UPANISHADS

The Upanishads are the philosophical portion of the Vedas.  The word upanishad means "sitting near a teacher," in the sense of "intimate sessions for the initiate."  In the form of dialogues, composed with memorization in mind, they teach the knowledge of God and record the spiritual experiences of the sages of ancient India. 

Of the 108 Upanishads that have been preserved (108 is a mystical number), the principal 10 are: Isha, Katha, Prasna, Mundaka, Mandukya, Chandogya, Brihadaranyaka, Aitareya, and Taittiriya.  Since Upanishads brought to a close each of the four Vedas, they became known as the Vedanta, "anta" meaning the end of the Vedas.

The Upanishads are, in general, agreed on one fundamental view, that the ground of all being, whether material or spiritual, whether in the form of  humans, animals, or gods, heaven, earth, or hell, is an all inclusive, unitary reality.  It is beyond apprehension by the senses, ultimate in substance, infinite in essence, and self-sufficient.  It is the only really existent entity.  It is called Brahman. 

Some Hindu scholars claim that Gautama Buddha was profoundly influenced by the Upanishads, but when one considers the horror with which many brahmins hold him, this must be taken with a grain of salt.  On the other hand, the Upanishads do correspond broadly to certain doctrines later developed in Mahayana Buddhism.