The enthusiasm that surrounded Leonardo’s anatomical studies and would continue, even after his death, to influence progress in this field of scientific activities can be explained by the fact that the results he had achieved were so extraordinary as to bring knowledge of the human body and its representation to a wholly new level. Interest in anatomy was not, in itself, new for artists – certainly not for Florentine artists; and in this they had much in common with doctors. On his return to Florence, Leonardo had realized that young Buonarroti had independently performed numerous dissections, and had then succeeded in drawing them with a level of detail that was on a par with that of Leonardo himself. Following the tradition of Italian artists, Michelangelo had pursued in his anatomical studies the truth about the visible body, namely the outermost parts of muscle, bone and nerves shown in representation. On the contrary, Leonardo was interested in a far deeper level, one that was closer to dissections carried out by practising doctors, as he sought to understand the function of the internal organs, those responsible for the causes of diseases. The different aims of artists and doctors have been clearly identified by modern scholars:
In the case of Renaissance art, the aims and methods of artists and doctors were too diverse to be able to interact. Indeed, their horizons and approaches were completely different, and would remain so for centuries to come; while the artist explored the form and structure of the human body, as well as its range of movements, the doctor was interested above all in the more complex internal organs, which are the principal origin of disease.26
The work that Leonardo had accomplished in this field as early as the 1480s had moved clearly in the direction of medical rather than artistic research, and at the same time had been curtailed by the prejudices and limits imposed in this area of study by the authority of medieval tradition. While Michelangelo (and perhaps Verrocchio before him), unimpeded by theoretical prejudice, drew and ‘saw’ exactly what he was dissecting on the marble table of the hospital of Santo Spirito, Leonardo, like many doctors, used these dissections to check medieval theories of how the human body worked. Some of his extraordinary drawings, complete with notes, illustrate the prevalence of this approach to anatomy, which was still medieval, and the fact that Leonardo, although subsequently mythologized as the forerunner of modern science, did not depart significantly from his contemporaries. Only Vesalius, in his treatise of 1543, would lay the basis for a new knowledge of anatomy that was to mark the dividing line between the old and the new, between medieval and modern, not unlike Copernicus with the theory of the Earth’s rotation. Yet it is also true that, when tracing Leonardo’s studies over the course of two decades, there is evidence not only of his gradual detachment from medieval theories and of the onset of a critical spirit that tended to free dissection from the theoretical prejudices of earlier treatises, Mondino’s in particular; it can also be seen how far Leonardo perfected the framework of knowledge throughout this process and drew closer to the synthesis that Vesalius would undertake 30 years later.
In his method of dissecting bodies and organs, Leonardo introduced a painter’s sensitivity that aided his comprehension of the dissected object and gave the graphic representation of the organ under investigation an unprecedented clarity. The capacity to control the representation of space allowed Leonardo’s anatomical drawings to make a qualitative leap that amply justifies the enthusiasm shown for these plates by both the artist and his contemporaries. Even before Vesalius, Leonardo seems to have understood that the progress of anatomic knowledge called for a highly sophisticated drawing technique, in which artistic sensitivity played an essential part. Once again, and without his realizing it, it was his artistic nature that allowed him to make progress in his work as an anatomist. After the overblown nineteenth-century exaggerations about the genius of Leonardo, who seemed to have invented and understood everything, we have now reached a more balanced conclusion about the real substance of Leonardo’s anatomical studies: without exaggeration, it is now believed that Leonardo did indeed renovate a number of dissection methods, and ‘the anatomical structures that he was the first to describe can be clearly identified, as well as some techniques that he introduced, such as mid-sagittal sections of the skull, the spine, the thorax, the pelvis, and transverse sections of the limbs’.27
