and each of these latter are also sub-divided into seven
sub-planes, all divisions being more or less arbitrary, shading into
each other, and adopted merely for convenience of scientific study and
thought.

The Great Physical Plane, and its Seven Minor Planes, is that division
of the phenomena of the Universe which includes all that relates to
physics, or material things, forces, and manifestations. It includes all
forms of that which we call Matter, and all forms of that which we call
Energy or Force. But you must remember that the Hermetic Philosophy does
not recognize Matter as a thing in itself, or as having a separate
existence even in the Mind of THE ALL. The Teachings are that Matter is
but a form of Energy--.that is, Energy at a low rate of vibrations of a
certain kind. And accordingly the Hermetists classify Matter under the
head of Energy, and give to it three of the Seven Minor Planes of the
Great Physical Plane.

These Seven Minor Physical Planes are as follows:

1. The Plane of Matter (A)
2. The Plane of Matter (B)
3. The Plane of Matter (C)
4. The Plane of Ethereal Substance
5. The Plane of Energy (A)
6. The Plane of Energy (B)
7. The Plane of Energy (C)

The Plane of Matter (A) comprises the forms of Matter in its form of
solids, liquids, and gases, as generally recognized by the text-books on
physics. The Plane of Matter (B) comprises certain higher and more
subtle forms of Matter of the existence of which modern science is but
now recognizing, the phenomena of Radiant Matter, in its phases of
radium, etc., belonging to the lower sub-division of this Minor Plane.
The Plane of Matter (C) comprises forms of the most subtle and tenuous
Matter, the existence of which is not suspected by ordinary scientists.
The Plane of Ethereal Substance comprises that which science speaks of
as "The Ether", a substance of extreme tenuity and elasticity, pervading
all Universal Space, and acting as a medium for the transmission of
waves of energy, such as light, heat, electricity, etc. This Ethereal
Substance forms a connecting link between Matter (so-called) and Energy,
and partakes of the nature of each. The Hermetic Teachings, however,
instruct that this plane has seven sub-divisions (as have all of the
Minor Planes), and that in fact there are seven ethers, instead of but
one.

Next above the Plane of Ethereal Substance comes the Plane of Energy
(A), which comprises the ordinary form