Why Has the Manas Existed Since Beginningless Kalpas?

Since beginningless kalpas, there have been two dharmas not born of causes and conditions: one is the eighth consciousness, Tathāgatagarbha, inherently existent from the outset, not produced by any dharma. The other is the seventh consciousness, the mental faculty, which has likewise coexisted with the eighth consciousness since the very beginning, not a dharma born subsequently, nor produced by the eighth consciousness through any condition. Nevertheless, the mental faculty remains a phenomenal dharma subject to arising and ceasing, an insubstantial dharma; it requires the eighth consciousness to continuously output seeds of consciousness to sustain its existence and must be continuously upheld by the eighth consciousness to endure.

Why is it that the mental faculty, having existed since beginningless kalpas and not born of causes and conditions, still belongs to the category of dharmas subject to arising, ceasing, and transformation? Because since beginningless kalpas, the mental faculty has inherently harbored ignorance—particularly the afflictions of greed, hatred, and delusion arising from a single thought—and remains unaware of its own illusory nature. Consequently, the view of self and the clinging to self cannot be eradicated by itself. It coexists with the eighth consciousness without vanishing. However, once the mental faculty exhausts the fundamental ignorance arising from a single thought, the clinging to self will be completely severed, and it will inevitably cease to exist. Only the eighth consciousness will remain, existing alone—formless, markless, free from clamor and commotion, in the quiescent state of Nirvana.