Jagadguru Śaṅkarācārya

“Even in the state of ignorance, when one sees something, through what instrument should one know That owing to which all this is known? For that instrument of knowledge itself falls under the category of objects. The knower may desire to know not about itself, but about objects. As fire does not burn itself, so the self does not know itself, and the knower can have no knowledge of a thing that is not its object. Therefore through what instrument should one know the knower owing to which this universe is known, and who else should know it? And when to the knower of Brahman who has discriminated the Real from the unreal there remains only the subject, absolute and one without a second, through what instrument, O Maitreyī, should one know that Knower?”
― Jagadguru Śaṅkarācārya