soul, but to find the psychical elements and the
constant laws which control their connections. Psychology became
experimental and physiological. For more than thirty years the
psychologists have also had their workshops. Laboratories for
experimental psychology have grown up in all civilized countries, and
the new method has been applied to one group of mental traits after
another. And yet we stand before the surprising fact that all the
manifold results of the new science have remained book knowledge,
detached from any practical interests. Only in the last ten years do
we find systematic efforts to apply the experimental results of
psychology to the needs of society.

It is clear that the reason for this late beginning is not an
unwillingness of the last century to make theoretical knowledge
serviceable to the demands of life. Every one knows, on the contrary,
that the glorious advance of the natural sciences became at the same
time a triumphal march of technique. Whatever was brought to light in
the laboratories of the physicists and chemists, of the physiologists
and pathologists, was quickly transformed into achievements of
physical and chemical industry, of medicine and hygiene, of
agriculture and mining and transportation. No realm of the external
social life remained untouched. The scientists, on the other hand,
felt that the far-reaching practical effect which came from their
discoveries exerted a stimulating influence on the theoretical
researches themselves. The pure search for truth and knowledge was not
lowered when the electrical waves were harnessed for wireless
telegraphy, or the Roentgen rays were forced into the service of
surgery. The knowledge of nature and the mastery of nature have always
belonged together.

The persistent hesitation of the psychologists to make similar
practical use of their experimental results has therefore come from
different causes. The students of mental life evidently had the
feeling that quiet, undisturbed research was needed for the new
science of psychology in order that a certain maturity might be
reached before a contact with the turmoil of practical life would be
advisable. The sciences themselves cannot escape injury if their
results are forced into the rush of the day before the fundamental
ideas have been cleared up, the methods of investigation really tried,
and an ample supply of facts collected. But this very justified
reluctance becomes a real danger if it g