The Biography of Leonardo da Vinci

The Biography of Leonardo da Vinci

Summary of “Leonardo da Vinci – The Biography” by Walter Isaacson: This book depicts the intimate and public life of Leonardo da Vinci, all the facets of his creative genius, at the junction of science, technology, and the arts. Leonardo da Vinci was an outlier, a polymath, a contrarian, a self-confessed non-conformist, a man of imaginationtalent, and curiosity, an exceptional and passionate observer, and an innovator who left an indelible mark on history. Walter Isaacson delves into the 7,200 pages of notes and sketches in da Vinci’s iconic notebooks to recount the captivating life journey of one of the greatest scholars of his time.

By Walter Isaacson, 2019, 595 pages.

Review and summary of the book “Leonardo da Vinci – The Biography” by Walter Isaacson


Characters and summary in chronological order

The book begins by describing all the people who played a major role in Leonardo’s journey. It then summarizes the periods of his life on an illustrated timeline.

Presentation of a great multidisciplinary genius

Walter Isaacson introduces Leonardo da Vinci.

He describes him as the most creative genius in history.

He is, among other things:

  • The author of the two most famous paintings in history: The Last Supper and The Mona Lisa.
  • The archetype of the Renaissance man because he knew how to combine art and science. Throughout his life, his scientific explorations shaped and nurtured his artistic work. As such, he was a talented artist, a great scientist, and an accomplished engineer all rolled into one.
  • He was enthusiastic, curious, inventive, passionate, even obsessive in countless fields: anatomy, optics, botany, geology, mechanics, military engineering, geometry, writing, hydraulics, architecture, etc. What he loved was learning: [learning all that it is possible to know about the world and, in so doing, discovering the place of the human race], writes Walter Isaacson.
  • An inspiration for those who believe in the beauty of creation. In other words, for all those who believe that [all the elements of the infinite work of nature], as he puts it, [are interwoven and wonderfully arranged.]
  • The innovator par excellence: a keen observer with a vivid imagination that was constantly churning, Leonardo infused his fantasy into his artistic and engineering work.
  • A charismatic man of “striking beauty and grace”: he is described as having an “imposing stature”, “remarkable strength”, a [haughty bearing when riding through the city on horseback], dressed in colorful outfits, a charming conversationalist, etc.
  • A nature lover known for his kindness and gentleness towards people and animals.

The starting point for the biography of Leonardo da Vinci is his notebooks, Walter Isaacson explains.

The author has, in fact, immersed himself in hundreds of pages of notes and scribblings, written by the hand of Leonardo, in order to restore his life and career.

Leonardo’s notebooks compile valuable information about the genius’ musings.

Each page is full of details of all kinds. These details, which people generally just gloss over, demonstrate his insatiable curiosity. Leonardo inventoried there year after year, non-stop, what he wanted to do, to learn, what amazed him, his questions. These notebooks and drawings also reveal, at times, the dark and troubled side of the artist, his feverish, creative, manic, and impassioned spirit.

In addition to his notebooks, Walter Isaacson explains that in writing this biography he also consulted numerous scientific articles and theses on Leonardo.

Drawing inspiration from Leonardo da Vinci

Lastly, Walter Isaacson confides that he realized, thanks to Leonardo da Vinci, to what extent the fact of marveling at the world can [enrich every moment of our lives.]

He states:

[The 15th century, the century of Leonardo, Columbus and Gutenberg, was an era of invention, exploration, and the spread of knowledge through new technologies. A period like ours, in short.]

This is why, Walter Isaacson believes, we all have much to learn from Leonardo da Vinci:

[We have so much to learn from Leonardo, from his ability to combine art, science, technology, humanities, and imagination, the recipe for creativity. From his ease in assuming a somewhat marginal status – bastard, homosexual, vegetarian, left-handed, easily distracted, and at times heretical – as well. Florence flourished in the 15th century because it embraced this type of personality. However, Leonardo’s perpetual curiosity and endless experimentation should above all remind us of the importance of instilling in ourselves and our children not only knowledge, but above all a willingness to question it, to let our imaginations guide us, and, like the outsiders and rebels throughout the ages, to think differently.]

Chapter 1 – Childhood

1.1 – Vinci, 1452-1464

The birth of little Leonardo

Walter Isaacson first traces the genealogy of Leonardo da Vinci from 1300 to his birth.

The author then tells us that Leonardo’s father was Piero Da Vincison of Antonio Da Vinci.

Born from a line of notaries, Piero became, like all the elders of his family for generations, also a notary. More ambitious than his father Antonio, who was idle and close to nature, Piero left Vinci, his small hometown, at an early age to develop his career in Florence. However, he continued to visit his family in Vinci on a regular basis, where he also had a relationship with Caterina Lippi, a 16-year-old orphaned peasant girl. Caterina had no money and a younger brother to support.

From the relationship between Piero and Caterina, Leonardo was born in the spring of 1452out of wedlock. When he was born, Leonardo, although illegitimate, was baptized. A great ceremony was organized. Many important aristocrats were invited. Leonardo was given 10 godparents, many more than usual.

Piero, aged 24, prosperous and prominent, was not of the same social class as Caterina. He, therefore, does not marry Caterina but would instead marry Albiera, a sixteen-year-old girl of equal standing, son of a Florentine shoemaker, to whom he was promised anyway.

However, for the sake of convenience and practicality, Piero arranged for Caterina to marry shortly after Leonardo’s birth. She married Antonio di Piero del Vaccha, a local farmer and furnace maker with ties to da Vinci’s family.

The childhood of Leonardo da Vinci

Little Leonardo’s childhood was split between his mother’s home and his father’s, who had a good relationship with each other:

  • Through Caterina and Accattabriga (nickname of Antonio di Piero del Vaccha), Leonardo would have 4 sisters and a brother.
  • Through Piero and Albiera, there would be no children (but Piero would have at least 11 children from a third and fourth marriage after Leonardo’s 24th birthday).

Leonardo also spent a lot of time, during his early childhood (up to 5 years), with his paternal grandfather Antonio. The latter lived with his wife and Leonardo’s uncle, Francesco, who was barely 15 years older than Leonardo. Francesco was a passionate idler who loved country leisure. He became Leonardo’s beloved uncle.

The captivating anecdotes and details shared by Water Isaacson allow us to relive the singular and happy childhood of the little genius.

Walter Isaacson explains that in the fifteenth century, illegitimacy was not so much a problem, especially among the nobility (popes had illegitimate mistresses and children). Children born out of wedlock could even rise to prestigious positions. However, this was not so well perceived among judges and notaries, who had to conform to social traditions.

Leonardo grew up between two worlds:

  • The guild of notaries forbidding illegitimate children: he escaped the profession of notarybut became familiar with the note-taking that was customary among notaries.
  • At the same time, he was free to pursue his creative activities. Having avoided Latin school, he became self-taught. He was proud to be so, as he called himself, a “man without letters” and [that this lack of formal education led him to become a disciple of experience and experimentation.]

1.2 Disciple of experience

The conditions in which Leonardo da Vinci grew up greatly favored his free-thinking attitude and the development of his talents. Because of his status, little Leonardo was never caught up in the [old-fashioned scholastic reasoning of medieval dogmas.] Certainly, by escaping from traditional thinking, Leonardo became an adult who:

  • Questioned order, established reasoning and authority: his method – an empirical approach to understanding nature – was based on experimentation, curiosity, and the ability to marvel at phenomena.
  • Was passionate about the wonders of nature and developed an extraordinary ability to observe shapes, shadows, movements, the flapping of wings, facial emotions, etc.

Moreover, the time was perfect for a child with such talents and ambitions: Italy had been at peace for 40 years, literary and mathematical skills were growing, income was increasing, manuscripts of ancient authors were arriving in Europe after the capture of Constantinople by the Ottomans. The city of Florence became [the cradle of the artistic and humanistic Renaissance.]

1.3 – Childhood memories

Walter Isaacson continues his biography of Leonardo da Vinci by recounting many anecdotes of Leonardo as a child (the memory of walking in a cave, or that of a kite that had opened his mouth while he was still in his crib).

The story sheds light on Leonardo’s personality: his motivations, his passions, his existential anxieties (inspired, for example, by the destructive powers of nature), his taste for scientific discoveries, and his capacity for imagination, two elements that he would intertwine throughout his life.

The author concludes the chapter on Leonardo’s childhood with the following:

[His curiosity about nature would always encourage him to continue his explorations, while his fascination and apprehension would be expressed in his art.]

Chapter 2 – Apprentice

In the second chapter of Leonardo da Vinci’s biography, Walter Isaacson recounts the young painter’s apprenticeship in Florence.

2.1 – The arrival of Leonardo da Vinci in Florence

Walter Isaacson first describes his move from Vinci to Florence.

In 1964, Leonardo was 12 years old. He left his hometown of Vinci to settle with his father in Florence. His grandfather Antonio had just died. His father Piero had just lost his wife, who died in childbirth.

The adaptation to this city life was not easy for young Leonardo, who was used to living in the countryside. Walter Isaacson mentions several of his writings in which he praises the contemplative and solitary life of the countryside and blames the city dwellers whom he describes as “infinitely malignant.”

Leonardo continued to paint and sculpt. He did not seem at all prepared to follow a career as a notary like his father. Piero did not impose anything on him. He knew, in any case, that it would be very difficult for him to circumvent the rule of the guild of notaries who did not want illegitimate children in their ranks.

2.2 – Florence

Walter Isaacson goes on to describe Florence as an unusually creative city in the 15th century. As the epicenter of arts and commerce, Florence was the perfect place for Leonardo.

The city benefited from pacifist relations, total freedom, majestic infrastructures (cathedral, universities, etc.), a flourishing economy (combining art, technology, commerce, and finance), and great humanist thinkers who advocated knowledge as a source of happiness.

