ke; makes a dozen paces through
the room, descends to the counting-house, dictates letters, and
forwards despatches. He jumps into his carriage, the horses snort,
and their driver is immediately at the Bank, on the Bourse, and among
his commercial friends. Before an hour has elapsed he is again at
home, where he throws himself once more into his easy chair with a
deep-drawn sigh, 'Thank God I am protected against the worst, and now
for further reflection.'

This complex mass of action, emotional, intellectual, and mechanical,
is evoked by the impact upon the retina of the infinitesimal waves of
light coming from a few pencil marks on a bit of paper. We have, as
Lange says, terror, hope, sensation, calculation, possible ruin, and
victory compressed into a moment. What caused the merchant to spring
out of his chair? The contraction of his muscles. What made his
muscles contract? An impulse of the nerves, which lifted the proper
latch, and liberated the muscular power. Whence this impulse? From
the centre of the nervous system. But how did it originate there?
This is the critical question, to which some will reply that it had
its origin in the human soul.

The aim and effort of science is to explain the unknown in terms of
the known. Explanation, therefore, is conditioned by knowledge. You
have probably heard the story of the German peasant, who, in early
railway days, was taken to see the performance of a locomotive. He
had never known carriages to be moved except by animal power. Every
explanation outside of this conception lay beyond his experience, and
could not be invoked. After long reflection therefore, and seeing no
possible escape from the conclusion, he exclaimed confidently to his
companion, 'Es muessen doch Pferde darin sein '--There must be horses
inside. Amusing as this locomotive theory may seem, it illustrates a
deep-lying truth.

With reference to our present question, some may be disposed to press
upon me such considerations as these: Your motor nerves are so many
speaking-tubes, through which messages are sent from the man to the
world; and your sensor nerves are so many conduits through which the
whispers of the world are sent back to the man. But you have not told
us where is the man. Who or what is it that sends and receives those
messages through the bodily organism? Do not the phenomena point to
the existence of a self within the self, which acts through the body
as through a