Astral Light

The French occultist Eliphas Levi (February 8, 1810 - May 31, 1875) used the term "astral light" to refer to the medium of all light, energy and movement, much in accordance with the theory of the luminiferous ether commonly held in the nineteenth century. In his view the astral light was a fluidic life force that fills all space and living beings.

General description

H. P. Blavatsky adopted the term and applied it in her writings, and regarded it as a lower aspect of Ākāśa:

Astral Light (Occult). The invisible region that surrounds our globe, as it does every other, and corresponding as the second Principle of Kosmos (the third being Life, of which it is the vehicle) to the Linga Sharira or the Astral Double in man. A subtle Essence visible only to a clairvoyant eye, and the lowest but one (viz., the earth), of the Seven Akâsic or Kosmic Principles.

The Astral Light is that which mirrors the three higher planes of consciousness, and is above the lower, or terrestrial plane; therefore it does not extend beyond the fourth plane, where, one may say, the Akâsa begins. There is one great difference between the Astral Light and the Akâsa which must be remembered. The latter is eternal, the former periodic. The Astral Light changes not only with the Maha manvantaras but also with every sub-period and planetary cycle or Round.

The "Great Serpent"

The Astral Light is originally a pure reflection of the higher planes (although they are reflected in a "reversed" way). However, since it also absorbs the emanations (thoughts and emotions) produced on our plane, in the course of human evolution it becomes "polluted". This pollution is reflected on earth and becomes a source of moral and physical suffering to humanity:

As the Esoteric Philosophy teaches us, the Astral Light is simply the dregs of Akâsa or the Universal Ideation in its metaphysical sense. Though invisible, it is yet, so to speak, the phosphorescent radiation of the latter, and is the medium between it and man’s thought-faculties. It is these which pollute the Astral Light, and make it what it is—the storehouse of all human and especially psychic iniquities. In its primordial genesis, the astral light as a radiation is quite pure, though the lower it descends approaching our terrestrial sphere, the more it differentiates, and becomes as a result impure in its very constitution. But man helps considerably in this pollution, and gives it back its essence far worse than when he received it.

Eliphas Levi calls it the great Serpent and the Dragon from which radiates on Humanity every evil influence. This is so; but why not add that the Astral Light gives out nothing but what it has received; that it is the great terrestrial crucible, in which the vile emanations of the earth (moral and physical) upon which the Astral Light is fed, are all converted into their subtlest essence, and radiated back intensified, thus becoming epidemics--moral, psychic and physical.

Read and study what Éliphas Lévi says of the Astral Light, which he calls Satan and the Great Serpent. The Astral Light has been taken too literally to mean some sort of a second blue sky. This imaginary space, however, on which are impressed the countless images of all that ever was, is, and will be, is but a too sad reality. It becomes in, and for, man—if at all psychic—and who is not?—a tempting Demon, his “evil angel,” and the inspirer of all our worst deeds. It acts on the will of even the sleeping man, through visions impressed upon his slumbering brain (which visions must not be confused, with the “dreams”), and these germs bear their fruit when he awakes.

Because of its nature, any clairvoyant, to be reliable, has to have the ability to raise beyond this plane:

The prototypes or ideas of things exist first on the plane of Divine eternal Consciousness and thence become reflected and reversed in the Astral Light, which also reflects on its lower individual plane the life of our Earth, recording it on its “tablets.” Therefore, is the Astral Light called illusion. It is from this that we, in our turn, get our prototypes. Consequently unless the Clairvoyant or SEER can get beyond this plane of illusion, he can never see the Truth, but will be drowned in an ocean of self-deception and hallucinations.

Occult phenomena

In Isis Unveiled Blavatsky writes that the Astral light is related to some occult and psychic phenomena:

The same as the sidereal light of Paracelsus and other Hermetic philosophers. Physically, it is the ether of modern science. Metaphysically, and in its spiritual, or occult sense, ether is a great deal more than is often imagined. In occult physics, and alchemy, it is well demonstrated to enclose within its shoreless waves not only Mr. Tyndall’s “promise and potency of every quality of life,” but also the realization of the potency of every quality of spirit. Alchemists and Hermetists believe that their astral, or sidereal ether, besides the above properties of sulphur, and white and red magnesia, or magnes, is the anima mundi, the workshop of Nature and of all the cosmos, spiritually, as well as physically. The “grand magisterium” asserts itself in the phenomenon of mesmerism, in the “levitation” of human and inert objects; and may be called the ether from its spiritual aspect.

Eliphas Lévi called it the “grand Agent Magique” (great Magic agent) although Mme. Blavatsky says this is so "only so far as Black Magic is concerned".

Additional resources

Theosopedia, s.v."Astral Light," by Vicente R. Hao Chin, Jr., accessed February 6, 2011, http://theosophy.ph/encyclo/index.php?title=Astral_Light.