In this incredible breeding ground of ideas, cultural life was very rich (shows, festivals, carnivals, and other grandiose entertainments). These events spurred the creativity of the many artists involved, especially young Leonardo.

Ultimately, [culture values above all those who master and combine different specialties: the polymaths], like Leonardo.

[The mixing of ideas from different disciplines became the norm as individuals with diverse talents mingle. Silk makers collaborated with goldbeaters to create enchanting garments. Architects and artists developed the science of perspective. Woodcarvers worked with architects to decorate the city’s 108 churches. Stores became workshops. Merchants became financiers. Craftsmen became artists… The city itself became a work of art.]

Behind the scenes, it was the Medici family that held the reins of power. Como de’ Medici, then his son, Peter, succeeded him, followed by the famous Lorenzo de’ Medici.

2.3 – Brunelleschi and Alberti

Walter Isaacson describes here the influence that the teachings of two particular “jacks-of-all-trades” had on Leonardo:

  • Filippo Brunelleschi(1377-1446), designer of the dome of Florence Cathedral. He embodied the multidisciplinary interests and the renewal of classical knowledge characteristic of the early Renaissance.
  • Leon Battista Alberti(1404-1472), Brunelleschi’s successor in the field of linear perspective. This other polymath of the Renaissance improved on many of his predecessor’s experiments and expanded his discoveries on perspective.

An artist, architect, engineer, and writer, Alberti was in every way similar to Leonardo: [the illegitimate son of a prosperous father, athletic and handsome, a confirmed bachelor, and fascinated by everything from mathematics to art.] He had a close friendship with Leonardo.

The author of the biography of Leonardo da Vinci concludes, regarding Alberti:

[His new methods advanced not only painting but also many other disciplines, from cartography to stage design. By applying mathematics to art, Alberti elevated the status of the painter and showed that the visual arts deserved the same rank as other humanistic disciplines, a cause that Leonardo would later champion.]

2.4 – Education

The only formal education that Leonardo received was an elementary education centered on mathematics applicable to the trade of an abacus school.

Leonardo was an absent-minded student (because he was interested in too many things) and good at geometry. Left-handed (which was considered an oddity at the time), he often wrote and drew from right to left so as not to alter his notes. On this point, the author notes that some passages in Leonardo’s notebooks are written this way:

[Leonardo wrote from right to left on some pages, from left to right on others, and systematically drew his letters backwards, from left to right. One cannot read them without a mirror.]

2.5 – Verrocchio

At the age of 14, Leonardo was old enough to learn a trade. His father arranged for him to be apprenticed to one of his clients, Andrea del Verrocchio. Verrocchio was a versatile artist and engineer who ran one of the best workshops in Florence. A qualified goldsmith, he was immediately captivated by the teenager’s talent.

Verrocchio’s workshop

Walter Isaacson describes, in this part of Leonardo’s biography, Verrocchio’s workshop in great detail. It looked more like a jeweler’s store than a fine art studio. In the living quarters above, craftsmen and apprentices lived and ate together, where they would [discuss mathematics, anatomy, dissection, antiques, music, and philosophy.] The work was collaborative. Objects and works were produced in large numbers.

Verrocchio was a master of kindness. Moreover, many artists stayed to live and work with him after their apprenticeship. This is also what Leonardo chose to do. Thus, at the age of 20, Leonardo became a master painter in the workshop. He joined the Florentine painters’ confraternity, the Compagnia di San Luca, [a sort of mutual aid or fraternity club that was experiencing a resurgence in popularity.]

The mutual influences of Verrocchio and Leonardo

Walter Isaacson then highlights, through the study of various works, the influence of Verrocchio on Leonardo and vice versa.

We first learn that it was Verrocchio who introduced Leonardo to geometryharmony in proportions, and mathematics in nature.

The author then presents the many common characteristics in the paintings of Verrocchio and Leonardo da Vinci: the playful smiles of his characters, the rich and fine curls, the care and anatomical details (muscles, veins), the subtleties of movement in a static work. The author studies in detail David, a sculpture by Verrocchio, as an example of these mutual influences: it is not clear who was influencing whom.

Moreover, the monumental project of installing a two-ton globe at the top of the dome of Florence Cathedral etched in the mind of young Leonardo [the idea that artistic and mechanical genius are closely linked.]

Lastly, the drapery studies that Leonardo made at Verrocchio’s encouraged him to [develop one of the key ingredients of his artistic genius: the ability to use light and shadow in such a way as to reinforce the illusion of volume of objects represented in two dimensions.]

Thus, it was in Verrocchio’s studio that Leonardo developed his two techniques, which are so unique to him and in which he excelled:

  • Chiaroscuro, which consists of [using contrasts of light and shadow  to give the illusion of relief and three-dimensional volume to drawings and two-dimensional paintings.]
  • Sfumato, which consists of [blurring lines and borders in order to represent objects as they appear to the naked eye, with a smooth outline.]

2.6 – The first known works of Leonardo da Vinci

By telling us the story of the first known works of Leonardo da Vinci, the author reveals how the latter ended up surpassing his master.

The warrior

One of Leonardo’s most famous early drawings is that of a Roman warrior in profile wearing an elaborately crafted helmet. This drawing is most likely related to a visit of the Duke of Milan to Florence, as recounted here by Walter Isaacson.

The aerial screw

The aerial screw (which resembles a prototype of a helicopter) is one of the first drawings of scenic machines created by Leonardo to entertain the public during the numerous Florentine festivals. A man of spectacle, Leonardo already enjoyed combining fantasy, realism, art, and engineering in his creations.

Arno Valley landscape

Found on a sheet of his notebooks, this is probably the oldest known art drawing by Leonardo; the drawing depicts the summer nature of Vinci in 1473.

Tobias and the Angel

Having become a master painter in Verrocchio’s workshop, Leonardo took part in this collective work. He created the dog and the fish in this painting. We can see here the power of the collaboration between Leonardo and his master. 

The Baptism of Christ

This painting shows the extent to which Leonardo eventually surpassed his master, particularly because he began to use oil paint and his unique technique of sfumato. The author aptly explains this transition:

[With the Baptism of Christ, Verrocchio went from master to collaborator with Leonardo. He helped him to study the sculptural elements of painting, especially modeling, as well as how moving bodies bend. But Leonardo, with his thin layers of translucent and transparent oil paint and his powers of observation and imagination, elevated art to an entirely different level. From the mists of the distant horizon to the shadow under the angel’s chin to the water at Christ’s feet, Leonardo was redefining the way the painter transforms and communicates what he observes.]

Annunciation and Madonnas

In addition to Leonardo’s collaborations with Verrocchio, Walter Isaacson describes four other paintings. These were done by Leonardo in his twenties while still working in Verrocchio’s studio: 

  • The Annunciation: with this painting, we understand that Leonardo was experimenting, at the time, with light, perspective, and the representation of human reactions.
  • Two small pious paintings of the Virgin and ChildThe Madonna with the Carnation, also known as the Munich Madonna(its current location), and The Benois Madonna, or Madonna Benois. 
  • Portrait of Ginevra de’ Benci: this is Leonardo’s first secular painting; it contains typical Leonardo features such as the “dense, lustrous curls of hair“, the “unconventional three-quarter pose“, a psychological portrait that conveys hidden emotions.

Chapter 3 – On His Own

3.1 – “Amore mascolino”

Accusations of sodomy

In 1476, at the age of 24Leonardo was accused of sodomy with a 17-year-old prostitute. The accusation was made anonymously in a tamburo (a box for receiving moral complaints). At that time, this kind of accusation was serious. An investigation was opened by the Officers of the Night (the vice squad of the time).

However, it turned out that four other people were accused. Among these men, one was from a high-ranking family linked to the Medici clan by marriage. The case was therefore closed [on the condition that no other accusations are made.] However, a new complaint was filed a few weeks later. It was again anonymous, and no witness could corroborate the facts. The charges were once again dropped under the same conditions.

Leonardo’s homosexuality

Emotionally and physically attracted to men, Leonardo never had a relationship with a woman. He repeatedly expressed his disgust for heterosexual intercourse. And his drawings reveal a much stronger fascination with the male body than with the female body.

However, Leonardo seemed to be quite comfortable with his homosexuality: he did not hide it (but did not boast about it either). He wasn’t ashamed of his sexual desires, which rather seemingly amused him.

Furthermore, Walter Isaacson explains that homosexuality was not uncommon in the artistic community in Florence nor in Verrocchio’s circle. And while sodomy remained a crimegay love was celebrated in salacious poems and songs.

Despite this, Leonardo’s sexual orientation undoubtedly contributes, according to the author, to his sense of uniqueness.


At this time, Leonardo’s most serious relationship was with Atalanta Migliorotti. Leonardo taught the lyre to this young musician nicknamed Salai, the imp. This nickname is easily understood when one reads his description: [a young man with the face of an angel but with an infernal personality.]

Salai would accompany Leonardo a few years later to Milan where he would pursue a successful musical career.

The rest of this biography reveals that he would remain at Leonardo’s side almost until his death.

3.2 – Feeling of abandonment and loneliness

According to Walter Isaacson, Leonardo felt abandoned at this time.

Although he had a good relationship with his father, Leonardo felt out of step. He could not find his place and considered himself an outsider:

[His father was becoming more and more successful and gained access to the upper echelons of the world as a legal advisor to the Medici, the most influential guilds and the churches. He was also a model of masculinity with his mistress, his three wives, and his five children. Leonardo was a marginal figure. The birth of his brothers and sisters reinforced his illegitimacy. As a bastard artist and a gay man twice accused of sodomy, he knew that he was projecting to others the image of a different man, and this was also how he perceived himself, but like many artists, he would eventually convert this into a strength.]

