the body that the mind can directly command and act on. The
muscles are preeminently the mind's instruments, the visible
and moving part of its machinery. They are thought carriers,
and during the growth period their functional activities are
organized into the mental life. This is why "we think in terms
of muscular movement," and why muscular training supplies a
natural need of the developing mind.

The normal boy says little or nothing of what he thinks, but
much of what he is doing or intends to do. He has the motor
mind, the instinct for doing things by which he builds the
brain and body. It is nature's way of laying the foundation in
the individual as by the more tedious process of evolution she
laid it in the race. The mental development of the normal
infant is indicated by the increasing accuracy and delicacy of
muscular coordination. The feeble-minded child very early shows
its mental defect in the clumsy use of its muscles. Because of
the functional relation of the voluntary muscles and the
mentality, physical training is in a large degree mental
training. When by such training we give dexterity to muscles of
the growing person we are making possible better mental
development; that is, because of this relation of the mind to
action there is a direct mental discipline in the thought-out
processes of physical activity. If, then, we make physical
development a part of our educational process, we are taking
advantage of race tendencies, we are starting the individual as
nature started the race; we are laying the foundation in the
individual as it was originally laid in the race; we are
building as the race built.