, like a wisp of cloud dotting the vast clear sky." This "mind" certainly refers to the tathāgatagarbha (Buddha-nature), but must the manas also perceive empty space along with the tathāgatagarbha? Then, is empty space inside or outside the manas? Or is the manas inside or outside empty space? The manas silently contains and perceives all dharmas without being confined within the physical body; it perceives dharmas throughout the ten directions and three times (past, present, future) along with the tathāgatagarbha. From this, we can see: how vast is our mind? Containing the vast emptiness.

The manas is also a consciousness-mind. The consciousness-mind does not operate inside, outside, or in the middle of the physical body because the consciousness-mind is formless and shapeless; one cannot say the consciousness-mind is inside or outside the physical body. Yet this consciousness-mind of the manas can encompass all dharmas inside and outside the physical body, functioning together with the tathāgatagarbha. Wherever the tathāgatagarbha is present, the manas necessarily accompanies it. The tathāgatagarbha cannot operate any dharma alone, except for essential objects (svabhāvaviṣaya). Where the manas is absent, there is no life phenomenon. If the manas were absent from the brain, not only would the brain cease to function, the entire physical body would cease to function, and life would not exist. The dharmas contacted by the five aggregates (skandhas) body are all operated by the tathāgatagarbha and are all accompanied by the manas; the manas perceives them all by relying on the tathāgatagarbha. Even the dharmas not contacted by the five aggregates body are also operated by the tathāgatagarbha and accompanied by the manas; the manas can equally perceive these dharmas.

For example, if someone recites the Buddha's name and attains samādhi, truly aspiring to be reborn in the Pure Land of Ultimate Bliss, then a lotus flower corresponding to them will appear in the lotus pond of that land. This lotus flower is not solely manifested by their tathāgatagarbha; rather, it is constructed by the tathāgatagarbha in accordance with the manas that aspires for rebirth in the lotus pond of the Pure Land. So, is the manas operating inside or outside the brain? At this time, the manas does not leave the brain or the physical body while simultaneously being present in the Pure Land of Ultimate Bliss. If one were to say the manas can only operate inside the brain, then how should the lotus flower in the Pure Land be explained? Whom does it belong to? The mind-made bodies (manomayakāya) of the great bodhisattvas are all governed by a single manas. Are the manas of each of their manifestations inside or outside the physical bodies?

Another example: when the eye consciousness sees ten people in front, upon which person's form does the eye consciousness actually make contact? Since ten people are seen simultaneously, the eye consciousness contacts the forms of all ten people at the same time; it is not said that it can only contact one person and not the others simultaneously. Similarly, the manas, relying on the tathāgatagarbha, can contact all dharmas simultaneously upheld by the tathāgatagarbha, without distinction between inside, outside, or in between. The same dharmas exist both inside and outside the indriya (subtle sense faculty, like the brain/nervous system). Both inside and outside the brain, the same dharmas exist, and the manas can perceive them all and ponder them all. But the actual situation is that sentient beings possessing an indriya, no matter where they go, cannot escape their indriya. Even if they run to the edge of heaven, they still do not leave their indriya. The manas's constant examination and pondering operate upon all dharmas; it ponders not only the dharmas within the indriya but also the dharmas outside the indriya. It grasps not only the body but also dharmas. It is precisely this grasping that is most difficult to deal with. The attachments of the three realms (triloka) and the mundane world—we are currently unable to free ourselves from them. All our thoughts are confined because our insight is limited.