The Science of Leonardo: Inside the Mind of the Great Genius of the Renaissance

by Fritjof Capra

  Francesco da Vinci, only sixteen years older than Leonardo, was very fond of his nephew and soon became a father figure to him. He was a gentle and contemplative man who loved nature and knew it well. He would have spent many hours with the boy, walking through the vineyards and olive groves that surrounded Vinci (as they do today), observing the birds, lizards, insects, and other small creatures that inhabited the countryside, teaching him the names and qualities of the flowers and medicinal plants that grew in the region.

  Doubtless it was Francesco who instilled in the young Leonardo his deep respect for life, his boundless curiosity, and the patience required for intimate observation of nature. Leonardo also began to draw early on in his childhood. In his Notebooks he listed “many flowers portrayed from nature” among the works he had produced in his youth,3 and his earliest extant drawing, done at age twenty-one, is a view of the Tuscan countryside of his childhood, tilled fields framed by the foothills and rocks of Montalbano.4

  It is striking that in this early drawing as well as in that of a ravine with waterbirds (Fig. 3-1) that he made a few years later, Leonardo already pictured the dramatic rock formations that would form the backgrounds of most of his paintings. It seems that his lifelong fascination with pinnacles of rocks, carved out by water and eventually turning into gravel and fertile soil, originated in his childhood experience of the mountain streams and rocky outcroppings that are typical of parts of the countryside around Vinci.

  As a young boy, Leonardo explored these mysterious rock formations, waterfalls, and caves. Over the years, their memory no doubt intensified as he embraced the ancient analogy of macro-and microcosm and began to view the rocks, soil, and water as the bones, flesh, and blood of the living Earth. Thus the rock formations of his childhood became Leonardo’s personal mythical language that would forever appear in his paintings.

  In Vinci, Leonardo attended one of the customary scuole d’abaco (“abacus schools”), which taught children reading, writing, and a rudimentary knowledge of arithmetic adapted to the needs of merchants.5 Students who prepared for university then moved on to a scuola di lettere (“school of letters”), where they were taught the humanities based on the study of the great Latin authors. Such an education included rhetoric, poetry, history, and moral philosophy.

  Being an illegitimate child, Leonardo was barred from attending university, and hence was not sent to a scuola di lettere. Instead he began his apprenticeship in the arts. This had a decisive influence on his further education and intellectual development. Being “unlettered” meant that he knew almost no Latin and was therefore unable to read the scholarly books of his time, except for the few texts that had been translated into the vernacular. It also meant that he was not familiar with the rules of rhetoric observed in philosophical disputations.

  In his later life, Leonardo constantly strove to overcome this handicap by educating himself in numerous disciplines, consulting scholars wherever he could and assembling a considerable personal library. On the other hand, he also realized that not being constrained by the rules of classical rhetoric was an advantage because it made it easier for him to learn directly from nature, especially when his observations contradicted conventional ideas. “I am fully aware that, not being a man of letters, certain presumptuous persons will think that they may with reason discredit me,” he wrote in his own defense as he approached forty. “Foolish folk!…They don’t know that my matters are worth more because they are derived from experience, rather than from the words of others, and she is the mistress of those who have written well.”6

  Figure 3-1: Ravine with waterbirds, c. 1483, Windsor Collection, Landscapes, Plants, and Water Studies, folio 3r

  Leonardo showed great artistic talent early in his youth; his synthesis of art and science was also foreshadowed early on. This is vividly illustrated in a story related by Vasari. When Piero da Vinci was asked by a peasant to have a “buckler” (a small wooden shield) decorated with a painting in Florence, he did not give the shield to a Florentine artist but instead asked his son to paint something on it. Leonardo decided to paint a terrifying monster.