Alongside this stimulating innovation, which was prompted by his method of artistic enquiry, learned in all probability during the years spent in Verrocchio’s workshop, and by his own interests, Leonardo brought to medical illustration a talent and a technical ability that had never been seen before in medicine. Carlo Pedretti drew attention to this, in straightforward terms, in his comments on the anatomical drawings from the late 1480s, writing with reference to the sections of the skull [Plate 49]:
There is no doubt that these drawings owe their incomparable artistic quality not only to the outstanding technical mastery of their execution and to an innate pictorial sense of form in space, but specifically to the scientific precision with which what is seen is absorbed and reproduced with absolute objectivity and attention to detail. It is therefore correct to talk of a miracle of precision and clarity in the most minute particulars, such as the dots used to indicate the spongiform matter of the dissected bone and the way in which sutures are represented with foreshortening (see the drawing on the verso). Therefore, when observing the start of the cut on the crown of the skull, where the two edges seem slightly parted, one immediately realizes that the teeth of the saw had to find the right angle before continuing with a decisive and steady cut right to the end.28
The detail noted by Pedretti is important for understanding the spirit in which Leonardo approached the study of anatomy in the late 1480s: on the one hand, there was a psychological filter in the form of the medieval and late classical theories through which he interpreted what he was actually dissecting; on the other, his artistic training as a superb copyist of nature (we need only think of the plaster-soaked fabrics drawn in Verrocchio’s bottega and the plants and flowers illustrated in his paintings) obliged him to record the minutiae of the body in painstaking detail and to resist the urge to show an idealized image, as an engraver or a draughtsman would have done when working for an anatomist. The lack of a precise join in the skull due to the teeth of the saw and to that first, uncertain act of dissection would have been eliminated by a professional anatomist’s draughtsman, but in Leonardo’s drawing it is preserved because his ingrained habit of recording the natural world cannot ignore any detail.
The duality of his recordings, at once ideal and naturalistic, becomes the principal reason for the fascination exercised by his drawings: they are as accurate as anatomical plates, but at the same time they lack that abstraction that the anatomist requires from his assistant draughtsman or engraver (as Vesalius would do, 30 years later). Of course, this visual excellence was coupled with a special technical talent for representation, the decision of the graphic line in the skull’s curves, the perfect identification of the light sources and the softly blended shadows in the chiaroscuro that allows him to re-create completely the ‘internal’ spatiality of the object – in this case the skull, which becomes an object of great beauty in itself, with its lights and shadows and forms as regular as a wicker basket filled with acanthus leaves. Never until Leonardo had there been an artist with such medical expertise or a doctor with such artistic ability.
It is precisely in this rather simple combination that we find the hypnotic fascination of his anatomical drawings. Those by Michelangelo, although the product of the same talent for seeing and representation, fall short by comparison because their sole purpose is artistic representation: Michelangelo showed no interest in medicine that went beyond the prescriptions for his kidney stones and the rhubarb he took for his digestive problems. From this we can understand why it was that Leonardo’s drawings are astonishing even when they betray a distinct lack of knowledge of anatomical function, as in the case of the famous drawing of the genito-urinary tract [Plate 50].
During this first phase of his anatomical studies Leonardo was not yet able to throw off the burden of authority and showed respect, indeed often reverence, in his adaptations, to the point of always using Mondino’s Anothomia as a guide during his own dissections. It was Mondino who, in keeping with Galenic teaching, described the two ducts in the penis (one for the passage of the vital spirit or soul, the other for sense-perception and for urine) and the seven cells of the womb, as they can be seen in this drawing. But the way of illustrating the curve of the vertebral spine is original to Leonardo, and he would return to it in a drawing of 1510 in the series of the so-called Ms. A of Anatomy [Plate 51].29 Contrary to everything that has been said over the past two centuries regarding Leonardo’s ability to anticipate the evolution of science, this drawing, with its paradoxical section of the penis and its dual imaginary canals, shows how Leonardo’s desire to verify the reality of the human body through experience was not sufficient, since he continued to see with his own eyes, in part, what classical authorities had taught him to see.
