If the standards of psychotherapy approximated to those in vogue in the field of organic medicine a lecture on the indications for psycho-analysis would be a comparatively brief and possibly tedious affair. Since, however, there is no uniform diagnosis of mental disorders, no exact account of the rationale of psycho-analytic treatment and no assented list of the modifications of treatment required in different forms of disorder, it is obvious that before we can usefully discuss indications for psycho-analysis or in other words the scope of psychoanalytic treatment we must arrive at a certain amount of agreement regarding the diagnosis and prognosis of mental disorders and the nature of psychoanalytic therapy.