  “To do what he wanted,” writes Vasari, “Leonardo carried into a room of his own, which no one ever entered except himself, a number of lizards, crickets, serpents, butterflies, locusts, bats, and various strange creatures of this nature. From all these he took and assembled different parts to create a fearsome and horrible monster…. He depicted the creature emerging from a dark cleft of a rock, belching forth venom from its open throat, fire from its eyes, and smoke from its nostrils in so macabre a fashion that the effect was altogether monstrous and horrible. Leonardo took so long over the work that the stench of the dead animals in his room became unbearable, although he himself failed to notice because of his great love of painting.”

  When Ser Piero came to see the finished painting, “Leonardo went back into the room, put the buckler on an easel in the light, and shaded the window. Then he asked Piero to come in and see it. When his eyes fell on it, Piero was completely taken by surprise and gave a sudden start, not realizing that he was looking at the buckler and that the form he saw was, in fact, painted on it. As he backed away, Leonardo stopped him and said: ‘This work certainly serves its purpose. It has produced the right reaction, so now you can take it away.’”

  The story illustrates several of the qualities that became essential elements of Leonardo’s genius. The painting is an expression of the boy’s fantasia, but it is based on his careful observation of natural forms. The result is a picture that is both fantastic and strikingly real, and this effect is greatly enhanced by the artist’s flair for the theatrical when he presents his work. Moreover, Vasari’s description of the youth working for long hours, undisturbed by the stench of rotting corpses, eerily anticipates the anatomical dissections Leonardo would vividly describe some forty years later.7

  APPRENTICESHIP IN FLORENCE

  At the age of twelve, Leonardo’s life changed dramatically. His grandfather died, and his uncle Francesco got married. As a result, Leonardo left Vinci to live with his father in Florence. A few years later he began his apprenticeship with the renowned artist and craftsman Verrocchio. Ser Piero, in the meantime, had remarried after his first wife died in childbirth. The exact sequence of Leonardo’s movements at this time of his life is uncertain. He may have stayed in the country with his grandmother a couple of years longer, or he may have joined Verrocchio’s workshop at the age of twelve. Most historians believe, however, that he began his apprenticeship at about age fifteen.

  Florence in the 1460s had no more than 150,000 inhabitants, but in its economic power and cultural importance it was on a par with Europe’s great capitals.8 It had trading posts in the major regions of the known world, and its wealth attracted scores of artists and intellectuals, who made it the focal point of the emerging humanist movement. The Florentines were proud of their city’s importance, its liberty and republican government, the beauty of its monuments, and especially of the fact that Florence had left its chaotic medieval past behind and embodied the spirit of a new era.

  Throughout the 1300s, Florence had been the scene of many deadly feuds; succeeding factions had fought openly in the streets, and the wealthy families had built their houses like citadels, often fortified with imposing towers. By the time Leonardo arrived in the city, most of these menacing fortresses had disappeared. Narrow and twisting medieval streets had been widened and straightened; the unhealthiest districts had been cleaned up, and the wealthy Florentine bourgeoisie were busy building magnificent palazzi, using the local sandstone known as pietra serena and the severe symmetries of the new Renaissance architecture to give their city a uniform air of noble elegance.

  To the adolescent Leonardo, arriving in Florence from a farm and a small village of a few dozen houses, this lively, enterprising, and beautiful city must have seemed like something out of a fairy tale. Brunelleschi’s magnificent dome, crowning the shining marble of Santa Maria del Fiore, the cathedra
l of Florence, was newly finished and already being admired as a wonder of the modern world. The river Arno was spanned by four bridges. In the city’s center, Leonardo would have frequently passed by the proud and stately palace of the Medici family. Near the Ponte Vecchio, one of the city’s great bridges, he would have seen the finely proportioned Palazzo Ruccellai, both built just before his birth. On the other side of the Arno, construction had begun on the imposing Palazzo Pitti. Two dozen more palaces would be built during the sixteen years Leonardo spent in Florence. This massive beautification of the city was supported by a huge number of workshops in which artists and artisans produced the required materials, works of art, and splendid decorations. During Leonardo’s apprenticeship, Florence could boast of 54 workshops for working marble, 40 goldsmiths, and 84 workshops for woodworking in addition to 83 for silk and 270 for wool.9

