Summary

Leonardo da Vinci (Italian: Leonardo di ser Piero da VinciListen, known as Leonardo da Vinci), born on April 14, 1452 in Vinci (Tuscany) and died on May 2, 1519 in Amboise (Touraine), was an Italian polymath, artist, organizer of shows and parties, scientist, engineer, inventor, anatomist, sculptor, painter, architect, town planner, botanist, musician, philosopher, and writer.

The natural child of a peasant woman, Caterina di Meo Lippi, and a notary public, Pierre de Vinci, he was raised by his paternal grandparents in the Vinci family home until the age of ten. In Florence, his father enrolled him for a two-year apprenticeship in a scuola d'abaco and then in the workshop of Andrea del Verrocchio where he worked with Botticelli, Perugino and Domenico Ghirlandaio.

He left the workshop in 1482 and presented himself mainly as an engineer to the Duke of Milan Ludovico Sforza. Introduced to the court, he obtained a few painting commissions and opened a workshop. He studied mathematics and the human body. He also met Gian Giacomo Caprotti, known as Salai, a ten year old child, a turbulent student in his workshop, whom he took under his wing.

In September 1499, Leonardo left for Mantua, Venice and returned to Florence. There he repainted and devoted himself to architecture and military engineering. For a year, he made maps for Caesar Borgia.

In 1503, the city of Florence commissioned him to paint a fresco, but he was relieved of this task by King Louis XII of France, who called him to Milan where, from 1506 to 1511, he was the sovereign's "ordinary painter and engineer". He met Francesco Melzi, his pupil, friend and executor. In 1504, his father died, but he was excluded from the will. In 1507, he was usufructuary of the lands of his deceased uncle.

In 1514, after a retreat to Vaprio d'Adda, Leonardo worked in Rome for Giuliano de' Medici, brother of Leo X, abandoning painting for the sciences and a project to drain the Pontine marshes. In 1516, Francis I invited him to France to the manor of Cloux with Francesco Melzi and Salai. He brought with him the Mona Lisa, which was probably finished on the spot and has survived the centuries as one of the most famous pictorial works in the world, if not the most famous. Leonardo died suddenly at Clos Lucé in 1519. His friend Francesco Melzi inherited his paintings, his notes and shared with Salai the vineyards that Leonardo had received from Ludovico Sforza.

Leonardo da Vinci was one of the so-called "polymaths" of his time: he mastered several disciplines such as sculpture, drawing, music and painting, which he placed at the top of the arts. Leonardo embarked on a meticulous study of nature and human expression: an image must represent the person, but also the intentions of his mind. He provides on his paintings a meticulous work of retouching and corrections using techniques specific to oil painting, hence the existence of unfinished paintings and his failures in painting frescoes. His studies are reflected in the countless drawings in his notebooks: drawing is, for this tireless graphomaniac, a true means of reflection. He records his observations, plans and caricatures which he uses when needed for engineering work or for the making of a painting.

Although Leonardo da Vinci is best known for his painting, he also defined himself as an engineer, architect and scientist. The knowledge initially useful for painting became for him an end in itself. His interests are numerous: optics, geology, botany, hydrodynamics, architecture, astronomy, acoustics, physiology and anatomy.

However, he had neither the education nor the research methods of a scientist. However, his lack of university training freed him from the academicism of his time: claiming to be a "man without letters", he advocated praxis and analogy. However, with the help of some scientists, he started writing scientific treatises, more didactic and structured, often accompanied by explanatory drawings. His search for automatism is opposed to the notion of work as the cement of social relations.

Leonardo da Vinci is often described as the symbol of the universal spirit of the Renaissance, the uomo universale or a scientific genius. But it seems that Leonardo himself exalts his art in order to gain the trust of his patrons and the freedom to carry out his research. Moreover, the biographers of the 16th century write very dithyrambic accounts of the life of the master, who was then known mainly for his paintings. Only the transcription of the Codex Atlanticus and the discovery of more than 6,000 sheets of his notes and treatises at the end of the 18th century bring Leonardo's research to light. Historians of the 19th and 20th centuries perceived him as a kind of genius or prophet of engineering. In the 21st century, this image is still very present in the popular imagination. However, in the 1980s, historians questioned the originality and validity of most of the master's research. However, the great quality of his graphic art, both scientific and pictorial, is still undisputed by the greatest historians and art critics, and many books, films, museums and exhibitions are devoted to him.

Childhood

Leonardo da Vinci was born on the night of Friday, April 14, 1452, between nine and ten thirty in the evening. According to tradition, he was born in a small tenant's house in the Tuscan village of Anchiano, a hamlet near the town of Vinci, but perhaps he was born in Vinci itself. The child was the result of an illegitimate love affair between Messer Piero Fruosino di Antonio da Vinci, a 25 year old notary and descendant of a family of notaries, and a 22 year old woman named Caterina di Meo Lippi.

Ser Piero da Vinci came from a family of notaries for at least four generations; his grandfather even became chancellor of the city of Florence. However, Antonio, father of Ser Piero and grandfather of Leonardo, married a notary's daughter and preferred to retire to Vinci to lead a peaceful life as a country gentleman, taking advantage of the income from the farms he owned in the town. Even if some documents name him with the particle Ser, he is not officially entitled to this title in the official documents: everything seems to prove that he has no diploma and that he has never even exercised a defined profession. Ser Piero, Antonio's son and Leonardo's father, took up the torch of his ancestors and found success in Pistoia and then in Pisa before settling in Florence around 1451. His office was located in the Palazzo del Podestà, the building of the magistrates that faced the Palazzo Vecchio, the seat of government, then called Palazzo della Signoria. Monasteries, religious orders, the city's Jewish community and even the Medici called on his services.

Although described by the biographer Anonimo Gaddiano as a "daughter of a good family", Leonardo's mother Caterina is traditionally thought to be the daughter of poor peasants and therefore far removed from the social class of Ser Piero. According to the disputed conclusions of a 2006 fingerprint study, she could be a slave from the Middle East. However, since 2017, research carried out on communal and parish documents or on tax registers tends to identify her with Caterina di Meo Lippi, daughter of small farmers, born in 1436 and orphaned at the age of 14.

Leonardo seems to be baptized the Sunday after his birth. The ceremony took place in the church of Vinci by the parish priest, in the presence of notables of the city and important aristocrats of the surroundings. Ten godparents - an exceptional number - witnessed the baptism: all of them lived in the village of Vinci and among them was Piero di Malvolto, the godfather of Ser Piero and owner of the farm where Leonardo was born. The day after the baptism, ser Piero returns to his business in Florence. In doing so, he arranged for Caterina to marry quickly with a local farmer and boiler maker who was a friend of da Vinci's family, Antonio di Piero del Vaccha, known as "Accattabriga (brawler)": perhaps he did this to avoid gossip for abandoning a mother and child. It seems that the child stayed with his mother for the time of his weaning - about 18 months - and then was entrusted to his paternal grandfather, with whom he spent the next four years, accompanied by his uncle Francesco. The maternal and paternal families remained on good terms: Accattabriga worked in an oven rented by ser Piero and they regularly appeared as witnesses in contracts and notarial acts for each other. In fact, the childhood memories recounted by the adult Leonardo allow us to understand that he considers himself a child of love. He writes about himself: "If coitus is done with great love and great desire for each other, then the child will be of great intelligence and full of spirit, vivacity and grace.

At the age of five, in 1457, Leonardo joined his father's family home in Vinci. The house, with a small garden, was a well-to-do one in the heart of the city, right next to the castle walls. Ser Piero married the 16 year old daughter of a rich cobbler in Florence, Albiera degli Amadori, but she died in childbirth in 1464. Ser Piero married four more times. From the last two marriages his ten brothers and two legitimate sisters were born. Leonardo seems to have good relations with his successive mothers-in-law: thus, Albiera has a particular affection for the child. In a note, he also describes his father's last wife, Lucrezia Guglielmo Cortigiani, as a "dear and sweet mother".

Leonardo was not raised by his parents: his father lived mainly in Florence and his mother took care of the five other children she had after her marriage. Instead, it was his uncle Francesco, 15 years his senior, and his paternal grandparents who provided his education. Thus, her grandfather Antonio, an avid idler, gave her a taste for observing nature, constantly repeating to her "Po l'occhio! ("Open your eyes!")". His grandmother Lucia di ser Piero di Zoso was also very close to him: a ceramist, she was perhaps the person who introduced him to the arts. Moreover, he received a rather free education with the other villagers of his age in which he learned to read and write.

Around 1462, Leonardo joined his father and Albiera in Florence. Although his father considered him as his own son from birth, he did not legitimize Leonardo, who was therefore unable to become a notary. Moreover, belonging to an intermediate social category between dotti and non-dotti, he could not attend one of those Latin schools where classical letters and humanities were taught: they were reserved for future members of the liberal professions and merchants from good families of the early Renaissance. At the age of ten, he entered a scuola d'abaco (a "school of arithmetic") for the sons of merchants and artisans, where he learned the rudiments of reading, writing, and especially arithmetic. The normal course of study was two years, and Leonardo left the school around 1464, the year he was twelve years old - the age at which he was sent as an apprentice to the workshop of Andrea del Verrocchio. His spelling, described as "pure chaos" by the historian of science Giorgio de Santillana, thus testifies to his shortcomings. Similarly, he did not study Greek or Latin, which, as exclusive supports for science, were nevertheless essential to the acquisition of scientific theory: he learned Latin - and even then, imperfectly - only as an autodidact, and only at the age of 40. For Leonardo, above all a free thinker and opponent of traditional thought, this incomplete education will remain a sensitive subject thereafter: faced with the attacks of the intellectual world, he will willingly present himself as a "man without letters", disciple of experience and experimentation.

Training at the workshop of Verrocchio (1464-1482)

Around 1464 - or 1465 at the latest - when he was about twelve years old, Leonardo began an apprenticeship in Florence. Sensing a strong aptitude, his father entrusted him to the workshop of Andrea del Verrocchio. In fact, Ser Piero da Vinci and the master already knew each other: Leonardo's father performed several notarial acts for Verrocchio; moreover, the two men worked not far from each other. In his biography of Leonardo, Giorgio Vasari relates that "Piero took some of his drawings and brought them to Andrea del Verrocchio, who was a good friend, and asked him if the boy would benefit from studying drawing. Verrocchio "was very surprised by the boy's particularly promising beginnings" and accepted him as an apprentice, not because of his friendship for ser Piero but because of his talent.

A renowned artist, Verrocchio was a polymath: a goldsmith and blacksmith by training, he was also a painter, sculptor and founder, but also an architect and engineer. As with most Italian masters of his time, his workshop was simultaneously in charge of several commissions. In addition to wealthy merchants, his main client was the wealthy patron Lorenzo de' Medici: he created mainly paintings and bronze sculptures, such as The Incredulity of St. Thomas, a tomb for Cosimo de' Medici, decorations for festivals, and took care of the conservation of ancient works for the Medici. In addition, in this workshop, they discussed mathematics, anatomy, antiquities, music and philosophy.

An inventory of the goods present in the place evokes, in no particular order, several tables and beds, a globe and books - collections of classical poems translated by Petrarch or Ovid, or humorous literature by Franco Sacchetti. The first floor is reserved for the store and its workshops; the upper floor provides accommodation for the craftsmen and apprentices who work there. In this place where masters and students met, Leonardo had Lorenzo di Credi, Sandro Botticelli, Perugino and Domenico Ghirlandaio as fellow students.

In fact, far from being a refined art studio, this bottega is a store where many art objects are made and sold: the sculptures and paintings are mostly unsigned and are the result of a collective work. Its primary objective is to produce works for sale rather than to promote the talent of one or another artist. Verrocchio seems to be a good and humane master, leading his workshop in a collegial manner to the point that many of his students, such as Leonardo or Botticelli, still stay with him several years after their apprenticeship.

Like all the newcomers to the studio, Leonardo was an apprentice (Italian: discepolo) and performed the most humble tasks (cleaning brushes, preparing materials for the master, sweeping floors, grinding pigments and ensuring that varnishes and glues were cooked). Gradually, he was allowed to transfer the master's sketch onto the panel. Then he becomes a journeyman (Italian: garzone): he is entrusted with the work of ornamentation or execution of secondary elements such as decoration or landscape. Depending on his abilities and progress, he can then carry out entire parts of the work.

Orders - creation of the copper sphere of the Dome

He discovered the ancient technique of chiaroscuro (Italian: chiaroscuro) which consists of using contrasts of light and shadow to create the illusion of relief and volume in two-dimensional drawings and paintings. While he was learning how to make colors, Leonardo experimented with mixing pigments with high proportions of transparent liquids in order to obtain translucent colors and thus study and model the gradations of draperies, faces, trees and landscapes: this is the technique of sfumato, which gives the subject imprecise outlines with the help of a glaze or a smooth and transparent texture.

Verrocchio also asked his pupil to complete his paintings, including the painting Tobias and the Angel, where he drew the carp being held by Tobias and the dog walking behind the angel on the left. Verrochio, more versed in the art of sculpture, is known for his representations of animals generally considered "unimportant" and "weak". It is therefore not surprising that the master entrusted the realization of the animals to his pupil Leonardo, whose keen sense of observation of nature seems obvious. However, for Vincent Delieuvin, this collaboration seems possible, but is not irrefutable, because it is based on conventional arguments: Verrocchio or the young Perugino are just as capable of drawing naturalistic themes in this way.

Leonardo also studied perspective in its geometric aspect, with the help of the writings of Leon Battista Alberti, and in its luminous aspect through the effects of aerial perspective. This technique, applicable only to oil painting, also allows him to shape his volumes and lighting in a more fluid way, and even to modify his paintings according to his ideas. This is why he does not try his hand at frescoes, which are too fixed and unchanging once they are placed on a wall or ceiling. It is probably for this lack of specific skills that he will not be invited to paint the walls of the Sistine Chapel in Rome between 1481 and 1482 with his fellow artists Botticelli, Perugino or Ghirlandaio.

In 1470, in The Baptism of Christ, Leonardo painted the angel on the far left, and partially completed other elements of the painting. X-ray analysis shows that a large part of the decoration, the body of Christ and the angel on the left, are made of several layers of oil paint with highly diluted pigments. According to Giorgio Vasari, Leonardo created a figure "so superior to all the other figures that Andrea, ashamed of being surpassed by a child, never wanted to touch his brushes again," an anecdote that historical research confirms.

In 1472, at the age of twenty, Leonardo completes his apprenticeship and can thus become a master. He seems to be on good terms with his father who still lives near the workshop with his second wife, but still without any other children. On the occasion of this completion, his name appears with those of Perugino and Botticelli in the Red Book of debtors and creditors of the Company of St. Luke, that is to say, in the register of the guild of painters of Florence, a sub-guild of that of doctors. In spite of this, he decided to remain in Verrocchio's workshop: in 1476, Leonardo was still mentioned there. He produced many decorations, devices or disguises for shows and festivals commissioned by Lorenzo de' Medici, including a standard for Julian de' Medici for a joust in Florence, or a mask of Alexander the Great for Lorenzo de' Medici.

In the summer of 1473, he returned to Vinci, where he seemed to find his mother, her husband Antonio, and the couple's children: "I am content to stay with Antonio", he wrote in his notes. On the back of the sheet of paper on which he wrote this passage is probably the earliest known art drawing by Leonardo: dated "Day of Our Lady of the Snows, August 5, 1473", it is an impressionistic panorama, sketched in pen and ink, showing a rocky relief and the green valley of the Arno, near Vinci - but it could just as well be an imaginary landscape. In addition to his mastery of different types of perception - in particular that which he later called "aerial perspective" - this sketch shows only a landscape, usually placed as a decoration: here it is the main theme of the work. As a good observer, Leonardo depicts nature for itself.

Court records from 1476 show that along with three other men, a denunciation accused him of sodomy with a prostitute Jacopo Saltarelli, a practice that was then illegal in Florence. All were acquitted of the charges, probably thanks to the intervention of Lorenzo de' Medici. This incident will be for many historiographers an indication of the homosexuality of the painter.

It was also in the 1470s that four paintings are mainly attributed to him: an Annunciation, ca. 1473-1475, two Madonna and Child (The Madonna with the Carnation, ca. 1472-1478, and The Madonna Benois, ca. 1478-1480), and the avant-garde portrait of a Florentine woman, Portrait of Ginevra de' Benci (ca. 1478-1480), in which Leonardo seems to have mastered oil painting and the technique of strongly diluted pigments more and more. In 1478, Leonardo received his first commission for an altarpiece for the chapel of the Palazzo della Signoria. Historians have only the preparatory drawings; they seem to have been used for the Adoration of the Magi, which he was commissioned to paint in 1481 and which he also left unfinished.

The Milanese years (1482-1499)

In 1482, Leonardo da Vinci was about thirty years old. He left Lorenzo the Magnificent and Florence to join the court in Milan. He will stay there for 17 years. The reasons for his departure are not known and art historians are reduced to speculating. Certainly he found the atmosphere around Ludovico Sforza more conducive to artistic creation, the latter wanting to make the city he had just taken over the "Athens of Italy". Perhaps he was also bitter about not having been selected for the team of Florentine painters responsible for creating the decorations for the Sistine Chapel. Moreover, Vasari and the author of the Anonimo Gaddiano assure that the painter was then charged by Lorenzo the Magnificent to offer his correspondent a lyre made of silver and shaped like a horse's skull, which Leonardo played perfectly. Finally, Leonardo arrived with the hope of deploying his talents as an engineer, as evidenced by a letter he had written to his host describing various inventions in the military field, and, incidentally, the possibility of creating architectural works, sculpted or painted.

However, it is rather his quality of artist that is first recognized since the court qualifies him as "Apelle Florentine", in reference to the famous Greek painter of Antiquity. This title gave him the hope of finding a position and thus receiving a salary instead of simply being paid by the work. Despite this recognition, commissions did not come because he was not sufficiently established in Milan and did not yet have the necessary connections.

He then met a local painter, Giovanni Ambrogio de Predis, who was well introduced to the court and who allowed him to make himself known to the Milanese aristocracy. De Predis offered Leonardo a place to stay in his studio and then in the house he shared with his brother Evangelista, whose address was "Parish of San Vincenzo in Pratot intus". The relationship was fruitful, since in April 1483 he was commissioned, together with the Predis brothers, to paint a picture by a local brotherhood; it was The Virgin of the Rocks, intended to decorate an altarpiece for a chapel recently built in the church of San Francesco Maggiore. As a mark of recognition of his status, he was the only one of the three artists to bear the title of "master" in the contract. Leonardo thus established, soon after his arrival in Milan, his own bottega within which collaborators such as Ambrogio de Predis or Giovanni Antonio Boltraffio, and pupils such as Marco d'Oggiono, Francesco Napoletano and later Salai, evolved.

