Paul Deussen originally published this book in German (Die Philosophic der Upanishads) a century back in 1899, which was rendered into English by A.S. Geden in 1906. The philosophy of the Upanishads, according to Paul Deussen, is the ''culminating point of the Indian doctrine of the universe'' and this point, he said, ''had been already reached in Vedic, pre-Buddhistic times; and in philosophical significance has been surpassed by none of the later developments of thought up to the present day.'' This English rendering has been reprinted on a persistent demand by the readers of Indian Philosophy.