(Prāṇa): The principle of energy; life force; vital energy; life breath. The Universal Life Force, which is a vibrant physical and psychic energy. The sum of all the forces of nature, including those that are latent, mysterious, and hidden in the human being, as well as those existing everywhere in the macrocosm. In common contexts, prana means “air.” From a spiritual perspective, even from ancient times prana has been equated with Brahman (the Absolute) as the transcendental source of all life. The Yoga Vasishtha (3:13:31) defines prana as the “vibratory power” (spanda shakti) that underlies all manifestation. This life force, prana, is not of a physical nature per se. It is not a material form of energy. It is, rather, a principle which sustains matter and which is deeply involved in matter’s very existence.