In 1490, he met the great Sienese polymath Francesco di Giorgio Martini in Milan on the occasion of the architectural consultation for the erection of the lantern tower of the Duomo of Milan, commissioned by Ludovico Sforza. Francesco di Giorgio Martini then took Leonardo with him to Pavia, where he was called to consult on the cathedral in Piazza del Duomo.

Back in Milan, Leonardo must have seen his position improve slowly but steadily. He became the "organizer of festivals and shows" given at the palace and invented theatrical machines that were successful. The pinnacle of his achievements, dating from 1496, is "a masterpiece of theatrical machinery for Danae by Baldassare Taccone in the palace of Giovan Francesco Sanseverino, where the lead actress is transformed into a star". More widely, his activity as an engineer was known, but he had to work hard to have it recognized. The plague episode in Milan in 1484-1485 was an opportunity for him to propose solutions to the theme of the "new city" that was then emerging. In 1487, Leonardo took part in a competition for the construction of the lantern tower of the cathedral of Milan and presented a model during 1488-1489. His project was not accepted, but it seems that some of his ideas were taken up by the winner of the competition, Francesco di Giorgio. So much so that in the 1490s he became, along with Bramante and Gian Giacomo Dolcebuono, a leading urban and architectural engineer. In fact, the Lombard archives readily refer to him as "ingeniarius ducalis", and it was in this capacity that he was sent to Pavia.

During this time, Leonardo devoted himself to technical-scientific studies, whether they concerned anatomy, mechanics (clocks and looms) or mathematics (arithmetic and geometry), which he noted scrupulously in his notebooks, certainly in order to draw up systematic treatises. In 1489, he prepared a book on human anatomy entitled De la figure humaine. He studied the different proportions of the human body, which led him to produce the Vitruvian Man, which he drew based on the writings of the Roman architect and writer Vitruvius. However, even though he defined himself as a "man without letters", Leonardo showed in his writings anger and incomprehension at the contempt in which he was held by doctors because of his lack of academic training.

Between 1489 and 1494, he also worked on an imposing equestrian statue in honor of Francesco Sforza, Ludovico's father and predecessor. At first he planned to make a moving horse. However, given the difficulties of such a project, he was forced to give up and return to a more classical solution, like that of Verrocchio. Only a huge clay model was made on April 20, 1493. But the 60 tons of bronze needed for the statue were used to cast cannons for the defense of the city against the invasion of the French king Charles VIII. The clay model was nevertheless exhibited in the Sforza palace and its creation contributed considerably to Leonardo's reputation at the Milan court. This led to his appointment to carry out several works in the palace, including a heating system and several portraits. It was during this period that he painted the portrait of Cecilia Gallerani, known as The Lady with an Ermine (1490), a Portrait of a Milanese Lady (known as La Belle Ferronnière), a Woman in Profile (certainly with Ambrogio de Predis), and perhaps the Madonna Litta, whose final execution on panel is attributed to Giovanni Antonio Boltraffio or Marco d'Oggiono. It is probably the Lady with an ermine that is decisive in Leonardo's engagement as a court artist. Among the commissions is the famous fresco The Last Supper executed in the refectory of the cloister Santa Maria delle Grazie. The clay horse was used as a training target and destroyed by the French mercenaries of Louis XII who invaded Milan in 1499.

On July 22, 1490, in a note written in a notebook dedicated to the study of light that served as his logbook, Leonardo indicated that he had taken in a ten-year-old child, Gian Giacomo Caprotti, in his studio in exchange for a few florins given to his father. The child quickly accumulated misdeeds. Thus Leonardo notes about him: "Thief, liar, stubborn, glutton"; from then on the child earns the nickname of Salai, from the contraction of the Italian Sala. However, the master was very fond of him and could not imagine parting with him. From then on, historians have wondered about the exact relationship between the forty-year-old and this child, then teenager with such a perfect face, and many from the 16th century onwards have seen this as confirmation of his homosexuality - and at the very least, of his taste for bad boys. Despite his poor artistic qualities, Salai was integrated into the painter's studio.

In 1493, Leonardo was forty years old. He notes in his tax documents that he is taking in charge, at his home, a woman named Caterina. He confirms this in a notebook: "On July 16

Finally, in the 1490s, some fragmentary documents suggest a conflict between Leonardo and Ambrogio de Predis and the brotherhood that had commissioned The Virgin of the Rocks for the church of San Francesco Maggiore: the painters complained that they were not being paid fairly and the commissioners that they had not received the work they had commissioned, even though it had been scheduled for December 1484 at the latest. This situation led the artists to sell the painting to a higher bidder: probably Ludovico Sforza himself, who offered the painting to the Emperor Maximilian or the King of France. In any case, a second version of the painting (now exhibited at the National Gallery in London) was painted between 1495 and 1508 and in the 16th century decorated the altarpiece of one of the chapels of the church of Saint Francis Major.

Years of wandering (1499-1503)

In 1499, Leonardo da Vinci was a painter living in Milan with Ludovico Sforza. Nevertheless, his life entered an important transitional phase: in September 1499, Louis XII, who claimed rights to the Visconti succession, invaded Milan and the painter lost his powerful protector, who fled to Germany to his nephew, Emperor Maximilian of Austria. He then hesitated about his allegiances: should he follow his former protector or turn to Louis XII who quickly made contact with him? Nevertheless, the French are quickly hated by the population and Léonard takes the decision to leave.

He then began a wandering life that led him in December 1499 to the court of the Duchess Isabella d'Este in Mantua. The art historian Alessandro Vezzosi hypothesizes that this was the final destination of his journey initially chosen by the painter. He painted a portrait of the Marquise at her request, but his free spirit was thwarted by the easily tyrannical nature of his hostess: he did not receive any further commissions from the court and, in March 1500, he set off again for Venice.

Although he stayed only a short time in Venice - since he left in April 1500 - he was employed there as an architect and military engineer to prepare the defense of the city, which feared an Ottoman invasion. Paradoxically, two years later he offered his services as an architect to the Turkish sultan, Bayezid II (the grandfather of Suleiman the Magnificent), who did not follow up. He did not paint in the city of the Doges but took care to present the paintings he had brought with him.

He finally returned to his native region and to Florence: a bank document has come down to us indicating that he withdrew 50 gold ducats from his account on 24 April 1500. It seems that he was first accommodated by the Servite monks of the city in the convent of the church of the Santissima Annunziata, of which his father was one of the procurators and which enjoyed the protection of the Marquis of Mantua. He was commissioned to paint an altarpiece depicting the Annunciation to decorate the high altar of the church. Filippino Lippi, who had already signed a contract to this effect, withdrew for the master, but the latter produced nothing.

In addition, he most likely brought back a carton, Saint Anne, the Virgin, the Child Jesus and Saint John the Baptist as a Child, which had been started very recently. It is a project of a "Trinitarian St. Anne", which was started, according to the hypotheses, to mark his return to his native city, or even "to impose himself on the artistic scene. When exhibited, it was a great success: Gorgio Vasari wrote that the Florentines "flocked to see it for two days". In the summer of 1501, Leonardo began The Madonna of the Spindle for Florimond Robertet, Secretary of State to the King of France.

In spite of these painting works, Leonardo da Vinci declared that he preferred to devote himself to other fields, in particular technical and military ones (clocks, looms, cranes, defensive systems for cities, etc.), and he was more willing to proclaim himself an engineer than a painter. Moreover, his stay with the Servite monks was an opportunity for him to participate in the restoration of the Church of San Salvatore al Vescovo, threatened by a landslide. He was also consulted on several occasions as an expert: to study the stability of the bell tower of the Basilica of San Miniato al Monte or when choosing the location for Michelangelo's David.

In fact, this was a period in which he showed a certain disdain for painting: in a letter dated April 14, 1501, in which he responded to the pressing requests of the Duchess of Mantua to obtain a portrait from the master, the Carmelite monk Fra Pietro da Novellara indicated that "mathematical experiments had so distracted him from painting that he could no longer bear the brush". However, this testimony must be put into perspective because Fra Pietro had to answer to Isabella d'Este, a likely ruler, who was impatient to obtain a painting by the master: how could his impatience be tempered if not by arguing that Leonardo was repulsed by painting? Finally, Leonardo seemed to be able to afford to refuse to work for such a prized Renaissance patron, since he was living off his savings in Milan. From April 24, 1500 to May 12, 1502, Leonardo remained mostly in Florence, but his life remained erratic. On April 3, 1501, Fra Pietro de Novellara testifies as follows: "His existence is so unstable and uncertain that one would say he lives from day to day.

In the spring of 1502, while working for Louis XII and for the Marquis of Mantua François II, he was called to the service of César Borgia, known as "le Valentinois", whom he had met in 1499 in Milan and in whom he thought he would find a new protector. On August 18, 1502, Cesare Borgia appointed him "architect and general engineer" with full authority to inspect the cities and fortresses of his domains. Between the spring of 1502 and, at the latest, February 1503, he travelled through Tuscany, the Marches, Emilia-Romagna and Umbria. Inspecting the newly conquered territories, he made plans and drew maps, filling his notebooks with his many observations, maps, working sketches and copies of works consulted in the libraries of the cities he crossed. During the winter of 1502-1503, he met the spy from Florence, Nicolas Machiavelli, who became his friend. In spite of the title of engineer of which he had dreamed, he finally left Caesar Borgia without the reasons for this decision being known: premonition of the Condottiere's imminent fall? Proposals from the Florentine authorities? Or dislike for the crimes of his protector? Whatever the case, Leonardo freed himself from the Valentinois in the spring of 1503. However, he did not immediately return to Florence, since he took part the following summer as an engineer in the siege of Pisa led by the Florentine army: he then took on the task of diverting the Arno River in order to deprive the rebellious city of water, but the attempt was a failure.

Second Florentine period (1503-1506)

In October 1503, Leonardo was once again established in Florence: he re-joined the Guild of Saint Luke - the city's painters' guild. He began to paint the portrait of a young Florentine woman named Lisa del Giocondo. The painting was commissioned by her husband and wealthy Florentine silk merchant Francesco del Giocondo. The portrait, known since then as the Mona Lisa, was completed around 1513-1514. While Leonardo turned away from the requests of the Duchess of Este, the acceptance of this commission has raised questions among scholars: perhaps it is the consequence of the link of personal knowledge between Francesco del Giocondo and Leonardo's father.

His return to the city was immediately marked by a prestigious commission from the city's councillors: he was to create an imposing mural commemorating the battle of Anghiari, which in 1440 saw Florence's victory over Milan. The work was to decorate the Great Council Chamber (now called the "Hall of the Five Hundred") located in the Palazzo Vecchio. The realization of the cartoon of The Battle of Anghiari will occupy a large part of the time and thoughts of the master for the years 1503 to 1505. Since Michelangelo received a concomitant commission on the opposite wall for The Battle of Cascina, the two painters worked in the same place. Michelangelo had always been hostile to him and the Anonimo Gaddiano reports that relations between the two men - who were aware of each other's genius - were becoming increasingly bitter. Despite this open rivalry, it appears that the young artist strongly influenced Leonardo (the reverse being less true), as evidenced by the studies of muscular male bodies, he who repelled these "austere nudes without grace, which look more like a bag of nuts than human figures. It was certainly under the influence of Michelangelo's work, and in particular his David, that Leonardo intensified his studies on human anatomy.

Six months after the beginning of his work, when the painter had already completed a part of his carton, a contract was drawn up by the sponsors, perhaps worried by the painter's reputation for never completing his projects. He was thus required to finish before February 1505 or face penalties for delay. In the end, neither he nor Michelangelo completed their work. He would thus complete only the central group - the struggle for the standard - which may remain hidden under frescoes painted in the mid-sixteenth century by Giorgio Vasari. His scheme is known only through preparatory sketches and several copies, the most famous of which is probably that of Peter Paul Rubens. Michelangelo's painting is known through a copy made in 1542 by Aristotele da Sangallo.

Still in 1503, the conflict with the commissioners of The Virgin of the Rocks continued: Leonardo had left his work (later called the "London version") unfinished when he left Milan in 1499, so that Ambrogio de Predis had to put his hand on it. Nevertheless, still complaining of being poorly paid, the artists submitted a request to the King of France on March 3 and 9, asking for a new salary supplement.

On July 9, 1504, Leonardo's father died: "On July 9, 1504, a Wednesday, at seven o'clock, died ser Piero da Vinci, notary in the palace of the Podestà, my father - at seven o'clock, aged eighty, leaving behind him ten boys and two girls. Sign of his trouble, despite a somewhat detached handwriting, he makes some mistakes: his father died at 78 years old and July 9 falls on a Tuesday; also, contrary to his habit, he does not write in mirror. Léonard is excluded from the inheritance because of his illegitimacy.

During this period, he resumed his anatomical studies at the Santa Maria Nuova hospital. There he worked on the cerebral ventricles and improved his technique of dissection, anatomical demonstration and his representation of the different planes of the organs. He even planned to publish his anatomical manuscripts in 1507. But, as with most of his work, he did not go through with it.

On April 27, 1506, in his legal dispute with the Milanese brotherhood of the church of San Fransesco, which commissioned The Madonna of the Rocks, the arbitrators appointed by the latter noted that the work was not finished and gave the artists - Leonardo and Giovanni Ambrogio de Predis - two years to complete their work.

Despite the strict contract binding him to his commission, the painter was asked on May 30, 1506 to leave his work on The Battle of Anghiari: Charles d'Amboise - the lieutenant general of King Louis XII, Florence's powerful ally - asked him to Milan for other artistic projects. The Florentine authorities reluctantly granted the painter a three-month leave of absence. Leonardo seemed to be fine with this: having experimented with a new type of painting on his fresco, inspired by Roman encaustic, the work had been damaged; he seemed to lack the courage to return to it. Moreover, thanks to this intervention in Milan, Leonardo was able to temporarily free himself from his Florentine obligations to resume work on The Virgin of the Rocks in Milan. The French authorities obtained a new postponement of the work until the end of September, then December 1507. In fact, the master did not return to his work.

Second Milanese period (1506-1513)

The reasons why Leonardo so easily left his work on The Battle of Anghiari are probably multiple: the pettiness of the patron, as Giorgio Vasari asserts; the insurmountable technical problems associated with his experiments on the work; the distended ties with his family - and hence with the city - following the legal actions brought by his brothers to disinherit him after the death of his father (the move to Milan imposed by the follow-up to the dispute opposing him to his patrons of The Virgin of the Rocks; the awareness that the kingdom of France, which sought him out, was more powerful and stable than Florence, whose economy and power were fragile; the awareness of his high artistic value, which allowed him to hope for an increase in prestigious commissions.

In any case, the letters sent to the gonfalonier of Florence, Pier Soderini, by Charles d'Amboise, on December 16, 1506, and then by King Louis XII, on January 12, 1507, are unequivocal: Leonardo would no longer work for Florence but for France; the Florentine authorities could only comply. It was therefore in this capacity that the master returned to Milan: in 1507, Louis XII made Leonardo his "ordinary painter and engineer" and granted him a regular salary, probably the best he had ever received.

The years of this second Milanese period remain rather unclear to scholars. However, they do know that in 1506 or 1507 he met Francesco Melzi, a young man from a good family then aged about fifteen, who was to remain a faithful pupil until the end of his life, a friend, his executor and his heir.

For two years he also made short trips back and forth between Milan and Florence. In March 1508 he was still in Florence, staying in the house of Piero di Braccio Martelli with the sculptor Giovanni Francesco Rustici; a few weeks later he returned to Milan, at the Porta Orientale in the parish of San Babila. In fact, it was not until September 1508 that he left Florence for Milan for good.

On his return to the Lombard capital, while continuing his anatomical studies, he resumed work on the painting of the Saint Anne, which he had abandoned for the creation of The Battle of Anghiari, and seems to have practically completed it between 1508 and 1513.

Leonardo's uncle, Francesco, died in 1507. In his will, he made his nephew Leonardo the heir to his farmland and two adjoining houses in the vicinity of Vinci. But the will was contested by Leonardo's half-siblings, who began legal proceedings. Leonardo appealed to Charles d'Amboise and, through Florimond Robertet, to the king of France to intervene in his favor. All reacted favorably, but the judgment did not progress. The lawsuit ends with a partial victory of Léonard who, with the support of the cardinal Hippolyte d' Este, brother of Isabelle, obtains only the usufruct of the property of his uncle and the money which it brings; the enjoyment of this property having to return to his half-brothers with his death.

On his return to Milan, after completing the painting of The Virgin of the Rocks on October 23, 1508, for which he received - after 25 years of legal disputes - the final payment, Leonardo abandoned his profession as a painter for that of researcher and engineer and rarely painted again: perhaps a Salvator Mundi (dated after 1507 but whose attribution remains debated), La Scapigliata (1508) and Leda and the Swan (but, this may be a studio painting done by an assistant between 1508 and 1513) and Saint John the Baptist as Bacchus and Saint John the Baptist, begun after 1510 and certainly completed while he was in Rome.

On his return from his military campaigns in May 1509, Louis XII made him the organizer of celebrations in the Lombardy capital: Leonardo distinguished himself in particular during the triumph of the King of France in the streets of Milan. He was interested in the effects of light and shadow on objects. He was also employed as an architect and hydrological engineer in the construction of an irrigation system.

Around 1509, stimulated by his meeting with the Lombard professor of medicine Marcantonio della Torre, with whom he collaborated, he continued his studies on human anatomy: resuming dissections, he studied the urogenital system, the development of the human fetus, the blood circulation and discovered the first signs of the process of arthrosclerosis. He also made numerous trips to the Santa Maria Nuova Hospital in Florence where he enjoyed the support of the doctors for his studies.

Charles d'Amboise died in 1511. King Louis XII gradually loses his influence on Milan and the Sforza gradually recover the duchy. Leonardo therefore lost his main protector in the person of Charles and decided to leave Milan. This marked the beginning of a period of several years during which he was in search of a new patron. In 1512, he stayed not far from Milan, in Vaprio d'Adda, in the "Villa Melzi", the family property of the parents of his pupil Francesco Melzi; he was also accompanied by Salai, who was now 35. Leonardo was 60 years old, far from the political turmoil of Milan, and he gave architectural advice on how to furnish the Melzi's large house, dissected animals (for lack of human bodies), finished a geology booklet (the Leicester Codex) and improved the paintings he had taken with him.