The influence of medieval prejudices on Leonardo’s mind is also apparent from the comments he made on testicles in the same drawing, which a completely unfounded popular tradition regarded as being the source of strength and virility: ‘How testicles are the cause of passion’. Likewise his repulsion for the other sex transpires from the remaining comments. The beauty of the young man and the almost non-existence of a physiognomy of the woman remind Pedretti of a comment noted on a sheet from 1510, which shows sketches of various hands: ‘The act of coitus and the parts used for this purpose are so ugly that if it were not for the beauty of the faces and ornaments of those engaged in the act [addendum above the line: and their unrestrained attitude] Nature would lose the human species’ [Plate 52].30 It is clear that, when Leonardo refers to the ugliness of the genital organs, he is thinking of the female genitalia rather than the male ones, to which he dedicated delightful witticisms, like that of the monk and the washerwoman. A note in the upper right-hand corner underlines Leonardo’s disgust for the physical union between man and woman: ‘these drawings will demonstrate the reason for many risks of injuries and illnesses’ – perhaps an allusion to the infections that some have associated with syphilis – a recent arrival in Europe – but that seem more generally to connect the dangers of intercourse to sexual pleasure.
Later on, during his years in Rome – in which he did not give up his anatomical studies – Leonardo showed a dangerous tendency to forge ahead with his critical judgement: when studying the relationship of the fetus with the mother he even came to cast doubt on the Aristotelian theory of the generation of the soul, which had been adopted by the church and reiterated by Pope Leo X. For his contemporaries, this brush with theological positions would be a mark of the artist’s heretical leanings in old age, which would be documented both in the first edition of Vasari’s Lives of the Artists (although they would disappear from the second) and in Lomazzo’s writings, giving rise to a crescendo of imaginary reports in the next centuries and fuelling outlandish legends about the artist’s studies of magic, the occult sciences and much else besides. Nothing could be further from the truth. Paola Salvi gives a balanced summary of Leonardo’s final achievements in his anatomical studies when she compares his work (which was unfortunately never known to contemporaries) to that of Vesalius. The treatise on anatomy published by the latter in 1543 is generally regarded as a turning point, one that closed an era and opened another, like the work of Copernicus; and she summarizes its key traits as follows:
The simultaneous presence of vast erudition and a critical relationship with the classical sources; the safe option offered by direct research on the human body as a source of knowledge; the integration of such precise – and artistically esteemed – illustrations into the text to stimulate research; the collaboration between the scientist and a typographical art at the highest technical level.31
But all these unique qualities – as scholars have noted – are already present in the work of Leonardo da Vinci. Unfortunately he was unable to bring his work to the attention of his contemporaries owing to the dispersion of his notebooks and the volume of disordered sheets and notes he left at his death.
The exile undergone by Leonardo’s brilliant anatomical studies affected both his artistic anatomy and the anatomy conventionally described as human, while his thought had circulated mainly through the Libro di pittura in the abridged edition of 1651 (judging by what we know now). Therefore it was Vesalius and Michelangelo who acquired renown as the pillars on which anatomical treatises for artists were based – the first by providing the analytical model for the description of the parts, the second by offering an interpretation of the greatness of the edifice of the human body through sculptural models, which could be easily integrated and compared with examples taken from classical statuary. Thus, through the plates engraved by Carlo Cesio and through the treatise of Bernardino Genga, not to mention the ‘real-life’ anatomical studies made during training, artists got engaged in a kind of anatomical research in which the cognitive component was weaker than the normative [precettistica], but the strongest results were nonetheless reminiscent of Leonardo’s penetrating method.32
There is no doubt that Leonardo was aware of how much he had achieved in the field of anatomy, and this explains his anxiety and happiness when, at Easter 1508, he announced to Francesco Melzi their shared project. Unfortunately, however, the artist once again made the kind of mistake that dogged his entire life: he relied too much on the protection of powerful patrons. On this occasion he turned to a king, Louis XII of France, who at the time seemed to hold the key to Europe’s destiny but who, within the space of a few short months, thanks to the intelligence of a pope who had no armies but excellent advisors, would become a marginal figure on the chessboard of Italian politics – to the point of not being able as much as to guarantee Leonardo’s position in Milan.
