Up to the present time the psychoanalytic investigator has turned his interest chiefly to the analysis of the individual psychologic problems. It seems to me, however, that in the present state of affairs there is a more or less imperative demand for the psychoanalyst to broaden the analysis of the individual problems by a comparative study of historical material relating to them, just as Freud has already done in a masterly manner in his book on "Leonardo da Vinci."9 For, just as the psychoanalytic conceptions promote understanding of the historic psychologic creations, so reversedly historical materials can shed new light upon individual psychologic problems. These and similar considerations have caused me to turn my attention somewhat more to the historical, in the hope that, out of this, new insight into the foundations of individual psychology might be won.
