from Giorgio Vasari’s account of Leonardo and his work on the Last Supper, his unconventional disposition, his salesmanship and the perplexing bent of secular humanism which was disconcerting to the defenders of the faith….
He also painted in Milan, for the Friars of S. Dominic, at S. Maria dell Grazie, a Last Supper, a most beautiful and marvellous thing; and to the heads of the Apostles he gave such majesty and beauty, that he left the head of Christ unfinished, not believing that he was able to give it that divine air which is essential to the image of Christ. This work, remaining thus all but finished, has ever been held by the Milanese in the greatest veneration, and also by strangers as well; for Leonardo imagined and succeeded in expressing that anxiety which had seized the Apostles in wishing to know who should betray their Master. For which reason in all their faces are seen love, fear, and wrath, or rather, sorrow, at not being able to understand the meaning of Christ; which thing excites no less marvel than the sight, in contrast to it, of obstinacy, hatred, and treachery in Judas; not to mention that every least part of the work displays an incredible diligence, seeing that even in the tablecloth the texture of the stuff is counterfeited in such a manner that linen itself could not seem more real….
…It is said that the Prior of that place kept pressing Leonardo, in a most importunate manner, to finish the work; for it seemed strange to him to see Leonardo sometimes stand half a day at a time, lost in contemplation, and he would have like him to go on like the labourers hoeing in his garden, without ever stopping his brush. And not content with this, he complained of it to the Duke, and that so warmly, that he was constrained to send for Leonardo and delicately urged him to work, contriving nevertheless to show him that he was doing all this because of the importunity of the Prior. Leonardo, knowing that the intellect of that Prince was acute and discerning, was pleased to discourse at large with the Duke on the subject, a thing which he had never done with the Prior: and he reasoned much with him about art, and made him understand that men of lofty genius sometimes accomplish the most wh en they work the least, seeking out inventions with the mind, and forming those perfect ideas which the hands afterwards express and reproduce from the images already conceived in the brain. And he added that two heads were still wanting for him to paint; that of Christ, which he did not wish to seek on earth; and he could not think that it was possible to conceive in the imagination that beauty and heavenly grace which should be the mark of God incarnate….
…Next, there was wanting that of Judas, which was also troubling him, not thinking himself capable of imagining features that should represent the countenance of him who, after so many benefits received, had a mind so cruel as to resolve to betray his Lord, the Creator of the world. However, he would seek out a model for the latter; but if in the end he could not find a better, he should not want that of the importunate and tactless Prior. This thing moved the Duke wondrously to laughter, and he said that Leonardo had a thousand reasons on his side. And so the poor Prior, in confusion, confined himself to urging on the work in the garden, and left Leonardo in peace, who finished only the head of Judas, which seems the very embodiment of treachery and inhumanity; but that of Christ, as has been said, remained unfinished. Read More:http://www.fordham.edu/halsall/source/vasari1.html
Freud:The slowness with which Leonardo worked was proverbial. After the most thorough preliminary studies he painted The Holy Supper for three years in the cloister of Santa Maria delle Grazie in Milan. One of his contemporaries, Matteo Bandelli, the writer of novels, who was then a young monk in the cloister, relates that Leonardo often ascended the scaffold very early in the morning and did not leave the brush out of his hand until twilight, never thinking of eating or drinking. Then days passed without putting his hand on it, sometimes he remained for hours before the painting and derived satisfaction from studying it by himself. At other times he came directly to the cloister from the palace of the Milanese Castle where he formed the model of the equestrian statue for Francesco Sforza, in order to add a few strokes with the brush to one of the figures and then stopped immediately.
According to Vasari he worked for years on the portrait of Monna Lisa, the wife of the Florentine de Gioconda, without being able to bring it to completion. This circumstance may also account for the fact that it was never delivered to the one who ordered it but remained with Leonardo who took it with him to France. Having been procured by King Francis I, it now forms one of the greatest treasures of the Louvre.
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.
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. Read More:http://www.bartleby.com/277/1.html