A Textbook of Theosophy | Page 9

the lowest of these octaves, the astral matter another group of octaves just above that, the mental matter a still further group, and so on.
Not only has each of these worlds its own type of matter; it has also its own set of aggregations of that matter--its own substances. In each world we arrange these substances in seven classes according to the rate at which their molecules vibrate. Usually, but not invariably, the slower oscillation involves also a larger molecule--a molecule, that is, built up by a special arrangement of the smaller molecules of the next higher subdivision. The application of heat increases the size of the molecules and also quickens and amplifies their undulation, so that they cover more ground, and the object, as a whole expands, until the point is reached where the aggregation of molecules breaks up, and the latter passes from one condition to that next above it. In the matter of the physical world the seven subdivisions are represented by seven degrees of density of matter, to which, beginning from below upwards, we give the names solid, liquid, gaseous, etheric, superetheric, subatomic and atomic.
The atomic subdivision is one in which all forms are built by the compression into certain shapes of the physical atoms, without any previous collection of these atoms into blocks or molecules. Typifying the physical ultimate atom for the moment by a brick, any form in the atomic subdivision would be made by gathering together some of the bricks, and building them into a certain shape. In order to make matter for the next lower subdivision, a certain number of the bricks (atoms) would first be gathered together and cemented into small blocks of say four bricks each, five bricks each, six bricks or seven bricks; and then these blocks so made would be used as building stones. For the next subdivision several of the blocks of the second subdivision cemented together in certain shapes would form building-stones, and so on to the lowest.
To transfer any substance from the solid condition to the liquid (that is to say, to melt it) is to increase the vibration of its compound molecules until at last they are shaken apart into the simpler molecules of which they were built. This process can in all cases be repeated again and again until finally any and every physical substance can be reduced to the ultimate atoms of the physical world.
Each of these worlds has its inhabitants, whose senses are normally capable of responding to the undulations of their own world only. A man living (as we are all doing) in the physical world sees, hears, feels, by vibrations connected with the physical matter around him. He is equally surrounded by the astral and mental and other worlds which are interpenetrating his own denser world, but of them he is normally unconscious, because his senses cannot respond to the oscillations of their matter, just as our physical eyes cannot see by the vibrations of ultra-violet light, although scientific experiments show that they exist, and there are other consciousnesses with differently-formed organs who can see by them. A being living in the astral world might be occupying the very same space as a being living in the physical world, yet each would be entirely unconscious of the other and would in no way impede the free movement of the other. The same is true of all other worlds. We are at this moment surrounded by these worlds of finer matter, as close to us as the world we see, and their inhabitants are passing through us and about us, but we are entirely unconscious of them.
Since our evolution is centred at present upon this globe which we call the earth, it is in connection with it only that we shall be speaking of these higher worlds, so in future when I use the term "astral world" I shall mean by it the astral part of our own globe only, and not (as heretofore) the astral part of the whole solar system. This astral part of our own world is also a globe, but of astral matter. It occupies the same place as the globe which we see, but its matter (being so much lighter) extends out into space on all sides of us further than does the atmosphere of the earth--a great deal further. It stretches to a little less than the mean distance of the moon, so that though the two physical globes, the earth and the moon, are nearly 240,000 miles apart, the astral globes of these two bodies touch one another when the moon is in perigee, but not when she is in apogee. I shall apply the term "mental world" to the still larger globe of mental matter in the midst of which our physical