Stay in Rome (1514-1516)

In September 1513, Milan gradually came back under the influence of the Sforzas and Rome welcomed the Florentine John de Medici, newly elected pope under the name of Leo X. Aesthete, bon vivant, eager to surround himself with artists, philosophers, people of letters, and favorable to the kingdom of France, he called upon Leonardo da Vinci to work in Rome with Julian de Medici, his brother. Leo X and Julian were the sons of Lorenzo de' Medici, Leonardo's first benefactor when the painter was still in his infancy in Florence. Leonardo was installed in the Belvedere Palace, the summer palace of the popes built thirty years earlier. An apartment was transformed to accommodate his lodgings, those of his students and his studio, which was equipped with the tools necessary for the production of colors. There he found the books and paintings he had left in Milan and had sent to Rome. The gardens of the palace allowed him to study botany and were also the setting for his favourite farces, for which he was responsible for the creation of several stage sets.

Leonardo seems to have had a distant but friendly relationship with his siblings at this time. In a letter found in his notes, he seems to have interceded in the difficult acquisition of a benefit - a paid position within the Church - for his older half-brother, then a notary in Florence. Other letters have been found that highlight the somewhat strained relationship between him and one of the younger brothers.

While in Rome, Raphael and Michelangelo were very active at this time and commissions for paintings followed one another, Leonardo seemed to refuse to take up the brush again, even for Leo X. He marks his will to be considered as an architect or a philosopher. Baldassare Castiglione, an author and courtier close to Leonardo, described him as "one of the best painters in the world, who despises the art for which he has such a rare talent and prefers to study philosophy. In fact, the only things that seem to connect him to painting are his further studies of color mixing and the sfumato technique, which allowed him to continue the meticulous retouching of the paintings he took with him. Among these are the Mona Lisa, the Saint John the Baptist and the Bacchus, probably his last painted works. He was also interested in mathematics, astronomy and concave mirrors and their possibilities of concentrating light to produce heat. He also managed to dissect three human bodies, which allowed him to complete his research on the heart. Although this practice did not cause any scandal, it did seem to cause a certain amount of commotion in the court circles and Leonardo was soon discouraged from pursuing this activity.

As Leonardo was interested in the sciences of engineering and hydraulics, he was involved, in 1514 or 1515, in a project to drain the Pontine marshes located 80 kilometers southeast of Rome, commissioned by Leo X to Julian de Medici. After visiting the area, Leonardo drew up a map of the region - to which Francesco Melzi added the names of the villages - with the various rivers to be diverted in order to bring the water to the sea, before they fed the swamps. The works began in 1515, but were immediately interrupted in the face of the disapproval of the local populations and were definitively stopped at the death of Julian in 1516.

It seems that Leonardo's stay in Rome was a period of depression for him because of refusals of commissions that interested him and conflicts with a German assistant whom he considered lazy, inconstant and not very loyal. This situation contributes to making him physically ill and very irritable. He may have suffered one of his first strokes, which would lead to his death a few years later - but this information is disputed. In 1516, he wrote down a bitter formula in a notebook, "i medici me crearono edesstrussono". This has been variously understood because it presents a play on words in its original language, as the term medici can refer to both "Medici" and "doctors": does Leonardo mean "The Medici created me and destroyed me" or "The doctors created me and destroyed me"? In any case, the note underlines the disappointments of his Roman stay. Perhaps he thinks that he will never be allowed to give his best on an important building site; or perhaps he complains about the "destroyers of life" that the doctors would be for the patient that he would be.

Last years in France (1516-1519)

In September 1515, the new king of France, Francis I, reconquered Milan at the battle of Marignano. On October 13, Leonardo attended the meeting between Pope Leo X and the French king in Bologna. Following the example of his predecessor Louis XII, the latter asked the master to move to France. Still loyal to Julien de Medici, Leonardo did not respond to this invitation. Nevertheless, March 17, 1516 marked a turning point in his life as Julien de Medici, who had been ill for a long time, died, leaving him without an immediate protector. Noting the lack of interest from any powerful Italian, he chose to settle in the country that had been asking for him for so long.

He arrived in the second half of the year in Amboise. He was then 64 years old. The king installed him in the manor of Cloux - today's Château du Clos Lucé - in the company of Francesco Melzi and Salai: he received a pension of 2,000 ecus for two years and his two companions 800 ecus and 100 ecus respectively. His Milanese servant, Battista da Villanis, also accompanied him. The sovereign, for whom the presence in France of such a prestigious guest was a source of pride, named him "first painter, first engineer and first architect of the king".

On October 10, 1517, Leonardo was visited by the Cardinal of Aragon; the travel diary of his secretary, Antonio de Beatis, is a precious testimony of the master's activities and state of health. The diary indicates that Leonardo, suffering from paralysis of the right arm, was no longer painting but was still making his pupils work efficiently under his direction; moreover, it states that Leonardo presented him with three of his major paintings, Saint John the Baptist, Saint Anne, the Virgin and Child Jesus Playing with a Lamb and the Mona Lisa, which he had brought from Italy; finally, it also presents a large number of works that he had written, devoted in particular to anatomy, hydrology and engineering.

Researchers wonder what King Francis I was looking for in this old man with a paralyzed right arm, who no longer painted or sculpted and who had put aside his scientific and technical research: At the most, he created in September 1517 an automaton lion for the king and organized festivities, such as the one given from April 15 to May 2, 1518 for the christening of the Dauphin; he thought about the king's urban projects, who dreamed of a new castle in Romorantin and planned to embellish some of the castles on the Loire; he worked on a project for canals linking the Loire and the Saône; finally, he put the finishing touches to some of his paintings, notably his Saint Anne, which he left unfinished at his death. Perhaps the king simply enjoyed conversing with him and was satisfied with his prestigious presence at his court.

In 1519, Leonardo was 67 years old. Feeling that his death was near, he had his will drawn up on April 23, 1519 before a notary in Amboise. Because of his position with the king, he managed to obtain a letter of naturality, which allowed him to circumvent the right of windfall, that is to say the automatic seizure by the king of the property of a foreigner who died without children on French soil.

According to this will, the vineyards once given to Leonardo by Ludovico the More are divided between Salai and Batista de Villanis, his servant. The land that the painter had received from his uncle Francesco is bequeathed to Leonardo's half-brothers - thus respecting the compromise reached at the end of the trial in which they had contested Francesco's inheritance in favor of the painter. His servant Mathurine receives a black coat with fur edges.

Francesco Melzi, finally, inherits "all the books that the testator has in his possession and other instruments and drawings of his art and his painting works". Researchers have long wondered about Salai's financial well-being after the death of the master: he would in fact have received many possessions in the early months of 1518 and would not have hesitated to sell some of them to Francis I during Leonardo's lifetime, such as his painting of the Saint Anne.

Leonardo died suddenly on May 2, 1519 at Le Clos-Lucé. What Gorgio Vasari describes as a "final paroxysm, messenger of death" is probably an acute stroke.

The tradition reported by Giorgio Vasari according to which Leonardo died in the arms of Francis I is probably based on one of the chronicler's exaggerations: on March 31, 1519, the Court was two days' walk from Amboise, at the Château de Saint-Germain-en-Laye, where the queen was giving birth to the future Henry II, royal orders were issued there on May 1 and a proclamation was published on May 3. The diary of François I does not mention any trip of the king until July. However, the proclamation of May 3 was signed by the chancellor and not by the king, whose presence is not mentioned in the council's records. Twenty years after Leonardo's death, Francis I said to the sculptor Benvenuto Cellini: "There has never been another man born in the world who knew as much as Leonardo, not so much in painting, sculpture and architecture, as he was a great philosopher.

In accordance with Leonardo's last wishes, sixty beggars carrying candles followed his coffin. He was buried in a chapel of the collegiate church of Saint-Florentin, located in the heart of the castle of Amboise. Nevertheless, the building was dilapidated by time, and in particular during the revolutionary period, and was destroyed in 1807; the tombstone then disappeared. The place was excavated in 1863 by the writer Arsène Houssaye who discovered bones that he linked to Leonardo da Vinci. These were transferred in 1874 to the Saint-Hubert chapel located not far from the present castle.

Leonardo da Vinci was trained in Florence by Andrea del Verrocchio in a number of different techniques and notions such as engineering, machinery, mechanics, metallurgy and physics. The young man was also introduced to music, studied superficial anatomy, mechanics, drawing techniques, engraving, the study of light and shadow effects and, above all, studied Leon Battista Alberti's book De Pictura, which was the starting point for his thoughts on mathematics and perspective. All this makes it possible to understand that, like his master and other artists in Florence, Leonardo joined the family of polymaths of the Renaissance.

The artist

For Leonardo da Vinci, painting is the master of architecture, pottery, goldsmithing, weaving and embroidery, and it has, moreover, "invented the characters of the various scripts, given numbers to arithmeticians, taught geometers the layout of the various figures and instructed opticians, astronomers, machine designers and engineers. Yet experts attribute to Leonardo, long known for his paintings, less than fifteen painted works. Many of them remain unfinished and others in the state of projects. But today Leonardo is also known as one of the most ingenious, most prolific minds: alongside the small number of his paintings is the enormous mass of his notebooks, witnesses of an activity of scientific research and meticulous observation of nature.

In the 15th century, artists were not yet in the habit of affixing their handwritten signatures to their works. It is only later that the use of the still unknown autograph becomes widespread. The author wishing to mark his work still does so in the impersonal form of inscriptions (often Latin) made inside or beside the painting. This does not fail to pose important problems in the search for attribution of works produced during the Renaissance.

In the 15th century, painting was still considered a simple manual work, an activity seen as contemptible. Its intellectual character was only affirmed by Leon Battista Alberti in his work De pictura (1435) since, he underlined, the creation of a painting implied the use of mathematics through the research of perspective and the geometry of shadows. But Leonardo wants to go further and, designating it as a cosa mentale, wishes to place it at the top of the scientific activity and integrating it in the traditional Artes Liberales of the Middle Ages. Thus, according to him, painting - which cannot be limited to an imitation of nature (of the subject) - finds its origin in a mental act: understanding. This mental act is then accompanied by a manual act: execution. The mental act is the scientific understanding of the intimate functioning of nature in order to be able to reproduce it on a painting. And it is only from this understanding that the execution takes place, the manual act requiring a know-how. Mental act and manual act cannot exist one without the other.

But to understand the functioning of nature, the simple observation without method of the phenomena is not enough, untiringly Leonardo observes and analyzes the phenomena by using the demonstration and the mathematical calculation. This method takes as its starting point the mathematical models that Alberti used in the search for perspective, and Leonardo extends it to all observable phenomena (lighting, body, figure, location, distance, proximity, movement and rest). The attraction that mathematics and geometry exerted on the painter probably originated in the Platonic school, which he probably discovered through contact with Luca Pacioli, author of Divina Proportione, in the years 1495 - 1499. His notebooks testify during these years of a great activity of research in mathematics and geometry. He also discovered Plato who, in his Timaeus, established a relationship between the elements and simple forms: earth

But, for Léonard who intends to place painting above the spirit and sciences, the quantitative sciences are not enough; in order to apprehend the beauties of nature, it is necessary to resort to the qualitative sciences. Following the Pythagoreans and Aristotle, Leonardo finds the origin of beauty in order, harmony and proportions. For Leonardo, in the field of art, the principles of quantity and quality are indissociable and from their relation is logically born the beauty. The perfection of mathematics serves the perfection of aesthetics. On the other hand, Leonardo evokes the presence of "true" contours and "visible" contours to opaque objects. The true contour indicates the exact shape of a body, but this is almost invisible to the untrained eye, and becomes more or less blurred depending on the distance or movement of the subject. He thus emphasizes the existence of a scientific truth and a visible truth; it is the latter that is represented in the painting.

"The mathematical sciences extend only to the knowledge of continuous and discontinuous quantity, but do not concern themselves with quality, which is the beauty of the works of nature and the decoration of the world.

- Leonardo da Vinci, Ms.Codex Urbinas 7v

For Daniel Arasse, the comparison between Alberti and Leonardo da Vinci is not limited to mathematics: for Alberti, painting is a mirror of nature, whereas for Leonardo, it is the painter's own mind that must be transformed in order to become a "conscious mirror" of nature. The painter is less interested in the "aspect" of things, but rather in his way of seeing them. He thus becomes "the very spirit of nature, and becomes the interpreter between nature and art; he resorts to the latter to bring out the reasons for his actions, subject to its own laws" (Codex Urbinas, 24v). The painter does not "remake" nature, he "completes" it. Vincent Delieuvin adds that the artist thus discovers the beauty and poetry of divine creation and selects from the diversity of nature the elements that are appropriate to construct a very personal vision of the world and of humanity. Leonardo makes the painter the "lord and god" of his art and compares the process of invention to that of God the creator.

Then, after the mental act comes the manual act, the noble work of the hand, which as an intermediary between the mind and the painting deals with "the execution much more noble than the said theory or science". This nobility resides, among other things, in the fact that this hand, in its work, goes so far as to erase the last trace of its passage on the painting. The eye is the window to the soul, the privileged sense of observation, the intermediary between man and nature. The eye and the hand work together, constantly exchanging their knowledge and it is from this exchange that, for Daniel Arasse, "the divine character of painting is tied up and that the creation of the painter is played out".

In the 15th century, the artists of the Quatrocento encouraged the integration of the arts into the liberal arts disciplines. In this sense, Leon Battista Alberti introduces the teaching of painting in rhetoric and presents it as a learned combination of elements such as outline, organization and color. He also adds to his presentation a comparison between painting and poetry. At this time, an intense reflection is made between the theorists of the Renaissance to determine which art belongs more to the cosa mentale. This debate called Paragone (it will lose gradually of its interest towards the middle of the XVIth century to die out then.

Between 1495 and 1499, Leonardo da Vinci took part and wrote a Paragone in the first part of his Treatise on Painting: where Alberti was satisfied with a comparison between painting and poetry, Leonardo compared it not only with poetry, but also with music and sculpture, presenting painting as a "total art", situated above all others.

"How painting surpasses all human work, by the subtle possibilities it conceals: The eye, called the window of the soul, is the principal way by which our intellect can fully and magnificently appreciate the infinite work of nature; the ear is the second, and it borrows its nobility from the fact that it can hear the account of the things the eye has seen."

- Leonardo da Vinci, Notebooks (Ms. 2185)

He thus presents painting as superior to poetry, because it is comprehensible by all, whereas poetry must be translated for all those who do not understand the language. Moreover, compared to music, painting presents a greater perenniality: the first is composed of notes, certainly harmonious, but is it not an art "which is consumed in the very act of its birth"? Painting is also superior to sculpture in that it offers colors while the sculpted material remains uniform. It also presents the possibility of representing all of nature where sculpture can only present one subject. Moreover, the sculptor has to work in the noise and the dust whereas the painter settles comfortably in front of his painting in the silence or listening to music or poetry.

The study of light and the mastery of its rendering are among the major subjects that Leonardo tackled in his pictorial research. It is, for him, a way to achieve the perfect retranscription of nature and to give an impression of movement. After his first studies of draperies, which he already carried out in Verrocchio's workshop, Leonardo felt the need to study the theories dedicated to optics. In Florence, during his formative years, he studied the treatise of Alhazen, the research of Roger Bacon, John Peckham and Vitellion. These readings allowed him to understand the theory of intromission: the eye is passive and receives the image and not the opposite, as announced by Plato and Euclid. Around 1480, he wrote in his notes his experiments on light and shadow and the drawings he added to them illustrate how shadows, direct and indirect, are formed on opaque bodies.

On the other hand, he also studied the writings of Leon Battista Alberti and assimilated, tested and perfected the algorithms of perspective and the variation in size that objects take on in relation to the distance and angle of view. However, in addition to Alberti's purely geometrical perspective, which, taken in isolation, is not sufficient to express distance in the open air, Leonardo brings two other types of perspective: aerial or atmospheric perspective and color perspective. Since the visual rays of an object weaken as it moves away, the eye registers the changes. As a result, objects lose their sharpness and color in proportion to their distance. Even if the Flemish painters of the 15th century were already using the Arian perspective, Leonardo's merit is to have theorized it through numerous experiments, including the darkroom.

Leonardo's first exercises in light are his famous drapery studies on linen. However, according to art historian Johannes Nathan, while the drawn studies are easily identifiable to Leonardo through the left-handed hatching, the drapery studies painted on linen canvas are not. Only one drawing has the characteristic left-handed hatching, and only the Draping Study for a Kneeling Figure, now in the Royal Collection at Windsor Castle, has an interrupted line of ownership and can therefore be attributed to Leonardo. Moreover, the many other studies on linen canvas generally presented as painted by Leonardo's hand require a method, the brush, far removed from that to which Leonardo is accustomed, such as the silver point or the pen. The historian Carlo Pedretti adds among these studies the one he calls Draped wrapping the legs of a seated figure for its similarity to the painting Saint Anne, the Virgin and the Child Jesus playing with a lamb.

In his portraits, especially those involving a Madonna, Leonardo's principle is to represent movement through the prism of emotion, that is, the ephemeral moment in which a movement is linked to an emotion. Thus, in the painting Madonna with a Carnation, Mary hands the Child a carnation, symbolizing his future sacrifice: Leonardo captures the moment when Jesus is about to seize the flower, that is, to accept his destiny, while his mother smiles, symbolizing this same acceptance.

"A figure will only be praiseworthy if it expresses with gesture the passions of its soul."

- Leonardo da Vinci, Treatise on Painting VIII.478

In Leonardo's work, the gesture is always depicted in an intermediate situation, between its beginning and its completion. The Mona Lisa is the most accomplished example of this, for the seated position of the model, despite its serene immobility, marks a movement: the left arm is fully rotated and rests on the right hand, which gives the impression that Mona Lisa is sitting down. In The Lady with an Ermine, Leonardo gives the hand of Ludovico Sforza's lover, Cecilia Gallerani, a movement that seems to be both holding the animal and tenderly caressing it; such a description echoes the history of the figure itself, the ermine being the symbol of the Sforzas. Carlo Pedretti describes another movement in the stillness in the painting St. Anne, the Virgin and Child Jesus playing with a lamb in which Mary is both sitting balanced on her mother's lap and leaning forward to draw the Child to her: her position thus presents "an oscillatory movement in which the forward thrust is counterbalanced by the natural return of the body's weight backwards, in accordance with the principle of inertia. In fact, according to Daniel Arasse, Leonardo pursued this quest to capture the moment of emotion through movement from the beginning of his career: from the creation of the Portrait of Ginevra de' Benci (around 1474 - 1476) to that of the Mona Lisa (between 1503 and 1516).

In addition, there are numerous representations of facial expressions, whether they appear in his drawings or paintings: anger, fear, rage, imploring, pain or ecstasy; their best examples are found in The Last Supper, The Adoration of the Magi or The Battle of Anghiari. Leonardo also seems to have made numerous pictorial attempts on the smile, particularly in the three paintings he kept with him until his death: The Saint Anne, the Saint John the Baptist and the Mona Lisa; the smile is the very expression of life, of its dynamism, of its ephemeral character and of its ambiguity.

