Leonardo da Vinci

by Sir Kenneth M. Clark

  To me it seems that those sciences are vain and full of error which are not born of experience, mother of all certainty, firsthand experience which in its origins, or means, or end has passed through one of the five senses. And if we doubt the certainty of everything which passes through the senses, how much more ought we to doubt things contrary to these senses—ribelli ad essi sensi—such as the existence of God or of the soul or similar things over which there is always dispute and contention. And in fact it happens that whenever reason is wanting men cry out against one another, which does not happen with certainties. For this reason we shall say that where the cry of controversy is heard, there is no true science, because the truth has one single end and when this is published, argument is destroyed for ever. But true sciences are those which, impelled by hope, have been penetrated by the senses so that the tongues of argument are silenced. They are not nourished on the dreams of investigators, but proceed in orderly sequence from the first true and established principles through successive stages to the end; as is shown by the elements of mathematics, that is to say number and measure, called arithmetic and geometry, which with complete truth treat of quantities both discontinuous and continuous. In them one does not argue if twice three makes more or less than six, or that the angles of a triangle are less than the sum of two right angles: all argument is reduced to eternal silence, and those who are devoted to them can enjoy them with a peace which the lying sciences of the mind can never attain—con eterno silenzio resta distrutto ogni arguizione, e con pace sono fruite dai loro devoti il che far non possono le bugiarde scienze mentali.

  CHAPTER FIVE—1485-1496

  WE have seen Leonardo fulfilling the chief duties of an artist at a Re-naissance court, painting portraits, supervising pageants, and doing those small engineering jobs which demanded unusual resource and skill in the handling of materials. In addition to these duties he undertook for the Duke two works which exacted the whole measures of his genius, the Horse and the Last Supper.

  The Horse is the title by which contemporaries always referred to his model for the equestrian monument to Ludovico’s father, the great condottiere Francesco Sforza. Such a monument had first been attempted in 1473 under Duke Galeazzo Maria, and after his death in 1476 the idea was taken up with enthusiasm by Ludovico. By the time Leonardo went to Milan it had become a symbolical undertaking, involving group prestige, like the building of a giant liner today. Leonardo may have had some hope of being employed on the work, since he mentions it at the end of the letter to Ludovico in which he recommends himself as a military engineer. ‘Again, I can undertake to work on the bronze horse which will be a monument to the immortal glory and eternal honour of your father the Prince, and the illustrious house of Sforza.’ There is no evidence that he had been offered the commission or that it was the chief motive of his journey to Milan, but when he had proved his competence in various kinds of work he was evidently ordered to try his hand at the monument. If Sabba Castiglione is right in saying that he worked on it for sixteen years, he must have begun it in 1483. His first conception is known to us from an engraving and two drawings which on grounds of style are datable before 1490 (Pl. 29). They show that in this early stage Leonardo had conceived the horse as prancing, in a pose similar to those which he had just studied in the background of the Adoration, but simpler and less twisted. We know how strongly this sequence of forms appealed to him and we can imagine how eager he was to carry it out in sculpture, where its full plastic possibilities could be realized. At that date no equestrian statue with a prancing horse can have been known, and if he could have executed one Leonardo would have surpassed in technical skill not only the recent glories of the Gattamelata and Colleoni monuments, but even the masterpieces of antiquity. But his ambition far outran his experience. The two drawings mentioned show no attempt to meet the problems of monumental sculpture. In one the horse’s raised forefeet are supported by an inadequate and unconvincing tree-trunk; in the other they rest on a prostrate foe, a motive common in antique reliefs, but far too complicated and unsubstantial for large-scale sculpture in the round. Even if Leonardo’s designs had been more sculptural, such a complete group could hardly have been cast in bronze at that date, and it is surprising that Leonardo, with his experience of casting camion, did not realize this. But this disregard for media of execution marked all his most important works. The Last Supper, the Battle of Anghiari, the canalization of the Arno were all damaged or even annihilated by this defect, which sprang not only from impatience and experimentalism but from a certain romantic unreality. By 1489 Ludovico had either realized or been informed of the impracticability of Leonardo’s design, and through the Florentine ambassador in Milan he wrote to Lorenzo de’ Medici asking him to recommend one or two masters more apt for the work. At about this period Leonardo gave up work on the horse. Apparently Lorenzo made no satisfactory recommendation; and on 23 April 1490 Leonardo notes, ‘I began the horse again.’ This time he seems to have realized that the project of a rearing horse was too ambitious, and returned to the traditional pose of a horse walking. There is good evidence of what this horse was to be like. It is shown complete in a small sketch in the right-hand bottom corner of a drawing at Windsor (P. 70), and in a red chalk sketch in the Codice Atlantico, f. 216 verso, a, where it is shown packed for transport, Leonardo taking his usual delight in the technical devices involved. Some drawings from nature at Windsor indicate the disposition of its limbs, and these hints of the pose are confirmed by representations of horses in contemporary bronzes and illuminated manuscripts which are almost certainly derived from the Sforza monument. The most interesting of all these reminiscences is the horse in Dürer’s engraving of the Knight and the Devil which was probably inspired by one of Leonardo’s final drawings for the monument. All these indications show a pose in strong contrast with the original project. Leonardo has not attempted to rival the recent triumph of his master, the nervous swaggering Colleoni, but has gone back to Donatello’s Gattamelata, with its slow-pacing horse giving the authority of movement appropriate to a great commander. But Leonardo’s horse is lighter and more classical, partly owing to the influence of certain antique bronzes, an equestrian statue in Pavia, known as the Regisole and the horses of St. Mark, and partly to the living models which he found in the Sforza stables. Some of the beautiful drawings done from nature at this time show that horses could be found as well-knit and delicate as those idealized by antiquity (Pl. 30). This series of nature studies, for the most part in silverpoint, shows Leonardo’s style at its most attractive. The observation is delicate and direct; the handling fresh and decisive, without the slow deliberation which takes the bloom from his later drawings of horses. They were made between 1490 and 1493. In July 1493 Leonardo was still taking notes of horses worth drawing, and that autumn he constructed a full-scale model in clay. On 30 November this model was exhibited at festivities held on the marriage of Bianca Maria Sforza to the Emperor Maximilian.