3.3 – Commercial failure; remarkable but unfinished paintings

Opening of Leonardo’s workshop

Leonardo opened his own workshop in 1477.  However, it was a commercial failure. In five years, he received only three known commissionsone that he never began and two that he abandoned. They include:

  • Adoration of the Magi: this altarpiece for the chapel of the Palazzo della Signoria is Leonardo’s first commission. He was only 26 years old at the time. Leonardo never finished this painting, yet it became one of the most influential unfinished paintings in the history of art, says Walter Isaacson, adding: [The Adoration of the Magi sums up Leonardo’s frustrating genius as an innovative and incredible demonstration of talent abandoned once past the stage of conceptualization.]
  • Saint Jerome: this remarkable painting, notably for its intense psychological aspect(painting the emotions of dozens of characters) is Leonardo’s first anatomical drawing. It also remains unfinished (although it was added to twenty years later by Leonardo, during his anatomical discoveries through dissections).

The study of these paintings gives Walter Isaacson the opportunity to underline two characteristics of Leonardo da Vinci that are found throughout his career:

  • That of rarely finishing his works.
  • That of always wanting to paint what he called “the motions of the mind”.

Leonardo da Vinci rarely finished the works he started. For the author, there are two reasons for this:

  • He was a perfectionist: therefore, he did not always feel up to finishing the colossal projects he imposed on himself. His idea of art was so high that it was impossible for him to execute it perfectly: [he saw defects even in what to others seemed like a miracle.]
  • Leonardo preferred conception over execution.

However, Leonardo did not generally leave paintings unfinished “by simply abandoning them.” He perfected them and sometimes kept them for years to make improvements. There are even many finished paintings (the Mona Lisa, for example) that he would never complete: he would take them with him and rework them as soon as he had new ideas.

[This is how he would die, surrounded by some of his masterpieces. As frustrating as this seems to us today, there is something poignant and captivating about Leonardo’s refusal to declare a painting finished and hand it over: he knew that he always had more to learn, that he had new techniques to master, and that inspiration could strike at any moment. And he was right.]

The motions of the mind

In his paintings, Leonardo da Vinci sought to translate the movements of the body (moti corporali), but also what he called the “atti e moti mentalithe attitudes and motions of the mind. Moreover, in his notebooks, the artist writes:

[A good painter has two chief objects to paint – man and the intention of his soul.  The former is easy, the latter hard, for it must be expressed by gestures and the movements of limbs.]

Leonardo was obsessed with the external manifestation of emotions. This can be seen in his art, but also in his anatomical studies. He tried to find out which nerves were connected to the brain and which to the spinal cord, which muscles they activated and which facial movements were linked together. [He even tried, by dissecting the brain, to determine the area responsible for the connection between sensations, emotions, and movements], says the author.

3.4 – Despair

Walter Isaacson concludes the third chapter of his biography of Leonardo da Vinci by referring to the artist’s inner conflicts: his melancholy, even his depressive state, his notebooks of the 1480s full of expressions of sadness, even anguish.

Chapter 4 – Milan

4.1 – Cultural diplomat

At the age of 30Leonardo da Vinci left Florence for Milan.

He left on a diplomatic delegation sent by Lorenzo the Magnificent (Lorenzo de’ Medici) to the Duke of Milan. Leonardo was, in fact, a diplomatic gift. His mission was to present himself to the Duke with his lyre, a silver instrument (partly) in the shape of a horse’s skull created by Leonardo and which he could play incredibly well.

Walter Isaacson recounts the journey of the diplomatic mission. Leonardo was accompanied by Salai (Atalanta Migliorotti), his “companion”. Both of them had plans of settling permanently in Milan. In fact, they would stay there for 17 years.

4.2 – Letter of application to Ludovic Sforza

Milan is a very different city from Florence. It was a city-state ruled by military figures who had seized power by force and had declared themselves hereditary dukes: the Viscontis and then the Sforzas.

When Leonardo arrived in Milan, it was Ludovic Sforza who ruled the city from his prestigious castle. Leonardo wrote him a letter in which he did not mention his gifts as a painter or musician (for which he had been sent), but he did mention his military and mechanical expertise and his engineering skills. He also offered his services to make an equestrian statue to the glory of Ludovico’s father. Leonardo hoped to please Ludovico Sforza, who knew he was [under constant threat of local revolt or French invasion.]

4.3 – Military engineer

While living in Florence, Leonardo designed several ingenious inventions for military equipment: a mechanism to repel the ladders of invaders attempting to scale a wall, another that ejects enemies who have reached the top of the walls, a rolling armored siege machine enabling a covered bridge to be erected over the fortifications of a castle, etc.

In Milan, Leonardo da Vinci improved on all these ideas. He invented innovative concepts of machines. He imagined ingenious military devices and weapons such as a scythe tank or his famous giant crossbow with a 24-meter span. However, nothing was ever built. The only military project Leonardo delivered to Ludovico was a study of the defenses of the castle of Milan.

4.4 – The ideal city

In Milan, Leonardo da Vinci also developed his interest in architecture. As in the military field, however, he created innovative concepts that he would never realize.

The best example Walter Isaacson describes is the plans Leonardo drew for a utopian city in the early 1840s after a plague took out a third of Milan’s inhabitants (a spread primarily related to unsanitary urban conditions).

This was a [radical concept combining his artistic sensibility with his visions as an urbanist]the creation of entirely new “ideal cities” that were both sanitary and aesthetically pleasing.

To do so:

[He relied on the classic analogy between the microcosm of the human body and the macrocosm of the Earth: cities are breathing organisms, which are flowing with fluids and must eliminate a series of wastes. Some time earlier, he had begun to study blood and the circulation of fluids in the body. In his analogical approach, he envisioned the best circulatory systems for urban needs, from commerce to garbage disposal.]

The author of Leonardo’s biography then explains how visionary this concept, like many of Leonardo’s other ideas, was. Yet, precisely because they were ahead of their time, these proposals were difficult to apply to the Renaissance, and, although relevant and brilliant, they failed to convince Ludovico Sforza.

Walter Isaacson concludes by asking:

[Had he implemented even a part of Leonardo’s plans, the entire complexion of cities could have been transformed, which could have reduced the plague epidemics and changed the course of history.]

Chapter 5 – Leonardo’s Notebooks

Walter Isaacson discusses here Leonardo’s natural tendency to take notes:

He spontaneously scribbled his observations and ideas, made lists, and drew sketches. In the early 1480s, shortly after his arrival in Milan, he began to take regular notes in notebooks, a habit that would accompany him throughout his life… He never separated from them and used them in the field.]

Walter Isaacson has studied Leonardo’s notebooks extensively. These were used by Leonardo to record his observations, especially scenes that involved people and emotions.

The author interprets this habit of noting as [the enthusiasm of a curious and insatiable explorer.] He sees in it [a catalog of his many passions and obsessions.] Almost everything is there, he says, except for personal and intimate revelations.

In all, over 7,200 pages of notes have been preserved (probably a quarter of what Leonardo wrote).

In this part of the biography of Leonardo da Vinci, Walter Isaacson suggests studying one of these notebook pages to observe the genius’ creativity at work.

It should be noted in particular that Leonardo used every little nook and cranny of each sheet (good quality paper being expensive). We see a jumble of ideas, sometimes mysterious. Dates are rarely specified. The ideas are written next to each other with no apparent link or at very distant periods.

Sometimes Leonardo would mention his intention to organize and rework these notes for publication. However, Water Isaacson concludes:

[As in painting, he began writing his treatises, modifying and improving them from time to time, without ever appearing to resign himself to disclosing a final version to the public.]

Chapter 6 – Court Entertainer

6.1 – Parties and shows

Leonardo da Vinci entered the Sforza court as a showman

Contrary to what he had hoped for when he arrived, Leonardo da Vinci finally entered the court of Ludovico Sforza not as an architect or engineer, but as a showman.

Ludovico Sforza frequently organized parties. These shows became a major source of entertainment at court:

[Architects, mechanics, musicians, poets, performers, and military engineers were all involved in such events. For Leonardo, who found himself in each of these professions, it was the ideal way to make a name for himself at the Sforza court.]

The artistic and technical side that the production of this type of event required appealed to Leonardo (set design, costumes, scenery, music, mechanisms, choreography, allegorical allusions, automata, and gadgets).

Walter Isaacson describes here, in detail, all the genius of the artist in this field too. Leonardo da Vinci’s shows were, indeed, known to be dazzling. Unfortunately, we have no physical trace of them, to the author’s regret.

The most emblematic Leonardo da Vinci productions at the court of Ludovico Sforza

Among the most emblematic shows, Walter Isaacson cites the extravagant sound and light show that Leonardo da Vinci mounted with the young nephew of Ludovico Sforza, Jean Galéas Sforza: The Ball of the Planets.

[Leonardo’s production was a triumph, and The Ball of the Planets brought him a certain amount of fame – more, in any case, than his career as a painter of unfinished paintings and his dreams as a military engineer. He particularly enjoyed the exercise. His notebooks show his interest in mechanisms and automatons used for set changes. He was born to play with fantasy and machinery.]

The author mentions two other stage productions:

  • One that clearly shows Leonardo da Vinci’s attraction to the exotic and terrifying, [his affinity forstrange demons and dragons.] This is the staging carried out at the wedding of Ludovic Sforza and Beatrice d ‘Este.
  • A comedy called Danaethat staged one of the most extravagant plays of the time, full of special effects and mechanical tricks designed by Leonardo.

Ultimately, for Leonardo da Vinci, show production:

  • Is fun.
  • Rather well paid.
  • Forces him to bring his fantasies to life and to see his projects through to the end: unlike painting, the shows are scheduled and must be ready when the curtain rises. It is therefore impossible to procrastinate.
  • Leads him to deepen his scientific research: for example, Leonardo studied birds to design flying machines with mechanical wings.
  • Stimulates his artistic and scientific creativity: his passion for theatrical gestures can be seen in the narrative paintings produced during this period.