In order to reproduce all the effects of light and shadow that he observed in nature, Leonardo sought to perfect his painting technique. On wooden panels (cypress, pear, rowan, walnut or most often poplar) prepared with Gesso and then with lead white, he traces an almost invisible drawing; after several other steps, he puts the shapes in colors with the help of glazes and in particular the shadows. These layers are made of oily mediums barely colored: the painter then obtains almost transparent flat areas that allow him to model the shadows and lights or to shape forms visible through a vague haze. This is what Leonardo calls "sfumato" in his writings, a technique that gives a slight blur to his outlines in the image of the reality visible in nature and which also allows him to evoke the slight movements of his models. Here too, the Saint Anne, the Mona Lisa and the Saint John the Baptist, are considered by art critics to be the pinnacles of this process.

Moreover, always in search of the right proposal in order to best retranscribe the emotions of his characters, Leonardo operated by trial and error: on numerous occasions, he returned to his subjects, corrected them or superimposed their shapes or contours, modified his first drafts, modelled his volumes and shadows little by little, and perfected the expression of the human soul according to his scientific discoveries or his observations.

However, the slowness and meticulousness of the master forced him to paint only with oil paint, this being the only technique which, because of its long drying time, allowed for countless retouching on the painting. This is undoubtedly why, during his apprenticeship, he did not try his hand at fresco painting and why he was not called upon, unlike many of his colleagues, to decorate the Sistine Chapel in 1481. The fresco of the Last Supper, which he painted on the wall of the refectory of Santa Maria Delle Grazie between 1495 and 1498, is a sorry example of this limitation, which he nevertheless tried to overcome clumsily. The use of oil paint glazes superimposed on tempera fillings - paint adapted to fresco, but drying too quickly for Leonardo - on a preparation of lime and Gesso does not allow the fresco to be preserved for long and is already considerably degraded during the 16th century.

However, this tireless quest for perfect beauty represents a brake in the painter's pictorial production, which does not hinder the production of numerous drawings and writings. The contemplation, observation and description of the phenomena that Leonardo sought to understand in order to bring his painting to perfection, encouraged him to work methodically and slowly; Leonardo sometimes left painting for a long time in favor of his research on nature. As a result, some of his works remain in the state of a project or sketch.

In addition, the incessant retouching of the outlines and compositions are also at the origin of this non finito which characterizes Leonardo's work. If the sfumato technique allows for so much modeling and research of the perfect shadow, the drying time of oil paint is no less long and considerably lengthens the gestation time of the work.

For Vincent Delieuvin, this state of incompletion is difficult to interpret. Whether it was intended or not, but it was almost the foundation of Leonardo's work, and it undoubtedly bears witness to a new trend of creative freedom. Unlike his first three perfectly finished paintings (The Annunciation, circa 1472 - 1475, Portrait of Ginevra de' Benci, circa 1474 - 1476, and The Madonna with the Carnation, circa 1473), the Adoration of the Magi, begun in 1482 but never completed, marks the beginning of a period in which he began works to which he did not feel the need to put an end. The Saint Jerome, circa 1483, is still very sketchy and the Madonna Benois, dated between 1478 and 1482, although it has a finished look, leaves behind an open window on an empty sky probably reflecting an unfinished landscape. Leonardo leaves some paintings with very finished parts and others in the state of sketches where he probably gives himself the freedom to find a better layout or to perfect the work later. This tendency seems so systematic that it could constitute a kind of pictorial experiment with its own artistic ambition: the non finito. The art historian even suggests that Leonardo may have - perhaps without realizing it - pushed the recreation of nature so far that he manages to reproduce its unfinished character.

For Leonardo da Vinci, who has a graphomaniac tendency, drawing is at the heart of his thought process and constitutes the "foundation" of painting. Drawing is a graphic act that is his only way to analyze and order his observations. He constantly represents everything he sees and writes down everything that comes to mind, without hiding his ideas, but mixing them up as he thinks, so much so that he seems to function by formal and thematic analogy.

Leonardo's hatching and handwriting indicate that he is left-handed, and this is a strong criterion for the attribution of his drawings - added to the fact that the majority of them have an unbroken line of ownership. However, this cannot be a sufficient criterion, as some of his right-handed students chose to follow his model to the point of imitating his left-handed hatching.

Leonardo's drawings are particularly difficult to classify: although his training was mainly in art, only a few of his drawings are studies of paintings, sculptures or constructions. Most of them are only indirectly related to art, such as physiognomy, anatomy, light or shadow, or even to scientific or technical research, such as cartography, military art or mechanics. It is clear that Leonardo did not draw any real boundaries between these fields: many of the documents contain simultaneous research in different areas; in this respect, the Study Sheet with geometric figures, with the head and torso of an elderly man in profile and with a study of clouds is a significant example. In fact, it seems that the master, in 1508, did not manage to classify his works, which were mostly composed of sketches, plans, projects or concepts arranged with each other.

This difficulty is compounded by the many retrenchments made in the collection, sometimes even by Leonardo. The efforts of his heir, Fancesco Melzi, to put the notes and drawings in order without damaging their integrity were later thwarted by Pompeo Leoni, an artist who came into possession of the documents around 1580 and cut out most of them. He pasted the result of his cuts in two books, one with the technical drawings that we now call the Codex Atlanticus kept in the Ambrosian Library in Milan, the other with other drawings that he considered artistic and that are kept in the Royal Collection at Windsor Castle. Even if this operation had a laudable aim, it led to mixtures: some drawings kept in the United Kingdom and considered technical should be in Milan and vice versa.

The early drawings indicate that Leonardo favored pen and brown ink over an initial outline in black stone or metal point. The first surviving preparatory drawings, such as the Study of the Arms and the Head in Profile, were probably used for the Annunciation and already show the use of hatching, which Leonardo used in many of his drawings to study the shadows. These allow us to see that the painter uses mostly his left hand to draw. From the time of his apprenticeship, the metal point seems to have been his favorite tool for its ability to render shadow transitions, as shown in The Condottiere, inspired by a work by Andrea del Verrocchio.

Around 1490, he discovered sanguine (red chalk) for its ease of blurring, which allowed him to render physiognomy and expressions in a more nuanced way. It seems that the use of silver lead gradually diminished in favor of sanguine, which he adopted until the end of his life and which he combined with other techniques, notably charcoal in the Portait d'Isabelle d'Este. In addition, chalk drawing offers similar possibilities to oil painting for the study of fluid transitions between dark and light areas. He also continued to use black or brown ink to draw the most precise contours.

According to Léonard, there is an aspect of the scientific reality which is intransmissible by painting: the clear contours. These are blurred by the painter because he must leave room for beauty, which is incompatible with this requirement of neatness. For Leonardo, only the technical drawing allows to represent the true contour of the opaque bodies.

Leonardo's originality stems from the fact that he considered sight to be the primary sense, and so he represented his observations in the most synthetic and complete way possible. This can be seen especially in his anatomical drawings, where the body parts are similar to his artistic studies: the result of the dissection of a human arm shows the muscles from different angles, in different sections, even though these views are impossible to obtain in dissection. His drawings can become schematic: thus he gradually gives up the representation of muscles for some kind of force transmission ropes. It seems that he even tried to represent the human body in its entirety: the Representation of the female body is a significant example. In spite of the mistakes he makes in anatomy - understandable in the 15th century - he offers a transparent representation of the complexity of the correspondences between the organs. By introducing a form of fiction into what he considered to be a scientific reality, he was the precursor of the modern scientific illustration that would take off at the end of the 14th century, notably in André Vésale's De Humani corporis fabrica.

His architectural drawings are not strictly speaking technical representations. This is first of all due to the analogy he makes between architecture and anatomy where the building would be the organ (the microcosm) while the city would be the body (the macrocosm). Moreover, he does not necessarily give scale plans that could have been used for any practical execution. Finally, his drawings turn out to be rather visionary transpositions of a certain idea of compact space of buildings as carved in the mass of a stone. The seductive character of these sketches does little to conceal their imaginary and impractical aspect. In fact, it seems that Leonardo has little understanding of the physical realities of architecture.

But, in general, it does not seem that the practical aspect of his research is important to him: Leonardo seeks above all new possibilities, whether they are feasible or not, because it is his curiosity and his imagination that move him. In this spirit, he conceived numerous studies on the flight of birds, on aerodynamics and on the possibilities of imitating the beating of wings in order to make man fly. Such a relentless search beyond the feasible combined with the fantastic character of his drawings, poses the hypothesis of a disdain for the real possibilities of realization in favor of a tireless scientific curiosity of the researcher.

Exact or true, the line of the scientific drawing limited to "the knowledge of the continuous and discontinuous quantity" must, in the preparatory drawing, become beautiful, harmonious and deal with "the quality, which is the beauty of the works of nature and the ornament of the world".

Unlike his contemporaries, a great many of Leonardo's sketches have come down to us. However, their destinations vary greatly: while some are not attached to any particular painting, others seem to have been used for several painted works - in contrast to the Mona Lisa, for example, which has no preparatory sketches. An important part of Leonardo's artistic drawings is devoted more to the exploration of the foundations of creation and the search for formal solutions without really aiming at a concrete application. Thus, the artist treats and collects his own drawings with care in order to call upon them when the occasion arises.

To find beauty and organize his composition, Leonardo used a more suggestive and rapid line than he did in his scientific drawings. His first drawing, dated by him to 1473, the Landscape of the Arno Valley, is characterized by a sure, energetic but still controlled line, while the preparatory sheets for the Benois Madonna present numerous attempts at discontinuous lines and repeated contours seeking rather to find the right movement than to respect anatomical rigor.

Taught or inspired by his master Andrea del Verrocchio, Leonardo discovered this method in his early years and seems to have adopted it under the name of componimento inculto, the "uncultivated composition". Some of his preparatory drawings take on the appearance of scribbles, a sort of blotch from which he selects the most appropriate outline for his composition.

The Madonna of the Cat is one of the best examples of this way of drawing, in which Leonardo researched composition and tried out numerous proposals: Leonardo makes several attempts covering each other; he then does not hesitate to turn the sheet of his drawing over to draw, by transparency, the line chosen among all those he has previously drawn to build his composition. This process is also visible in a study for Saint Anne, the Virgin and the Child Jesus.

The Adoration of the Magi also illustrates the componimento inculto: a study by infrared reflectography reveals the presence of the underlying drawing which presents numerous discontinuous and abundantly repeated strokes, especially on the group of characters on the right; the drawing simultaneously studies so many postures that it appears as a dark and rather shapeless area.

It seems that this practice of uncultivated composition - which Giorgio Vasari described in 1550 as "license in the rule" - set a precedent in the history of Renaissance art: by privileging the physical and spiritual movement of characters over their external forms, it frees the painter from the duty of imitation and invites him to transcend this imitation towards a more complete restitution of life in its entirety and in its globality.

Leonardo proposes to go beyond the faithful imitation of external forms to the benefit of a study of the movements of the figures which translate their inner feelings. These movements are the subject of many studies by Leonardo. Even his scientific studies echo this reflection: thus his work on the flow of water or on apparently static landscapes translates a desire to represent movement in fixity.

"The good painter must paint two important things: the man and the intentions of his mind. The first is easy, the second delicate, for it must be obtained by the representation of the gestures and movements of the limbs."

- Leonardo da Vinci, Treatise on Painting TPL 180

The language of the body is also a means of telling a story: Leonardo seeks to assign the right gesture to each character by not hesitating to go back over the contours of his models, to superimpose the different positions of the limbs and even to exaggerate the poses or distort the anatomy, as in the Grotesque Figure that he drew around 1500.

For Leonardo, the emotions of the moment are immediately reflected in the model's face. In the 15th century it was not uncommon to link a person's features with his character, in relation to the theory of humors according to which the health of a person depends on the balance between the four humors that form the character (bile, sanguine, atrabilary and phlegmatic): Leonardo thus assumes the existence of a direct link between the character of a person and his physiognomy (physiognomy).

Leonardo illustrates this thought in numerous caricatures, most of which are composed of the heads of older men, sometimes confronted with those of a young man, or of characters who oppose each other by their gender or by their mirrored features. For example, in the drawing of the Five Grotesque Heads, Leonardo contrasts the positive character of a character wearing a laurel wreath with the negative character of the grimacing faces of four other characters surrounding him.

These caricatures are undoubtedly attempts to analyze the structure of the face in relation to Leonardo's anatomical work, or they may reflect a comic intention, perhaps in relation to the comedy or burlesque poetry of which the painter was fond. Giorgio Vasari reports that if Leonardo saw a person with an interesting face, he would follow them all day long to observe them and at the end of the day, "he would draw them as if they were right in front of him. In any case, Leonardo seems to have drawn inspiration from many preparatory drawings in this set of caricature sketches for the elaboration of The Adoration of the Magi, The Battle of Anghiari or The Last Supper. He also recommended that his students study physiognomic details in order to obtain the best motifs: a passage in the Treatise on Painting indicates, for example, that Leonardo divided the different shapes of noses into three categories, which themselves included several sub-categories.

Leonardo's studies of human proportions are part of his graphic research on the painter's artistic activity. These studies are mainly about man, horses and more rarely about animals.

The interest in human proportions is then ancient: from Antiquity, the sculptor Polyclitus made several and, since the Middle Ages, many artists follow the less exact canon known as "Mount Athos" which divides the human body into nine parts; it is only in the fifteenth century that Leon Battista Alberti perfects this canon. From 1489 onwards, Leonardo worked on a draft treatise entitled De la figure humaine (On the Human Figure) in which he studied human proportions by taking numerous systematic measurements on two young men. He thought to study the proportions of the different parts of the body between them, including them in a readable geometrical scheme and no longer mainly established in absolute measures. However, his work remains very experimental: in the drawings of human heads, the grid that underlines the proportions is only laid down after having drawn the subject. This means that the work is still in the research stage. Leonardo adds the measurements from an image that is familiar to him and for which he does not yet follow a fixed pattern of proportions, as Albrecht Dürer (1471-1528) would do a few years later in 1528.

However, among all Leonardo's studies of proportions, the Vitruvian Man represents an exception: it is a careful study, which departs from all his previous research and for which he makes a long series of measurements.

The study of Vitruvian Man that Leonardo undertook constituted a challenge to the human proportions that had been established since antiquity. This work originates from the research of the Roman architect Vitruvius (1st century BC) who, in his De architectura libri decem, relies on a Greek system called "metrology". Vitruvius works on a fractional system in which the distance between the outstretched arms is equivalent to the height of an adult man; this height is divided into several parts with a system of proportions of the human body using the duodecimal system whose denominators are even - a methodology that will endure until the introduction of the meter in the 19th century.

Breaking with the ancient duodecimal system and with ancient proportions, Leonardo's empirical research contradicts the canon produced by the ancient metrological system: thus he reduces to 1⁄7, the proportion of feet to body height when Vitruvius estimated it at 1⁄6; similarly, redrawing Vitruvian Man, he revises its measurements and resolves the ancient canon by placing the center of homo ad circulum (the circle) at the navel and that of homo ad quadratum (the square) above the pubis.

From a purely artistic point of view, one may wonder whether the Vitruvian Man, a drawing so well done, with such an elaborate layout and emanating from such precise research, still has any connection with Leonardo's artistic activity. The normal work of a painter does not require so many calculations. Moreover, no other study of Leonardo's reaches such an artistic level and degree of accuracy compared to this work, which, after all, is an interpretation of a point of view that was not originally his own. This could be an indication of a more ambitious project than a simple study: the Vitruvian Man is perhaps intended to be placed at the opening or closing of a treatise. It seems that, faced with the difficulties that the Vitruvian Man project has brought to light, Leonardo stopped producing any further studies of proportions.

Since his training at the workshop of Verrocchio, Leonardo is a great lover of comedy and burlesque poetry, he loves the theater and the party, the entertainment, the wonders and the automatons are for him the fabulous ground of new inventions and inspirations for his research. From then on he took part in the elaboration of several theatrical sets and shows organized by his sponsors: for Laurent de Médicis, in Florence, he participates in the decoration of festivals and takes care of the conservation of ancient works, in Milan, in 1490, with the help of his machinery, he creates the staging of the Feasts of Paradise in the castle of the Sforza with whom he is "ordinator of the festivals" in 1515, in Florence still, he draws the plans of a mechanical Lion which is sent to Lyon for the coronation of François Ier with whom he ends his life by organizing shows and marriages.

Several drawings and studies relating to this activity reflect Leonardo's thirst for allegorical and spectacular representations. In particular, the caricatures of grotesque characters, but also the so-called "allegorical" drawings, which held great fascination for the spectators and patrons of the 15th century: the idea that a simple drawing could have a hidden meaning or a cryptic message aroused great attraction in the literate public. These allegories often enliven processions, tournaments or stage performances or are often simple drawings or rebus intended to entertain.

However, the messages contained in the allegories often lie in the combination of an image and a text, and therein lies perhaps a contradiction in Leonardo's belief that the image is superior to the word: an allegorical image is only complete if it submits to a text. In any case, Leonardo drew sketches with captions such as "Virtue struggling against envy" or in the Allegory of the Lizard, symbol of truth, "The lizard faithful to the man, seeing the man asleep, fights the snake; and realizing that he cannot defeat it, he runs over the man's face and wakes him up so that the snake cannot harm the man", a caption without which the image is difficult to understand. In another sheet Allegory of Human Enterprises, Leonardo rains down a series of everyday objects and writes, "O sad humanity, how many things do you not submit to for money!"

Other allegories are devoid of text, such as the Woman Standing in a Landscape, which, in addition to illustrating Leonardo's belief that an image should represent not only the person but also the intentions of his mind, draws the viewer's attention to an area outside the landscape that seems to appeal to an unknown part of his imagination. There is a consensus to identify the character in the drawing with Matelda, Dante's last guide in Purgatory, who appears to him in Canto XXVIII in the Divine Comedy when she indicates the route to heavenly Paradise. Matelda explains to Dante the movements of air and water and the origin of vegetation. According to Daniel Arasse, this vision, in which grace is combined with an explanation of phenomena, must undoubtedly have seduced Leonardo. The allegory of the wolf and the eagle, while it remains one of the last allegories of Leonardo's very carefully drawn work, also lacking an explanatory text, is still the subject of much debate among experts as to the meaning that should be attached to it: the inconstancy of fortune left to the whims of the wind, or the ship of the Church whose pilot - apparently a wolf (or a dog) - sets course for a royal eagle. This is still an open debate as many details of the design, such as the crown apparently bearing French lilies, are still unknown and not certain to carry any meaning.

Leonardo da Vinci left no sculpted work behind. However, it is very likely that he was introduced to this art by his master Andrea del Verrocchio - himself mainly known for his sculptures - during his years of apprenticeship in his workshop: he certainly participated in the creation of several of his works, including the Incredulity of Saint Thomas, dated between 1466 and 1483. It is possible that he also practiced this art for his own account: he mentions in his notebooks some sculpted works, such as an enigmatic History of the Passion, and presents himself in 1482 to the Duke of Milan as being able to sculpt marble, bronze or clay; Gorgio Vasari also mentions the making of a "group of three bronze figures that surmount the northern door of the baptistery, a work by Giovanni Francesco Rustici, but carried out under Leonardo's direction.

