The Dharma Consciousness Perceived by Manas Is Not Necessarily Known

Question: Sometimes while walking, even though I cannot see anyone following behind me, I still know that someone is there. How is this known? Are the people and objects behind me part of the internal manifestation within the back of the head? Can form dust enter the ultimate faculty at the back of the head without being transmitted through the eye faculty?

Answer: The people and objects behind cannot be transmitted to the ultimate faculty at the back of the head through the eye faculty, because the eye faculty does not face the rear. In the Śūraṅgama Sūtra, the Buddha stated that the eye faculty possesses only eight hundred merits out of the total twelve hundred merits, meaning that the eye faculty can perceive form dust directly in front and about two-thirds to each side, but cannot perceive beyond that. Therefore, knowing that someone is following behind is an awareness of the isolated shadow realm of dharma dust, known by the isolated sixth consciousness, and does not involve perceiving actual form dust. This isolated shadow realm of dharma dust is contacted and known by the manas (seventh consciousness). The manas considers this information important and alerts the sixth consciousness to be aware of it. The manas clearly knows an immense number of dharmas, but cannot express them. Since the sixth consciousness cannot access what the manas knows, it remains unaware. Thus, while a person may say "I do not know," the manas actually does know.

Sneezing is a sudden occurrence for which the sixth consciousness has no mental preparation; it is initiated by the manas. When a ghost approaches, the sixth consciousness remains unaware, but the body may shiver—this is triggered by the manas. Before a significant event occurs, the sixth consciousness does not know what will happen, yet one may inexplicably feel joyful or uneasy—this is initiated and hinted at by the manas.