The subtle body or astral body was proposed by many philosophers, it is the intermediate between the intelligent soul and the mental body, composed of a subtle material. In many recensions, the concept ultimately derives from Plato's philosophy, although the same or similar ideas have existed throughout the world long before Plato's time: it is related to an astral plane, consisting of the planetary heavens of astrology. The term was adopted by the Theosophists and Neo-Rosicrucians of the 19th century.
The idea has its roots in religious accounts common throughout the world of the afterlife, in which the journey or "ascent" of the soul is described in terms of "an ecstatic ... mystical or out-of-body experience in whereby the spiritual traveler leaves the physical body and travels in his subtle body (or dream body or astral body) to 'higher' realms".