Some sources indicate the existence of preparatory exercises in terracotta: Gorgio Vasari mentions in 1568 "smiling women's heads and children's heads" and, in 1584, Giovanni Paolo Lomazzo lists among the works in his possession a "Head of Christ as a Child". These sculptures, now lost, have been the subject of research by numerous specialists and art historians since the 19th century, but no consensus has been reached on them. However, three terracottas are sometimes attributed to him, but with caution: an Angel exhibited in the Louvre in Paris, a Saint Jerome and a Virgin and Child in the Victoria and Albert Museum in London. However, these three sculptures, although typical of Florentine art of the Quattrocento, are too far removed from Leonardo's early paintings to be formally attributed to him with certainty.

Leonardo's best-known sculptures are the commissions for equestrian works carried out for the Duke of Milan Ludovico Sforza, Gian Giacomo Trivulzio (1508-1510) - whose preparatory drawings in the form of a series of pen-and-ink drawings are on display in the Royal Collection at Windsor Castle - and then probably for the French king Francis I (1517-1518). It was on the first project that Leonardo worked most ardently and for which there are the most studies: Ludovico Sforza commissioned a statue in memory of his father Francesco in 1483. Leonardo conceived two successive projects: the first, very ambitious with a rider dominating an enemy lying on the ground, was abandoned in favor of a second one presenting Ludovico riding a horse at a walk. But this new model, for which no preparatory drawings exist, was given a monumental dimension: measuring 7.2 meters - three times larger than life - the statue required about 70 tons of bronze.

Only a few plans of the mold of a piece that was to be used for the making of the statue have survived. A terracotta model was made and impressed all the contemporaries of the master. But, according to his own admission, "the work is so great that I doubt it will ever be finished. Indeed, everything came to a halt in November 1494 when the bronze that was to be used for the giant statue was requisitioned and melted down to make weapons against the French army that threatened the duchy that was finally invaded in 1499. The clay model was then destroyed by French crossbowmen who used it as a target.

In his Paragon of the Arts, Leonardo placed sculpture well below painting because he considered it less universal than the latter. However, the art historian Vincent Delieuvin notes that the artist seeks to give his paintings a relief close to sculpture and that the figures in his paintings naturally take on a "dynamic gesture, whose foreshortening effects rival the three-dimensionality of sculpture.

In 1482, Leonardo left Florence for Milan. According to Giorgio Vasari, he was carrying a gift from Lorenzo de' Medici for Ludovico Sforza: a silver lyre in the shape of a horse's skull. He is probably accompanied by the talented musician Atalanta Migliorotti to whom he seems to have taught the handling of the lyre. Leonardo was considered at the time to be a very good lyre player, a master of music, an inventor of instruments and a designer of fabulous shows both at the Milanese and French courts. The artist's engineering drawings contain, in fact, several studies for drums and wind instruments with keyboards, viols, flutes and bagpipes as well as automata and hydraulic systems for theater machines. These aim to improve the use and efficiency of the machines, and some of his inventions in this field were taken up a few centuries later. Although no musical compositions are known to Leonardo, his notebooks also contain several proofs that he mastered the use of notes. These are most frequently ingenious riddles or rebus. Paolo Giovo and Giorgio Vasari point out that Leonardo knew how to sing very well, in particular by accompanying himself with the lira da braccio.

At the end of the 15th century, this combination of mastery of the arts was not really rare in the profession of painter or sculptor: even if Leonardo was one of the first "painter-musicians", they became more and more numerous and found their social success in music as well as in painting. In this matter, Leonardo has his peers among Andrea del Verrocchio, his master, Le Sodoma, Sebastiano del Piobo or Rosso Fiorentino.

The engineer and the scientist

During the Renaissance, scientists and engineers of the 15th century perceived the limits of their fields: certain scientific theories were questioned while the scientific approach was neither theorized nor fixed, and the means of reporting research and studies remained textual and very little graphic. Nevertheless, if they were able to perceive new principles, they were unable to extract themselves from the heritage of their predecessors.

In this context, Leonardo da Vinci defined himself as an engineer, architect and scientist: from the 1480s onwards, he wished to give his art a more detailed, more profound scientific meaning. He then embarked on a meticulous study of nature and developed his knowledge of geology, botany, anatomy, human expression and optics. But while this knowledge was initially acquired to serve painting, it gradually became an end in itself. He began to write several treatises on anatomy and the movements of water. These notes, sometimes with a title, are structured around a more didactic and structured style.

Nevertheless, he was not the only "universal artist" of his time. Among his most famous predecessors are Guido da Vigevano (around 1280 - after 1349), Konrad Kyeser (1366 - after 1405), Jacomo Fontana (known as "Giovanni") (1393-1455), Filippo Brunelleschi (1377- 1446), Mariano di Jacopo (known as "Taccola" who proclaimed himself the "Sienese Archimedes") (1382 - around 1453) and among his contemporaries Bonaccorso Ghiberti (1451 - 1516), Giuliano da Sangallo (1445 - 1516) and Francesco di Giorgio Martini (1439 - 1501).

Leonardo da Vinci attended a scuola d'abaco, a school for future merchants that provided the knowledge strictly necessary to carry out their activity. He did not attend a "Latin school" where the classical humanities were taught. In fact, he studied neither Greek nor Latin, which, as exclusive supports for science, were nevertheless essential for the acquisition of scientific theory and, above all, were the supports for a stable and specific vocabulary. Nevertheless, even if he recognizes this difficulty in the access to the Latin language, Léonard claims towards the end of his life to have enough vocabulary in the vernacular to be able to do without the first one: "I have in my mother tongue such a great number of words, that I should deplore my lack of perfect comprehension of the things, rather than a lack of a vocabulary necessary to express the concepts of my mind".

The weakness of his theoretical background, especially in mathematics, is a difficulty for Leonard. In the long run, it was only by frequenting specialists in the fields he intended to invest that he could progress: Luca Pacioli in 1496 for mathematics or Marcantonio della Torre for anatomy for example. Moreover, for lack of a fixed, precise and adapted technical vocabulary, he loses as many conceptual features, which limits some of his reasonings. In the same way, his lack of mastery of Latin forbids him a direct access to scientific works, those being for the most part written in this language.

His lack of university training is finally felt in the absence in his research of any structured and coherent methodology, an absence correlated with a difficulty in choosing between a systematic approach to his subject of study and an empirical approach. However, it is notably thanks to the frequentation of specialists that he manages to find a balance between the description of the detail and the overall vision of his subject of study.

Leonardo da Vinci entered the workshop of Andrea del Verrocchio as an apprentice around 1464 at the age of 12, where he received a multidisciplinary training that combined art, science and technique and where drawing techniques were commonly combined with the study of superficial anatomy and mechanics.

Thus, his research is often treated in a transdisciplinary manner: his subject is considered in all its manifestations, and he does not stop at the simple knowledge of engineers but wishes to add theoretical reflections from mathematics and philosophy. This approach, which stems from his self-taught and multidisciplinary training, distinguishes him from the engineers of his time.

A "man without letters", as he defined himself, Leonardo showed in his writings anger and incomprehension at the contempt in which he was held by doctors because of his lack of university training. In reaction, Léonard became a freethinker, an opponent of traditional thought and presented himself rather as a disciple of experience and experimentation. Thus, his lack of university training is paradoxically what frees him from the fixed knowledge and methods of his time. This is how he achieved a true synthesis between the theoretical knowledge of his time and the observations resulting from the engineer's practice. In fact, Leonardo's science is based on the power of observation.

A man of his time, Leonardo da Vinci took on the heritage of antiquity, the Middle Ages, and his engineering and scientific predecessors of the Quattrocento, as shown in his first human anatomical representations, which combine traditional beliefs, observations from animal dissections, and pure speculation. Often unable to distance himself from the scientific theories of his time, he tried to reconcile his innovative discoveries with the tradition of his time. He sometimes even ended up drawing only what he expected to see instead of what he saw. In fact, his scientific notes sometimes give "a diffuse feeling of impasse": thus, concerning the heart, "limited both in his direct experiments and by the accepted physiology of the heart of his time, he seems condemned to describe in ever greater detail the passage of blood through the valves. It is at this point that his work as an anatomist seems to have come to an end".

Finally, Leonardo's work is a reflection of his deep personality: like his pictorial production, his scientific and technical work is marked by incompleteness. Thus, the various treatises he wanted to write (anatomy, mechanics, architecture, hydraulics, etc.) remained systematically in draft form.

Leonardo da Vinci produced until the end of his career several thousand pages of studies which represent only a portion of his work - many of them are lost. It is the most extensive and varied testimony to the thinking of his time.

As his career progressed, his ambition was to produce a systematic treatise for each field of activity he tackled: treatise on painting at the end of the 1480s, on anatomy in 1489, on the mechanics of the human body (elementi machinali) in 1510 - 1511, on the movement of water after 1490, on architecture between 1487 and 1490, on the anatomy of the horse (which would have been written according to Giorgio Vasari but disappeared in 1499), on optics in the years 1490-1491. But, of all these projects, none succeeded. Only a Treatise on Painting was produced thanks to the work of his pupil Francesco Melzi, who compiled all the writings collected on the subject in the master's documents, which he inherited in 1519.

The thorough and systematic character of his work is a powerful indication of this desire to write treatises: it is this systematic character that allows Andrea Bernardoni to describe a treatise on mechanisms as "an absolute novelty for the history of mechanics". Moreover, rarely before him had drawing taken on such importance: it was always pedagogical and combined precision and "stylization to remain legible".

Despite modern research that seeks to downgrade the innovative and isolated nature of Leonardo's work, historians of science recognize several contributions from him.

One of his most important contributions is his use of technical drawing, since he was one of the first engineers to deploy such precise and precise techniques of graphic representation of his ideas (an aspect already mentioned above). Moreover, he gives it a value as great as the descriptive text. In fact, he possesses exceptional drawing skills, in addition to his great ability to perceive the globality of his subject of study and his precise literary style: this is particularly evident in his anatomy studies, which are thus "among the most advanced ever produced". He applied the techniques of anatomical representation to any technological subject: he systematized the association of different techniques with plans in exploded form, turning around his subject from several points of view. He is the only one among his predecessors and contemporaries to do so.

Another difference with his contemporaries is that Leonardo's technical drawing, thanks to the artistic techniques of perspective or the rendering of shadows, prefigures industrial drawing as it is still used today: in comparison, Daniel Arasse finds that the drawings of renowned engineers such as Francesco di Giorgio Martini "show a certain awkwardness. Such use of technical drawing is unique among Leonardo's contemporary engineers.

Another contribution of Leonardo da Vinci in the scientific and technical field is the systematic character of his research: translating his reflections, his technical drawings and his descriptions testify to an attention as acute for the detail as for the whole of his object. His methodology proposes as many round trips to obtain the most complete study possible. In fact, the master presents "a need to rationalize that was ignored until then among technicians".

Moreover, Leonardo da Vinci brings a "radically new approach" that prefigures the modern experimental approach and that Pascal Brioist qualifies as "proto-experimental": nevertheless, it should not be seen as an approach identical to that of the laboratory such as it was set up by Robert Boyle in the 17th century, but rather as one based on the workshop, where the proof is sought only in materiality; in the same way, he proposes thought experiments that do not rely on an experimental protocol.

Finally, Leonardo managed to free himself from the knowledge and methods of his time, notably because of his lack of university training. In fact, he has a real capacity to contradict the theories of his time. He presented intuitions that would only be reformulated and validated several centuries later, such as his hypothesis of the formation of fossils, which was remarkably accurate and in contradiction with the explanations of his time, linked to biblical literature or alchemy. Moreover, the novelty of his technical works and in particular the research of automatism is certainly due to the fact that they are not explored by his contemporaries since the "economic profitability of the work thanks to the automation of the mechanical operations of production" is not then part of the centers of interest of the society taking into account the relation to work and the social relations.

Leonardo da Vinci's interests were extremely numerous: optics, geology, botany, hydrodynamics, architecture and engineering, but also astronomy, acoustics, physiology and anatomy, to name but a few. Among these, human anatomy was the field he studied most assiduously throughout his career.

Human anatomy was Leonardo's favorite subject of study among all those he studied. It is a work born of the need to improve the pictorial description of the figures he represents in his paintings.

His first documented works date back to the mid-1480s: at first they are representations made when he had probably never performed a dissection of the human body. Then, they are the result of observations of human material obtained thanks to his protectors: a leg around 1485-1490, skulls from April 1489, then whole bodies very quickly... At the end of his life, he will have performed "more than thirty" dissections.

In fact, if his first works are the setting in image of medieval representations, his reports, in particular graphic, become of a remarkable precision. For Leonardo had all the qualities of a great anatomist: a great capacity for observation, manual dexterity, talent for drawing and the ability to put into words the results of his observations. Moreover, his graphic qualities were nourished by his work in other disciplines such as engineering, architecture and art: multiplication of points of view (rotation around the subject, cross-section according to the plan, exploded view, serial drawings, etc.) and techniques (black stone or, more rarely, charcoal for the underlying drawing, cross-hatching, wash).

He often had difficulties in obtaining human bodies, as when he moved into the family villa of his pupil Francesco Melzi following the French conquest campaign in 1512-1513 on Milan. He then turned to the dissection of animals: pigs, monkeys, dogs, bears, horses ... Indeed, he believes that "all land animals have similar muscles, nerves and bones and vary only in length or size," allowing him to progress on human anatomy. Thus, one of his first reports of dissection concerns a bear around 1488-1490: Leonardo considers this animal interesting because it is a plantigrade whose foot offers physiological resemblances with that of the man. Nevertheless, the animal that fascinated him most during his career was the horse, an interest that clearly originated in the 1480s with the commission for the Sforza Monument.

In fact, all aspects of human anatomy are studied in depth - structural anatomy, physiology, conception, growth, expression of emotions and senses - as well as all its domains - bones, muscles, nervous system, cardiovascular system, organs (bladder, genital organs, heart, etc.). So much so that at the end of his career, Leonardo was "able to better understand the articulation between the details and the whole, and to proceed from the cause to understand the effect, trying to analyze the properties of the elements that the autopsy revealed to him.

Optics is at the center of Leonardo da Vinci's research to establish his Treatise on Painting and to further improve the practice of his art, including the technique of sfumato.

At the beginning of his career, during his research on the eye, he took up Leon Battista Alberti's theory of the "visual pyramid", of which the eye would be the summit and which would allow him to establish the rules of perspective, but it seemed to him that this theory did not really take into account the three-dimensional reality: he then corrected it by what he called the "spherical" or "natural" perspective.

Concerning light rays, he reasoned in terms of shadow and light: his theory is that the image of objects is emitted by the latter and is projected onto the retina of the beholder.

To study the eye and light rays, he imagined all sorts of devices to simulate and study the functioning of the eye, but without succeeding in discovering the role played by the brain in the inversion of the image, allowing the upright view of an image projected backwards.

It is particularly in the Codex Leicester, that Leonardo studies astronomy. It appears that his astronomy "is of an optical nature" and is interested in the diffusion of light between celestial bodies - primarily the Moon and the Sun.

His research proposes some original intuitions. He notes his observations on the light coming from the Moon: he concludes that it is indeed the light of the Sun which is reflected on its surface which reaches the Earth. Therefore, he provides an interesting explanation of the halo of the new moon.

Nevertheless, he remains, like his contemporaries, resolutely geocentric.

Leonardo da Vinci will never be a real mathematician: because of his schooling, he has only a basic knowledge. From then on, he only used very simple notions in his scientific and technical research and researchers noted his frequent errors in calculation in elementary operations. He therefore had to be guided, explained and advised by recognized mathematicians. His meeting in 1496 with the mathematician Luca Pacioli - whose mathematical treatise, De divina proportione, he illustrated around 1498 - was thus fundamental: it stimulated his taste for the field and modified his way of seeing the world. He came to consider that all natural elements are governed by mechanical systems which are themselves governed by mathematical laws. Finally, he praised mathematics for the state of mind "of rigor, coherence and logic" that it is necessary to acquire to approach anything: does he not warn, "Let no one read me in my principles who is not a mathematician"?

The study of plants enters very early in the repertoire of graphic studies of Leonardo da Vinci and has its origin in the questioning of a faithful representation of nature in his pictorial works. His work is so precise in the latter that the accuracy of the plants they contain can constitute a clue to attribution to the master, as is the case with The Virgin of the Rocks in its version in the Louvre dated 1480 - 1486, or, on the contrary, inaccuracies constitute so many clues to refuse the attribution of the version preserved in the National Gallery.

In general, Leonardo da Vinci uses a much more structured approach than in other scientific fields, the object of study being composed of a great wealth of subtle details. These representations are the result of long observation sessions of plants in the region of Milan and in the Italian Alps. Not only does he faithfully render each constituent element of the plant studied, but he does so according to a plastic staging including light effects and arrangement of forms in space.

Finally, some of the manuscripts preserved in the library of the Institut de France are devoted to botanical studies and suggest that his ambition was to produce, around 1510 - 1511, "a treatise on botany applied to the pictorial representation of plants".

Many aspects of geology were studied by Leonardo: the study of fossils, the nature of sedimentary rocks, the presence of marine fossils in these rocks, hydrology, the origin of sediments, the causes of erosion by runoff, the nature of terrestrial forces and the first principles of isostasy. In 1939, the enthusiasm of the Anglo-Saxon world at the time of the English publication of the writings of geology of Léonard makes that this one is even called the "father of the modern geology"; at least the contemporary historians of sciences recognize him to be one of the precursors of it.

His main geological observations date back to his stay at the court of Ludovico Sforza in Milan between 1482 and 1499: the city is indeed located not far from the Alps where he often went, especially to Monte Rosa where he observed the movements formed by the rock strata and where he found fossils.

Léonard proposes rather innovative ideas explaining the presence of fossils on the reliefs by the fact that they were covered by the sea, an idea rediscovered and reformulated 150 years later by Nicolas Sténon. He also considers that the phenomenon of deposition of fossils in homogeneous layers of sedimentary rocks, in strata, constitutes a slow natural process. These two elements then call into question the biblical story.

He also studies the phenomenon of erosion by runoff: he investigates the relationships between the slope that a river descends, its flow and the consequences in terms of erosion. Consequently, he proposes hypotheses concerning the way in which sediments are deposited according to their mass and the flow of the watercourse.

Moreover, he had the intuition, still confused, of the principle of isostasy according to which the continents rise while erosion reduces their mass and, in so doing, transfers an equivalent mass of sediments to the ocean basins - a principle scientifically described by the American geophysicist Clarence Edward Dutton in 1872.