  Leonardo had for some time been considering the casting of his colossus and has left several drawings relating to the work. But the casting did not take place. On 17 November 1494, Ludovico sent the whole of the bronze collected for the horse to his brother-in-law, Ercole d’Este. It was made into cannon. The full-scale model continued to stand in the Corte Vecchia of the Castello, where it was seen and admired by many famous visitors to Milan, who refer to it and the Last Supper in almost equal terms. According to Bandello Leonardo continued to work on it while painting the Last Supper, and this is confirmed by Sabba Castiglione’s statement quoted above. We have no evidence that Ludovico revived the project of casting it in bronze, and Leonardo does not again refer to work on it, but in an incoherent and fragmentary letter to the Duke he writes ‘of the horse I say nothing because I know that times are bad’. When the French entered Milan the connoisseurs expressed much admiration for the model: but the soldiers used it as a target. Finally it was taken to the Court of Ferrara, where it fell to pieces.

  It
is difficult for us to understand contemporary enthusiasm for the monument. Apart from the fact that it no longer exists, we can hardly believe that the model of a walking horse, however large and well contrived, could have given Leonardo the opportunity of displaying that gift of poetical evocation which seems to us the peculiar beauty of his work. But to the Renaissance, who valued his mastery of the means of expression more, perhaps, than the spirit expressed, the mere size of the horse was an impressive achievement. A great mass of inert matter had been given form and life. Moreover, he had established for the animal, which was second only to man in importance and ‘nobility’, a canon of perfection. His studies of the ideal proportion of the horse were known to his contemporaries,{51} and seemed to invest his model with that final authority which the Renaissance hoped to find in a union of antique art and mathematics. All this we can hardly realize from the few surviving drawings for the Sforza memorial: but when, twenty years later, Leonardo returned to the problem with the design for a monument to Marshal Trivulzio, we can follow in a relatively large series of drawings some of the calculations by which he strove for perfection.

  We have now reached what is commonly held to be the climax of Leonardo’s career as a painter, the Last Supper (Pl. 31). It is a point at which the student of Leonardo must hesitate, appalled at the quantity of writing which this masterpiece has already evoked, and at the unquestionable authority of the masterpiece itself. And almost more numbing than this authority is its familiarity. How can we criticize a work which we have all known from childhood? We have come to regard Leonardo’s Last Supper more as a work of nature than a work of man, and we no more think of questioning its shape than we should question the shape of the British Isles on the map. Before such a picture the difficulty is not so much to analyse our feelings as to have any feelings at all. But there are alternatives to the direct aesthetic approach. We may profitably imagine the day when the Last Supper did not exist, and Leonardo was faced with a blank wall and an exacting patron.

  The Last Supper was painted at the command of Ludovico il Moro for the refectory of the Convent of Dominican friars at Santa Maria delle Grazie, Milan. It was probably begun in 1495, but the archives of the convent have been destroyed and our meagre documents date from 1497 when the painting was nearly finished. On 29 June in that year the Duke sent a memorandum to his secretary Marchesino Stanga, asking him to order Leonardo the Florentine to finish the work begun in the refectory of the Grazie and then to see to the other end wall of the refectory.{52} This implies that work on the Last Supper was far advanced; and Pacioli, in the dedication of his Divina Proportion, dated 9 February 1498, speaks of it as if it had been completed. In compensation for the dearth of documents, we have several accounts of the work by eyewitnesses, including one by the novelist, Bandello, which, familiar as it is, I must quote again, for nothing else gives such a vivid idea of Leonardo at work.

