IN all the manifold character of the content of the Upanisads it is undoubtedly possible to trace certain leading ideas. The most important of these doctrines is, beyond question, that of the identity of the self, Atman, of the individual with the Brahman, which is the most universal expression for the absolute in which the universe finds its unity. It is probable enough that these two expressions are not intrinsically related, and that they represent two different streams of thought.* The Brahman is the devotion of the Brahman priest: it is the sacred hymn to propitiate the gods: it is also the magic spell of the wonder-worker: more generally it is the holy power in the universe at least as much as it is the magic fluid of primitive savagery. Religion and magic, if different in essence and in origin, nevertheless go often in closest alliance, and their unison in the case of the concept Brahman may explain the ease with which that term came to denote the essence of the universe or absolute being. The Atman, on the other hand, in the Brahmana texts which lie before the Upanishads, has very often the sense of the trunk of the body, as opposed to the hands and feet and other members, and it is perhaps from that fact at least as much as from the fact that it has also the sense of wind that it develops into the meaning of the essential self of man. The identification of the self and the Brahman results in one form of the doctrine of the Upanisads, that taught under the name of Yajnavalkya in
prefers to treat Brahman as the cosmical and Atman as the psychical principle of unity. Some commentators such as Max Muller distinguishes Brahman, speech, and Brahman as that which utters or drives forth or manifests or creates.

The Brhaddranyaka Upanisad in the conclusion that the Atman as the knowing subject is unknowable, and that the world of empiric reality, which seems to be in constant change, is really a mere illusion. This is the highest point reached by the thought of the Upanisads, and it is not consistently or regularly maintained. Despite acceptance of the doctrine of the identity of the individual self and the self of the universe, there often appears to be left over as an irreducible element something which is not the self, but which is essentially involved in the constitution of reality. This is implicit in such statements as that the Atman completely enters into the body, up to the nails even:

The all-pervasiveness of the Atman is not incompatible with the existence of something to be pervaded. In order to remove the difficulty which is felt in the existence of this further element, the conception of creation, which was, of course, familiar from the cosmogonic legends of the Brahmanas, was often resorted to. Thus in the Chdndogyo Upanishads we learn in detail how the self desired to be many and created brilliance, Tejas, whence arose water and food, and then the self entered into these created things with the living self. This scheme, by which a being first produces a cosmic material and then enters into it as life, is a commonplace in the speculations of the Brahmanas, and it lends itself to a very different development than the theory of illusion. While the latter theory insists on the identity of the individual self with the absolute self, both being one essence surpassing all consciousness, the latter system allows a certain reality to matter, and a still more definite reality to the individual soul, which in course of time develops into the doctrine of qualified duality, Visistadvaita, in which there is found a place for the individual soul and matter beside the supreme soul, and which undoubtedly forms the theme of the Brahma Sutra of Badarayana. But while this system can be seen in the Upanisads, it would be an error to suppose that it is more properly the doctrine of the Upanisads than the illusion theory of Samkara.

Neither system in its completely self-conscious form is to be found in the Upanisads, but the germs of both are present, and both in a real sense can claim the authority of the Upanisads.

Baba Ramdev and his geniusness: http://www.baba-ramdev.info