The translations and explanatory notes of the Mantras given here are meant not so much to provide a word-to-word translation and a commentary of every word thereof, but to give the essential purport of the Mantras and the central meaning they convey to the spiritual aspirant. The notes given here are mainly intended for the Sadhaka who is not very particular about a theological, ritualistic or formal traditional explanation of the Upanishads, but is interested in knowing their philosophical implications directly bearing upon the practice of the Yoga of Knowledge.

—Swami Krishnananda