Upaniṣad is Vedanta: ‘The end of the Vedas, of Vedic Understanding’, a word-play on the fortuitous convergence of the metaphoric and literal, as they are located at the concluding part of the Vedic contracting cone. Abstraction and metaphysical content rise as the cone shrinks.
The tradition descended from oral-teaching to written word around 1,000 BCE. The dialogues of Uddalaka and his son Svetaketu in the Chandogya Upaniṣad, the first of the two oldest extant Upanishads, lay-out the pioneering of the ‘Inward Turn’, the first seed that finally birthed the formulation of Shūnyam.
The assumed Subject had to be first clearly identified, the Inquirer’s Platform laid bare, prior to any investigation on an Object. Honest Inquiry began inwards, backwards.
It was here and for the first time, the Inquirer as the Subject of Inquiry, the platform from which he views his world, was being recognized as pivotal in any understanding of Brahman. The modern assumption that the Subject can be ignored as long as the Object was clearly in view was, after repeated and painful experimentation, found to be false.
[A laying-out of the Inquirer, making transparent his presumptions and closeted prejudices, is part of the ‘Scientific Stance’, an integral element of what today is termed ‘Scientific Method’. The roots of Formal Meditation Practice begin here. See the later Posts.]
In time there spread a wider appreciation of the issues involved. That this type of Inquiry was of a very special and perilous character, that any inquiry on the nature of the Subject, by an assumed Subject, was fraught with miscues, wrong turns and short stops.
The Inquirers of the Chandogya, didn’t go all the way. They stopped short of Shūnyam, settling instead for a ‘Subtle Inner Essence’.
Words like ‘Subtle’ and ‘Inner’ are properties not associated with ‘True Nothing’. Unless they were used in the spirit of ‘Skillful Means’, as a helpful pedagogic bridge. Perhaps they were. But this ‘Subtle Inner Essence’ terminus pervades later Vedanthic exegesis as the ‘Inner’ or ‘True’ Self.
Shūnyam was still an unknown construct and did not become formalized for another several centuries. But it’s root took life here.