The Knowing of the Manas and the Knowing of the Mind Consciousness

Question: Since the manas is also a consciousness, it should be able to perceive external objects. Why is it that when a person is in a coma, there is not the slightest perception of external objects?

Answer: The knowing of the manas can only be known when the mind consciousness knows it. We all take the knowing of the mind consciousness as our knowing, and whatever the mind consciousness does not know, we say we do not know. But the fact that the mind consciousness does not know does not mean that the manas does not know either. Therefore, when we are sleeping dreamlessly or in a coma—when the mind consciousness has ceased—the knowing of the manas cannot be transmitted to the mind consciousness, and so we do not know. Even when the mind consciousness is operating normally without ceasing, without wisdom one still does not know the knowing of the manas. When the mind consciousness lacks wisdom, it does not know what kind of mental activity the manas is engaged in. Therefore, whether the manas possesses the introspection of self-validating cognition (svasaṃvedana) cannot be observed by the mind consciousness, and whether the manas knows of its own existence also cannot be observed by the mind consciousness. So when the mind consciousness cannot observe it, one should not make judgments about how the manas is or is not.