it is said in Cat.  Br. ix. 4. 3. 3 (from the literal meaning of ’sitting below’).[5] Instead, therefore, of seeing in upan[=i]sad, Upanishad, the idea of a session, of pupils sitting down to hear instruction (the prepositions and verb are never used in this sense), it may be that the Upanishads were at first subsidiary works of the ritualistic Br[=a]hmanas contained in the [=A]ranyakas or Forest Books, that is, appendices to the Br[=a]hmana, ostensibly intended for the use of pious forest-hermits (who had passed beyond the need of sacrifice); and this, in point of fact, is just what they were; till their growth resulted in their becoming an independent branch of literature.  The usual explanation of ‘Upanishad,’ however, is that it represents the instruction given to the pupil ‘sitting under’ the teacher.

Although at present between two and three hundred Upanishads are known, at least by name, to exist, yet scarcely a dozen appear to be of great antiquity.  Some of these are integral parts of Br[=a]hmanas, and apparently were added to the ritualistic works at an early period.[6]

While man’s chief effort in the Brahmanic period seems to be by sacrifice and penance to attain happiness hereafter, and to get the upper hand of divine powers; while he recognizes a God, who, though supreme, has yet, like the priest himself, attained his supremacy by sacrifice and penance; while he dreams of a life hereafter in heavenly worlds, in the realm of light, though hardly seeking to avoid a continuation of earthly re-births; nevertheless he frees himself at times from ritualistic observances sufficiently to continue the questioning asked by his Vedic ancestors, and to wonder whither his immortal part is definitively going, and whether that spirit of his will live independently, or be united with some higher power, such as the sun or Brahm[=a].

The philosophical writings called Upanishads[7] take up this question in earnest, but the answer is already assured, and the philosophers, or poets, of this period seek less to prove the truth than to expound it.  The soul of man will not only join a heavenly Power.  It is part of that Power.  Man’s spirit (self) is the world-spirit.  And what is this?  While all the Upanishads are at one in answering the first question, they are not at one in the method by which they arrive at the same result.  There is no systematic philosophy; but a tentative, and more or less dogmatic, logic.  In regard to the second question they are still less at one; but in general their answer is that the world-spirit is All, and everything is a part of It or Him.  Yet, whether that All is personal or impersonal, and what is the relation between spirit and matter, this is still an unsettled point.