the one accepted end of restoring the health of the patient. He
has to ask thus in general: what has psychology to-day to offer which
can be applied in the interests of medicine?

It would be an inexcusable narrowness to confine that chapter of applied
psychology which is to deal with the psychomedical problems to the work
of psychotherapy. Medicine involves diagnosis of illness as well as
therapeutics. Between the recognition and the treatment of the illness
lies the observation of its development and all this is preceded by
steps towards the prevention of illness. In every one of these regions,
psychology may be serviceable. Psychotherapy is thus only one special
part of psychomedicine. But the situation becomes still more complex by
the fact that the illness to be treated or the disturbance to be removed
may stand in different relations to the psychophysical processes. The
illness may be a disturbance in the psychophysical brain parts, or it
may belong to other brain parts which are only in an indirect way under
the influence of mental states or which are themselves indirectly
producing changes in the mental life. And finally the disturbance may
exist outside of the brain in any part of the body, and yet again
through the medium of brain and nervous system it may produce effects in
the mind or be open to the influence of the mind. Thus we have entirely
different groups of medical interests and it would be superficial to
ignore the differences.

Both psychodiagnostic and psychotherapeutic studies must be devoted to
cases in which the mind itself is abnormal, further to cases in which
the normal minds registers the abnormalities in other parts of the body,
and finally to cases in which the normal mind influences abnormal
processes in the body. These latter two cases have to be subdivided into
those where the bodily disturbance still lies in the brain parts and
those where it lies outside of the brain. But the situation becomes
still more complex by the mutual relations of those various processes.
The impulse to take morphine injections may have reached the character
of a mental obsession and thus represent an abnormality of the mind, but
yielding to it produces at the same time disturbances in the whole body
which thus become again external sources for abnormal experiences in
otherwise normal layers of the mind.

Of course the interest of the psychologist as such remains always
related to the psychological factor, b