he race in earlier ages.

CHAPTER V.

THE EVOLUTIONARY FIELD

In a treatise on elementary theosophy the solar system may be reckoned
as our universe and we shall have no need of considering more than a
small fragment of even that. It is septenary in constitution, as may be
seen in its vibrations expressed in color and sound. Beyond the seven
colors of the prism we have only tints and outside the seven notes we
can get only overtones or undertones. There are likewise seven planes in
the system but less than half of them require our attention, for the
evolutionary field of the human soul is the three lower planes, known as
the physical, astral and mental. When the human being has outgrown them
in evolution he passes on to superhuman evolution.

The word "plane," so often encountered in theosophical literature,
should perhaps have some definition. It has a wide application and is
used as a synonym for region, place, sphere or world. In referring to
the physical plane the term embraces all we know of earth and sky and
life through the physical senses.

There are seven planes in our solar system because of the seven
different combinations of its ultimate atoms. Each plane consists of a
totally different grade of matter than the next plane, but all have for
their base the ultimate atom of the solar system. When modern science
discovered, to its astonishment, that the physical atom was a composite
body it confirmed the theosophical teaching that the ultimate physical
atom was _not_ the final point of division. Theosophy teaches that when
the ultimate physical atom is disintegrated its particles become the
coarsest matter of the next plane or region above it--the astral plane.
The process repeated with astral matter results in driving its ultimate
atom from the highest level of the astral plane or world to the lowest
of the mental plane. That scientist who said that the atom is the brick
of the universe stated a great truth, for of its combinations all forms
are built; and if the idea be applied to the ultimate atom of the solar
system it will then be true that of such "bricks" all the planes are
built.

The relationship of the planes to each other is that of interpenetrating
spheres of matter. The physical plane, consisting of the earth and its
atmosphere, is surrounded and interpenetrated by the astral plane, or
world, which is an enormously larger globe of exceedingly tenuous
matter. This vast sphere of invisi