It is quite possible that the conception of a beaming jovial and happy Leonardo was true only for the first and longer period of the master's life. From now on, when the downfall of the rule of Lodovico Moro forced him to leave Milan, his sphere of action and his assured position, to lead an unsteady and unsuccessful life until his last asylum in France, it is possible that the luster of his disposition became pale and some odd features of his character became more prominent. The turning of his interest from his art to science which increased with age must have also been responsible for widening the gap between himself and his contemporaries. All his efforts with which, according to their opinion, he wasted his time instead of diligently filling orders and becoming rich as perhaps his former classmate Perugino, seemed to his contemporaries as capricious playing, or even caused them to suspect him of being in the service of the "black art." We who know him from his sketches understand him better. In a time in which the authority of the church began to be substituted by that of antiquity and in which only theoretical investigation existed, he the forerunner, or better the worthy competitor of Bacon and Copernicus, was necessarily isolated. When he dissected cadavers of horses and human beings, and built flying apparatus, or when he studied the nourishment of plants and their behavior towards poisons, he naturally deviated much from the commentators of Aristotle and came nearer the despised alchemists, in whose laboratories the experimental investigations found some refuge during these unfavorable times. The effect that this had on his paintings was that he disliked to handle the brush, he painted less and what was more often the case, the things he began were mostly left unfinished; he cared less and less for the future fate of his works. It was this mode of working that was held up to him as a reproach from his contemporaries to whom his behavior to his art remained a riddle. Many of Leonardo's later admirers have attempted to wipe off the stain of unsteadiness from his character. They maintained that what is blamed in Leonardo is a general characteristic of great artists. They said that even the energetic Michelangelo who was absorbed in his work left many incompleted works, which was as little due to his fault as to Leonardo's in the same case. Besides some pictures were not as unfinished as he claimed, and what the layman would call a masterpiece may still appear to the creator of the work of art as an unsatisfied embodiment of his intentions; he has a faint notion of a perfection which he despairs of reproducing in likeness. Least of all should the artist be held responsible for the fate which befalls his works.