mark out the limits which are set up for the working capacity of psychoanalysis in biography so that every omitted explanation should not be held up to us as a failure. Psychoanalytic investigation has at its disposal the data of the history of the person's life, which on the one hand consists of accidental events and environmental influences, and on the other hand of the reported reactions of the individual. Based on the knowledge of psychic mechanisms it now seeks to investigate dynamically the character of the individual from his reactions, and to lay bare his earliest psychic motive forces as well as their later transformations and developments. If this succeeds then the reaction of the personality is explained through the coöperation of constitutional and accidental factors or through inner and outer forces. If such an undertaking, as perhaps in the case of Leonardo, does not yield definite results then the blame for it is not to be laid to the faulty or inadequate psychoanalytic method, but to the vague and fragmentary material left by tradition about this person. It is, therefore, only the author who forced psychoanalysis to
