g the hand, and see how the
psychological analysis applies in this movement. We note in the first
place that we are concerned only with the third, fourth, and fifth
particulars of Prof. Ladd's analysis. These are:

The idea of the movement.

The fiat of will which directs that this movement be performed.

The discharge of the requisite motor impulses, along the nerve-tracts,
to the muscles whose contraction constitutes the movement.

It will be simpler, and will answer the purpose equally well, to combine
the third and fourth elements, and to consider as one element the idea
of the movement and the fiat of will to execute the movement.

_The Idea of a Movement_

The mental picture of a purposed movement is simple and direct. No
reference is involved to the muscles concerned in the performance of the
movement. When you will to raise your hand, the action is pictured to
your mind as the raising of the hand, and nothing more. Certain muscles
are to be contracted. But the mental picture of the movement does not
indicate what these muscles are, in what order they are to be brought
into play, nor the relative degrees of strength to be exerted by each
muscular fiber. You do not consciously direct the muscles in their
contractions.

_The Discharge to the Muscles of the Nerve Impulse_

How then are the muscles informed that their contraction is called for?
They have no independent volition; each muscular fiber obeys the impulse
transmitted to it by the nerve, from the nerve center governing its
action. These nerve centers are in their turn controlled by the central
nervous mechanism. And in complex voluntary movements the central
nervous mechanism is under the control of the higher cerebral centers.
The wish to raise the hand appears to the mind as an idea of the hand
being raised. This idea is translated by the central nervous mechanism
into a set of motor nerve impulses. Does consciousness or volition come
into play here? Not at all. On this point Prof. Ladd remarks: "As to the
definite nature of the physical basis which underlies the connection of
ideas of motion and the starting outward of the right motor impulses,
our ignorance is almost complete."

Is it necessary for the performance of a complex muscular action that
the individual know what muscles are involved and how and when to
contract them? No; this knowledge is not only unnecessary, it is even
impossible. Prof. Ladd says of this: "It would be a great mista