In this volume my friend and pupil, Marie Bonaparte, has directed the light of psycho-analysis upon the life and work of a great writer of a pathological type. Thanks to her interpretative efforts, we can now understand how much of the characteristics of his work were determined by their author's special nature; but we also learn that this was itself the precipitate of powerful emotional ties and painful experiences in his early youth. Investigations of this kind are not intended to explain an author's genius, but they show what motive forces aroused it and what material was offered to him by destiny. There is a particular fascination in studying the laws of the human mind as exemplified in outstanding individuals.