When one compares these reports about Leonardo's way of working with the evidence of the extraordinary amount of sketches and studies left by him, one is bound altogether to reject the idea that traits of flightiness and unsteadiness exerted the slightest influence on Leonardo's relation to his art. On the contrary one notices a very extraordinary absorption in work, a richness in possibilities in which a decision could be reached only hestitatingly, claims which could hardly be satisfied, and an inhibition in the execution which could not even be explained by the inevitable backwardness of the artist behind his ideal purpose. The slowness which was striking in Leonardo's works from the very beginning proved to be a symptom of his inhibition, a forerunner of his turning away from painting which manifested itself later.[8] It was this slowness which decided the not undeserving fate of The Holy Supper. Leonardo could not take kindly to the art of fresco painting which demands quick work while the background is still moist, it was for this reason that he chose oil colors, the drying of which permitted him to complete the picture according to his mood and leisure. But these colors separated themselves from the background upon which they were painted and which isolated them from the brick wall; the blemishes of this wall and the vicissitudes to which the room was subjected seemingly contributed to the inevitable deterioration of the picture.[9] The picture of the cavalry battle of Anghiari, which in competition with Michelangelo he began to paint later on a wall of the Sala de Consiglio in Florence and which he also left in an unfinished state, seemed to have perished through the failure of a similar technical process. It seems here as if a peculiar interest, that of the experimenter, at first reënforced the artistic, only later to damage the art production.