This time the illusion lasted for just over a year. The artist was paid a regular stipend, about 30 scudi a month, by the French government until April 1509, and the one who benefited from this in the first place was Salai. In July 1509 Louis XII returned to Milan after the triumph at the battle of Agnadello, and Leonardo was again able to stage one of those festivities that had made him famous. It took the form of a combat, in a public square, between the lion and the dragon, in which the former symbolized the republic of Venice and the latter the French state. But the lion was also a fox and was already planning an alliance that would corner the dragon. Leonardo himself derided the arrogance of Venice when he jotted down a remark that seemed, to him and many others, the boastful claim of braggarts: the Serenissima had announced that its coffers were deep enough to afford a war that could last for ten years and cost up to 36 million in gold [ducats]. But the news was taken extremely seriously by Pope Julius II, who had turned precisely to Venetian bankers to finance his wars by pledging the papal tiara. Julius had never pardoned Louis XII for calling a schismatic council at Pisa; and he engineered a complete reversal of Italy’s political alliances by forming the Holy League of October 1511, which brought together the papacy and Venice, along with the Swiss cantons, the king of Naples, Ferdinand of Aragon, and, after some hesitation, Maximilian of Austria, who was still holding Ludovico il Moro’s sons at Innsbruck. The destiny of the French was cast, and with it that of the state of Milan – and Leonardo’s.
These were difficult months. D’Amboise died on 10 March 1511 and the new governor was not on such familiar terms with Leonardo. Francesco Melzi’s father stepped in to protect him by hosting him at Vaprio d’Adda, in the family villa on the river, in the middle of lush woods and far from the disorders of the city. But even this solution was not an easy one. Salai was unpopular with everyone: traces of annoyance and of the arguments caused in the small household by the all too obvious relationship between the rapacious young assistant and the old master, who no longer had the strength to turn down the young man’s increasingly invasive demands, can be found in Leonardo’s accounts as well as in some mocking drawings made by pupils in Leonardo’s codices. An offensive sketch in the Codex Atlanticus dates from precisely these months: in it, alongside Salai’s name, someone has added a roughly sketched orifice penetrated by a male member. One of the most controversial drawings also dates from the same period, revealing more clearly than anything the tensions created by Salai’s presence in the house, and above all his relationship with the master [Plate 53]. It shows the figure of a youth, standing in a three-quarters pose and holding his hand up to his chest while he points upwards with his right hand, in a gesture that would later be copied in the Saint John now in the Louvre. The sketch represents Salai and was made by one of Leonardo’s pupils, who returned to studies done by the master for the project of a youthful Saint John that he had already imagined during his Florentine years: the saint had his left hand on his chest while the right held a bowl, symbol of the future baptism. Leonardo almost certainly never made a painting of this figure, but at least a copy of the design has survived and is now in the Galleria Borghese in Rome [Plate 54].
