by Martin Kemp
The decoration of the refectory was part of a campaign by the duke to aggrandize the Dominican monastery, which was close to Sforza Castle. In 1495, Giovanni Donato da Montorfano (c. 1460–c. 1502) had painted a large fresco of the Crucifixion on the opposite wall in the refectory, to which the portraits of Ludovico, Beatrice, and their two sons were later added, probably under Leonardo’s supervision. The great architect Donato Bramante (1444–1514) was adding a massive centralized crossing and dome to the rather old-fashioned church.
Few drawings for The Last Supper survive. These rapid sketches on a sheet at Windsor represent some of the artist’s earliest thoughts. The study at the top left shows that he was planning to separate Judas from Christ and the disciples in a conventional manner, placing him on the near side of the table. To the right of this sketch, Leonardo considers the incident in which Judas rises to dip his bread into the same bowl as Christ, which serves to announce that it is Judas who will betray him. Such narrative fluidity in planning the standard subject is highly unusual for the time.
The large geometrical construction of an octagon from a given line using a circle, below the figure sketches, was the first drawing on the page. It probably reflects Leonardo’s collaboration with Luca Pacioli and relates directly to the two small architectural sketches to the left, for a vault on an octagonal base. The two columns of numbers do not make obvious sense as a sum or sums, or as a proportional series. Might they be measurements? Similar sets of numbers are on the reverse of the page, together with some mechanical and architectural sketches.
“To the right . . . Leonardo considers the incident in which Judas rises to dip his bread into the same bowl as Christ, which serves to announce that it is Judas who will betray him. Such narrative fluidity in planning the standard subject is highly unusual for the time.”
34. The Last Supper
c. 1495–97, Milan, Refectory of Santa Maria delle Grazie
35. Saints Thomas, James the Greater, Philip, Matthew, Thaddeus, and Simon (detail from The Last Supper)
36. Study for St. James the Greater and Designs of a Domed Corner Pavilion for a Castle
c. 1496, Windsor, Royal Library, 12552
37. Study for the Head of St. Bartholomew or Matthew
c. 1496, Windsor, Royal Library, 12548
Leonardo’s majestic composition has been recognized as the definitive Last Supper, even though it had begun to deteriorate badly soon after its execution and became more widely known through drawn, painted, and engraved copies than via the original.
High on the wall, Leonardo has created a perspectival stage set for the profound drama. The geometric framework of the coffered ceiling and receding tapestries plunge into depth, perspectively converging on Christ at the calm focus of the spiritual turmoil. On either side, each of the disciples reacts with individualized shock to Christ’s terrible pronouncement that one of their number will betray him. In the Gospel of St. Mark, this incident is followed by the institution of the Eucharist, in which Christ informs his followers that the bread is his body and the wine his blood. Leonardo signals both pronouncements, as a kind of extended moment.
We seem to be presented with an illusion of the “large upper room” described in Mark 14, in which the disciples and Christ met on the eve of Christ’s arrest, but the space relates to that of the refectory in an ambiguous manner. The ideal viewpoint of the perspective construction is inaccessibly high above our heads. The coffered ceiling passes upward behind the screen of the three lunettes to an undetermined height, while the sidewalls cannot be continuous with those of the actual room if two disciples are to be seated at either end of the table. This ambiguity reduces the problem of the incongruous perspective of the painted space when it is viewed from a variety of positions in the refectory. We might also notice that there is not enough room for thirteen figures to be seated behind the table. Leonardo’s mural is a compelling contrivance and is not pretending to be a piece of literal reportage.
Saints Thomas, James the Greater, Philip, Matthew, Thaddeus, and Simon (detail from The Last Supper).
Study for St. James the Greater and Designs of a Domed Corner Pavilion for a Castle, c. 1496.
Study for the Head of St. Bartholomew or Matthew, c. 1496.
In the years before painting The Last Supper, Leonardo was much engaged with the dynamic systems of human motion and emotion in which the nerves convey sensory information to the central clearinghouse of the mind, which then transmits the resulting impulses of motion to the face, limbs, and body. Every individual expresses his or her own concetto dell’anima, the intention or purpose of one’s mind or soul, through a system of neurological plumbing that generates facial expressions, speech, and bodily actions. In The Last Supper, Leonardo has orchestrated the individualized reactions in groups of three in a brilliantly rhythmic manner.
Drawings for four of the disciples’ heads survive. They show how Leonardo was striving for sharp characterization and vivid spontaneity of reaction, probably sketching from life. The red chalk drawing for St. James the Greater (opposite page, top right) captures the young saint’s anxious terror. He starts back in revulsion at the thought of betrayal—“Is it I?” he asks—but inclines his head forward to see clearly Judas’s hand closing in on the bread that will signal his companion’s treachery. In the mural (see detail, opposite page, top left, second figure from the left) James’s arms are thrown wide, as if in anticipation of the Crucifixion. Accounts of Leonardo at work record that he spent many hours contemplating his creation, working out exactly these kinds of profound resonances.