  Leonardo’s apprenticeship came about as a result of the connections his father had. When Leonardo came to live with Ser Piero, he brought with him the drawings he had made in Vinci. “One day,” Vasari tells us, “Piero took some of Leonardo’s drawings to Andrea del Verrocchio (who was a close friend of his) and earnestly begged him to say whether it would be profitable for the boy to study drawing.10 Andrea was amazed to see what extraordinary beginnings Leonardo had made and he urged Piero to make him study the subject. So Piero arranged for Leonardo to enter Andrea’s workshop.” Ser Piero had not shown much concern for his son’s early education, but with the choice of Verrocchio he redeemed himself. Of all the workshops in Florence, Verrocchio’s was the most prestigious, the best connected, and for Leonardo the ideal place to nurture his talents.

  Andrea del Verrocchio, who was about the same age as Leonardo’s uncle Francesco, was a brilliant teacher. Originally trained as a goldsmith, he was a skilled craftsman, an accomplished painter, and a noted sculptor. He also had considerable engineering skills. He had excellent connections to the Medici family and a solid reputation, and hence received a steady stream of commissions. It was well known in Florence that his workshop could handle every kind of request.

  Verrocchio’s workshop, like those of the many other Florentine artists and artisans, was quite different from the painters’ studios of subsequent centuries. In his biography of Leonardo, Serge Bramly gives us a vivid description.

  This was a bottega, a shop—just like that of the shoemaker, butcher, or tailor—a set of ground-floor premises opening directly onto the street…an awning was pulled down to act as a door or shutter. The living quarters would be at the back or upstairs. Artists’ materials would be hanging on the walls, alongside sketches, plans, or models of work in progress, while ranged around the room would be a collection of sculptors’ turntables, workbenches, and easels; a grindstone might stand alongside a firing kiln. Several people, including the young apprentices and assistants (who generally lived under the same roof as the master and ate at his table), would be working away at different tasks.11

  The bottega of a master like Verrocchio would produce not only paintings and sculptures but also a vast variety of objects—pieces of armor, church bells, candelabras, decorated wooden chests, coats of arms, models for architectural projects, and banners for festivities as well as sets and scenery for theatrical performances. The works leaving the bottega (even those of the highest quality) were rarely signed and usually produced by the master with a team of assistants.

  Leonardo spent the next twelve years in this creative environment, during which he diligently followed the rigorous course of a traditional apprenticeship.12 He would have drawn on tablets and familiarized himself with the artists’ materials, which could not be bought ready-made but had to be prepared in the workshop. Pigments had to be freshly ground and mixed every day; he would have learned to make paintbrushes, prepare glazes, apply gold to backgrounds, and finally, after several years, to paint. In addition, he would have absorbed considerable technical knowledge by watching the master work on a variety of projects. Over the years, as he honed his skills by imitating his elders, he and the other apprentices would have increasingly participated in the bottega’s production until he was finally designated a master craftsman and accepted into the appropriate association, or guild, of craftsmen.

  In Verrocchio’s workshop, Leonardo was introduced not only to a wide variety of artistic and technical skills, but also to many exciting new ideas. The bottega was a place where lively discussions of the latest events took place daily. Music was played in the evenings; the master’s friends and fellow artists dropped by to exchange plans, sketches, and technical innovations; traveling writers and philosophers visited when they passed through the city. Many of the leading artists of the time were drawn to Verrocchio’s bottega. Botticelli, Perugino, and Ghirlandaio all spent time there after they were already accomplished masters to learn novel techniques and discuss new ideas.

  The Florentine bottega of the fifteenth century fostered a unique synthesis of art, technology, and science, which found its highest expression in Leonardo’s mature work. As historian of science Domenico Laurenza points out, this synthesis lasted for just a hundred years: by the end of the sixteenth century, it had dissolved.13 For Leonardo’s own artistic and intellectual development, the years he spent in Verrocchio’s workshop were decisive. His way of working and his entire approach to art and science were shaped significantly by his long immersion in that workshop culture.

