A part of the "Vedas", a collection of ancient manuscripts which form the basis for the Hindu religion, the "Upanishads" are ancient Sanskrit texts which contain arguably the most important spiritual aspects of the Hindu faith. Of the more than two hundred "Upanishads", the ones of principal importance, Chandogya, Kena, Aitareya, Kaushitaki, Isa, Katha, Mundaka, Taittiriyaka, Brhadaranyaka, Svetasvatara, Prasna, and Maitriyana, are presented here in the translation of famed Indologist and Sanskritologist F. Max Muller, which first appeared in the "Sacred Books of the East" volumes I and XV. The central theme of the "Upanishads" is not that of a ritualistic systematic philosophy but as Muller describes to "know thy true self, that which underlines thine Ego, and find it and know it in the highest, the eternal Self, the One without a second, which underlies the whole world." Noted for its thorough annotations and scholarly detail this edition of the "Upanishads" will bring great insight to students of the Hindu faith. Muller's complete two volume translation is presented here in a single volume printed on a premium acid-free paper.