is, to pass from the region of conscious mind into that of
subconscious mind, and to acquire a permanent domicile there. Professor
Elmer Gates, of Washington, has demonstrated this physiologically in his
studies of brain formation. He tells us that every thought produces a
slight molecular change in the substance of the brain, and the repetition
of the same sort of thought causes a repetition of the same molecular
action until at last a veritable channel is formed in the brain substance,
which can only be eradicated by a reverse process of thought. In this way
"grooves of thought" are very literal things, and when once established the
vibrations of the cosmic currents flow automatically through them and thus
react upon the mind by a process the reverse of that by which our voluntary
and intentional in-drawing from the invisible is affected. In this way are
formed what we call "habits," and hence the importance of controlling our
thinking and guarding it against undesirable ideas.

But on the other hand this reactionary process may be used to confirm good
and life-giving modes of thought, so that by a knowledge of its laws we may
enlist even the physical body itself in the building up of that perfectly
whole personality, the attainment of which is the aim and object of our
studies.

XV.

THE SOUL.

Having now obtained a glimpse of the adaptation of the physical organism to
the action of the mind we must next realize that the mind itself is an
organism which is in like manner adapted to the action of a still higher
power, only here the adaptation is one of mental faculty. As with other
invisible forces all we can know of the mind is by observing what it does,
but with this difference, that since we ourselves _are_ this mind, our
observation is an interior observation of states of consciousness. In this
way we recognize certain faculties of our mind, the working order of which
I have considered at page 84; but the point to which I would now draw
attention is that these faculties always work under the influence of
something which stimulates them, and this stimulus may come either from
without through the external senses, or from within by the consciousness of
something not perceptible on the physical plane. Now the recognition of
these interior sources of stimulus to our mental faculties, is an important
branch of Mental Science, because the mental action thus set up works just
as accurately through the physical