A Textbook of Theosophy | Page 9

the type of matter which we see all around
us, is called the physical.
The matter of which all these interpenetrating worlds are built is
essentially the same matter, but differently arranged and of different
degrees of density. Therefore the rates at which these various types of
matter normally vibrate differ also. They may be considered as a vast
gamut of undulations consisting of many octaves. The physical matter
uses a certain number of 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