6.2 – Music

Initially, Leonardo was sent to the Sforza court for his musical talents. So, when he went there, he brought a personal version of an instrument popular at the time. It was a kind of lyre in the shape of a horse’s skull that Leonardo held in his hands like a violin. He made it himself.

Walter Isaacson tells us that in fact, Leonardo invented many other new instruments as part of his activities as a showman. In this regard, he writes:

[Leonardo’s musical inventions were the product of his engineering instinct and his attraction to entertainment. He invented original ways of controlling the vibrations, and thus the pitch and timbre of sounds produced by bells, drums, and strings.]

The artist’s notebooks are filled with such sketches. The most complex instrument that Leonardo imagined, however, the author tells us, was the “viola organista,” a hybrid between the violin and the organ.

The author also emphasizes Leonardo’s dazzling talent for singing and improvising accompaniment on the lyre.

6.3 – Allegorical and grotesque drawings

Leonardo was also a talented draftsman. The author of the biography of Leonardo da Vinci depicts various artistic creations including two series of particularly interesting drawings.

Allegorical drawings

This series of allegorical drawings was probably produced by Leonardo to illustrate stories told to the court assembly. For Walter Isaacson, even though they represent people, some of his drawings would seem to reveal Leonardo’s inner demons.

The grotesques

Leonardo da Vinci called this series of strange portraits: “visi mostruosi“, in other words, “monstrous faces“, or his “grotesques“. These caustic portraits combine the beauty and ugliness that Leonardo could skillfully perceive in everything. These small caricatures (most are smaller than a credit card) were probably made as satires to illustrate funny stories or performances presented at the castle.

6.4 – Literary entertainment

Fables, tales, comical stories, and wordplay

Leonardo da Vinci was also an “exceptional conversationalist and storyteller,” says Walter Isaacson. This is evidenced by his literary diversions read and recited at court. Walter Isaacson lists here everything that Leonardo da Vinci created in this register when he worked at the Sforza court: numerous moral tales and fables, a bestiary (a set of short stories about animals with a moral at the end), “prophecies” (short enigmas, trick questions), visual word games (cryptograms, pictograms, and rebus with a message to be deciphered), riddlesjests, etc.

These literary amusements were full of funny stories and jokes. They also showed Leonardo’s love for animals.

Short stories and fanciful tales

Leonard also liked to write stories that mixed realism and fantasy. In his notebooks, short stories, sometimes in the form of letters, describe mysterious adventures and countries.

Walter Isaacson refers to two of these notable stories:

  • The Letter to Dei, which was presumably performed at a party at the Sforza court. This short story is about a well-traveled character telling his fabulous stories. [The apocalyptic scenes of destruction and the flood that annihilates all earthly life] found in this story is a theme constantly revisited by Leonardo.
  • A story, composed of a series of letters written by a prophet and a hydraulic engineer sacred sultan of Babylon: in addition to addressing once again the theme of the flood and destruction, it [illustrates a dream that Leonardo cherished: becoming a hydraulic engineer.]

According to Walter Isaacson, although Leonardo’s stories were written to entertain the court, something deeper emerges: they allow us, the author contends, [to catch a glimpse of the turmoil and torment of the psyche of the man behind the showman.]

Chapter 7 – Personal Life

7.1 – Remarkable beauty and infinite grace

In Milan, Leonardo was known for his talents, but also [for his charm, athletic stature, and kindness.]

Many of the prominent intellectuals from Milan and Florence referred to Leonardo in their letters and writings in glowing and cordial terms.

The various testimonies gathered by Walter Isaacson describe him as an inventive genius, but also as a kind and generous man, surrounded by friends, who attracted the affection of all. They all underscored his great elegance, describing his very long curly beard and his exuberant but always distinguished attire (his clothes were colorful and he often wore a pink cape that came just to his knees).

Leonardo da Vinci was portrayed as a man who owned nothing, yet was always surrounded by servants and horses. He was said to be [motivated neither by wealth nor by material possessions.] As such, he spent [much more time learning than he did in pursuit of profit.]

Lastly, the author mentions Leonardo’s love for animals, which led him to be a vegetarian for most of his life and to never wear [anything with blood or that would allow anyone to harm a living being] (he dressed, for example, in linen). Also, the painter Vasari, who knew him, recounts:

[Often, when he would go by an aviary, he would take some birds out of the cages, pay them to the seller and let them fly away to regain their lost freedom.]

7.2 – Salai

Among Leonard’s young companions, the one who meant the most to him (by far) was [a rascal nicknamed Salai.] He moved in with Leonard, who was then 38 years old:

[Salai was more than a helper. He was actually Leonardo’s assistant, companion, secretary, and, probably for a period of his life, lover.]

Salai was described as being a[thief, liar, stubborn, and greedy.] His antics were the cause of constant bickering between the two men. In the end, however, Leonard was very patient and tolerated Salai’s conduct for years.

7.3 – Young men and old men

Walter Isaacson notes here a theme that recurs regularly throughout Leonardo da Vinci’s career: that of the confrontation between youth and old age.

It can be seen, he says, in his works, especially in a series of drawings of an old man and a young man face to faceallegorical drawings of Pleasure and Sorrow:

[The young character embodying Pleasure looks like Salai. He stands back to back with the old man who represents Sorrow. They are intertwined. Their bodies merge as their arms intertwine. Pleasure and Sorrow are represented as twins …], Leonardo writes in his drawing, “for one is never without the other.”

Chapter 8 – Vitruvian Man

8.1 – A tiburio for the cathedral of Milan

In this eighth chapter of the biography of Leonardo da Vinci, Walter Isaacson tells the story of one of Leonardo’s most famous drawings: The Vitruvian Man.

It all began in 1487. Leonardo entered the competition that followed the Milanese authorities’ call for projects to build a tiburio (= a lantern tower) on top of the cathedral of Milan.

This tiburio was a complex construction: the structure was fragile and the gothic style of the cathedral had to be respected. Many architects had previously failed. The best artists-engineers-architects of the Italian Renaissance were candidates for the project. They decided to work together and share their ideas. On this occasion, Leonardo befriended two of them: Donato Bramante and Francesco di Giorgio.

Francesco di Georgio was a multi-talented craftsman, ranging from art to engineering. The project of the tiburio of the cathedral of Milan is ultimately granted to him. Leonardo withdrew from the project but emerged rich from the collaboration: together they created interesting concepts and designs [with the aim of harmonizing human proportions with those of religious buildings.]

8.2 – Trip to Pavia with Francesco di Giorgio

During a trip to Pavia in 1490, Francesco and Leonardo began to discuss the architectural treatise that Francesco was writing.

Francesco di Giorgio explained that he had relied on the work of Vitruvius (a soldier in Caesar’s Roman army who had become an architect) to establish the guiding principle of his treatise: [all the arts and all the rules of the world are derived from a correctly constituted and proportioned human body.]

Francesco referred to Vitruvius’ analogy between the microcosm – constituted by man – and the macrocosm – constituted by the earth. The evocation is powerful. According to Vitruvius:

[Just so the parts of Temples should correspond with each other, and with the whole. The navel is naturally placed in the center of the human body, and, if in a man lying with his face upward, and his hands and feet extended, from his navel as the center, a circle be described, it will touch his fingers and toes. It is not alone by a circle, that the human body is thus circumscribed, as may be seen by placing it within a square. For measuring from the feet to the crown of the head, and then across the arms fully extended, we find the latter measure equal to the former; so that lines at right angles to each other, enclosing the figure, will form a square.]

Leonardo was inspired by Vitruvius’ descriptions of the proportions of the human body. He too was convinced that the proportions of the human body were similar to those of a well-designed temple and to those of the world.

8.3 – Birth of the famous drawing of the Vitruvian Man

Leonardo and his friends begin to draw a man, arms and legs apart, at the center of a church and the universe

Back in Milan, at a dinner party, Leonardo and Francesco discussed Vitruvius’ work with Giacomo Andrea, who was also a member of the circle of architects and engineers gathered by Ludovico at the Milan court. Following this exchange, Giacomo would draw Vitruvius’ proposal. He produced a simple versiona man in a circle and a square.

Then Leonardo decides to create his own version. This one differed from the drawings of his friends Francesco di Giorgio and Giacomo Andrea by “its scientific accuracy” as well as by “its artistic qualities”, says Walter Isaacson. In this drawing, the man with the intense gaze and curly hair seems to be in motion, vibrant, and energetic. He exudes naturalness and poise.

The famous drawing of Vitruvian Man, symbol of the harmony between man and the universe, is born!

The symbol of universal humanism

For Walter Isaacson, [this masterpiece embodies the association of the human and the divine]:

[Leonardo’s Vitruvian Man embodies a moment in history when art and science combine to allow mortal minds to probe timeless questions about their identity and their place in the great universal order. It also symbolizes an ideal humanism that celebrates the dignity, worth, and rationality of the human as an individual. In this circle and square, it is our essence that we perceive through that of Leonardo da Vinci, naked between the earthly and cosmic.]

In his Vitruvian Man, Leonardo combines many other concepts and ideas. Among these concepts, Walter Isaacson cites:

  • The mathematical challenge of squaring the circle.
  • The analogy between the microcosm that is the human being and the macrocosm that is the earth.
  • The human proportions discovered during his anatomical research.
  • The geometry of squares and circles in the architecture of churches.
  • The transformation of geometric figures.
  • The alliance of mathematics and art in what is called “the golden ratio” or “the divine proportion“.

8.4 – Collaboration

Lastly, the author explains that Leonardo da Vinci liked to be surrounded by friends, companions, students, assistants, colleagues, and thinkers. The  Vitruvian Man attests to the fact that he liked to collaborate and think with others. Walter Isaacson writes:

[His thinking … was informed not only by his own experience or reading but also by conversations with friends and colleagues. For Leonardo, as for most multidisciplinary thinkers in history, ideas are above all a matter of collaboration.]

