formal sacrifice. They, thus, helped to bridge
Brihadaranyaka Upanishad a passage speaks about the fortunes of the soul
and develops the doctrine of the transmigration of soul and, in close
connection with it, the doctrine of karma also.
Place of Upanishads
The word Upanishad consists of three words—upa meaning ‘near’, ni
meaning ‘down’ and shad meaning ‘be seated’. So, Upanishad means, ‘be
seated at the feet of the Guru to receive the teaching.’
    The Upanishads constitute the Vedanta (Vedaanta or the end of the
Vedas), not merely because they constitute the last part of them, but more
importantly because the Vedas are their ultimate teaching, reaching out to the
highest metaphysical state, beyond which is only the realm of silence.
    The earliest Upanishads are also a part of the Vedas, and are therefore a
part of the Shruti. They constitute the fundamentals of Vedic philosophy. This
repository of knowledge contains within it an exposition of the origin of the
Universe, the nature of Brahman and the jivatman, the relation between mind
and matter, etc. Therefore, the main topic of the Upanishads is the ultimate
knowledge—the identity of the Brahman and the jivatman—Tat tvam asi or
‘You are That’ (Chandgogya Upanishad) and the quest for unity in diversity
(Mundaka Upanishad). The Upanishads are the first scriptures where the law
of Karma appeared as taught by Yajnavalkya (Brihadaranyaka Upanishad).
    The characteristics of the Upanishads are their universality and the total
absence of any dogmatism. They are the highest philosophy ever conceived
by the human mind. Totally there are 108 Upanishads, though only the first
12 are part of the Vedic literature.
    1. Twelve major Upanishads
        (i) Aitareya and the Kauhsitaki which belong to Rig Veda
        (ii) Chandgogya and Kena to Sama Veda
        (iii)Taittiriya, Katha, Shvetashvatara, Brihada- ranyaka and Isha to
             Yajur Veda
        (iv) Prashna, Mundaka and Mandukya to Atharva Veda
    2. Twenty three Samanayayuvedanta Upanishads
    3. Twenty Yoga Upanishads
    4. Seventeen Samnyasa Upanishads