The pose, the gentle inclination of the face and the studies for the left hand can be found in sketches made by the master and his pupils, all datable to the Florentine period between 1503 and 1506. The features of the face leave little doubt that the model for the study (and the painting) was, once again, Salai, the Satyr who had enchanted Leonardo. The negative reaction to this enchantment is evident in the large phallus that an anonymous pupil has drawn, quite clearly, between the young man’s legs. This member and its forceful erection emphatically draw attention to the real nature of the attraction that the angelic Salai exerted over Leonardo, offering the observer a visible and unmistakeable contrast between the sweetness of the face and the brutality of the instrument of pleasure. The nature of the drawing would appear to exclude the presence of Leonardo’s hand even in the upper part. In all likelihood, one of his pupils copied a drawing that Leonardo had made of Saint John holding the bowl, but ‘completed’ it with a male member in the lower part, adding an ironic reflection on the qualities of the handsome Salai. Considering the burlesque nature of the drawing, and its timing, it is possible to suggest that the drawing was made by Tommaso Masini, also known as Zoroastro, who lived with Leonardo for many years, both in Milan and in Florence, and collaborated in 1506 with the first attempts to transport the Battle of Anghiari onto the wall of the Palazzo della Signoria.33
No one had any illusions about the nature of the relationship between Leonardo and Salai and about the price that Leonardo paid for it. The house and vineyard that Ludovico il Moro had given Leonardo, located close to his Last Supper, were now lived in by Salai’s father, and the other pupils struggled to put up with his arrogance. The gossip that had given rise to those cruel sonnets about Leonardo’s preferences ten years earlier started to circulate again. Vox populi, carefully ignored by the sixteenth-century exegetes, would explode in an ironic dialogue between Phidias and Leonardo written by Giampaolo Lomazzo, who, as an artist and a Lombard, was able to discover details of events earlier in the century through the Melzi family and other witnesses. In blunt terms, Lomazzo described the carnal passion that bound Leonardo to the young Salai, although even Vasari was careful to comment only on his exceptional beauty:
Leonardo Salai was the one I loved most in my life, and there were many.
Phidias And did you ever play the game from behind that Florentines love so much?
Leonardo And how many times! Just think how beautiful he was, especially when he was about fifteen.
Phidias Are you not ashamed to say these things?
Leonardo Ashamed? Why? There is nothing that is more praised than this among the virtuous; and I will demonstrate that this is true using very good reasons.34
Girolamo Melzi, Francesco’s father, knew how to tolerate and shield from scandal Leonardo’s sexual inclinations, which were not particularly original for the time, and he protected him even when the Swiss began to set fire to the countryside around Milan. In those days the French army was like a bear attacked by a pack of hounds. Leonardo watched the fires lit by the Swiss in disbelief, realizing that his own future was also going up in smoke, together with any hope of concluding his studies. His host, Girolamo Melzi, began talks with the representatives of the new regime as the armies continued their relentless advance. In a rearguard action and a stroke of good luck, the French won the bloody battle of Ravenna on 11 April 1512, and for a few days Leonardo deceived himself that he could return to live in what he regarded as his city, the only one where he had friends and a house.
Cardinal Giovanni de’ Medici, Lorenzo’s son, was brought to Milan as an illustrious prisoner. He had been sent to the battlefield by Julius II, as the cardinal legate, but had fallen into the hands of the French. At Milan, the cardinal was treated with great respect and he, too, made every effort to win the goodwill of the king and his dignitaries, all of whom had come under Julius II’s interdict, by granting whatever forms of spiritual immunity lay within his power. Giovanni was little more than a boy (he was born in 1475) when Leonardo had left Florence; but he was after all a Medici. From Milan the cardinal was transferred to France, but as he was travelling into exile he was freed by a small army of peasants and returned to the armies of the League, by then closer to victory. Even his liberation was seen as a good augury, a sign that Fortune was by then determined to punish the French.
Conditions in Milan rapidly deteriorated, as they also did in Tuscany, which was accused in no uncertain terms of abetting the French, as Leonardo knew too well. Giovanni de’ Medici, soon to become Pope Leo X, and his brother Giuliano, the only one in the family to possess political acumen, rapidly took advantage of this political earthquake and opened negotiations with the League officials in Mantua for the restoration of the Medici rule in Florence. To give his city and its surrounding territory a clear sign of the ire that awaited those who rebelled against the Medici, the cardinal led the Spanish troops in person as they besieged Prato in August 1512. The resistance of the local militia was overcome on 29 August. The sack of the town, which came after a siege rendered even more brutal by the summer heat and by the fields scorched by peasants, was one of the most horrific episodes of Italian history. The future pope deliberately turned his head while soldiers engaged in outrageous acts of cruelty. Reports of citizens being skinned alive and boiled and of the mass rape of boys and girls were soon doing the rounds of Italy. The atrocities were toned down in the diplomatic prose in which Giuliano brought the news of the town’s capture to Isabella d’Este, who had given hospitality first to Leonardo and then to the Medici brothers.