The court of Milan, which brought together musicians, artists, architects, engineers, mathematicians, medical researchers, and scientists of all backgrounds, was the perfect fertile ground for Leonardo. There he could learn constantly, satisfy his insatiable curiosity, and exchange ideas and visions with others.

Chapter 9 – The Horse Monument

9.1 – Residence at court

In 1489, Ludovico Sforza asked Leonardo to create a monument. It was to be the equestrian statue to the glory of his father that he had promised to erect in the letter he had sent him seven years earlier. This bronze horse would have to be gigantic.

This new responsibility, in addition to others as impresario and organizer of festivals and shows, ensured Leonardo an official place in court. Leonardo da Vinci became a painter and one of the Duke’s four principal engineers. [This was the situation he had always dreamed of], according to Walter Isaacson.

Also, Ludovico Sforza provided him with:

  • Accommodation: rooms for him and his assistants as well as a workshop in the Corte Vecchia, a castle in the city center.
  • A generous salary: to compensate for some of his late payments, the Duke also offered Leonardo a vineyard near Milan which would generate a small income for the rest of his life.

9.2 – Design and casting of the equestrian statue

The commission of the equestrian statue to Leonardo was intended to establish the legitimacy of the Sforza family in Milan. For this reason, it would have to be as large as possible. It was therefore planned to be 7 meters high.

Leonardo began by collecting precise measurements of horse anatomy through dissections. Leonardo then created a mold and a version of the horse in clay. At the time of casting the molten bronze, the artist faced various challenges, which would require a high level of expertise in metals and systems.

When he managed to solve these problems, in 1494, Milan was in the grip of Charles VIII’s French troops who were invading Italy. The Sforzas decided to use the bronze dedicated to the statue to make three cannons. These cannons were never used because the French took Milan very easily in 1499.

The huge clay horse was eventually destroyed by the French archers who used it for target practice. As for the mold, despite several requests for payment, it was never returned by the French authorities. [Leonardo’s horse ended up joining, in spite of itself, the other potential masterpieces and aborted dreams of the master…], concludes Walter Isaacson.

Chapter 10 – Scientist

In this chapter of the biography of Leonardo da Vinci, Walter Isaacson expands on four major characteristics of Leonardo da Vinci.

He highlights that Leonardo was a self-taught scientist, who was curiousvery observant, and worked on the basis of theory and experimentation and made extensive use of analogies.

10.1 – Leonardo, the autodidact

Lacking formal education and academic knowledge (he knew neither Latin nor ancient Greek), Leonardo accumulated specialized knowledge through his experience and his reading (Gutenberg’s technology had just arrived in Italy and printers and publishing houses were flourishing).

His library was full of scientific, poetic, and literary works. It contained books on military machinery, agriculture, music, surgery, health, Aristotelian science, Arabic physics, palmistry, lives of famous philosophers,  but also, treaties of art and architecture, fables, collections of poems, religious publications, writings devoted to mathematics, etc.

Speaking of Leonardo da Vinci, Walter Isaacson writes:

[His bookish appetite was fierce and extensive. However, he also liked to tap into the brains of others… This is how Leonardo became a disciple of experience and knowledge. More importantly, it is in this way that he comes to see that science progresses when the two interact. This helps him to understand that knowledge is born from the marriage of experimentation and theory.]

10.2 – Leonardo, the keen observer and the natural experimenter

Leonardo da Vinci, adds Walter Isaacson, possessed [the eye of the observer, the hindsight of the skeptic, and the curiosity of the scientist.]

Therefore, he observed events in an attempt to deduce recurring patterns and understand the natural forces at work. As the years went by, his taste for reading made him realize that experience and theory are, in fact, complementary.

[His ability to bring experience and theory together makes him one of the earliest examples of how keen observation, insatiable curiosity, experimentation, questioning of dogma, and the knack for identifying correlations between disciplines can greatly advance knowledge.]

10.3 – Leonardo, master of analogies

[An intuitive sense of the unity of nature enabled Leonardo’s eyes and mind to leap from one realm to another and to perceive connections.]

As a telling example of his analogical approach, here is an excerpt from his notebooks:

[All the branches of a tree, in whatever degree of height they are joined, are equal to the size of the trunk. All the branches of the waters, endowed with an equal movement, at each degree of their length, equal the size of the river, their father.]

This rule still bears his name: “da Vinci’s rule”.

[It has been validated in situations involving branches of limited widths: the sum of the cross-sectional area of all branches above a branching point is equal to the cross-sectional area of the trunk or branch immediately below the branching point.]

Leonardo also found similarities between light, sound, magnetism, and the reverberations of percussion caused by a hammer blow: all radiate and often propagate in waves.

10.4 – Leonardo, insatiably curious

Leonardo da Vinci possessed [an omnivorous, almost fanatical curiosity], according to Walter Isaacson.

This curiosity focused on subjects that [would not interest anyone over the age of 10 in the least], the author notes. He wondered, for example: Why is the sky blue? How are clouds formed? Why do we only see in a straight line? What is yawning? What is the nerve that determines the movement of the eyes and makes one move the other? He became interested in exploring the tongue of the woodpecker, the jaw of the crocodile and the placenta of the calf.

This insatiable curiosity went with a keen sense of observation, [of rare intensity], says the author:

[His keen eye served as an ally to his curiosity. He was able to fix his gaze on elements that went unnoticed by the common man…  Leonardo’s eye was exceptionally adept at observing movement.]

In his notebooks, Leonardo da Vinci explained his method for developing his observational skills. He said he scrutinized each detail independently.

Chapter 11-12-13-14 – Birds, Mechanical Arts, Mathematics and the Nature of Man

In the following chapters of Leonardo da Vinci’s biography (11, 12, 13, 14), Walter Isaacson explains, in great detail, all the discoveries, and everything that fascinated Leonardo throughout his life and career.

Leonardo’s works are all very thorough. The fields are incredibly varied (birds, mechanical arts, mathematics, nature of man, etc.). Unfortunately, the vast majority of these works were never shared publicly. In fact, Leonardo’s intention was often there, but it was overshadowed by his much stronger interest in the discovery of concepts than in their realization or publication.

Despite this, the scholarly research of the visionary genius has moved the world forward. Many experts of all kinds have been inspired by his work to develop major theories and break new ground.

It is impossible to mention here the incredible amount of things that Leonardo undertook, but here is a summary.

Chapter 11 – Birds and Flight


Leonardo explored the anatomy of birds, the movement of wind, the concepts of gravity and density. He sought to understand how birds maneuvered their wings. After 20 years of study, Leonardo decided to compile his observations in a treatise with the aim of publishing them (the Codex on the Flight of Birds, 18 folios). However, this treatise would remain unfinished.

The possibility of creating flying machines

Leonardo combined engineering, physics and anatomy to create flying machines, mainly for his theatrical productions (self-propelled human flight, devices with mobile wings, and gliders).

[Despite the beauty of his artistic representations and the ingenuity of his concepts, he never succeeded in creating a human-powered flying machine capable of taking off by itself. It would be another 500 years before human beings would achieve this feat.]

Chapter 12 – The Mechanical Arts


Leonardo da Vinci’s fascination with movement inevitably led him to take an interest in machines and humans, which he saw as devices designed to move (with similar components such as ropes and tendons). He drew the elements that enable such movement to better understand the mechanical functions and principles and invented various machines.

Perpetual motion

Leonardo understood that [if we could eliminate all the forces that slow down a moving object, it could move indefinitely in the same direction] (work that would foreshadow that of Newton, 200 years later).


The author describes all the impressive discoveries and conclusions of Leonardo da Vinci on this subject (on the ratio of friction factors, lubrication, the instrument for measuring friction, the principle of rolling, the alloying of metals to reduce friction, etc.). All were well ahead of their time:

[Once again, Leonardo was three centuries ahead of his time… By working on machines, Leonardo developed a mechanistic vision of the world that was to become Newton’s. He considered that all the movements of the universe were the same. He considered that all the movements of the universe – those of our limbs, those of the cogs in the machines, those of the blood in our veins and those of the water in the rivers – answer to the same laws. These laws being analogous, the movements in a domain are comparable to those in another domain. We find a logical, recurring pattern.]

Chapter 13 – Mathematics


Leonardo da Vinci’s sense of geometry helped him to formulate the laws of nature. It also enabled him to understand the laws of perspective. Leonardo shared his love of geometric shapes and harmonic ratios with Luca Pacioli, a close friend and mathematician at the court of Milan, who became an excellent teacher for Leonardo. Luca published a book in which he examined what he called “the divine proportion” (this divine proportion is present in all Leonardo’s works). Leonardo created the mathematical illustrations inside. He drew complex variants of Plato’s solids (such as the rhombicuboctahedron, made up of 26 faces, 8 triangles surrounded by 18 squares) and innovated by representing them in a very realistic way (play of shadows, visible edges).

Geometric transformations

Leonardo was particularly intrigued by the way in which the shapes of objects change when they are moved.  He was also interested in the transformation of geometric shapes (from a square to a circle of identical area or from a globe to a cube of equivalent volume).

Squaring the circle

Leonardo was fascinated (and obsessed) by a concept inherited from the ancient Greek mathematician Hippocrates. This concept was the lunula, a geometric shape comparable to a quarter moon.

[Hippocrates discovered a marvelous mathematical fact about this object: by creating a lunula by overlapping a large circle and a smaller circle, it is possible to draw a right-angled triangle inside the larger of the two semicircles formed, the surface of which is identical to that of the lunula.  This is the earliest technique for calculating the exact area of a curved shape (a circle or lunula) and replicating its surface in a straight-sided shape (like a triangle or rectangle).]

Leonardo intended to create a treatise on the subject entitled De ludo geometrico (On the game of geometry). He filled pages of notebooks on the subject; however, this work would never be published either.

