n view of the
experimental investigations, and the emotions and volitions of the
criminal were understood with a new insight. Here, too, the last step
was taken. Instead of being satisfied with experiments which the
psychologist had made for his own purposes, the students of legal
psychology adjusted experiments to the particular needs of the
courtroom. Investigations were carried on to determine, the fidelity
of testimony or to find methods for the detection of hidden thoughts
and so on. Efforts toward the application of psychology have
accordingly grown up in the fields of pedagogy, medicine, and
jurisprudence, but as these studies naturally do not remain
independent of one another, they all together form the one unified
science of applied psychology.[2]

As soon as the independence of this new science was felt, it was
natural that new demands and new problems should continue to originate
within its own limits. There must be applied psychology wherever the
investigation of mental life can be made serviceable to the tasks of
civilization. Criminal law, education, medicine, certainly do not
constitute the totality of civilized life. It is therefore the duty of
the practical psychologist systematically to examine how far other
purposes of modern society can be advanced by the new methods of
experimental psychology. There is, for instance, already, far-reaching
agreement that the problems of artistic creation, of scientific
observation, of social reform, and many similar endeavors must be
acknowledged as organic parts of applied psychology. Only one group of
purposes is so far surprisingly neglected in the realm of the
psychological laboratory: the purposes of the economic life, the
purposes of commerce and industry, of business and the market in the
widest sense of the word. The question how far applied psychology can
be extended in this direction is the topic of the following
discussions.

III

MEANS AND ENDS

Applied psychology is evidently to be classed with the technical
sciences. It may be considered as psychotechnics, since we must
recognize any science as technical if it teaches us to apply
theoretical knowledge for the furtherance of human purposes. Like all
technical sciences, applied psychology tells us what we ought to do if
we want to reach certain ends; but we ought to realize at the
threshold where the limits of such a technical science lie, as they
are easily overlooked, with resulting confu