The Thirteen Principal Upanishads

In the Long History of man's endeavor to grasp the fundamental truths of being, the metaphysical treatises known as the Upanishads' hold an honored place. They represent the earnest efforts of the profound thinkers of early India to solve the problems of the origin, the nature, and the destiny of man and of the universe, or-more technically the meaning and value of 'knowing' and 'being'. Though they contain some fanciful ideas, native speculations, and inadequate conclusions, yet they are replete with sublime conceptions and with intuitions of universal truth.
Here are found intimations of the inadequacy of mere nature worship and of the falsity of an empty ceremonialism. Here are expressed the momentous discoveries that the various gods of polytheistic belief are but numerous special manifestations of the One Power of the universe, and that the supreme object of worship is this variously revealed, partially elusive, all-comprehending unitary Reality. Still more momentous are the discernments that man is of more significance than all the forces of Nature; that man himself is the interpretation as well as the interpreter of Nature, because he is akin to the reality at the heart of the universe; indeed, that the One God, the great intelligent Person who is immanent in the universe, is to be found most directly in the heart of man. Here in the Upanishads are set forth, in concrete example as well as in dogmatic instruction, two opposing theories of life: an ignorant, narrow, selfish way of life which seeks temporary, unsatisfying, unreal ends; and a way of life which seeks to relate itself to the Supreme Reality of the universe, so as to escape from the needless misery of ordinary existence into undying bliss.
These important texts, the earliest of which can hardly have taken form later than the seventh century B. C.,2 are still attracting devoted readers, as they have during the past twenty-five centuries. The student of the history of philosophy who desires to know some of the earliest answers reached in India for the ever insistent problems of man and the universe and for the ideals of the highest existence; the special student of India who strives to understand the essence as well as the externals of its culture; the religious teacher and worker in East and West who seeks to apprehend the aspirations and spiritual. ideals of the Hindu soul; the educated English-speaking Hindu who feels a special affection for, and interest in, the sacred writings of his native land; and the deep thinker who searches in arcane texts for clues to the solution of life's mysteries-all of these students will turn constantly to the Upanishads as an authoritative compendium of Indian metaphysical teachings. It has been my aim to prepare for such students and readers a faithful rendering of the original Sanskrit texts-a translation which will show exactly what the revered Upanishads say.
In presenting this new version I would first pay due respect to Professor F. Max Müller, that eminent figure of an earlier generation of Sanskrit scholars, who, in volumes I and XV of the Sacred Books of the East (1879, 1884), published an English translation of twelve of the Upanishads.