Moreover, this research made Leonardo determined to solve a mathematical enigma from antiquity: squaring the circle. The genius undertook vain calculations bordering on obsession.

Chapter 14 – The Nature of Man

This chapter opens our eyes to Leonardo’s passion for everything that has to do with the nature of man: anatomy, the skull, human proportions, etc.

Anatomical drawings

Leonardo began studying anatomy early in his career as a painter in Florence to improve his artistic technique.  He was particularly interested in the functioning of the nervous system and how visual information was processed, and then in how tissues, veins, muscles and nerves should be represented from various angles.

Skull drawings

In 1489, Leonardo focused his anatomical studies on skulls. The human brain is essential for the painter who seeks, in his drawings and paintings, to represent the inner emotions through gestures. It is, in fact, the brain that receives and processes visual and sensory information and then transmits the appropriate reactions to the muscles.

The study of human proportions

Leonardo was passionate about the detailed analysis of human proportions and measurements. He produced a number of drawings, diagrams, and descriptions in this regard. Here is a small sample of Leonardo’s notes on this subject, shared by Walter Isaacson in “Leonardo da Vinci – The Biography“:

[The space between the top of the nose, where the eyebrows begin, to the bottom of the chin is equivalent to two-thirds of the face… The greatest width of the face corresponds to the space between the mouth and the hairline, and it is one-twelfth of the total height… From the top of the ear to the top of the head, the distance is the same as from the bottom of the chin to the tear duct of the eyes. And the same as the distance from the tip of the chin to the tip of the jaw… The hollow of the cheeks is halfway between the tip of the nose and the top of the jaw… The big toe is the sixth part of the foot if measured in profile… The distance from the end of one shoulder to the other is twice the face… From the navel to the beginning of the penis is the length of a head.]

[The list goes on and on], the author says. Leonard also wrote about what happens when each one moves:

[He who kneels reduces his height by a quarter… When the heel is raised, the tendon and the ankle are separated by the width of a finger… This sitting portion, which goes from the seat to the top of the head, will be half the height of the man plus the width and length of the testicles.]

The universal measure of the human

Reading his notebooks, we understand the reason for this obsession: Leonardo expressed his intention to discover what he called “the universal measure of the human being.”

Walter Isaacson closes the chapter as follows:

[This quest, which was the essence of his artistic and scientific work, defined his life.]

Chapter 15 and 16 – Virgin of the Rocks and Milan Portraits

Although employed as an impresario, then as a sculptor and finally as a consultant in church design by Ludovico Sforza, Leonardo da Vinci remained a painter first and foremost: [He was a painter in Florence and would remain one for the rest of his life], states Walter Isaacson.

The 15th and 16th chapters of the biography of Leonardo da Vinci are then devoted to his most outstanding paintings. Each of them contains a captivating story told by Walter Isaacson in a very skillful way: he recounts the commissions, the techniques used by Leonardo, what he wanted to expresswhat was going on in his life at the time, and the influences that such events or knowledge had on his works, etc.

It would take far too long to summarize all this information in this article, but the paintings in question are below.

The Virgin of the Rocks

This painting exists in two versions:

  • One is kept in the Louvre: this painting is [a striking example of how the painter’s scientific knowledge contributes to the mastery of his art.]
  • The other is exhibited at the National Gallery in London: in this version, light is used in a way [never before seen in the history of painting.]

The story of this painting is also an opportunity for the author to emphasize the importance of collective work in Leonardo’s workshop.

[We tend to see artists as isolated creators, locked away in their garrets, waiting patiently for inspiration to come. But as Leonardo’s notebooks and the process of creating his Vitruvian Man reveal, artistic creation was a collegial affair for him.]

Portrait of a Musician

For some, this is Franchino Gaffurio, a friend of Leonardo’s who became conductor of the choir of the cathedral in Milan. However, it would appear to be the portrait of Atalanta Migliorottiknown as Salai, Leonardo’s young musical companion who left Florence to move with him to Milan.

The portrait of Cecilia Gallerani, the Lady with an Ermine

With this painting, Walter Isaacson tells us the captivating and romantic love story of Cecilia Gallerani, [a middle-class Milanese beauty] and Ludovico Sforza. The author informs us that the portrait of Cecilia, known as the Lady with an Ermine:

  • Was commissioned by Ludovico at the height of their relationship, around 1489, when she was 15 years old.
  • Is so vivid and emotionally charged that it would be considered groundbreaking throughout Europe: it introduces the idea that it is possible, in a portrait, to express the thoughts of its subject through their posture and gestures. Walter Isaacson explains here Leonardo’s talent for this:

[Leonardo captured the narrative of a moment involving the inner life of the subjects and the world outside the painting. In the ensemble composed of the hands, legs, and eyes, in the mysterious smile of the young woman, we distinguish the movements of the body and the soul.]

La Belle Ferronnière

This is likely the portrait of Lucrezia Crivelli, Ludovico’s official mistress. Walter Isaacson studied this painting in detail. Two key features of the painting are as follows:

Light and shadow

[No painter has ever captured so well the way in which shadows and light can give a three-dimensional appearance and perfect modelling to a face.]

The character’s gaze

In this portrait, the master continues to experiment with [the bewitching gaze that pursues the viewer wherever he goes.] Leonardo’s talents in perspective, shading, and modeling are what create this effect:

[The two eyes examine you independently, whether you are moving away from or towards the painting, whether you are passing to one side or the other.]

The Beautiful Princessor The Beautiful Milanese Princess

The story of this painting is as exciting as it is bizarre!

[The portrait is a seductive work, but not stunning… What makes this portrait interesting is above all the quest led by Silverman to prove its authenticity.]

In this part of the biography of Leonardo da Vinci, Walter Isaacson relates, in a thrilling way, the epic story of this painting, from its auction in 1998, (the author and subject of which had still remained unknown) and sold for $ 18,000 (US), to its authentication in 2011, which raised its value to nearly 150 million dollars.

For several years, specialists have sought to know if La Belle Princesse was indeed a painting by Leonardo da Vinci. Years went by, going through many twists and turns on the question, without anyone ever reaching an agreement.

It is finally in 2011 that the mystery would be resolved. After many plot twists, it was discovered that this drawing was originally part of a bound work, that it was likely the portrait of Bianca Sforza, illegitimate daughter of the Duke, and that it was likely to have been painted by the hand of the master himself.

Since then, some continue to doubt the painting’s authenticity. However, whatever the final outcome of the story, the author tells us, what is interesting to retain from this adventure are the “vivid emotions” and “scientific surprises” that such a work of authentication generates.

In short, the story of this painting highlights the [skillful mix of investigative work, technological wizardry, historical research, and connoisseur’s flair] that it took to authenticate this creation. Here also, all is a matter of interdisciplinarity and union of the artistic and scientific forces.

Chapter 17 – The Science of Art

Walter Isaacson devotes this chapter of Leonardo da Vinci’s biography:

  • To the artistic vision of Leonardo da Vinci.
  • To the unique and ingenious scientific techniques and processes employed by Leonardo da Vinci in his works.

17.1 – Painting is art and science

To introduce Leonardo’s vision of art, Walter Isaacson recounts his success at the paragone (the name given to evenings of debate and intellectual discourse on various subjects: mathematics, art, philosophy, etc.) organized at the Sforza castle in 1498.

That evening, Leonardo demonstrated exceptional talent for oratory. His argumentation underlined the link between pictorial art, optics, and the mathematical principles of perspective. Leonardo wished to elevate the work and social status of painters. He communicated two key ideas:

  • “Painting is not only an art but also a science”: indeed, according to Leonardo, one must understand perspective and optics to be able to represent three-dimensional objects on a flat surface. Based on mathematics, one can then consider painting as an intellectual as well as a manual creation.
  • “Painting appeals not only to the intellect but also to the imagination”: according to Leonardo, painting is a highly creative act that requires the combining of observation and imagination.

Leonardo’s presentation was so impressive that the Duke of Milan invited him to write a treatise on it. Once again, this treatise would never be completed for publication. It was Leonardo’s assistant heir Francesco Melzi who would publish, based on the artist’s writings, following his death, the Trattato della pittura (Treatise on Painting) by Leonardo da Vinci and who bore witness to his famous paragone speech.

17.2 – The pictorial techniques of Leonardo da Vinci: shadows, forms without lines, optics, and perspective

  • Shadows and shapes without lines

Thanks to his keen sense of observation, Leonardo knew how to paint skillfully the gradations of color tones, the subtle shadows, and the delicately blurred and smoky outline of objects. These techniques of chiaroscuro and sfumato are truly unique to Leonardo.

  • Optics

By studying optics (dissections of eyeballs in particular), Leonardo understood, for example, that it is not possible to [see the true outline of opaque bodies very precisely.] His discoveries in this field greatly influenced his painting.

  • Perspective

For Leonardo, the study of perspective was inseparable from painting and optics. Leonardo’s greatest discovery and contribution in this field is what is called linear perspective. Leonardo went even further and innovated by describing what he called “aerial perspective” (which explains how objects in the distance become less distinct).

Chapter 18 – The Last Supper

Walter Isaacson tells the long personal and artistic story behind the famous narrative painting of The Last Supper.

18.1 – Leonardo da Vinci’s eccentric way of working

After telling us the story of the commission for this painting, Walter Isaacson describes Leonardo’s eccentric way of working and his habit of procrastination:

[A priest recounted how Leonardo ‘would arrive at dawn and climb the scaffolding,’ then ‘stand there, brush in hand, from sunrise to sunset, forgetting to eat and drink, painting without let-up’.] Some days, however, he would paint nothing at all. [He would remain alone in front of his work for an hour or two, contemplating it… When his obsessions coalesced with his penchant for procrastination… He would suddenly arrive in the middle of the day, ‘climb the scaffolding, grab a brush, give one or two small strokes to one of the figures, and then suddenly leave’.]