Like his botanical knowledge, his knowledge of the materials he describes is so accurate that his depictions of rocks are indicators to help authenticate his works: this is the case, for example, with the version preserved in the Louvre Museum of The Virgin and the Rocks or with the painting Saint Anne, the Virgin and the Child Jesus playing with a lamb.

All subjects of architecture are explored by Leonardo da Vinci during his career: religious architecture (civil architecture), military architecture (fortifications and the elements that constitute them). His work is mainly known through the hundreds of pages of drawings and sketches he left behind, in which he left few written reflections and indications. Nevertheless, the concrete realizations resulting from his plans are rare and are not always attributable with certainty. In fact, his work in this field is mainly theoretical: this does not, however, harm his reputation among his contemporaries, because the project and its realization have an identical value.

It was in the service of Ludovico Sforza in Milan in the 1480s that his reputation as an architect was born, when he took part in a competition for the construction of the lantern tower of the cathedral of Milan: his project was certainly not selected, but it seems that some of his ideas were taken up by the winner of the competition, Francesco di Giorgio. So much so that in the 1490s he became, along with Bramante and Gian Giacomo Dolcebuono, a leading urban and architectural engineer under the title of "ingeniarius ducalis".

Leonardo's models were predecessors of the first part of the Renaissance such as Filippo Brunelleschi and Francesco di Giorgio; his work is in line with the first Renaissance, visible especially in northern Italy, and is marked by archaism. He is thus singled out among his contemporaries like Bramante who were inspired by ancient architecture and the rediscovery of the ruins of Rome. This is why his ideas are particularly appreciated in France where he "does not introduce new forms, but daring ideas".

His vision of architecture is hygienist: considering that the building must fit into its environment like an organ in an organism, he willingly sees himself as a doctor acting on a sick body. Moreover, he shows his concern for the good health of the building as much in its component materials as in its structure: nature of the materials, play of balances and taking into account the weaknesses inherent in the forms that are drawn. Finally, salubrity and circulation become central considerations in the context of the well-being of the inhabitants.

His work methodology emphasizes the representation in aerial perspective, which is quite unique among the architects of his time who prefer the plan presentation

His contribution to architecture is to combine a rigorous framework with an abundant imagination. Moreover, his strength lies in the interdisciplinary nature of his thinking, unlike architects who specialize in their field. Moreover, as far as private architecture is concerned, Leonardo resolutely deviates from the proposals of his contemporaries and remains attached to the functionality of the buildings he designs, of which the staircase is a central element.

If his interest for architecture is very variable since he lightens or even suspends his work in the field between 1490 and 1506, his interest for the military architecture remains constant: his principal employers in this last field will be Venice and César Borgia known as "the Valentinois". He also relied on the reflections of Francesco di Giorgio Martini, Baccio Pontelli, Giuliano da Sangallo and his brother Antonio da Sangallo the Old.

If his contemporaries were not at first convinced of his expertise in the field, it was only after 1492 that he was taken seriously, after having trained with Milanese military engineers. In fact, he took up the ideas of his contemporaries and promoted the circular form, the idea of lowering the fortifications and the emphasis on bastions. However, he was not content to simply take up these ideas but went to the end of their logic: primacy given to the lowering, horizontality and round shape.

Leonardo da Vinci's reflections on urban planning are conducted in four main moments: during the reign of Ludovico Sforza, while in Milan; for the French king's envoy to Milan, Charles d'Amboise; during his second stay in Florence from 1512 onwards; and finally, during his stay in France from 1516 to 1519.

The theme of the "new city" or "ideal city" that emerged after the plague in Milan in 1484-1485 was the origin of his reflections on the field: in order to correct the problems of overpopulation of urban centers, he imagined a "two-level city" in which the management of water flows was studied in detail. He took up these ideas again when he was commissioned by François I in 1516 to think about building a new castle in Romorantin.

In this field, he benefits from the influence of the works of Bernardo Rossellino and Leon Battista Alberti. Nevertheless, he brings some quite innovative reflections on circulation and salubrity: streets and lanes; circulation and function of water; and well-being of the inhabitants.

There are several reasons why Leonardo da Vinci created cartographic drawings and they are linked to his activity as a civil and military engineer: for military purposes; for hydrographic surveys (reclamation of marshes, navigability of rivers and canals, irrigation systems, regulation of watercourses); and for topographic knowledge of northern and central Italy. Nevertheless, Leonardo's cartographic work was not put into practice.

His sources of inspiration are multiple, the first of which is the treatise on Geography by Claudius Ptolemy, dated from the middle of the second century, Paolo Toscanelli, whom he met and introduced to the work of geometry.

He produced two types of cartographic drawings: simple pen-and-ink drawings and colored maps (such as the representation of the Val di Chiana). However, these representations are considered works of art in themselves: in fact, during the Renaissance, cartography was often the work of great artists such as Leonardo da Vinci or Albrecht Dürer. The Plan of Imola, for example, is described by Daniel Arasse as Leonardo's "most impressive, most successful, most beautiful" map and, according to Frank Zöllner, as "the most important of Leonardo's cartographic drawings," "considered an incunabulum of modern cartography.

For a long time, Leonardo has been considered the creator of modern cartography: by the way he represented the orthogonal view of the map and by using tonal differences according to the altitude; then by his methodology when he used on the Plan of Imola a system of surveying, which used a central point corresponding to the center of the circle drawn on the map, allowing to measure with precision the dimensions of the buildings and the roads

Leonardo da Vinci was indeed an engineer in the sense of the term as it was used in his time: "inventor and builder of "machines" (complex machines and simple mechanisms) of all kinds and for all possible functions". His work thus consists in providing technical solutions to any civil or military problem. He paid constant attention to the field throughout his career, which resulted in drawn studies and long descriptions.

However, there is only one document that is reputed to list Leonardo da Vinci as a professional engineer in Milan. But it is undated and anonymous. Moreover, a cursory examination is sufficient to understand that Leonardo is only listed in a list of three names with the more generic qualification of "ingeniarius et pinctor", which corresponds to the title of artist-engineer, and not in the list of ducal engineers, which includes about ten names.

His first contact with the world of engineering was during his training in the workshop of Andrea del Verrocchio on the construction of the dome of the cathedral of Santa Maria del Fiore in Florence. In fact, the earliest traces of his interest in the field date back to 1475 with drawings of mechanisms already very elaborate.

Leonardo also inherited a tradition from Antiquity, which certainly continued with Filippo Brunelleschi and especially Francesco di Giorgio Martini, an engineer of whom Leonardo possessed and annotated a copy of one of his works.

Leonardo's originality lies in the constancy of his interest in engineering, the importance and variety of the subjects he studied, and above all his "technical inventiveness". This is particularly evident in the variety and richness of the documentation he left behind, the quantity of which is unparalleled among the engineers of his time. Moreover, although he drew inspiration from his predecessors, it was not possible for Leonardo to study an existing system without trying to improve it with his knowledge and intuitions. His objective in creating machinery is to create a complex object from the simplest and most traditional mechanisms possible: thus, even a critical researcher like Bertrand Gille recognizes that with the master "there is progress in each element of each machine".

However, it is to his activity as an engineer and inventor that Leonardo da Vinci owes most of his universal fame in contemporary times, and this, since the 19th century: according to a romantic vision, he would be both a genius inventor and a visionary whose creations would foreshadow what would only be invented several centuries later - only limited, for example, by the lack of a source of energy other than animal power.

Although he has to his credit some inventions and his inventiveness, contemporary research insists on the fact that, contrary to the legend that relates to his work, Leonardo's inventions are rather repeats of inventions or thoughts already envisaged by others - such as the diving suit or the parachute - or of methods of technical graphic representations, such as the exploded view. In fact, according to Pascal Brioist, Leonardo is profoundly a man of the Middle Ages and not a man of the future: deeply marked by his predecessors, he synthesizes all the knowledge of his time.

Traditionally, five fields share unequal shares of Leonardo's attention: weapons and war machines, hydraulic machines, flying machines, general mechanics and party machines. But several others can be added.

Leonardo da Vinci had a difficult start in the field of military engineering. Indeed, the inventions - mostly military - that he boasted of being able to build to Ludovico Sforza in a letter of motivation to arrive in Milan did not exist: either it was pure exaggeration, or he was only taking ideas from others, which was all the easier since he was leaving his territory, in this case Florence. In fact, he lists: bridges, scaffolding and stairs, tools for destroying walls and fortresses, siege machines, bombers and mortars, secret passages, tanks, weapons for naval battles, ships that could withstand bombs, in other words, all kinds of equipment that could be used both for the protection of the city and for a siege. The Milanese authorities did not let themselves be deceived, although the duchy suffered from a lack of engineers in this field.

His sources of inspiration were numerous, first among which was the treatise De re militari (1472) by Roberto Valturio, which he owned and annotated, but also the writings of Konrad Kyeser, Vitruvius, Leon Battista Alberti, but also, closer to him, Mariano di Jacopo, Francesco di Giorgio Martini, Le Filarète and Aristotile Fioravanti. Among the weapons he studied were crossbows mounted in batteries, a giant crossbow, mortars with explosive projectiles (around 1484-1488), a submarine with a spinning system that could pierce the hull of ships, an armored car chariot, a chariot with scythes designed to cut the hocks of soldiers and their horses in the early 1480s...

It was only after 1492 that he was taken seriously, after having trained with local military engineers. However, it was a rather theoretical subject for him and, in his descriptions to his potential sponsors, he readily boasted of the deadly nature of his inventions. However, he became particularly indisposed by the field after visits to the battlefields and ended up describing the war as "pazzia bestialissima" (a "bestial madness").

As the pinnacle of the quest for technical creation, the flying machine is the object of engineering research to which Leonardo da Vinci devoted the most time during his career: he devoted nearly 400 drawings, including 150 flying machines. It is one of the most famous reflections of the engineer, even if this work is known only recently.

Of course, Leonardo was not the first to take an interest in the subject, but he was the first to do so in such a constant, thorough and systematic way. Thus, one of his contemporaries, Giovan Battista Danti, is said to have built a machine that would have allowed him to make gliding flights over Lake Trasimeno around 1498. Although it is not strictly speaking a flying machine, Leonardo da Vinci studied the parachute, the drawing of which is a flagrant reworking of a drawing dated around 1470.

Leonardo experimented successively with three types of flying machines. The first is the "flying screw" - also referred to as the "flying propeller" by scholars - which, since its discovery at the end of the nineteenth century in the master's documents, has sometimes been attributed to him as the originator of the helicopter. However, it is a reworking of a drawing from Mariano di Jacopo's treatise De ingeneis, published in 1431. Moreover, this machine of almost 10 meters in diameter with an enormous mass would only be a play on the mind: in the commentary on his drawing, Leonardo notes that the object can certainly be made but in small dimensions, in cardboard and with a metal spring.

The second type of flying machine is the machine with flapping wings or ornithopter for which he decides that "there is no other model than the bat", it was to be moved by the only muscular force of its pilot. As his research progressed, he noticed that this was insufficient and added mechanical forces which, nevertheless, still did not provide enough energy. He thus turns in the years 1503-1506 towards a gliding machine

From 1505 onwards, he focused on fixed-wing machines, relying solely on ascensional forces. His glider has wings inspired by those of bats. He is reputed to have tried to fly as early as 1493 in Milan and then in April 1505 from Mount Ceceri, in Fiesole, a village near Florence. But these attempts are, according to historians of science, more of a legend.

The studies on flight and on the flying machine are the occasion of more or less conscious and more or less formulated discoveries: principle of action-reaction - theorized two centuries later by Isaac Newton -; a ratio weight-muscular power incomparably more favorable to the bird - which is determined four centuries later by Étienne-Jules Marey; principle of inverse proportionality between speed and section within the framework of the mechanics of the fluids; optimization of the center of gravity of a flying object. Finally, for his research, he observed and was inspired by the anatomy and flight of birds and, as such, according to Pascal Brioist, he is "the father of biomimicry".

In this field, Leonardo da Vinci possessed undeniable qualities: he proved to be an observant and imaginative mechanic and a brilliant draughtsman, even if his degree of skill is not known. Most of his innovations in this field were made in the 1490s.

His subjects of study are extremely varied: we find many automata, then in fashion, such as the spring-loaded automobile, the mechanical lion intended for the royal festivities in 1515 which made the admiration of his protectors; he also creates a drawing of a bicycle which we do not know if it is an autograph drawing or if it is the hand of one of his pupils. It may even date from the time of the transfer of the manuscript by French troops in 1796 to the Institut de France. Nevertheless, the machines on which Leonardo paid the most attention are - after the flying machines - the loom: he places the invention of the loom on the same level of importance as that of the printing press because it constitutes, according to him, "an invention more beautiful, more subtle, carrying better gains".

In this field as elsewhere, the master was inspired by his predecessors: Francesco di Giorgio Martini, Roberto Valturio. In fact, in studying winches and cranes, Leonardo places himself in the intellectual context of the engineering of his time, since these devices are the most studied and represented mechanisms in Renaissance treatises on machines. Most of these mechanisms were born from the mind of Filippo Brunelleschi.

In the field of general mechanics, Leonardo da Vinci was not the absolute precursor that the past has made him out to be: in fact, he mainly tried to improve what already existed and to solve problems of detail. Nevertheless, his real contribution lies in the search to mechanize and automate current operations in order to save time and energy and because it is a source of innovation. His thinking is such in this field that he is sometimes called by modern observers the "prophet of automation".

Lastly, he worked, like many of his contemporaries, to solve the problem of perpetual motion, but he quickly realized that this research was futile. He thus produced drawings of mechanisms in order to prove the impossibility by the absurd: "O speculators of perpetual motion, how many vain chimeras have you created in this quest? Go and take your rightful place among those who seek the Philosopher's Stone".

Hydraulics was one of Leonardo da Vinci's favorite areas of study from 1477-1482. But his work, in the 1490s, on the "Ideal City" in Milan, constitutes a founding enterprise in the field since the management of water in terms of flow constitutes the central point of his thinking. Another aspect of his reflection, he was interested in it during his stay in Venice in 1500 when the city was looking for solutions to defend itself from a possible invasion by the Turks: he proposed to flood the surroundings of the city-state as a means of defense. Then, during his stay in Rome, he studied the means of evacuating the stagnant waters of the Pontine marshes south of Rome. But the death of his patron, Cardinal Giuliano de' Medici, put a stop to the work.

The Codex Leicester (ca. 1504-1508), the most extensive and complete work of the master on the subject, deals exclusively with water in all its manifestations and was written while Leonardo was in Tuscany. Leonardo's research included topographical surveys, calculations, excavation projects, plans for locks and dams; he also considered hydraulic machines as sources of energy other than animal power.

Here too, he is part of a line of engineers such as Mariano di Jacopo (known as "Taccola"), who, in his technological treatise De Ingeneis, was already designing engineering works including siphon bridges, aqueducts, tunnels, Archimedes' screws or norias, and Francesco di Giorgio Martini, who designed a number of machines powered by hydraulic energy (pumps, fulling machines, saws or mills), and, finally, Leon Battista Alberti and his De Re Aedificatoria, which focuses on the power of waterways and whirlpools.

Leonardo's work on hydraulics made his skills in this field recognized by his contemporaries. François I charged him with the development of the river as part of the king's urban planning project in Romorantin.

His activities led him to study various projects, among which was the defense of Venice from a possible Turkish attack by flooding land areas with the waters of the Isonzo River. Contrary to the widespread idea that his studies never lead to concrete realizations, it seems that some tests were carried out with success since in 1515 and 1515, he evokes them in his notes.

Between 1493 and 1494, he wrote the beginning of a Treatise on Water in which his ambition was to set up a methodology combining theory and experience, or even to give precedence to theoretical knowledge over practice: thus, he conducted experiments with colored water and models with glass walls, from which he drew conceptual conclusions.

In fact, his contributions are undeniable in the field: he was the first to systematically study the formation of river beds. In the same way, no one before him articulated to such an extent, "as in Milan, a hygienic urbanistic enterprise and a planning of the development of the region based on the control of water".

However, he remains a son of his time, with his erroneous theories. Thus, Bertrand Gille notes that "if Leonard indeed possesses knowledge on the nature and on the virtual power of water vapor, he arrives, after very correct views, at total aberrations. In one passage, he shows us the origin of rivers in volcanic heat.

The thought of Leonardo da Vinci

Leonardo was taught in the so-called abbaco schools, where practical instruction was given, particularly in applied mathematics, intended for merchants. The Rule of Three was taught, which was applied to a succession of analogies between several examples treated. A complementary moral and religious education was given, consisting of commented readings of texts such as novels of chivalry or various writings in the vernacular. Leonardo did not receive the teaching of the scuole di lettere preparing him for the university, he learned neither classical Latin nor ancient Greek and the reading of the authors of Antiquity was accessible to him only through rare translations.

Faced with the mockery of the men of letters Léonard claims to be a "man without letters" and affirms a culture of direct experience, a mixture of empiricism which frees itself from the pre-established theorems and of naturalism for which all that exists can be explained by natural causes or principles. He distrusted the "lying sciences" and, more indirectly, theology, preferring to deduce the theory from experience: "first, I will carry out an experiment before going any further, because I intend to first allege the experience, and then to show by reasoning why this experience necessarily produces this result". But, from 1490 onwards, Leonardo consumed a great deal of books; he became aware of the importance of Praxis and of the need for experience to evolve within a theoretical framework: observation and theory are complementary, if the former is the source of the latter, the latter must be validated by other observations.

Léonard dreams of a total synthesis of knowledge giving access to a form of grace. This brings him closer to the Neoplatonists with whom he undoubtedly had some contact, but, being ignorant of Latin and Greek, he could not really know them. However, like them, his thought is built around an analogy between the human organism and the structure of the world, the microcosm and the macrocosm. Until the early 1500s, this way of thinking guided him in all his research: he used this methodology, for example, to develop his anatomical research, to draw inspiration from the whirlpools of water to design the hair of his characters, to study his flying machines by observing the flight of birds, or to draw up the plans of a city that he considered to be a human body that would need a "doctor-architect" to heal it. But, towards the end of his life, this search for grace was thwarted by a growing pessimism in which, in his vision of the world, nature hinders the work of men by its destructions.

Leonardo's handwriting and the hatching of his drawings indicate that he is left-handed: this is the best way to attribute drawn works to him. Although he was able to write right side up - he wrote without inversion to sign and annotate notarial contracts - and probably painted with both hands, his handwriting is often specular, so scholars have long believed that he encrypted his writings to hide them from curious eyes. This is not the case: the normal way of writing for a left-handed person presents the risk of staining the paper by sliding his hand over the still wet ink; this is the reason put forward by Leonardo's friend, the mathematician Luca Pacioli, who also explains that his writings are easily readable by simply using a mirror. Finally, a written note dated 1473 proves that he had been writing in this way since his youth in order to record the most banal subjects.