The ink drawings on the bottom left of the same page as the red chalk portrait of St. James the Greater show Leonardo’s plans for what looks like a domed pavilion at the corner of a castle. Was this a feature planned for the suite of rooms in the castello that Ludovico was remodeling in the later 1490s, which was to include the Sala della Asse?
The deterioration of The Last Supper mural was recorded in the sixteenth century. The cause was Leonardo’s experimental technique. The traditional medium for murals was fresco, in which successive areas of paint are applied to fresh patches of moist plaster, bonding securely as the layers dry. Fresco demanded fast-paced execution of preplanned designs. It was also limited to those pigments that were compatible with the fresco medium. Leonardo’s contemplative pace of painting, his tendency to change his mind during the course of execution, and his personal way of handling light, shade, and color predisposed him to seek an alternative way of painting on a wall.
He decided on a technique that was close to that employed on wooden panels. He laid down an upper layer of fine plaster, on top of which he added a surface of white lead. Once this had dried, he painted in vivid colors, using egg as a binder. The original effect must have been sensational, but over the longer term, adhesion broke down between Leonardo’s layers of paint and priming on a wall that was subject to Milanese dampness.
Successive restorations over the centuries strove to rescue Leonardo’s visionary image, often involving much repainting. The most recent conservation effort, conducted over long years from 1977 to 1999, aspired to strip off all the added paint, leaving bright fragments of the artist’s original paint layers floating in softly tinted zones of added color that lend some overall coherence to the composition. Some remarkable effects emerged: the wonderfully succinct still life on the table; the embroidery and crisp folds of the tablecloth; the hooks from which the floral tapestries hang; and the facial expressions of those disciples’ heads that are least damaged.
We can supplement what is visible with the few drawings, such as that for St. James the Greater, and the wonderfully characterized profile study in red chalk on red paper (opposite page, bottom left), which is for St. Bartholomew at the extreme left of the mural or, less probably, for St. Matthew, third from the right.
That the mural should have survived at all is remarkable. In 1943, during an Anglo-American air raid, an incendiary bomb exploded nearby, demolishing the vault o
f the refectory and one sidewall. The Last Supper, protected by planks, sandbags, and scaffolding, somehow remained reasonably intact, as did the three lunettes, decorated with brilliantly naturalistic floral wreaths, surrounding the heraldic shields of Ludovico and Beatrice and their firstborn son, Massimiliano.
38. Four Grotesque Characters Mocking an Old Man
c. 1495, Windsor, Royal Library, 12495r
As a teller of painted stories, Leonardo was fascinated by the use of faces to convey appropriate characters and emotions. There were two factors involved: the fixed features or “signs” of the face; and the passing expressions that convey someone’s reaction to particular events. The fixed “signs” were the subject of the classical and medieval science of physiognomy, which typically drew parallels between human faces and those of animals (see also pages 13 and 113). Although Leonardo did not apply the formulas of physiognomics in a dogmatic manner, he was convinced that the workings of our minds could be reliably read from the combination of fixed and mobile features.
In tandem with his desire to capture the harmonic proportions of beautiful faces, Leonardo also made very extensive studies of physiognomies that departed radically from the norm. Quick pen sketches of grotesque heads of men and women, many elderly, proliferate erratically across his drawings and notebooks. Sometimes they are little more than impetuous scribbles; at other times they are closely observed, often pairing a man who exhibits bizarre features with a female counterpart. Leonardo recommended that the artist carry a small notebook to record extravagantly unusual characters. His grotesques were once very popular and were in tune with burlesque humor in Renaissance literature.
The drawing here is unusual in that it combines five elaborately characterized men in a way that implies a narrative. The central man, portrayed in Roman profile like an emperor on a coin, is crowned with a wreath of oak. He adopts a bemused air of dignity, like a king of fools, while his companions mock him in a variety of ugly ways. There is a drawing at Windsor in which an aged and pug-faced crone, accompanied by a grinning man, is reaching leftward, just as the central man here is reaching out to the right. Was Leonardo planning to unite them in a grotesquely improbable marriage? He once wrote rather unpleasantly that “there is no woman so ugly that she does not find a lover, unless she is monstrous.”
39. Two Human Skulls, Sectioned, with Proportional Analyses
1489, Windsor, Royal Library, 19057r
A set of eight skull studies on five pages at Windsor comprise the most coherent and purposeful of Leonardo’s early anatomical illustrations. One of them is dated 1489. It cannot be doubted that the drawings are based upon one or more actual skulls that Leonardo had sawn through and to which he added a schematic vertebral column. The bony structures are recorded with nuanced subtlety in parallel shading with a fine pen and brown ink.
The sectioning technique he employed in the studies is very remarkable, presenting an unprecedented view of exterior and interior morphology of the cranium and jaw. No one had yet demonstrated the frontal sinus in this way. The studies are not, however, straight exercises in descriptive anatomy, but are concerned with the divine “architecture” of the cranium and its relationship to the mental functions within.
In the upper drawing the artist was exploring the central “pole” of the cranium and its conjunction with the horizontal axis that runs diametrically across its equator. The proportional analysis exhibits a strong affinity with the system of geometry that underlies his architectural studies of centralized “temples” (see pages 86–87). We are invited to admire the “dome” of the skull as created by God, the supreme artifex (maker or designer) of all things in nature.
