Is the Manas Aware in the Absence of Consciousness?

Some say: Since the manas (mental faculty) is also a form of consciousness, it should perceive external phenomena. Why, then, does a person in a coma show no awareness of the external environment? The explanation is this: The lack of perception during coma is due to the cessation of the mano-vijñāna (discriminating consciousness). However, the manas itself still perceives. When the manas perceives, if the mano-vijñāna has ceased, it remains unaware of the manas's perception. Even if the mano-vijñāna does not cease, if it lacks the wisdom of discernment, it still cannot recognize the perceptual function of the manas. This is because the knowing of the manas must be known by the mano-vijñāna before sentient beings can become aware of it. Sentient beings take the knowing of the mano-vijñāna mind as their knowing; what the mano-vijñāna does not know is considered unknown.

But the mano-vijñāna not knowing does not mean the manas also does not know. Therefore, during dreamless sleep, coma, or when the mano-vijñāna disappears, the knowing of the manas cannot be conveyed to the mano-vijñāna. Consequently, the mano-vijñāna remains unaware, and since the mano-vijñāna is unaware, sentient beings remain unaware. Even if the mano-vijñāna functions normally without disappearing, when it lacks wisdom, it still cannot recognize the knowing of the manas. When the mano-vijñāna lacks wisdom, it remains ignorant of the mental activities of the manas or what it perceives. Thus, whether the manas possesses the self-reflexive awareness (svasaṃvitti) cannot be observed by the mano-vijñāna; whether the manas knows its own existence also cannot be observed by the mano-vijñāna. Therefore, when the mano-vijñāna cannot observe these aspects, one should refrain from making judgments about whether the manas functions in a certain way or not.