The 15th century saw an intellectual and social split between theoretical and practical science. Leonardo is a striking example of this: in the inventory of books that he possessed in 1505, researchers do not find any work of philosophy, history, theology or literature, but rather works of popularization of philosophy or science.

To these two sciences correspond two scripts: the humanistica and the mercantesca. The latter is used for the translation of texts in vulgar language (Dante, Boccaccio...), for the personal diaries and for the chronicles. This writing is also of use in the XVth century among the artists of botteghe (workshops) like Andrea del Verrocchio. Popular books such as small technical treatises or cookbooks are also written in mercantesca and are often accompanied by drawings as on the notebooks of Leonardo. There is also another form of writing: the lettera mancina, "left-handed letter", freer, more spontaneous and used for oneself.

The art historian Catherine Roseau notes that it could be that Leonardo - who advised his students to look at their paintings through a mirror in order to see them with fresh eyes - found in this form of writing his own way of belonging to the world, as if he saw himself as the inverted microcosmic image of the macrocosm of the world. Through the use of specular writing, Leonardo could feel like a mirror held up to the world, presenting it with a more imaginary reality.

The psyche of Leonardo da Vinci

Compared to other historical figures of his time, Leonardo leaves behind one of the most consistent testimonies that a historian could possess about the cerebral activity of a human being, but almost nothing about his emotions, his tastes and his feelings. The snippets of sentences that hint at a more subjective feeling are very rare, atypical or incomplete. For example, the death of his father is commented on in only two brief notes, one of which is written in normal handwriting, from left to right, whereas his handwriting is usually reversed. Leonardo does, however, write a few fables that allow us to understand his state of mind with regard to this or that aspect of his life.

Daniel Arasse underlines the contradictory personality of Leonardo: a lover of nature and life, but fascinated by the sounds of war; a kind, attractive and affable man, a man of the court and yet an inveterate solitary researcher for whom grace and knowledge are one and the same (see above the allegory of the Woman Standing in a Landscape), certain aspects of his work, such as his grotesque characters - which he describes as "ideal uglinesses" -, his dragons, his allegories or some of his prophecies, seem to indicate that he is inhabited by dark ideas about humanity as well as about himself. His choice of vegetarianism seems to have its source in this, and the prophecies and drawings of floods sweeping away all traces of human activity increase towards the end of his life. He even came to create a real partition between his private emotions and his public life and to pass for a sort of whimsical magician, often the organizer of their parties and shows, as well as for a wise magician so dear to the Neoplatonists. But this magician seems for Arasse to be a kind of mask, a persona, that Leonardo the "man without image" - even painting can leave nothing of the identity of the artist while this one must intimately identify himself with his subject - that doesn't seem to him to be anything else than a "wandering form" chosen "as a screen for himself, that of a philosopher artist, lover of an original beauty, demiurge of fictions, investigator of all things, put aside God".

The sad tale of a country stone probably illustrates one reason for Leonard's isolation. Surrounded by colorful flowers, attracted by its city sisters, the stone rolls down the sloping path to the city where it is crushed by passers-by, dirtied by animal droppings and polished by the various movements of the city. This fable seems to express that Leonardo misses the peaceful childhood life he led with his adopted parents in the Vinci countryside. Even if he is attracted by the lights of the courts and the cities in which he organizes shows and whimsical parties Leonardo seems to look, like stone from afar and with nostalgia, "this place of solitude and serene peace" that he left to live "in the city, among people of infinite malignity".

Leonardo's notebooks contain many maxims celebrating solitude and the countryside: "Leave your family and friends, cross mountains and valleys to join the countryside" or "as long as you are alone, you are your own master". In fact, for the painter the pictorial activity requires to be carried out well, "a profane form of contemplative life" and insists several times on the obligation to be alone in order to meditate on his art: "the painter must be solitary, to consider what he sees, to speak with himself". All this, even if drawing in company remains beneficial in order to take advantage of the benefits of emulation and Leonardo spends most of his life in Florence, Milan and Rome, in contact with the crowded centers of creativity and commerce, generally surrounded by his students, companions or in search of patrons.

Leonardo da Vinci had many friends who were well known in their respective fields and who had an important influence on the history of the Renaissance. These included the mathematician Luca Pacioli, whose book De divina proportione he illustrated; Caesar Borgia, in whose service he spent two years; Lorenzo de' Medici and the physician Marcantonio della Torre, with whom he studied anatomy. He met Michelangelo, whose rival he was, and showed an "intimate connivance" with Nicolaus Machiavelli, the two men developing a close epistolary friendship. Leonardo does not seem to have had close relationships with women, except with Isabella d'Este, for whom he painted a portrait at the end of a journey that took him to Mantua. This portrait seems to have been used in preparation for a painting, now lost. He was also a friend of the architect Jacopo Andrea da Ferrara until the latter's execution in Milan in 1500.

During his lifetime, his extraordinary inventive abilities, his "exceptional physical beauty", his "infinite grace", his "great strength and generosity", and the "formidable breadth of his mind", as described by Vasari, aroused the curiosity of his contemporaries. But beyond his friendships, Leonardo kept his private life very secret. His sexuality is often the subject of studies, analyses and speculations that began in the middle of the 16th century and were revived in the 19th and 20th centuries, notably by Sigmund Freud in A Childhood Memory of Leonardo da Vinci, published in 1910, for which several exegetes demonstrate the existence of certain inconsistencies, notably by Meyer Schapiro in 1956 and Daniel Arasse in 1997. The latter sees, in the story analyzed by Freud and in the fable of the Guenon and the bird (also written by Leonardo), a fear of maternal suffocation and an acceptance of his situation of illegitimate child.

"Finding a nest of little birds, the guenon was very happy; they were able to fly, she kept only the little one. Full of joy, she took it in her hands and went to its nest and began to consider the birdie and kiss it. And, out of ardent tenderness, she kissed it so much and embraced it, so that she choked it. This is said for those who, having wrongly corrected their sons, these end badly."

- Leonardo da Vinci, Codex Atlanticus folio 67 r-a

Unlike Michelangelo, a pious man divided between asceticism and self-imposed celibacy, Leonardo was not a practicing Catholic and did not feel any torment at the idea of having male companions, among whom was one of his turbulent students: Gian Giacomo Caprotti, known as Salai. In the Italy of the Quatrocento and more particularly in Florence, love between men was not socially rejected, even if the practice of sodomy remained severely repressed. Francesco Melzi, Leonardo's pupil and adopted son whose gentle beauty resembled that of Salai, wrote that Leonardo's feelings were a mixture of love and passion. The role that Leonardo's sexuality plays in his art seems to be very present especially in the androgynous and erotic impression that is evident in many of his drawings and in his paintings Bacchus and St. John the Baptist. However, the supposedly platonic and courteous, even repressed, homosexuality of the artist remains hypothetical. He even seems to have had heterosexual relations with a courtesan named Cremona. In any case, it remains very difficult to pronounce on the morals of Leonardo who, moreover, declares that he feels repugnance for coitus.

"The act of coitus and the members that contribute to it are of such hideousness that, were it not for the beauty of the faces, the ornaments of the actors and the restraint, nature would lose the human species."

- Leonardo da Vinci

Leonardo is reputed to be a vegetarian. But this dietary choice, generally attributed to the gentle artist who buys caged birds on the markets in order to set them free as described by Gorgio Vasari, is motivated by stranger and more terrible images: he violently condemns human nature for the atrocities that its ancestral carnivorous character can cause. For him, man, "King of the wild beasts" whose gullet is a "tomb for all animals" is, unlike the animal, capable of killing his fellow creatures for pleasure: "but you, besides your children, devour father, mother, brothers and friends; and that is not enough for you, you go hunting in the territory of others, taking other men, mutilating their virile limbs and testicles, fattening them up and passing them through your own throat". But he also uses expressions such as "animals that are castrated", "animals that are used to make cheese" and "dishes cooked with sows" to describe this cannibalism. This choice of food seems to be confirmed by a letter that the explorer Andrea Corsali addresses from the Indies to Giuliano de' Medici: "They do not feed themselves with food containing blood, and even between them they do not allow that one harms any animated thing, like our dear Leonardo da Vinci".

The art critic Alessandro Vezzosi recalls, however, that Leonardo practiced vivisection and that he sometimes bought meat. Moreover, the painter makes the same remarks about the fruits of the earth: "Nuts, olives, acorns, chestnuts and others, many children will be torn from their mother's arms, with merciless blows, and thrown to the ground and mutilated" (Codex Atlanticus, 393 r.).

"Man, if you are really, as you describe, the king of animals, - I would have said rather the king of brutes, the greatest of all!  - why do you take your subjects and children to satisfy your palate, for reasons that turn you into a tomb for all animals? Doesn't Nature perhaps produce simple food in abundance? And if you cannot be satisfied with such simple foods, why do you not prepare your meals by mixing them together in a sophisticated way?

- Leonardo da Vinci, Quaderni d'Anatomia II 14 r

To the sources of the legend

The main period sources that concern Leonardo da Vinci are, on the one hand, his notebooks that he wrote throughout his life and, on the other hand, three documents that are almost contemporary to him: a chapter from The Lives of the Best Painters, Sculptors and Architects by the painter Giorgio Vasari; the Anonimo Gaddiano an anonymous manuscript dated in the 1540s; and Libro dei sogni written in the 1560s by Giovanni Paolo Lomazzo whose painting master was a former student of Leonardo. In addition, Leonardo's contemporaries Antonio Billi, a Florentine merchant, and Paul Jove, an Italian physician and historian, wrote two shorter accounts.

His research sheets, which have survived to the present day, represent some 7,200 pages of notes and sketches. However, they constitute only a portion of the quantity of documents that the master left behind at his death. Their collection in various codices was collected, organized and assembled by various enthusiasts, sometimes long after the painter's death. Written throughout his career, they are made up of notes, mathematical calculations, flying machines, theatrical props, birds, heads, angels, plants, weapons of war, fables, riddles, sketches and various reflections; moreover, all these notes appear in them following the thread of thought, as if guided by chance alone. These notebooks are an enormous source of information on which researchers rely to try to understand the "feverish, creative, manic and sometimes exalted" mental functioning of the master.

The Vite by Giorgio Vasari (born in 1511, eight years before Leonardo's death), was published in 1550. The first true work of art history, it was revised and completed in 1568 on the basis of more detailed interviews with people who had known Leonardo. But Vasari was a Florentine who was proud of his city, and he offered an almost dithyrambic portrait of Leonardo, who was described, along with Michelangelo, as one of the fathers of an artistic "renaissance" (the first written trace of this term). The book is a mixture of verified facts and hearsay, hagiography and anecdotes intended to strike a chord.

The Anonimo Gaddiano (the title of which comes from the name of the family that first owned it) is an anonymous manuscript dating from around 1540, which, like the Vite, also includes picturesque details, both embellished and accurate, about Leonardo.

The Libro dei sogni, finally, is an unpublished manuscript written by Giovanni Paolo Lomazzo in which he gives important information about Leonardo - and, in a very loquacious way, about his sexual orientation - from interviews with one of the master's pupils.

From history to myth

Historically, Leonardo da Vinci represents the ideal figure of the artist-engineer, that is to say, the universal spirit of the Renaissance period, seen as a character between Faust and Plato, who dedicated his life to the search for knowledge. This image is based on the image of the universal man of the Renaissance, described by the Anonimo Gaddiano in his formula, "He was so exceptional and universal that he can be said to have been born of a miracle of nature", and as the contemporary public sees him. In 1965, the art critic Liana Bortolon (it) praised his genius in her book The Life and Times of Leonardo: "Because of the multiplicity of his interests, which led him to question all areas of knowledge, Leonardo can rightly be considered the universal genius par excellence, with all the disquieting connotations that the term has. Faced with such a genius, anyone is as uncomfortable today as they were in the 16th century. Five centuries have passed, but we still look at Leonardo with admiration.

Such a perception corresponds to the image that Leonardo tried to build for himself during his lifetime: he wished to make his mark on history and therefore sought to magnify his art, to gain freedom from his patrons and to multiply his scientific and engineering research - especially in the military field. In fact, this idealized vision was contemporary to him: his fame was such that his arrival at the court of King Francis I conferred immense prestige on the latter, and the legend that describes a king holding a dying Leonardo in his arms is a symbol of this. Later, in his Vite, Giorgio Vasari introduces his chapter on Leonardo da Vinci with this praise:

"Heaven in its goodness sometimes gathers on a mortal its most precious gifts, and marks with such an imprint all the actions of this privileged person that they seem to testify less to the power of human genius than to the special favor of God. His prodigious skill made him triumph easily over the greatest difficulties. His strength, his skill, his courage had something truly royal and magnanimous about them; and his fame, brilliant during his life, grew even greater after his death."

It is mainly to his paintings that Leonardo owes his fame, "his reputation as a painter. Thus, when he arrived at the Milanese court of Ludovico Sforza in 1482, it was his talent as an artist that was first recognized since he was received with the title of "Florentine Apelle", in reference to the famous Greek painter of antiquity. This title gave him the hope of finding a position and thus receiving a salary instead of simply being paid by the work. Later, Vasari emphasized the fact that Leonardian art had made it possible to "draw a line under the Middle Ages and its art alien to nature", as it alone had made it possible to raise pictorial art to a higher level. Reinforcing this judgment, Baldassare Castiglione, author of the Book of the courtier, wrote in 1528: "Another of the greatest painters of this world, who looks from above his art in which he is without equal".

Supporting this aura, the first bilingual French-Italian edition of his Treatise on Painting (Trattato della pittura di Leonardo da Vinci), was published in Paris in 1651. His paintings were not studied at the time, only being rediscovered, as were his Notebooks: the first notebook to be studied corresponds to unpublished excerpts from the manuscripts of the Codex Atlanticus, which the Italian physician Giovanni Battista Venturi transcribed in 1797 in Paris.

Later, his figure as an artist was praised by writers such as Johann Heinrich Füssli in 1801, for whom "when Leonardo da Vinci appeared with a splendor that distanced the usual excellence: composed of all the elements that constitute the essence of genius. This vision is confirmed by authors such as Théophile Gautier, who described him in 1857 as one of those artists who "are said to have inhabited superior and unknown spheres before coming to be reflected on the canvas", Sar Péladan or Walter Pater, who drew up "a mysterious and disquieting portrait", or, finally, Charles Baudelaire, who, in "The Lighthouses" in his collection of poems Les Fleurs du mal, celebrates the ambiguity of the smiles of the characters in his paintings:

Finally, the famous art historian Bernard Berenson wrote in 1896: "Leonardo da Vinci is the only artist of whom it can be said with perfect accuracy: everything he touched was transformed into an object of eternal beauty. Whether it be the cross-section of a skull, the structure of a weed, or a study of muscles, he has, with his sense of line, light, and shade, forever transformed it into values that communicate life; and all without meaning to, for most of these magical sketches were thrown away to illustrate a purely scientific thought, which alone absorbed his mind at the time."

Nevertheless, if his contemporaries recognize the quality of his art, they emit all the same reserves because of the incompleteness which characterizes it: Baldassare Castiglionne thus regrets that he "despises an art where he excels and is infatuated with philosophy; and he has in this field of the ideas so strange and so many chimeras that he would not know how to paint them with his painting".

The scientific and technical fields have undoubtedly completed the forging of the legend of an omniscient and absolute Leonardo among the contemporary public: besides the painter and draughtsman of immense talent, Leonardo is indeed perceived as an outstanding technician and the visionary inventor of modern technological objects, such as the airplane, the helicopter, the parachute, the submarine, the automobile or the bicycle.

However, the discovery, first by scientists and then by the general public, of this aspect of his career is relatively recent, since it only dates back to the turn of the 18th and 19th centuries with the rediscovery of the more than 6,000 sheets of paper bearing his research - 12,000 pages - that Leonardo left behind. Initially forgotten after the death of the master in 1519, his scientific and technical activity was somewhat rediscovered with the partial reappearance in 1797 of his notebooks, compiled and published by Giovanni Battista Venturi. The quantitative importance of these notes made him quickly perceived as an "absolute and solitary precursor who, with centuries of advance, would have preceded the humanity in all the fields of the activity and the knowledge". In the middle of the 20th century, the historian of science and technology Bern Dibner made him a "prophet" of engineering, "the greatest engineer of all time", his work being that of a visionary all the more deserving because he was evolving in a context where technologies were still rudimentary and energy sources were still relatively limited. In 1866, Hippolyte Taine wrote: "There can probably be no example in the world of a genius so universal, so capable of blossoming, so filled with nostalgia for the infinite, so naturally refined, so far ahead of his own century and the following centuries. In 1895, Paul Valéry praised Leonardo's thinking: "I propose to imagine a man whose actions would have appeared so distinct that if I were to suppose a thought for them, there would be none more extensive. And I want him to have a feeling of the difference of the things infinitely lively, whose adventures could well be named analysis. I see that everything orients him: it is to the universe that he always thinks, and to rigor (obstinate rigor, motto of L. de Vinci ". Finally, Bernard Berenson affirms that "however great he was as a painter, he was no less renowned as a sculptor and architect, musician and improviser, and that all artistic occupations, whatever they were, were in his career only moments taken away from the pursuit of theoretical and practical knowledge. It would seem that there was scarcely a field of modern science that he did not either foresee in vision or clearly anticipate, nor was there even a field of fruitful speculation in which he was not a free agent; and as if there was hardly any form of human energy that he did not manifest. Today, the perception that the general public has of the artistic, scientific and technical work of the master is sometimes so far from the historical reality that some observers consider that "the myth has taken precedence over history".

Leonardo da Vinci beyond myth and legend

The image of Leonardo as an artist has suffered little from contemporary criticism and science: his Treatise on Painting was not published until 1651; Leonardo was then known only as an artist until the 18th century. In addition, his documents were partially compiled in 1919 by Luca Beltrami and later by Gerolamo Calvi, but it was not until 1998 that all of his codices were fully published. Thus, from the end of the 19th century, modern art history "which relies on sources, documents and facts, and establishes coherent criteria" is especially concerned with re-evaluating on these scientific bases the attributions to the painter of works that the art historians of the early 19th century had too easily granted to him in order to please the museums seeking to take advantage of the painter's fame in order to attract the public. It is thus only from the years 1870-1880 that the catalog of the painted works of the master stabilizes scientifically at a number of 17 to 19 paintings. However, the art of the master is not questioned by critics and observers: his drawing is still considered inimitable, with a perfect mastery of the techniques at his disposal; as for his pictorial work, it is still recognized among the jewels of Western art, bearing formal innovations and demonstrating undeniable technical qualities.

