Part III. Friedrich Nietzsche's Personality and Psychotherapy

As the psychic processes act parallel with the brain stimulae, so physiological psychology goes side by side with brain physiology. Where the latter does not as yet offer sufficient knowledge, physiological psychology may make purely provisional investigation into psychic appearances, but always accompanied by the thought that for these psychic appearances the possibility of a parallelism with cerebral processes must also be proved.” Even if one does not fully endorse this statement of Theodor Ziehen, (compare his Leitfaden der Physiologischen Psychologie, Guide to Physiological Psychology, p. 2) one will have to admit that it has proved itself exceptionally fruitful for the methods of psychology. Under the influence of his point of view which he expresses, this science has attained truly scientific knowledge. But one must be quite clear about the significant light which the observation of the pathological soul appearances throws upon the connection between psychic appearances and the corresponding physiological processes. Pathological experimentation has rendered great service to psychology as well as to physiology. The abnormal facts of the soul life clarify the normal ones for us. But it must be especially important to follow abnormal manifestations into those realms where the soul activity intensifies to the point of the highest spiritual achievements.