t the mind is a
manifestation of the super-soul, or he may be a materialist, and in
either case he may at the same time and with perfect consistency
believe, as a practical scientist, that the mind is a "cause" and has
bodily action as its "effect."

Naturally this point of view offers no difficulties whatever to the
spiritualist. He already looks upon the mind or soul as the "originating
cause" of everything.

[Sidenote: Thoughts Treated as Causes]

But the materialist, too, may in accordance with his speculative theory
continue to insist that _brain-action_ is the "originating cause" of
mental life; yet if the facts show that certain thoughts are invariably
followed by certain bodily activities, the materialist may without
violence to his theories agree to the great practical value of _treating
these thoughts as immediate causes_, no matter what the history of
creation may have been.

Whatever the brand of your materialism or your religious belief, you
can join us in accepting this practical-science point of view as a
common platform upon which to approach our second fundamental
proposition, that "all bodily activity is caused, controlled and
directed by the mind."

[Sidenote: Scientific Method with Practical Problems]

Ignoring all religious and metaphysical questions, we have, then, to ask
ourselves merely: _Can the mind be relied upon to bring about or stop or
in any manner influence bodily action? And if it can, what is the extent
of the mind's influence?_

In answering these questions we shall follow the method of the practical
scientist, whose method is invariably the same whatever the problem he
is investigating.

This method involves two steps: first, the collection and classification
of facts; second, the deduction from those facts of general principles.

[Sidenote: Uses of Scientific Laws]

The scientist first gathers together the greatest possible array of
experiential facts and classifies these facts into sequences--that is to
say, he gathers together as many instances as he can find in which one
given fact follows directly upon the happening of another given fact.

Having done this, he next formulates in broad general terms the common
principle that he finds embodied in these many similar sequences.

Such a formula, if there are facts enough to establish it, is what is
known as a scientific law. Its value to the world lies in this, that
whenever the given fact shall again occur our knowledg