In the lower drawing Leonardo turned in more detail to the proportional music of the cranium. He wrote in the upper note that “where the line am is intersected by the line cb, there is the confluence of all the senses, and where the line rm is intersected by the line hf, there the pole of the cranium is located, at one-third of the base of the head, and so cb is one half.”
At the bottom of the page he added one of his characteristic notes of instruction: “remember when you represent this half head from inside make another shown from the outside oriented in the same direction as this one so that you may be better able to comprehend the whole.”
“The sectioning technique he employed in the studies is very remarkable, presenting an unprecedented view of exterior and interior morphology of the cranium and jaw. No one had yet demonstrated the frontal sinus in this way.”
40. Vertical and Horizontal Sections of a Human Head with a Vertical Section of an Eye and a Vertical Section of an Onion
c. 1489, Windsor, Royal Library, 12603r
At first sight, this highly schematic demonstration of the brain, eye, and cranial nerves in pen and red chalk seems to have little to do with the observational accuracy of the 1489 skull studies on page 72. However, Leonardo’s efforts to understand the internal functioning of the brain and senses are at one with his search for the structure and proportions of its protective container. On one of the skull studies (see page 72), he noted that the “confluence of all the senses” lies at the intersection of two of the key axes in the cranium.
His conception of the brain reworked traditional ideas, most notably that the ventricles or cavities were taken as the sites of mental activity. Without modern microscopy, the “gray matter” seemed unpromising and was thought to be no more than protection for the ventricles. The three ventricles were each assigned localized functions in the traditional manner. Leonardo’s preferred arrangement identified the first as the “receptor of impressions,” which took in data from all the senses. In the second ventricle was the senso comune (the “collective sense”), where information from all the senses was correlated, in company with the key faculties of imagination, intellect, and voluntary and involuntary motion. At the end of the system, the third ventricle acted as a flask to store memories. The soul, which was served by all the faculties, resided at the center of this neurological kingdom.
The horizontal section of brain at bottom right, in which a sectioned head is hinged open, shows the convergence of sight and hearing. Sight, as the “noblest sense,” operates though the geometrical instrument of the eye, acting as the “window of the soul” via a short optic channel. The round “crystalline humor” at the center of the eye is again traditional, and there was no sense at this time of the lens as a focusing device. Leonardo later injected the ventricles with wax and demonstrated their actual shapes (see pages 168–69).
To help us visualize the eight protective layers (including the hair) that surround the brain, he ingeniously provided a sketch of a sectioned onion.
41. Studies of Light and Shade on Spheres
c. 1490, Paris, Bibliothèque de l’Institut de France, MS Ashburnham II 13v
Florentine painters had pioneered the use of linear perspective to construct geometrical spaces, and they had developed systematic ways of describing light, shade, and cast shadows. Leonardo was the first to subject shadow to optical analysis.
In the illustrated example, he studies a sphere illuminated from a window. For the sake of his analysis, he takes four equidistant points across the aperture. The upper sector, designated m, will be brightest since it receives the impact of light from a, b, c, and d. Band n will “be seen” (as Leonardo put it) fully from b and c but incompletely from a and d. And so on, until q at the base of the sphere will receive no direct light. The shadows cast behind the sphere are graded in a corresponding manner, with a conical umbra and three degrees of penumbra. Leonardo knew, of course, that the actual effects were continuously graded, not banded, but he was demonstrating that proportional laws govern the intensity of illumination on different parts of an object, together with its “primary shadows” and its “secondary shadows.”
Shadows, he wrote, are “in the nature of universal things, which are more powerful at their origins and grow weaker towards the end.” In a notable act of lateral thinking, he compare
d the conical shadow to an “oak tree that is more powerful at the point of its emergence from the ground; that is to say, where it is thickest.”
The overarching rule is Leonardo’s pyramidal law, which determines that a dynamic motion diminishes in proportion to the distance from its origin. Thus, if a thrown ball will travel 10 yards (9 meters), when it has traveled 5 yards (4.5 meters) its speed will have diminished by half. Perspective works like this. Something that is 5 yards away will look twice as big as the same thing 10 yards away. Gravity also acts pyramidally, albeit in reverse, in that a falling body will gain proportional increments of speed.
42. Studies of the Angular Impacts of Light on a Man’s Profile and Three Illuminated Spheres
c. 1490, Windsor, Royal Library, 12604r
Leonardo is here proposing a rule for the intensity of light on an irregular body illuminated from a point source of light. A complex form like the human head presents a variety of planes to the impinging light. As always, Leonardo sought to apply mathematics to phenomena in the natural world.
He considered that light acts as a material force, striking or “percussing” any form that it strikes—much like a thrown ball or a sword striking a direct or glancing blow on a surface. The percussion will be most powerful when the light impacts perpendicularly, as at g (located at the depression on the man’s forehead). The points f and h (above and below g) will also exhibit something close to maximum illumination. It looks as if e (above f) will subtend at about a 45-degree angle to the surface, and the illumination on the surface there will therefore be about half that at f. As the angle diminishes, the impact of the light reduces proportionately.