Leonardo read both versions of the revolution: the accounts told by the terrorized escapees and those that filled the diplomatic correspondence. Like other figures of the time, Leonardo seems hardly to have reacted to the first: the atrocities of war were a recurrent and perhaps necessary evil, on which he might have reflected in technical rather than humanitarian terms. In the autumn of 1512 a new possibility opened up, perhaps a new illusion, but nonetheless an unhoped for opportunity for him to find powerful new protectors. The Medici returned to Florence immediately after the sack of Prato, while the air was still thick with smoke from the fires that burnt in the not too distant town. Soderini had been promptly dismissed and the city celebrated the entry of Giuliano and Giovanni as if for years it had been waiting for nothing else. In the name of his old friendship with Lorenzo, Leonardo could rely on the support of Lorenzo’s sons. Once Soderini’s supporters, with whom Leonardo had not been on his best behaviour, were removed, the new government could welcome Leonardo back to his native city.
The atmosphere in Milan had become distinctly chilly with the onset of winter, and the change of regime meant that everyone had to realign with the victors, who in this instance were the old masters. On 29 December 1512 the legitimate son of Ludovico il Moro, Massimiliano Sforza, made his triumphal entry into the city, accompanied by his half-brother Cesare, son of the same Cecilia Gallerani whom Leonardo had painted years earlier, just before she became pregnant. Girolamo Melzi – Francesco’s father and Leonardo’s protector – successfully swapped allegiances and once again entered the services of the Sforza, whom he had previously abandoned. But things were much more difficult for Leonardo. In the early winter of 1513 the artist weighed up the possibility of leaving Milan for Florence. It would not be an easy move, because there were all the notebooks to take, dozens upon dozens of volumes that he was trying to reorganize with the help of young Francesco; there were unfinished paintings, including the wonderful Saint Anne, which had already been copied and recopied by his pupils and sold to Milanese collectors. But fate tempted him with an extraordinary event.
The aged Julius II, the warrior pope, died in early February and on 9 March Giovanni de’ Medici was elected as his successor. Before that election Leonardo had never felt so close to the summit of power, even when he had been welcomed and defended by the king of France. The Medici had been his patrons since his youth, and later on he would write in a couplet: ‘The Medici created me and destroyed me.’ But, right then, his only thought was for the greatness and friendship of the family. The festivities given by Leo X on the occasion of his election and coronation immediately became an object of amazement and admiration, and all the more so for Leonardo, who regarded himself as the leading expert and producer of courtly celebrations. The city was bedecked with tapestries and garlands and embellished with painted triumphal arches, and fistfuls of gold coins were thrown by boys turned for the occasion into winged genii and suspended from ephemeral structures, rapidly erected in Rome: all this was reminiscent of a splendour that Leonardo had known since infancy, with the jousts organized by Lorenzo in Florence, the mounted processions of the Magi, the gold and jewels displayed by the retinues of dignitaries. No one in Europe could surpass the Medici in organizing celebrations and in the promotion of art; and, despite his age, his disappointments, and the cumbersome presence of his unfinished works, the 60-year-old artist was certainly not lacking in either curiosity or enthusiasm.
The invitation to move to Rome came from the pope’s brother, Giuliano, and it could not have been otherwise. Over the decades Leo X had built up a reputation for his munificence and for the elegance of his feasts, but it was Giuliano who paid the bills, as his biographers were keen to point out. If Leo X embodied the spendthrift side of the family, Giuliano had inherited the refined taste for art and culture for which his father and grandfather had been renowned. There was very little time to organize his journey south, and Leonardo arrived in Rome before the gold dust had even settled after dancing in the air during the festivities held in September for the pope’s coronation and for his brother Giuliano. Leonardo and his small household had set off on another adventure: ‘Left Milan for Rome on the 24th day of September 1513, with Giovanni, Francesco de Melzi, Salai, Lorenzo and il Fanfoia.’35 This time they were leaving to conquer the city of cities: Rome.