Kena 40

By this text the teacher confirms the idea that Brahman is unthinkable, because unconditioned. Therefore he says: He who considers It beyond thought, beyond sense-perception, beyond mind and speech, he alone has a true understanding of Brahman. They who judge a living being from his external form and sense faculties, know him not; because the real Self of man is not manifested in his seeing, hearing, speaking. His real Self is that within by which he hears and speaks and sees. In the same way he knows not Brahman who thinks he knows It by name and form. The arrogant and foolish man thinks he knows everything; but the true knower is humble. He says: "How can I know Thee, who art Infinite and beyond mind and speech?" In the last portion of the text, the teacher draws an impressive contrast between the attitude of the wise man who knows, but thinks he does not know; and that of the ignorant who does not know, but thinks he knows.