at an early period he began to write, apparently at the age of 23. It was at this age, and only a few months after his marriage, that on account of some excess he was for a time confined in Vincennes. He was destined to spend 27 years of his life in prisons, if we include the 13 years which in old age he passed in the asylum at Charenton. His actual offenses were by no means so terrible as those he loved to dwell on in imagination, and for the most part they have been greatly exaggerated. His most extreme offenses were the indecent and forcible flagellation in 1768 of a young woman, Rosa Keller, who had accosted him in the street for alms, and whom he induced by false pretenses to come to his house, and the administration of aphrodisiacal bonbons to some prostitutes at Marseilles. It is owing to the fact that the prime of his manhood was spent in prisons that De Sade fell back on dreaming, study, and novel-writing. Shut out from real life, he solaced his imagination with the perverted visions--to a very large extent, however, founded on knowledge of the real facts of perverted life in his time--which he has recorded in _Justine_ (1781); _Les 120 Journées de Sodome ou l'Ecole du Libertinage_ (1785); _Aline et Valcour ou le Roman Philosophique_ (1788); _Juliette_ (1796); _La Philosophie dans le Boudoir_ (1795). These books constitute a sort of encyclopedia of sexual perversions, an eighteenth century _Psychopathia Sexualis_, and embody, at the same time, a philosophy. He was the first, Bloch remarks, who realized the immense importance of the sexual question. His general attitude may be illustrated by the following passage (as quoted by Lacassagne): "If there are beings in the world whose acts shock all accepted prejudices, we must not preach at them or punish them ... because their bizarre tastes no more depend upon themselves than it depends on you whether you are witty or stupid, well made or hump-backed.... What would become of your laws, your morality, your religion, your gallows, your Paradise, your gods, your hell, if it were shown that such and such fluids, such fibers, or a certain acridity in the blood, or in the animal spirits, alone suffice to make a man the object of your punishments or your rewards?" He was enormously well read, Bloch points out, and his interest extended to every field of literature: _belles lettres_, philosophy, theology, politics, sociology, ethnology, mythology, and history. Perhaps his favorite reading was travels. He was minutely familiar with the bible, though his attitude was extremely critical. His favorite philosopher was Lamettrie, whom he very frequently quotes, and he had carefully studied Machiavelli.