In this development the vibrations of outer matter play the part of the steel, which, on striking flint, causes the life latent within the latter to dart forth. Each vibration which strikes the soul arouses therein a dormant faculty, and when all the vibrations of the universe have touched it, this soul will have developed as many faculties as that universe admits of, until, in the course of successive worlds, it becomes increasingly divine in the one Divine Being. In order that all the vibrations of which a universe is capable may reach the soul the latter must surround itself with all the different types of atoms that exist in the world, for every vibration is an atomic movement, and the nature of the vibration depends on the quality of the atoms in motion. Now, the first part of evolution consists in condensing round vital centres[60] (souls) atoms aggregated in combinations of a progressively increasing density, on to those that make up the physical plane; when the soul has thus clothed itself with the elements of all the planes, the resulting form is called a "microcosm"—a small Cosmos—for it contains, in reality, all the elements contained in the Universe. During this progressive development, the soul, which thus effects its "fall" into matter, receives from all the planes through which it passes and from all the forms in which it incarnates, varied vibrations which awake within it correspondingly responsive powers and develop a non-centred, diffused, non-individualised consciousness.
In the second phase of evolution, the forms are limited, the vibrations they receive are transmitted by specialised sensorial groups, and the soul, hitherto endowed with a diffused consciousness, begins to feel varieties of vibrations that grow ever more numerous, to be distinguished from the surrounding world, to separate itself, so to speak, from everything around; in a word, to develop self-consciousness. This separation first takes place on the physical plane; it is made easier by hard, violent contacts, and the forms, in their turn, become more complex, varied, and specialised in proportion as the soul is the more perfectly individualised. When it has developed all the self-conscious responsive powers in the physical body, it begins to develop those faculties which have as their organs of transmission the finer bodies, and as planes of vibration the invisible worlds.
In our planetary system the number of the invisible planes is seven.[61] Each of them in turn supplies the soul with a form; thus, when evolution—which in its second phase successively dematerialises matter, i.e., disassociates the atoms from their combinations, beginning with the denser ones—has dissolved the physical plane, the human soul will utilise, as its normal body, a finer one which it is at present using as a link between the mental and the physical bodies. Before this dissolution is effected, however, human beings will have developed, to some extent, several finer bodies, already existing, though hitherto not completely organised.
The first of these bodies, the astral—a very inappropriate name, though here used because it is so well known—is a copy, more or less, of the physical form in its general aspect; the resemblance and clearness of the features are pronounced in proportion to the intellectual development of the person, for thought-vibration has great influence over the building up of the centres of force and of sensation in this body.[62]
The second is an even finer aggregate, composed of mental substance and assuming, during incarnation, the form of a smaller or larger ovoid—the causal body—surrounding the physical form.[63] At its centre, and plunged in the astral body during incarnation, is another kind of ovoid not so large and composed of denser substance—the mental body.[64]
Above these states of matter, at the present stage there appears no form to the consciousness of human beings, though perfect seers can perceive, within the causal body, still higher grades of matter, which will only subsequently become centres of self-consciousness.
During incarnation, the soul, in the majority of men, is clearly conscious of itself and of its surroundings only when it is functioning through the nervous system (the brain); when it leaves the denser body, during sleep, its consciousness is in the astral body, and there it thinks,[65] but without being conscious of what is taking place around it. After disincarnation, it generally becomes highly conscious in its astral body, where it passes its purgatorial life; and this latter endures until the soul leaves the astral body. As soon as the latter is thrown off, consciousness centres in the mental body; this is the period of Devachan or Heaven. When the mental body is put off, paradise is at an end, and the soul, sheathed only in the causal body, finds itself on a very lofty plane, but here, consciousness is vague, when we are dealing with a man of average development. Instead of laying aside this garment, as so far it has done with the rest, it recommences, after the lapse of a certain time, another descent into the matter of the lower planes and a new incarnation begins.
To the centre of the causal body are drawn atoms from the inner mental plane; these represent a new mental body.[66] When this latter has been formed, there are attracted to it atoms of the astral plane, and these form a new astral body; the soul, clothed in these two sheaths, if one may so express it, is brought into conscious or unconscious relation, according to its degree of development, with the two corresponding planes, lives there generally for a short time, and is directed to a mother's womb, in which is created the visible body of flesh within the centre of its astral body.
This force of atomic attraction has its centre in the causal body, a kind of sensitive plate on which are registered all those vibrations which disturb or affect human vehicles during incarnation. This body is, in effect, the present abode of the soul, it represents the terminal point of human consciousness,[67] the real centre of man.[68] It receives all the impressions of the plane on which it finds itself, as well as those which come to it from the lower planes, and responds to them the more readily as it has now attained a fuller development. It possesses the power to attract and to repel; a microcosm, it has its outbreathing and inbreathing, as has the Macrocosm; like Brahmâ, it creates its bodies and destroys them, although in the vast majority of mankind it exercises this power more or less unconsciously and under the irresistible impulsion of the force of evolution—the divine Will. When it attracts, it causes to recur within itself the vibrations it has received and registered—like a phonographic roll—during the past incarnations; these vibrations reverberate in the outer world, and certain of them attract from this world[69]—in this case the mental world—the atoms capable of responding to them. When they have created the mental body, other vibrations can be transmitted through this body to the astral world and attract atoms which will form the body bearing the same name—the astral—and finally other vibrations, making use of these two bodies as a means of transmission, will affect the physical plane and attract atoms which will assist in the building up of the denser body.