word of the
passing naturalistic movement, and yet in another way it tries to be the
first word of the coming idealistic movement; and because it is under
the influence of both, it speaks sometimes the language of the one, and
sometimes the language of the other. That brings about a confusion and a
disorder which must be detrimental. To transform this vagueness into
clear, distinct relations is the immediate duty of science.

Indeed it may be said that psychotherapy is the last word of a
naturalistic age, because psychotherapy finds its real stronghold in a
systematic study of the mental laws, and such study of mental laws,
psychology, must indeed be the ultimate outcome of a naturalistic view
of the world. Realism begins with the analysis of lifeless nature,
begins with the study of the stars and the stones, of masses and of
atoms. At a higher level, it turns then to the living organism, studies
plants and animals and even brings the human organism entirely under the
point of view of natural law. When science has thus mastered the whole
physical universe, it finally brings even the mental life of man under
the naturalistic point of view, treats his inner experiences like any
outer objects, tears them in pieces, analyzes them, and studies them as
functions of the nervous system. A scientific psychology is thus reached
which is the climax of realism, because it means that even the ideas and
emotions and volitions of man are treated as natural phenomena, that
their causes are sought and that their effects are determined, that
their laws are found out. To apply this realistic knowledge of the mind
in the interest of therapy is merely to use it in the same way in which
the engineer uses his knowledge of physics, when he wants to harness
outer nature. As that is possible only when theoretical science has
reached a certain height of development, it can indeed be said that
practical psychotherapy on a scientific basis can be considered almost
as the ultimate point of a realistic movement; it cannot set in until
psychology has reached high development, and psychology cannot set in
unless biology has preceded it.

There is no doubt that we are still far from this last phase of the
realistic period. The practical application of scientific psychology is
still a new problem. Experimental psychology began about twenty-five
years ago; at that time there existed one psychological laboratory.
To-day there is no university in the world