Professor Freud developed his system of psychoanalysis while studying
the so-called borderline cases of mental diseases, such as hysteria and
compulsion neurosis. By discarding the old methods of treatment and
strictly applying himself to a study of the patient's life, he
discovered that the puzzling symptoms had a definite meaning, and that
there was nothing arbitrary in any morbid manifestation. Psychoanalysis
always showed that they referred to some definite problem or conflict of
the person concerned. It was while tracing back the abnormal to the
normal state that Professor Freud found how faint the line of
demarcation was between the normal and neurotic person, and that the
psychopathologic mechanisms so glaringly observed in the psychoneuroses
and psychoses could usually be demonstrated in a lesser degree in normal
persons. This led to a study of the faulty actions of everyday life and
later to the publication of the Psychopathology of Everyday Life.