Astral Body is the spiritual, ether-like counterpart of the physical body. The body is composed of astral material and is an exact energy duplication of the physical form that it encompasses. This energy body is attached to the physical body, usually at the naval, by a silver-like cord. The astral body accompanied by the mind is capable of travel during period in which the physical body sleeps. Such an act is referred to as "astral projection."
In Theosophy the use of the term astral body denotes the link between the nervous system and the cosmic reservoir. This astral body is the instrument of passions, emotions, and desires, and, since it interpenetrates and extends beyond the physical body, it is the medium through which these are conveyed to the latter. When separated from the physical body during sleep, or by the influence of the use of drugs, or in cases of accidents, it takes with it the capacity of sensation and only by its return can pain be felt.
During these separation periods the astral body is an exact replica of the physical body and it is extremely sensitive to thought, the aspirations of the dead and dying resemble in minute detail the physical bodies that they recently departed.
The Astral World is thought to be attainable to clairvoyants and the appropriate body is visible to them.
According to the Theosophical teachings on the subject of thought, the aspiration is not the abstraction that it is commonly considered to be, but composed of definite forms the shape of which depends on the quality of thought, and it also causes vibrations, which are seen as colors. Therefore, clairvoyants may determine the state of the man's development from the appearance of his astral body.
The nebulous appearance indicates an imperfect development, while an ovoid appearance is an indication of a more perfect development. Colors, too, are indicative of the kind of thought; their variety within the astral body indicates the possessor's character. Inferior thoughts produce loud colors, so rage; for instance, will be recognized by the red appearance of the astral body. The contrary is true of higher thoughts, which are recognizable by the presence of delicate colors, religious thought for instance, causing a blue color. The colorization of the astral body is more familiar to those within the physical realm of life. Inhabitants usually are not acquainted with the bodies higher than the astral bodies.
There is a definite Theosophical theory concerning the emotional state and other functions of the astral body. The matter of which it is composed does not possess intelligent life, but rather possesses a kind of life that enables it to convey an understanding of its own existence and desires. This life is in a descent stage of evolution, as the turning point has not been reached yet, as far as the astral body is concerned. The possessor of the attached physical body, however, has commenced to ascend; and, therefore, there continues to be opposition between the astral and physical bodies.
The divergency lies within the opposition between the grosser and finer thoughts or matter that eventually resides within the astral body. The constitution of the astral matter is, therefore, altered; the grosser thoughts demanding their medium gross astral matter, the purer thoughts demanding fine astral matter. In life, at periods, one type of matter may get the upper hand; the stronger matter may diminish the weaker matter altogether. During physical life the different kinds of matter in the astral body intermingle, but at physical death the elementary life in the matter of the astral body seeks instinctively after self-preservation, and it therefore causes the matter to rearrange itself in a series of seven concentric sheaths, the densest being outside and the finest being inside.
While physical vision depends on the eyes, astral vision depends on the various kinds of astral matter being in a condition of receptiveness to different undulations. The various kinds of matter within the astral body are aware of their own kind; thus, fine matter is aware of fine matter, and gross matter is aware of gross matter, and so on. As the result of rearrangement only the grossest matter of the astral body is visible since it is the kind of matter that compose the thick outer sheath. Under such circumstances, the new denizen of the astral sphere sees only the worst of it, and also only the worst of his fellow denizens, even though they are not in so low of a state as himself.
The state in which the denizen finds himself is not eternal, but a part of an evolutionary process by which the sheath of the grossest astral matter gradually wears away, and the individual remains clothed in the six less gross sheaths. With the passage of timeless durations these too gradually dissipate, being resolved into their compound elements, and as last when the final disintegration of the least gross sheath occurs, the individual departs the Astral World and enters the Mental. Such a rearrangement of the astral body is not, however, inevitable, and those who have learned and know, are capable of preventing it at physical death. When such prevention occurs, the change appears to be very small, so that the so-called dead continue living and doing the work that they did in their physical bodies.