There are over 150 _Upanishads_ enumerated by Orientalists, who credit the oldest with being written _probably_ about 600 years B.C.; but of _genuine_ texts there does not exist a fifth of the number. The _Upanishads_ are to the _Vedas_ what the _Kabalah_ is to the Jewish _Bible_. They treat of and expound the secret and mystic meaning of the Vedic texts. They speak of the origin of the Universe, the nature of Deity, and of Spirit and Soul, as also of the metaphysical connection of Mind and Matter. In a few words: _They_ CONTAIN _the beginning and the end of all human knowledge, but they have ceased to_ REVEAL _it_, since the days of Buddha. If it were otherwise, the _Upanishads_ could not be called _esoteric_, since they are now openly attached to the Sacred Brâhmanical Books, which have, in our present age, become accessible even to the Mlechchhas (out‐castes) and the European Orientalists. One thing in them—and this, in all the _Upanishads_—invariably and constantly points to their ancient origin, and proves (_a_) that they were written, in some of their portions, _before_ the caste system became the tyrannical institution which it still is; and (_b_) that half of their contents have been eliminated, while some of them have been rewritten and abridged. “The great Teachers of the higher Knowledge and the Brâhmans are continually represented as going to Kshatriya [military‐caste] kings to become their pupils.” As Professor Cowell pertinently remarks, the _Upanishads_ “breathe an entirely different spirit [from other Brâhmanical writings], a freedom of thought unknown in any earlier work, except in the _Rig Veda_ hymns themselves.” The second fact is explained by a tradition recorded in one of the MSS. on Buddha’s life. It says that the _Upanishads_ were originally attached to their _Brâhmanas_ after the beginning of a reform, which led to the exclusiveness of the present caste system among the Brâhmans, a few centuries after the invasion of India by the “Twice‐born.” They were complete in those days, and were used for the instruction of the Chelâs who were preparing for Initiation.