  One important influence on Leonardo’s future work habits was the use of a libro di bottega (“workbook”), which all apprentices had to keep.14 It was a journal in which they recorded technical instructions or procedures, personal reflections, solutions to problems, and drawings and diagrams of their ideas. Continuously updated, annotated, and corrected, the libro di bottega provided a daily record of the activities in the workshop. Its composite character of accumulated notes and drawings, without any particular organization, is recognizable in many pages of Leonardo’s Notebooks.

  Shortly after Leonardo began his apprenticeship, Verrocchio received a commission for his biggest and most spectacular engineering project yet—the construction of a gilded copper ball, 2.5 meters in diameter, or roughly seven feet, to be placed together with a cross on top of the marble lantern of Brunelleschi’s dome. The famous architect had died before being able to crown his masterpiece, but had left detailed plans for the lantern and copper ball, which Verrocchio was charged to execute. The project took three years, and the young Leonardo was able to observe every stage of it, and likely contributed to it as well.15

  It was a complex project, involving securing the lantern to withstand strong winds; precisely casting, shearing, and welding the copper ball’s many sections; and finally, hoisting the heavy ball and cross to the top of the lantern by using special hoisting devices, designed by Brunelleschi himself. The welding alone was a major feat of science and engineering, because there were no welding torches in the fifteenth century. Small welds could be executed at the forge, but the copper ball was so big that the only way to weld it with a hot flame at precise points was to use concave mirrors to “burn” a weld (a technique that had been known since antiquity). Manufacturing such concave mirrors required considerable knowledge of geometrical optics and very precise grinding equipment. This explains Leonardo’s frequent studies of the geometry of “fire mirrors,” as he called them, in his early drawings.16 They later led him to formulate sophisticated theories of optics and perspective.

  The project was finally completed in 1471. Contemporary chroniclers recorded that on May 27 of that year a large crowd gathered in front of the Duomo to watch the hoisting of the great gilded ball, perfectly smooth and shining, to the top of the marble lantern, where, after a fanfare of trumpets, it was secured to the plinth to the sounds of the “Te Deum.” It was a spectacle that Leonardo never forgot. Forty-five years later, when he was over sixty and working on the design of a large parabolic mirror in Rome, he wrote in his Notebook as a reminder to himself, “Remember how we welded together the ball of Santa Maria
del Fiore!”17

  Toward the end of Leonardo’s apprenticeship, Verrocchio was working on a picture of the Baptism of Christ (Fig. 3-2). Since the youth had shown great promise, the master let him paint parts of the background and one of the two angels. These portions of the painting, the first record we have of Leonardo as a painter, already show features of his distinctive style. In the background, we see wide, romantic hills, rocky cliffs, and water flowing from a pool in the far distance all the way to the foreground, where it forms small waves rippling around the legs of Christ. Close inspection of this flow of water in the original painting, now in the Uffizi Gallery, reveals several tiny waterfalls and turbulences of the kind that fascinated Leonardo throughout his life.

  Figure 3-2: Andrea del Verrocchio and Leonardo da Vinci, Baptism of Christ, c. 1476, Uffizi Gallery, Florence

  Equally striking is the originality of Leonardo’s angel. Its grace and beauty are far superior to those of Verrocchio’s, which the master could not fail to notice. “This was the reason,” reports Vasari, “why Andrea would never touch colors again; he was so ashamed that a boy understood their use better than he did.” Indeed, it seems that from that time on, Verrocchio concentrated on sculpture, and left the execution of paintings to his senior assistants.18

  YOUNG MASTER PAINTER AND INVENTOR

  At the age of twenty, Leonardo was recognized as a master painter, and in 1472 he was admitted to the guild of painters known as Compagnia di San Luca. Curiously, the company was included in the guild of physicians and apothecaries, which was based at the hospital of Santa Maria Nuova. For Leonardo, this was the beginning of a long association with the hospital. For many years he used the guild as a bank for his savings, and it was at Santa Maria Nuova that he found his first opportunities to perform anatomical dissections.