“The philosophers, and especially those who were initiated into the Mysteries, held that the astral soul is the impalpable duplicate of the gross external form which we call body. It is the perisprit of the Kardecists and the spirit-form of the spiritualists.
Above this internal duplicate, and illuminating it as the warm ray of the sun illuminates the earth, fructifying the germ and calling out to spiritual vivification the latent qualities dormant in it, hovers the divine spirit. The astral perisprit is contained and confined within the physical body as ether in a bottle, or magnetism in magnetized iron.
It is a centre and engine of force, fed from the universal supply of force, and moved by the same general laws which pervade all nature and produce all cosmical phenomena. Its inherent activity causes the incessant physical operations of the animal organism and ultimately results in the destruction of the latter by overuse and its own escape.
It is the prisoner, not the voluntary tenant, of the body. It has an attraction so powerful to the external universal force, that after wearing out its casing it finally escapes to it. The stronger, grosser, more material its encasing body, the longer is the term of its imprisonment.
Some persons are born with organizations so exceptional, that the door which shuts other people in from communication with the world of the astral light, can be easily unbarred and opened, and their souls can look into, or even pass into that world, and return again. Those who do this consciously, and at will, are termed magicians, hierophants, seers, adepts; those who are made to do it, either through the fluid of the mesmerizer or of “spirits”, are “mediums”.
The astral soul, when the barriers are once opened, is so powerfully attracted by the universal, astral magnet, that it sometimes lifts its encasement with it and keeps it suspended in mid-air, until the gravity of matter reasserts its supremacy, and the body redescends again to earth.”
H. P. Blavatsky