The Upanishads, which were compiled somewhere around 900 BC, comprise the last portion of the Vedas, called the Vedanta, or «end of the Vedas.» This work consist of more than one hundred treatises written in both prose and verse between the eight and sixth centuries BC.
The range of their subject matters makes them one of the most remarkable collections of writings created by humanity. They not only antedate all other philosophic works, but their ethical, spiritual, social, religious, humanistic, and literary revelations and qualities also preceded such development in other create world cultures.
The term relates to the method of teaching: the pupil sat opposite (upa-ni-sad) the teacher. Though these books have had, understandable, an incalculable influence on the East, their emergence into the Western consciousness has made then very significant to both eminent teachers and the ever-expending public.
There are a vas array of subjects that the Upanishads deal with including the essential nature of the Divine Principle, life-discipline that is required for salvation, the revealing of an individual soul (atman), which is centered through its union with the universal Atman–the universal Supreme Being (Brahman); and the belief that this Supreme Being is the source and goal of every human being.
However, in the radical Chandogya Upanishad there is the daring declaration tat tvam asi «that are thou» or «you are Brahman.» Further concepts discussed are the nature of eternal life, transmigration, and the crucially consequential notion of maya. The Upanishads also describe the unifying principles in the universe in elemental terms such as power, breath, and food, thus uniting matter and spirit. A.G.H.
Sources:
Riland, George, The New Steinerbooks Dictionary of Paranormal, New York, Warner Books, Inc., 1980, 321 Rice, Edward, Eastern Definitions: A Short Encyclopedia of Religions of the Orient, Garden City, New York, Doubleday, 1978, p. 391