The designation _astral_ is ancient, and was used by some of the Neo-platonists. Porphyry describes the celestial body which is always joined with the soul as “immortal, luminous, and star-like.” The root of this word may be found, perhaps, in the Scythic _aist-aer_—which means star, or the Assyrian _Istar_, which, according to Burnouf has the same sense. As the Rosicrucians regarded the real, as the direct opposite of the apparent, and taught that what seems light to _matter_, is darkness to _spirit_, they searched for the latter in the astral ocean of invisible fire which encompasses the world; and claim to have traced the equally invisible divine spirit, which overshadows every man and is erroneously called _soul_, to the very throne of the Invisible {xxvi} and Unknown God. As the great cause must always remain invisible and imponderable, they could prove their assertions merely by demonstration of its effects in this world of matter, by calling them forth from the unknowable down into the knowable universe of effects. That this astral light permeates the whole cosmos, lurking in its latent state even in the minutest particle of rock, they demonstrate by the phenomenon of the spark from flint and from every other stone, whose spirit when forcibly disturbed springs to sight spark-like, and immediately disappears in the realms of the unknowable. Paracelsus named it the _sidereal light_, taking the term from the Latin. He regarded the starry host (our earth included) as the _condensed_ portions of the astral light which “fell down into generation and matter,” but whose magnetic or spiritual emanations kept constantly a never-ceasing intercommunication between themselves and the parent-fount of all—the astral light. “The stars attract from us to themselves, and we again from them to us,” he says. The body is wood and the life is fire, which comes like the light from the stars and from heaven. “Magic is the philosophy of alchemy,” he says again.[30] Everything pertaining to the spiritual world must come to us through the stars, and if we are in friendship with them, we may attain the greatest _magical_ effects.