The artist’s methods fascinated the public but worried Ludovico Sforza. So much so that the Duke eventually summoned Leonardo da Vinci. During their exchange, Leonardo shared with the Duke his views on the powers of creativity. Here is a passage from the book that summarizes his words:

[Leonardo explained to his boss that it (creativity) sometimes requires going slowly, pausing, and even procrastinating, because all of this allows ideas to marinate. Intuition needs to be nurtured. Men of ambitious genius sometimes do their greatest work when they work the least], he explained to the Duke, [for their minds are consumed with their ideas and the perfection of their conceptions, into which they then give form.]

18.2 – The many talents of Leonardo da Vinci reflected in The Last Supper

The Last Supper is an extremely lively work. It illustrates the reactions of the apostles just after Christ told them that he knew one of them was going to betray him. The viewer can discern many of Leonardo da Vinci’s talents in this painting.

Walter Isaacson covers them all in detail:

  • His gift for representing movementgestures to show the intentions of the mindmoti dell’anima (movements of the soul).
  • The elements of perspective:
    • The vanishing point (Christ’s forehead) towards which all the orthogonal lines tend and converge.
    • The tapestries painted in such a way as to be aligned with the actual tapestries of the room (illusion that the painting is an extension of the room).
    • Complex perspective: optical tricks mean that the work can be viewed from the front, from the side or while walking without it appearing distorted.

Lastly, the author summarizes, [The Last Supper is a mixture of scientific perspective and theatrical license, of intellect and fantasy worthy of Leonardo.]

Unfortunately, this painting has been rapidly deteriorating (it was in very poor condition even 20 years after its completion). At least six attempts to restore the work have been made over the centuries. Most of them have only made things worse.

Chapter 19 – Personal Turmoil

In this chapter, Walter Isaacson elaborates on two significant moments in Leonardo’s personal life:

The death of his mother Caterina

Widowed in her sixties, Leonardo’s mother died of malaria. However, in his notebooks, Leonardo expressed no emotion. He wrote nothing about this event and [was content to take note of the costs related to her funeral], reveals the author.

Professional difficulties

[When he began painting The Last Supper around 1495, Leonardo was at the height of his career. Since his official appointment as artist and engineer to the Sforza court, he was comfortably ensconced in Milan’s ancient palace, the Corte Vecchia, with his retinue of assistants and students. A renowned painter, he was also admired as a sculptor for his gigantic equestrian statue in clay, adored as a show organizer and respected for his research in optics, aeronautics, hydraulics, and anatomy. However, his life fell into instability in the late 1490s, after the death of Caterina and the completion of The Last Supper.]

Walter Isaacson recounts here all the professional setbacks that Leonardo da Vinci experienced during this period, including:

  • Due to the lack of substantial commissions, Leonardo had to accept small, uninteresting assignments in order to live.
  • Several quarrels because of unfinished orders and payment problems.
  • The bronze intended for the casting of the equestrian statue he was making was requisitioned (to make cannons and thus protect Milan from the French invasion).
  • He entered into conflict with the Duke, who reproached him for not progressing with his orders, while Leonardo reminded him of the delay in his salary for two years.

Finally, when Louis XII, just crowned King of France, took Milan in 1499Leonardo da Vinci decided to leave the city. Eighteen years after his arrival, Leonardo da Vinci returned home to Florence.

Chapter 20 – Florence Again

20.1 – The return

This chapter first traces Leonardo’s journey to Florence. During stops in Mantua and Venice, Leonardo brought his military expertise against the threat of an Ottoman invasion. In particular, he designed a mobile wooden lock (never implemented). He also had the idea of a corps of underwater defenders equipped with diving suits.

The author then recounts all that the city of Florence went through during Leonardo’s absence. So, when the latter set foot on the pavement of Florence, he discovered a city far from the cultural avant-gardism he had once known. A radical monk against homosexuality, sodomy, and adultery, had all books, works of art, clothes and make-up products burned at the stake (it is called the “Bonfire of the Vanities”). Although public opinion turned against him, hanged and burned him, the confidence of Florence was shaken. In the aftermath of these reactionary disturbances, [his exuberance fell to a low ebb, and the finances of his government and brotherhoods ran dry.]

However, on his return, Leonardo began the most productive period of his life. It was at this time that he began to paint the Mona Lisa and the Virgin and Child with St. Anne, his two most remarkable paintings, as well as an image of Leda and the Swan.

He also worked as an engineer, offering his services for the construction of structurally complex buildings and churches, and serving the military interests of Caesar Borgia.

Finally, he immersed himself in new mathematical and anatomical studies.

20.2 – Life at 50

Walter Isaacson describes Leonardo da Vinci, at the age of 50, as an unusual character:

[Rather than conforming to custom, he took pride in being different; he dressed and behaved like a dandy… Leonard made sure that his companion, Salai, then 24 years old, dressed with similar panache, usually in pink and old rose as well.]

Leonard lived comfortably. He spent as much on clothing as on education (he owned 116 books).

20.3 – The unrealized portrait of Isabella d’Este

In this chapter, the author of the biography of Leonardo da Vinci tells the long story of the portrait of Isabella d’Este, sister-in-law of Ludovico Sforza, Marquise of Mantua, which Leonardo da Vinci never finished.

Walter Isaacson’s long account of this episode takes the reader into the heart of the tumultuous liaisons and power struggles of the Italian Renaissance. Above all, he describes how Isabella d’Este was extremely tenacious and insistent for years to obtain a portrait of the master. Strong-headed and notable patron of the arts, the Marchioness went to great lengths to send her letters, persevere in her correspondence, and make numerous tempting proposals, even going to Florence in person to meet Leonardo… In vain. Leonardo da Vinci would never carry out this commission. According to the author, it could, however, have been lucrative, and he could have delegated much of it to his assistants. [However, Leonardo, while not rich, was above that], the author says with amusement.

Lastly, Walter Isaacson concludes, this story shows how unwilling Leonardo could be [when it came to fulfilling commissions that bored him]. It is revealing of [his dilatory style] and [his distant attitude towards wealthy patrons.] Leonardo da Vinci refused to become anyone’s subordinate:

[He was not interested in painting for an insistent patron, nor was he motivated by money. He would paint portraits if the subject seduced him, as in the case of Portrait of a Musician, or if a powerful executive asked him to, as Ludovic did for his mistresses. It was not his clients who dictated.]

20.4 – Madonna of the spindle

Lastly, the author mentions one of the most influential paintings of Leonardo da Vinci: Madonna of the spindle, delivered to the French court and copied extensively. This painting was the subject of long debates when it was necessary to identify the true work of the master to simple copies. The author revisits all these discussions. The most interesting part of this story, he says, is the collaboration and teamwork that took place in the collaborative workshop opened by Leonardo upon his return to Florence.

Chapter 21 – Saint Anne

In this chapter of Leonardo’s biography, Walter Isaacson traces the history, the different versions and studies all the pictorial details of a major painting in the artist’s work: The Virgin and Child with Saint Anne or the Saint Anne, which features the Virgin Mary sitting on her mother’s lap.

According to Walter Isaacson, this painting [expresses the supreme aspect of Leonardo’s artthe spiritual connection and analogy between the earth and the human.] Of all the painter’s paintings, this is the most complex and elaborate. It is often considered a masterpiece on par with the Mona Lisa, [perhaps even surpassing it in the complexity of its composition and the figures’ movements].


[In its final form, this painting combines most of the elements of Leonardo’s artistic genius: a scene transformed into a narrative, physical movement responding to the emotions felt, brilliant depictions of the dancing of light, a delicate sfumato, a landscape consistent with geological reality, and a color-driven perspective. This painting has been referred to as Leonardo’s ‘ultimate masterpiece’.]

Chapter 22 – Paintings Lost and Found

Walter Isaacson traces, in this chapter of the biography of Leonardo da Vinci, the history of the two lost paintings of Leonardo.

He explains that Leonardo, like most artist-craftsmen of his time, never signed his work and that in his notebooks he never mentioned what he was painting or making, nor the buyers or where his works were kept.

The two lost paintings that Walter Isaacson refers to here are:

Leda and the Swan

Walter Isaacson describes this painting as a celebration of the fertility of nature. According to him, it goes beyond the field of eroticism to focus on a story revolving around procreation, birth. The author also indicates that when Leonardo began to paint Leda, he adopted Francesco Melzi, author of the copy of the painting, who became his surrogate son and heir.

Salvator Mundi(Savior of the World)

Discovered in 2011, the story of this painting is similar to that of La Belle Princesse. The author traces the process undertaken to authenticate it, which is very revealing of Leonardo’s work.

Chapter 23 – Caesar Borgia

In this chapter, Walter Isaacson recounts a period when Leonardo da Vinci worked with Caesar Borgia, known as a cruel, “sociopathic” and ruthless warrior.

23.1 – Borgia, a ruthless warrior

The author first describes how power-hungry and bloodthirsty Caesar Borgia, illegitimate son of the libertine pope Rodrigo Borgia, came to power by having his brother stabbed. Then, he tells how Borgia invaded Milan in 1499 and then Florence in 1501 by joining forces with the French king Louis XII.

Being able to cross the Florentine territory, Borgia left to conquer other cities.

He hired two people to help him in his negotiationsFrancesco Soderini as well as the famous Nicolas Machiavelli, well-educated but poor (son of a failed lawyer), a keen observer, possessing [an exceptional pen and a fine understanding of power games.]

23.2 – Leonardo enters Borgia’s service

Leonardo joined Borgia on the orders of Machiavelli and the leaders of Florence as a military engineer and innovator. By this time, Leonardo had no desire to touch a paintbrush. He took on the role of a man of action.

