Who sends the mind to wander afar? Who first drives life to start on its journey? Who impels us to utter these words? Who is the Spirit behind the eye and the ear?

It is the ear of the ear, the eye of the eye, and the Word of words, the mind of mind, and the life of life. Those who follow wisdom pass beyond and, on leaving this world, become immortal.

There the eye goes not, nor words, nor mind. We know not, we cannot understand, how He can be explained: He is above the known and He is above the unknown. Thus have we heard from the ancient sages who explained this truth to us.

~ Katha Upanishad