The figure of the painter is still marked by an almost divine aura in the public imagination and is hardly questioned by art historians and critics. The artist's fame is such that exhibitions devoted to him attract crowds and his works sell for exorbitant sums: thus, on November 15, 2017, his painting Salvator Mundi, whose authenticity recognized in 2005 is often questioned, is sold in New York at Christie's for the sum of $450.3 million, making it the most expensive painting in the world and in history.

If the figure of the artist remains praised, that of the scientist and engineer, on the other hand, is strongly relativized in the contemporary era. His posterity in these fields was built up in fits and starts, according to the diffusion, the oblivion and then the rediscovery of his writings as well as those of his predecessors and contemporaries: if he benefits from a real recognition on behalf of his contemporaries, his work undergoes a relative oblivion after his death; a recognition of his qualities, excessive and late, is born at the time of the rediscovery of these in the XIXth century; this recognition is strongly doubted in the middle of the XXth century then is relativized at the beginning of the 1980s.

Thus, the second half of the 20th century saw a strong questioning and even a disavowal of his qualities in engineering following, in particular, the work of Bertrand Gille for whom "the technical science of Leonardo da Vinci is extremely fragmentary, it does not seem to go beyond a certain number of particular problems, treated very narrowly". It appears that many of Leonardo's sketches, notes and treatises are not original inventions, but the result of a compilation of older knowledge. Thirdly, with the 1980s, we witness a return to a balance between the two extremes of an idealized figure and a completely banalized figure.

In the 1980s, Leonardo da Vinci's work was put back into context: it appeared that many of the master's inventions were in fact "fresh proposals and reinterpretations of solutions coming from an already elaborate and well-articulated technological fabric", but if this appropriation was indeed effective, it was carried out in a systematized manner. To make matters worse, it is precisely his most advanced and revolutionary work that is the least known. In the field of anatomy, for example, Leonardo's work was not rediscovered and published until 1890, despite the work of sorting out the mass of documents that Francesco Melzi carried out in the fifty years following the painter's death, and while Pompeo Leoni was completing the organization of the loose leaves that he assembled in the form of a codex. However, despite their qualities, these works seem to be perceived only as curiosities.

The re-evaluation of Leonardo's work and contribution in the context of Renaissance engineering allows us to look at "Leonardo as one of the main witnesses of his time and use his manuscripts to offer a more complete vision of the technological panorama of the Renaissance". Therefore, according to the historian of science Alexandre Koyré, Leonardo da Vinci should not be seen as a "technician" but rather as a "technologist", thus underlining "his propensity to consider technique far beyond the exclusively empirical, i.e. theoretical, point of view". Lastly, for Pascal Brioist, if one cannot speak of an experimental approach but of a proto-experimental approach concerning Leonardo's method, it is all the same a "radically new approach". Nevertheless, one should not see in Leonardo's experiment an identical approach to that of the laboratory such as it was set up by Robert Boyle in the 17th century but remains based on the workshop where the proof is sought only in materiality; in the same way, he proposes thought experiments which are not based on an experimental protocol.

Nevertheless, this scientific knowledge does not prevent the survival within the general public of the image of "a brilliant painter, an omniscient scientist, the inventor of many technologies of our time, but also the initiate of the secrets of all civilizations".

Exhibitions and museums

According to this perception, the current fame of Leonardo da Vinci is such that he has become "a label, a consumer product, a cultural icon" that many museums cannot do without.

Numerous important exhibitions are offered to an ever-growing public. They can be general, such as the one organized from October 24, 2019 to February 24, 2020 on the occasion of the 500th anniversary of his death at the Louvre Museum in Paris, bringing together a large number of masterpieces (including ten of his paintings) attributed to him, as well as his notebooks, and attracting more than one million visitors. They can also be thematic: devoted to his drawings, from May 5 to July 14, 2003, at the Louvre in Paris; to his drawings of the human body, at the Metropolitan Museum of Art in New York, from January 22 to January 22, 2003; to a particular work, such as around the painting of Saint Anne in Paris at the Louvre Museum, from March 29 to June 25, 2012; to his technological and architectural work at the Montreal Museum of Fine Arts from May 22 to November 8, 1987.

In addition, many museums devote permanent exhibitions to the master, such as the Museum of Science and Technology Leonardo da Vinci in Milan, which has a gallery dedicated to the master, or are entirely dedicated to him, such as the museum of the Château du Clos Lucé in France, or the Leonardo da Vinci Museum in Vinci.

Writings of Leonardo da Vinci

The form of the supports on which Leonardo writes his texts varies from one to the other, the objective pursued or the availability of the paper controlling the format: they can be loose sheets as well as notebooks, small or big, that he always carries with him to take notes; moreover, these documents are marked by the plethoric and disordered character of their contents. The analysis of this one allows to know the method of work of their author: "he assembles them with observations, questionings and judgments, reports of discussions and new experiments . He proceeds by hypotheses and interrogations. The backtracking, underlining, additions and deletions that interrupt the flow of the sentences attest to the extraordinary immediacy of the writing and the drawings. Leonardo wrote his scientific, technical and artistic works (including his studies for his paintings and sculptures) but also notes on the events of his life ("On July 9, 1504 at 7 a.m. died Ser Piero da Vinci"), including dates and times, his moods, his thoughts (Manuscript H includes his motto "Rather death than defilement"), fables or philosophical meditations.

He bequeathed all of these writings to Francesco Melzi, his trusted friend and favorite student. Melzi preserves them so jealously that Giorgio Vasari, in his Vite, states: "he keeps and hoards the manuscripts as if they were relics". Desperately trying to sort through the mass of these documents, he only managed to reconstruct the Treatise on Painting planned by his master. At his death in 1570, his son Orazio left them abandoned. The collection was coveted by relatives of the Melzi family: Lelio Gavardi took 13 notebooks with him in the hope of selling them, but when this failed, he gave them to one of his friends, Ambrogio Mazzenta. In 1582, learning of the Melzi's lack of interest in all these documents, Pompeo Leoni, an Italian sculptor in the service of Philip II of Spain, successfully decided to acquire them, as well as part of the 13 notebooks held by Mazzenta: he transferred them in 1590 to Madrid where he worked. Upon his death in October 1608, his son Miguel Angel inherited them, and an inventory taken in 1613 counted 16 of the master's books. In 1622, some of the notebooks were purchased by Galeazzo Arconati, who donated them in 1636 to the Ambrosian Library in Milan. Around the beginning of the 1630s, another part of these notebooks was bought by Thomas Howard, 14th Earl of Arundel, brought to England and formed the Arundel Codex; it is possible that he also acquired a collection that would form the Windsor Codex - without researchers being convinced of the actual path of this codex. Finally, only two of the notebooks remain in Spain in the royal collections, where they were rediscovered in 1966.

Ultimately, only a portion of Leonardo's manuscripts - about 40 percent of his writings by some estimates - are preserved and scattered among Paris, Milan, London, Turin, Madrid, and Los Angeles, but the recent rediscovery of those in Madrid gives researchers hope that more will be found.

The Codex Arundel, kept at the British Library in London, was begun in 1508 while the master was still living in Florence. It is a collection of notes taken in no particular order, and although Leonardo was interested in physics, optics, astronomy and architecture, he was especially interested in mathematics. Purchased by Lord Arundel from Pompeo Leoni, and "unlike many other Leonardo manuscripts", "it was not made up of separate sheets, but of fascicles that have for the most part retained the structure intended by their author".

The Codex Atlanticus is kept in the Ambrosian Library of Milan. It is one of the notebooks transferred in 1636 to the Ambrosian Library of Milan together with the notebooks that later belonged to the Institut de France; like the latter, it was seized by Napoleon in 1795 and deposited in the Bibliothèque Nationale, but was recovered by the Ambrosian Library at the fall of the Empire in 1815. It is the largest collection of Leonardo's manuscripts and covers a period of forty years of the master's life, from 1478 to 1519. All fields are covered: physics, mathematics, astronomy, geography, botany, chemistry, war machines, flying machines, mechanics, town planning, architecture, painting, sculpture and optics.

The Forster Codex, kept at the Victoria and Albert Museum in London, is composed of 5 manuscripts bound in 3 notebooks. It passed into the collection of Earl Lytton from that of Pompeo Leoni, and belonged to John Forster - from whom it takes its name - who bequeathed it to the collections of its current owner in 1876. It covers the years 1487 to 1505. The subjects covered are mainly hydrology and hydraulic machines, topology and architecture.

The Leicester Codex, formerly known as the Hammer Codex, began at the transition between Florence and Milan in 1506 and ran until the 1510's. Its history is linear: around 1690, it was acquired by Giuseppe Ghezzi who sold it in 1717 to Thomas Cook, the future Earl of Leicester; it was then acquired in 1980 by Armand Hammer; Bill Gates acquired it in 1994 at a new auction. The 18 double-sided sheets that make up the book are mainly concerned with water, but also with astronomy.

The Codex Trivulzianus is kept in the Trivulzian Library in the Sforza Castle in Milan. In 1632 it was bought by Count Galeazzo Arconati, who donated it in 1637 to the Ambrosiana Library, and then, after a period of disappearance, it was sold in 1750 to the Trivulzio family. It was originally composed of sixty leaves, some of which have now disappeared. It is dated around 1487, the beginning of the master's career. It contains numerous studies of caricatures as well as architectural sketches; moreover, its particularity is to include lists of words in Latin - Leonardo's attempt to develop his mastery of vocabulary, particularly scientific vocabulary, in this language.

The Codex Madrid consists of two volumes, the first written between 1490 and 1499 and the second between 1503 and 1505, and is kept in the National Library of Spain in Madrid. Having been purchased from the heirs of Pompeo Leoni by a Spanish art collector, Don Juan de la Espina, with the aim of offering them to the King of Spain. They arrived in the royal collections in 1712, but were lost for a time due to referencing errors, only to be rediscovered 252 years later, in 1966. Codex Madrid I is essentially from the 1490s but is reworked in 1508, which suggests that it is in fact made up of two independent parts; it is mainly concerned with mechanics, especially clock-making, and the care taken with it indicates that it may be the matrix of a draft treatise on the subject. The Codex Madrid II is itself made up of two parts: the first, corresponding to a notebook dating from the years 1503-1505, deals with hydrology and military engineering, while the second, a notebook dating from around 1491-1493, is mainly concerned with the construction of the Sforza Monument.

The Codex on the Flight of Birds, also known as the Turin Codex, is kept in the Royal Library of Turin following its acquisition through the Sabachnikoff donation by the Italian royal family in 1893. Composed of 18 leaves, dating from around 1505, it focuses particularly on the problem of bird flight, which Leonardo deemed necessary to study in order to improve his flying machine; the codex also contains a few marginal architectural sketches, diagrams and drawings of machines.

The Windsor Codex, consisting of two hundred and thirty-four leaves dating from 1478 to 1513-1515, was purchased by Lord Arundel from Pompeo Leoni and entered the British royal collection around 1690. Purchased by Lord Arundel from Pompeo Leoni, it entered the British royal collections around 1690. Composed mainly of drawings devoted to anatomy (about 200 drawings), it covers about thirty years of the master's life. It also includes a smaller number of drawings of animals (especially horses) and landscapes (about 60 sheets).

The Manuscripts of the Institute: manuscripts A, B, C, D, E, F, G, H, I, K, L and M. The notebooks transferred in 1636 to the Ambrosian Library in Milan were seized in 1795 by Napoleon Bonaparte and transferred to the Institut de France where they still remain (Manuscrits de l'Institut, numbered A to M): following the fall of the Empire in 1815, all the goods seized by the regime in foreign lands were returned, but the small notebooks of the Institut, neither claimed nor located, were simply forgotten by the victors. Only the notebook that had been stored in the National Library, the Codex Atlanticus, was returned to Milan. They form a set of 12 notebooks of reduced format and "having kept the structure and composition that Leonardo had given them". Considered in chronological order, the manuscripts are composed as follows

The Treatise on Painting is not, strictly speaking, a work by Leonardo da Vinci but a compilation of his writings on the subject - writings that he intended to organize into a treatise from the 1490's. Having inherited all of Leonardo's documents, Francesco Melzi endeavored until his death to reconstitute the work planned by his master. This manuscript by Francesco Melzi is kept in the Vatican Library under the reference Codex Urbinas latinus 1270. The first bilingual French-Italian edition is based on this Codex Urbinas latinus 1270 and was published in Paris in 1651.

Nevertheless, this version of the Treatise suffers from defects that have been recognized for a long time and that Nicolas Poussin described thus in 1696: "I do not believe that one should bring to light this Treatise of Léonard which, to say the truth, is neither in good order, nor sufficiently well digested".

In 1987, André Chastel published a renewed and recontextualized compilation of these writings of the master, recognized by art historians for its quality.

Leonardo da Vinci in popular culture

A phenomenon of exhibitions, Leonardo is also a phenomenon of publishing. There are so many scientific books devoted to him that it is impossible to draw up an exhaustive list; likewise, the novels in which his figure is portrayed, such as the 2003 bestseller The Da Vinci Code, a novel that combines historical facts and scriptural artifice. Dan Brown then gave a new impetus to the interest in Leonardo and relied on the controversial essay The Sacred Enigma written in 1982 by British journalists Henry Lincoln, Michael Baigent and Richard Leigh. The novel was adapted into a film by Ron Howard in 2006 and grossed $757 million, making it one of the most successful films ever.

Similarly, the figure of the Florentine master is represented and used in other art forms so extensively that it is not possible to list them all: in television series (Leonardo in 2022), comic books (Leonardo, a humorous series by Bob de Groot and Turk) or video games (The Secrets of Da Vinci: The Forbidden Manuscript by Kheops Studio in 2006).

In France, in 2015, 94 schools were named after Leonardo, which is a rare occurrence for a foreign personality.

Sources

1. Leonardo da Vinci
2. Léonard de Vinci
3. Dans un mémorial, Antonio da Vinci note ainsi la naissance de Léonard, son petit fils : « Un petit-fils m'est né, fils de mon fils Ser Piero, le samedi quinzième jour d'avril à trois heures de la nuit. Il a reçu le nom de Lionardo » (« Nachue un mio nipote figliulo di Ser Piero mio figliulo a di 15 daprile in sabato, a ore 3 di notte. Ebbe nome Lionardo »)[2]. À cette époque en Italie, le jour commence à la tombée de la nuit de la veille : le jour de la naissance de Léonard tombe donc le vendredi 14 dans le système de décompte des jours contemporain[1].
4. ^ 23 aprile secondo il calendario gregoriano.
5. ^ La definizione di "uomo universale" è stata contestata da Benedetto Croce, il quale ha rilevato come fosse diffusa presso i contemporanei la fama di apoliticità di Leonardo per il suo noto disinteresse per gli affari pubblici. Questo aspetto della personalità di Leonardo non si adatta quindi alla definizione di "uomo universale" ma piuttosto la «bilateralità di attitudini, attitudine di pittore e attitudine di scienziato naturalista; e l’aggettivo "universale" (ecco la conclusione cui volevamo giungere) esprime enfaticamente e iperbolicamente la maraviglia destata da quella duplice attitudine, degna certamente di maraviglia» (in B. Croce, Saggio sullo Hegel, p. 224)
6. ^ Vasari, p. 255.
7. Są to opinie osób takich jak: Giorgio Vasari, Giovanni Antonio Boltraffio, Baldassare Castiglione, „Anonimo” Gaddiano, Berensen, Hipolit Taine, Henry Fuseli, Rio, Bortolon.
8. Istnieje 15 znaczących obrazów, których autorstwo przypisywane jest przez historyków Leonardowi. Głównie są to obrazy na desce, lecz również fresk, duży rysunek na papierze i dwa dzieła, które znaleziono we wczesnych stadiach prac. Dodatkowo istnieje pewna liczba innych prac w różny sposób przypisywanych Leonardowi.
9. Odrestaurowana obecnie zagroda wiejska Campo Zeppi w Anchiano jest uważana za miejsce urodzenia artysty, lecz brak na to niepodważalnych dowodów. Najprawdopodobniej takie przekonanie powstało w połowie XIX wieku. Jako pierwszy pisał o tym Emanuele Repetti, jednak jest to opinia mało wiarygodna. Przeczy jej fakt, że budynek został kupiony przez rodzinę da Vinci 30 lat później. Z notatek Antonia da Vinci, dziadka Leonarda wynika natomiast, że narodziny miały miejsce w miasteczku Vinci. W 1452 r. właścicielem domu, opisywanego wówczas jako tłocznia oliwy, był Tomma di Marco. Z rodziną da Vinci łączyła go wspólna profesja oraz fakt, że 18 października 1499 r. dziadek Leonarda sygnował jako świadek umowę przekazującą udział we własności domu innym osobom. Z uwag umowy wynika, że Antonio da Vinci przebywał wówczas w tym domu.
10. W 1494 r. wypędzono Medyceuszy i władzę sprawował rząd republikański, do którego gremium kierowniczego należał sekretarz Republiki, Nicoló Maccia.
11. Em meados do século XV, a Itália não era propriamente um país, sendo formada por pequenos reinos e cidades-Estado independentes, cada qual com o seu próprio soberano, moeda, leis e exércitos. Essas cidades se desenvolviam comercial e culturalmente, visando a ideia amplamente difundida pelos Médicis de tornarem-se centros culturais e exemplos, e, assim, alcançar a imortalidade.[3]
12. Existem 15 obras de arte significativas que são creditadas, tanto inteira, como parcialmente, a Leonardo pela maioria dos historiadores da arte. Este número é formado, principalmente, por pinturas realizadas sobre madeira, mas, também incluem um mural, um desenho grande feito em papel e duas obras que estavam em estágios iniciais de seu preparo. Existem diversas outras obras que lhe foram atribuídas, sem a unanimidade dos acadêmicos.
13. Segundo o crítico de arte britânico, Jonathan Jones, antigo juiz do Prêmio Turner, autoridades florentinas teriam ocasionado uma competição entre Leonardo e Michelangelo, evento que, segundo ele, é de conhecimento dos historiadores, embora pouco discutido. Em seu livro The Lost Batles: Leonardo, Michelangelo and the artistic duel that defined renaissance discute como uma possível competição se desenrolou em torno dos afrescos de A Batalha de Anghiari e A Batalha de Cascina, de Leonardo e Michelangelo, respectivamente, e, apesar de ambos ficarem inconclusos, como Michelangelo teria ganhado a competição em 1506 lhe garantindo uma reputação — o que mais tarde poderia ter resultado na sua participação na Capela Sistina. O autor acredita que a história tenha compensado a derrota de Leonardo, o que foi muito reforçado no século XIX, com a redescoberta de seus cadernos e junto sua genialidade.[9]
14. Técnicas científicas modernas como a metalurgia e a engenharia ainda estavam em sua infância durante o Renascimento,