In the chapter of the Aitareya Upanishad, Atman is asserted to have existed alone prior to the creation of the universe. It is this Atman, the Self or the Inner Self, that is then portrayed as the creator of everything from itself and nothing, through heat. The text states that the Atman created the universe in stages. First came four entities: space, maram (earth, stars), maricih (light-atom) and apas (ur-water, cosmic fluid). After these came into existence, came the cosmic self and eight psyches and principles (speech, in-breathing, sight, hearing, skin/hair, mind, out-breathing, reproductivity). Atman then created eight guardians corresponding to these psyches and principles. Then, asserts Aitareya Upanishad, came the connective principles of hunger and thirst, where everything became interdependent on everything else through the principle of apana (digestion). Thereafter came man, who could not exist without a sense of Self and Atman.