section_path: Philosophy and practice/The Mahāvākyas - the identity of Ātman and Brahman/That you are
section_name: That you are
paragraph_text: That you are
  
  The longest chapter of Shankara's Upadesasahasri, chapter 18, "That Art Thou," is devoted to considerations on the insight "I am ever-free, the existent" (sat), and the identity expressed in Chandogya Upanishad 6.8.7 in the mahavakya (great sentence) " tat tvam asi ", "that thou art." In this statement, according to Shankara, tat refers to Sat, "the Existent" Existence, Being, or Brahman, the Real, the "Root of the world," the true essence or root or origin of everything that exists. "Tvam" refers to one's real I, pratyagatman or inner Self, the "direct Witness within everything," "free from caste, family, and purifying ceremonies," the essence, Atman, which the individual at the core is. As Shankara states in the Upadesasahasri:
  
  Up.I.174: "Through such sentences as "Thou art That" one knows one's own Atman, the Witness of all the internal organs." Up.I.18.190: "Through such sentences as " the Existent" right knowledge concerning the inner Atman will become clearer." Up.I.18.193-194: "In the sentence "Thou art That" he word "That" means inner Atman."
  
  The statement "tat tvam asi" sheds the false notion that Atman is different from Brahman. According toNakamura, the non-duality of atman and Brahman "is a famous characteristic of Sankara's thought, but it was already taught by Sundarapandya" (c. 600 CE or earlier). Shankara cites Sundarapandya in his comments to Brahma Sutra verse I.1.4:
  
  When the metaphorical or false atman is non-existent, child, body are sublated. Therefore, when it is realized that 'I am the existent Brahman, atman ', how can anyduty exist?
  
  From this, and a large number of other accordances, Nakamura concludes that Shankar was not an original thinker, but "a synthesizer of existing Advaita and the rejuvenator, as well as a defender, of ancient learning."