The astral plane, also called the astral realm or the astral world, is a plane of existence postulated by classical, medieval, oriental, and esoteric philosophies and mystery religions. It is the world of the celestial spheres, crossed by the soul in its astral body on the way to being born and after death, and is generally believed to be populated by angels, spirits or other immaterial beings. In the late 19th and early 20th century the term was popularised by Theosophy and neo-Rosicrucianism. Another view holds that the astral plane or world, rather than being some kind of boundary area crossed by the soul, is the entirety of spirit existence or spirit worlds to which those who die on Earth go, and where they live out their non-physical lives. It is understood that all consciousness resides in the astral plane. Some writers conflate this realm with heaven or paradise or union with God itself, and others do not. Paramahansa Yogananda wrote in Autobiography of a Yogi, "The astral universe . . . is hundreds of times larger than the material universe . . .[with] many astral planets, teeming with astral beings." (p.416) When Alice Bailey writes of seeing "Masters . . . upon the inner spiritual planes [who]. . . work with Christ and the planetary hierarchy," she refers to a vision she had of the unseen astral realm that these and countless other beings inhabit. Christ being in that realm, it is hard to construe it as a non-heaven. The "World of Al-Ghaib" and the "World of Barzakh" are related concepts in Islam. In Judaism, it is known as the "World of Yetzirah", according to Lurianic Kabbalah. History Plato and Aristotle taught that the stars were composed of a type of matter different from the four earthly elements - a fifth, ethereal element or quintessence. In the "astral mysticism" of the classical world the human psyche was composed of the same material, thus accounting for the influence of the stars upon human affairs. In his commentaries on Plato's Timaeus, Proclus wrote; Man is a little world (mikros cosmos). For, just like the Whole, he possesses both mind and reason, both a divine and a mortal body. He is also divided up according to the universe. It is for this reason, you know, that some are accustomed to say that his consciousness corresponds with the nature of the fixed stars,