  Many a time (he says) I have seen Leonardo go early in the morning to work on the platform before the Last Supper; and there he would stay from sunrise till darkness, never laying down the brush, but continuing to paint without eating or drinking. Then three or four days would pass without his touching the work, yet each day he would spend several hours examining it and criticizing the figures to himself. I have also seen him, when the fancy took him, leave the Corte Vecchia when he was at work on the stupendous horse of clay, and go straight to the Grazie. There, climbing on the platform, he would take a brush and give a few touches to one of the figures: and then suddenly he would leave and go elsewhere.

  Such irregular methods meant that the painting could not be al fresco; and in fact, we know that Leonardo used a medium containing oil and varnish. The wall was damp and as a result the painting very soon began to suffer. Already in 1517 Antonio de Beatis noted that it was an excellent work although it had begun to perish, either through the dampness of the wall or some other mischance; and Vasari, who saw it in May 1556, describes it as ‘so badly handled that there is nothing visible except a muddle of blots’. By 1642 Scanelli can write that of the original there remain only a few traces of the figures and those so confused that it is only with great pains that one can make out the subject. In face of such evidence it is hard to resist the conclusion that what we now see on the wall of the Grazie is largely the work of restorers. We know that the painting has been restored four times since the beginning of the eighteenth century, and was probably restored several times before. In 1908 it was thoroughly cleaned by Cavenaghi, who gave a most optimistic report on the picture, saying that only the Christ’s left hand was seriously repainted. He adds ingenuously that Leonardo was ahead of his time in that he seems to have employed a medium not usually found till the late sixteenth century. Cavenaghi was such a brilliant technician that his word is usually accepted, but in this case there is overwhelming evidence to prove that he was mistaken. It is inconceivable that a painting which by all accounts was a hopeless wreck in the sixteenth and seventeenth centuries could have survived till our own day more or less intact, and concrete evidence of restoration is provided by a comparison of the Apostles’ heads in the fresco with those in early copies. Perhaps the best examples are the two independent series of drawings at Weimar and Strasbourg, which were done direct from the original by Leonardo’s pupils, and show none of the personal variations which occur in a painted copy. Now these drawings agree in certain differences from the painting as we now have it, and in each case the drawing is clearly superior both in sentiment and design. Take four of the Apostles on the left of Christ. In the original, St. Peter, with his villainously low forehead, is one of the most disturbing figures in the whole composition; but the copies show that his head was originally tilted back in foreshortening. The restorer was unable to follow this difficult piece of drawing and has rendered it as deformity. He shows a similar failure to cope with an unusual pose in the heads of Judas and St. Andrew. The copies show that Judas was originally in profit perdu, a fact confirmed by Leonardo’s drawings at Windsor. The restorer has turned him round into pure profile, with considerable damage to his sinister effect. St. Andrew was almost in profile; the restorer has turned him into the conventional three-quarters. He has also made the dignified old man into an appalling type of simian hypocrisy. The head of St. James the Less is entirely the restorer’s invention, and gives the measure of his ineptitude.

  It is worth insisting on these changes because they prove that the dramatic effect of the Last Supper must depend entirely on the disposition and general movement of the figures, and not on the expression of the heads. Those writers who have complained that the heads are forced or monotonous have been belabouring a shadow. There can be no doubt that the details of the fresco are almost entirely the work of a succession of restorers, and the exaggerated grimacing types, with their flavour of Michelangelo’s Last Judgement, suggest that the leading hand was that of a feeble mannerist of the sixteenth century.{53}

  But in spite of the depressing insistence of these facts, some magic of the original remains, and gives the tragic ruin in Santa Maria delle Grazie a quality lacking in the dark smooth copies of Leonardo’s pupils. Luminosity, the feeling for atmosphere, which distinguishes all Leonardo’s genuine work from that of his pupils, must have distinguished the Last Supper also: and the fresco, perhaps from its very vagueness, has kept a certain atmospheric quality. As we look at them these ghostly stains upon the wall, ‘faint as the shadows of autumnal leaves’, gradually gain a power over us not due solely to the sentiment of association. Through the mists of repaint and decay we still catch sight of the superhuman forms of the original; and from the drama of their interplay we can appreciate some of the qualities which made the Last Supper the keystone of European art. We can recognize Leonardo’s power of invention by the simple means of comparing his treatment of the subject with any other which had preceded it. The Last Suppers of Ghirlandajo and Perugino, painted only a year or two earlier, show fundamentally the same composition as that which had satisfied the faithful f
or almost a thousand years. Eleven apostles sit on the far side of a table, each one quiet and separate. Sometimes they talk to each other, or drink their wine. Our Lord sits in the middle with St. John reclining uncomfortably on his lap. Alone, on the near side of the table, is Judas. We have seen how Leonardo’s departure from the traditional iconography of the Adoration involved a change in his whole interpretation of the drama. The same is true of the Last Supper. The older painters had represented the moment of communion, a moment of calm in which each apostle might wish to sit alone with his thoughts. Leonardo, as is well-known, chose the terrible moment in which Jesus says ‘One of you will betray me.’ Immediately this row of quiet individuals is unified by emotion.