We find a wonderful, and wonderfully illuminating, question included in Shankara’s poem “Atma Bodha,” or “Knowledge of the Self.” The poem is here translated by Sri Ramana Maharshi.
The questioner, experiencing doubt, is deeply puzzled. “If,” he states, “the Self cannot be known by the intellect, there will be no knower to know the Self and the Self cannot be known.” The question implicit in this statement is this: how is it possible to know the Self if the mental and physical senses have been shown not to be able to gain access to the Self? In other words, what’s left (“of the person,” you might say) to know the Self?
Shankara replies, “To see a light, no other light is needed. So also, the Self being self-effluent, needs no other means of knowledge. It shines of itself.”
Two remarks are in order. First, Shankara, who helped rejuvenate the Advaita teachings in 8th CE India, helpfully reminds his listener that while the perceiver, say, is the knower of its the apparent perceptible world, the Self requires no dualistic structure. In fact, the Self as Itself is not a dualistic structure (advaita: “one with a second”). Therefore, “to know,” as Aristotle might have said, is said in different ways. Dualistic knowing differs from nondual knowing. Thus, it is said: the Self knows Itself by being Itself.
Second, the questioner, quite naturally yet mistakenly, is asking the question from the vantage point of personal consciousness. Consequently, he’s puzzled by how personal consciousness can have a “faculty” that will enable it to “bridge” the “divide” between itself and the Self. But this is all, as it were, null and void. Wondering what “instrument” will allow him, as personal consciousness, to “approach” and then “merge with” Universal Consciousness just goes to show where the mistake lies. No “further sense,” apart from and exclusive of the mental and physical senses, is needed just because Universal Consciousness needs, and can have, no bridge to Itself. It always already is Itself!
In language, sometimes we say that enlightenment is just Universal Consciousness recognizing Itself, but even that, owing to the dualistic structure of language, is a bit of a fudge.
Put differently, once the mental and physical senses “fall off,” there is only Pure Awareness as Pure Awareness. The Self self-knows, shining of Itself, through Itself, as Itself. A common analogy might bring this second point home: once the “obscurations” of the clouds are gone, there is only vast, empty, open sky. Isness, self-luminous awareness, and abiding peacefulness.