<P> More than 200 Upanishads are known, of which the first dozen or so are the oldest and most important and are referred to as the principal or main (mukhya) Upanishads . The mukhya Upanishads are found mostly in the concluding part of the Brahmanas and Aranyakas and were, for centuries, memorized by each generation and passed down orally . The early Upanishads all predate the Common Era, five of them in all likelihood pre-Buddhist (6th century BCE), down to the Maurya period . Of the remainder, 95 Upanishads are part of the Muktika canon, composed from about the last centuries of 1st - millennium BCE through about 15th - century CE . New Upanishads, beyond the 108 in the Muktika canon, continued to be composed through the early modern and modern era, though often dealing with subjects which are unconnected to the Vedas . </P> <P> With the translation of the Upanishads in the early 19th century they also started to attract attention from a western audience . Arthur Schopenhauer was deeply impressed by the Upanishads and called it "the production of the highest human wisdom". Modern era Indologists have discussed the similarities between the fundamental concepts in the Upanishads and major western philosophers . </P> <P> The Sanskrit term Upaniṣad (from upa "by" and ni - ṣad "sit down") translates to "sitting down near", referring to the student sitting down near the teacher while receiving spiritual knowledge . Other dictionary meanings include "esoteric doctrine" and "secret doctrine". Monier - Williams' Sanskrit Dictionary notes--"According to native authorities, Upanishad means setting to rest ignorance by revealing the knowledge of the supreme spirit ." </P> <P> Adi Shankaracharya explains in his commentary on the Kaṭha and Brihadaranyaka Upanishad that the word means Ātmavidyā, that is, "knowledge of the self", or Brahmavidyā "knowledge of Brahma". The word appears in the verses of many Upanishads, such as the fourth verse of the 13th volume in first chapter of the Chandogya Upanishad . Max Müller as well as Paul Deussen translate the word Upanishad in these verses as "secret doctrine", Robert Hume translates it as "mystic meaning", while Patrick Olivelle translates it as "hidden connections". </P>

Which is a religious text of hinduism that means sitting near a teacher