Is the constant deliberation of the manas in the brain or in the space outside the brain?

If the manas were to constantly deliberate outside the brain, it would have nothing to do with oneself; and if the manas could exist in empty space, whose manas would that be? Who would execute the results of its deliberation? How could the faculties and sense-objects come into contact to give rise to the six consciousnesses that provide feedback on the manas's deliberation? Therefore it is said that the manas cannot possibly be in the empty space outside the brain. What lies outside the brain? Is it necessarily empty space? The Śūraṅgama Sūtra says: Empty space is produced within your mind, just as a single cloud appears in the great sky. This mind, of course, refers to the tathāgatagarbha, but does the manas also need to rely on the tathāgatagarbha to discern empty space? Then is empty space inside or outside the manas? Or is the manas inside or outside empty space? The manas silently encompasses and discerns all dharmas, and is not confined within the material body; the dharmas of the ten directions and the three periods of time can all be discerned through the tathāgatagarbha. From this, one can see: how large is our mind, after all? It encompasses the great void.

The manas is also a conscious mind. The conscious mind does not operate inside, outside, or in between the material body, because the conscious mind is formless and without marks; one cannot say that the conscious mind is inside the material body or outside it. And the manas, this conscious mind, can govern all dharmas both inside and outside the material body, operating together with the tathāgatagarbha. Wherever the tathāgatagarbha is, the manas is surely following; the tathāgatagarbha cannot operate any dharma on its own, except for the fundamental realm (the object-aspect in itself). Where the manas is absent, there is no phenomenon of life. If the manas were absent from the brain, not only would the brain cease to function, the entire material body would cease to function, and life would no longer exist. The dharmas that the body of the five aggregates can come into contact with are all operated by the tathāgatagarbha, and all have the manas following along; the manas can discern them all by relying on the tathāgatagarbha. And the dharmas that the body of the five aggregates cannot come into contact with are also operated by the tathāgatagarbha, and also have the manas following along; the manas can likewise discern these dharmas.

For example, if someone attains meditative concentration (samādhi) through recollection of the Buddha (buddhānusmṛti) and truly wishes to be reborn in the land of bliss (sukhāvatī), then a lotus flower will appear for him in the lotus pond of the land of bliss. This lotus flower is not merely manifested by his tathāgatagarbha; rather, it is built by the tathāgatagarbha, following the manas that has made the vow of rebirth, in the lotus pond of the land of bliss. So does the manas operate inside the brain or outside the brain? At this time, the manas is neither apart from the brain nor apart from the material body, and at the same time is in the land of bliss. If the manas could only operate inside the brain, then what about the lotus flower in the land of bliss? To whom does it belong? The mind-made bodies (manomaya-kāya) of all the great bodhisattvas are all governed by a single manas; is the manas of each emanation body inside or outside the material body?

Take another example: if the eye consciousness sees ten people in front of it, upon which person's physical form is the eye consciousness actually contacting? Since it sees ten people simultaneously, the eye consciousness has contacted the physical forms of all ten people at the same time; it is not the case that it can only contact one person and not the others simultaneously. The manas is the same: relying on the tathāgatagarbha, it can contact all the dharmas held and sustained by the tathāgatagarbha simultaneously, without distinction of inside, outside, or in between. Inside and outside the supreme faculty (indriya) there are the same dharmas; inside and outside the brain there are the same dharmas, and the manas can take all of them as its object and deliberate upon all of them. But the actual situation is that sentient beings who possess a supreme faculty, no matter where they go, cannot escape their own supreme faculty; even if they run to the edge of the sky, they cannot walk out of the supreme faculty. The manas's constant deliberation is upon all dharmas; it deliberates not only on the dharmas within the supreme faculty, but also on the dharmas outside the supreme faculty. He not only grasps at the body, but also grasps at dharmas, and this grasping is the hardest to deal with. The attachments of the mundane world of the three realms — we are still unable to free ourselves from them now; all of our thinking is restricted, because our insight is limited.