psychology (that is, the psychology in its phase of "brain-action") the
ancients possessed a knowledge of transcendental astronomy, called
astrology; of transcendental chemistry, called alchemy; of
transcendental psychology, called mystic psychology. They possessed the
Inner Knowledge as well as the Outer Knowledge, the latter alone being
possessed by modern scientists. Among the many secret branches of
knowledge possessed by the Hermetists, was that known as Mental
Transmutation, which forms the subject matter of this lesson.

"Transmutation" is a term usually employed to designate the ancient art
of the transmutation of metals--particularly of the base metals into
gold. The word "Transmute" means "to change from one nature, form, or
substance, into another; to transform" (Webster). And accordingly,
"Mental Transmutation" means the art of changing and transforming mental
states, forms, and conditions, into others. So you may see that Mental
Transmutation is the "Art of Mental Chemistry," if you like the term--a
form of practical Mystic Psychology.

But this means far more than appears on the surface. Transmutation,
Alchemy, or Chemistry on the Mental Plane is important enough in its
effects, to be sure, and if the art stopped there it would still be one
of the most important branches of study known to man. But this is only
the beginning. Let us see why!

The first of the Seven Hermetic Principles is the Principle of
Mentalism, the axiom of which is "THE ALL is Mind; the Universe is
Mental," which means that the Underlying Reality of the Universe is
Mind; and the Universe itself is Mental--that is, "existing in the Mind
of THE ALL." We shall consider this Principle in succeeding lessons, but
let us see the effect of the principle if it be assumed to be true.