Leonardo da Vinci was welcomed with open arms by [the most impetuous warrior of the time.]  Leonardo, Borgia, Machiavelli and his court settled in the fortified city of Imola between Caesarea and Bologna. Borgia relied on Leonardo da Vinci to make the city even more impregnable than it was.

“Imagine the situation,” says the author:

[For three months in the winter of 1502-1503, as if in a historical fantasy film, three of the most fascinating characters of the Renaissance – the brutal, power-drunk son of a pope, a devious and immoral writer-diplomat, and a dazzling painter longing to become an engineer – hid away in a small five-by-eight-block walled town.]

It was during this stay in Imola, in the company of Machiavelli and Borgia, that Leonardo conceived a “new military weapon”: accurate, detailed, and easy-to-read maps.

In particular, he drew a plan of Imola, [which can be considered his greatest contribution to the art of war], says Walter Isaacson. It is, according to Isaacson, [a magnificent work of military utility in an innovative style, which combines, in an inimitable way, art and science.]

23.3 – Leonardo’s departure from Borgia’s services

Borgia did not cease to commit acts of cruelty and horrible murders with the aim of intimidating the population. After a series of particularly barbaric episodes (one of the victims, Vitellozzo Vitelli, was a friend of Leonardo who had lent him a book by Archimedes), Leonardo decided to leave Borgiaafter 8 months in his service.

To conclude on this episode of the life of Leonardo da Vinci, Walter Isaacson reflects on the reasons that led the genius to work with such a ruthless man:

[Why would a man who wrote in his notebooks aphorisms decrying murder and whose personal morality led him to be a vegetarian agree to work with the most brutal murderer of his time? This partly reflects Leonardo’s pragmatism… Leonard managed to curry favor with the right actors at the right time and knew when to switch sides. That’s not all: although he knew how to distance himself from most of the events of his time, he seemed attracted by power.]

The author also explains this by Leonardo’s propensity to attach himself to strong men. Perhaps, as Freud said, because they represent [surrogates for the absent, though virile, father of his childhood.] Moreover, Leonardo, [who had just turned 50, had dreamed for more than two decades of being a military engineer], Walter Isaacson concluded. Also, this job was a chance for Leonardo to live out his military fantasies: [he seized it before understanding that dreams can turn into nightmares.]

Chapter 24 – Hydraulic Engineer

This long chapter of Leonardo’s biography is devoted to Leonardo’s work in the field of hydraulics.

As we read through the pages, we become aware of Leonardo’s hydraulic genius as well as his fascination with the phenomena of water flow. In Leonardo’s notebooks, a multitude of sketches and descriptions of mechanisms and techniques reveal all his work of research and observation in this field.

24.1 – The diversion of the Arno River

Among the hydraulic projects on which Leonardo worked, the diverting of the Arno River is one of the most significant.

In proposing this diversion project to the authorities in Florence, Leonardo presented them with a very bold political and economic strategy: Florence could thus have access to the sea and reconquer the city of Pisa [without storming the walls of the city or brandishing a single weapon.]

The author accounts for the decisive role of Leonardo da Vinci in this project. We learn, for example, that he was able to calculate, in detail, the amount of rubble to be moved and the time needed to do so (number of men and working days), and that he created an ingenious crane-shaped machine with a system of rails.

But in the end, the supervision of the work was assigned to another engineer. The latter decided not to follow the plans devised by Leonardo. He opted for another solution that ended up, as Leonardo had predicted, in failure, even causing flooding in the entire region. The initial idea of diverting the river was subsequently abandoned.

Leonardo, for his part, embarked on another project: the creation of a waterway between Florence and the Mediterranean Sea.

However, [likely scalded by the fiasco of the Arno diversion project, the Florentine authorities, short of money, gave up on the more ambitious project, which led Leonardo to shelve his aspirations in this area.]

24.2 – Draining the Piombino marshes

A few weeks after the abandonment of the diversion project, the Florentine authorities sought Leonardo’s expertise once again. They asked him to build a fortress and to drain the marshes surrounding the castle of Piombino.

Leonardo then designed fortifications, moats and secret passages to be used in case of a plot. He also designed a complete system, including a “centrifugal pump“, to siphon off the water from the marsh, but the mechanism, although perfectly thought out in theory, turned out to be impractical.

In the end, all these projects conceived by Leonardo were too fanciful to be implemented in reality and were therefore never realized. They do, however, demonstrate Leonardo’s imagination and ability to [conceive projects that constantly push back the boundaries of technical possibilities.]

Walter Isaacson concludes on Leonardo’s innovative talents:

[Every genuine vision requires a willingness to go too far and an acceptance of the possibility of failure. Innovation requires a distortion of reality. Things imagined by Leonardo have often been realized, albeit centuries after they were conceived. Diving equipment, flying machines, and helicopters are now part of our daily lives. Swamps are drained with pumps and a highway has been built along the canal that Leonardo designed. Sometimes the imaginary becomes a gateway to the real.]

Chapter 25 – Michelangelo and the Lost Battles

This chapter of Leonardo’s biography traces two key aspects of Leonardo’s life:

  • The story of the fresco of The Battle of Anghiari.
  • Leonardo’s rivalry with Michelangelo.

25.1 – The Battle of Anghiari fresco for the Florence Town Hall

The commission for The Battle of Anghiari could have been the most important work of Leonardo’s life had he completed it.

The fresco celebrates the victory of Florence’s fighters over the Duchy of Milan in a sprawling battle in 1440, and features horsemen and hand-to-hand combat on one-third of the 53-meter wall of the imposing assembly hall of the Palazzo della Signoria, Florence’s City Hall.

Walter Isaacson tells the fascinating story of the conception of this work and studies all the details of this painting.

25.2 – The rivalry with Michelangelo

The Battle of Anghiari is also important in Leonardo’s life because it brought him into competition with a young rival, who was chosen to paint another large fresco in the entrance to the Town Hall. This rivalboth professional and personal, was Michelangelo.

The saga recounted by Walter Isaacson in this chapter highlights the contrasting styles of the two greatest painters of the century.

Leonardo da Vinci and Michelangelo: two personalities at odds

When Leonardo da Vinci returned from Milan, Michelangelo had become the new artist in vogue in Florence. The Medici took him under their wing. However, the young painter had a reputation for being quarrelsome, unlike Leonardo. He had rivalries with many artists and was particularly contemptuous of Leonardo.

[Michelangelo, then 25 years old, was a well-known but irascible sculptor, in contrast to Leonardo, then 48 years old, who was known as a genial and generous painter surrounded by many friends and young students.]

Michelangelo’s slovenly, ascetic lookwith his hunched back, was in contrast to Leonardo’s handsome, muscular, elegant look, with colorful furs and clothes.

Moreover, unlike Leonardo, who was not Catholic:

[Michelangelo was a pious man torn in his faith between agony and ecstasy. Both were homosexuals, but while Michelangelo suffered from this and apparently imposed celibacy on himself, Leonardo experienced no torment and was open to the idea of having male companions.]

The divergent artistic approach between the two

In his fresco, Michelangelo portrayed a dozen naked muscular men. Leonardo, who was not at all in the habit of denigrating other painters, criticized these nudes several times, reproaching Michelangelo for painting like a sculptor.

[The divergent approach of the two artists represented the two schools of Florentine art: that of Leonardo, Andrea del Sarto, Raphael, Fra Bartolomeo and others, who readily resorted to the technique of sfumato and chiaroscuro, and the more traditional approach adopted by Michelangelo, Agnolo Bronzino, Alessandro Allori and others, who preferred a drawing with very sharp outlines.]

25.3 – Project abandonment

In the end, neither Leonardo’s fresco nor Michelangelo’s would ever be completed.

Leonardo procrastinated and struggled to make his oil paint mixtures adhere to the wall. He eventually left for Milan, leaving his painting unfinished. [Leonardo was a perfectionist], says the author: [faced with challenges that many artists would simply choose not to take, he could not bring himself to ignore them and preferred to abandon his brushes.]

Michelangelo also left Florence for Rome. He remained there for 10 years and painted the ceiling of the Sistine Chapel during this period.

Chapter 26 – Return to Milan

26.1 – Death of Ser Piero

Piero, Leonardo’s father, died at the age of 78. He left nothing to Leonardo.

The relationship between Leonardo and his father had always been complex. Although Piero helped his son to obtain various pictorial commissions, Leonardo did not always keep his commitments. This surely caused tension between them.

Piero was married four times and had 11 children by his last two wives. The age difference between Leonardo and his half-siblings (they could all be his children) was such that they would not consider him a potential family heir.

So, when he learned that his father had left him nothing, Leonard became disturbed. For even if he did not deliberately decide to disinherit Leonard, his father knew well that after his death his property would be divided among his legitimate sons only if he had not done anything beforehand.


[Leonardo was born illegitimate, his father did not recognize him as a child and, upon his death, he ‘delegitimized’ him even more so.]

26.2 – Departure from Florence and adoption of Francesco Melzi

In 1506, Leonardo da Vinci moved to Milan for the second time. His decision to leave Florence was probably due to two things. First, he did not seem to want to continue [struggling for his battle scene] and [competing with an artist younger than himself who painted like a sculptor.] Second, he probably no longer wanted to live in the same city as his half-siblings.

Leonardo stayed in Milan for seven years. It was there that he met Francesco Melzi, the 14-year-old son of a prominent nobleman, a former civil engineer, who had also been a captain of the militia. A student of art, Francesco was an excellent draftsman.

Leonardo went on to spend a lot of time in Francesco’s large family villa overlooking Milan.

[Leonardo, then 55 years old, had neither son nor heir. The young Francesco was a budding artist with some talent, whose gentle beauty was reminiscent of Salai. With his father’s permission, Leonardo adopted him… Leonardo became a sort of legal guardian, godfather, adoptive father, teacher, and employer of young Melzi… Francesco Melzi would stay by Leonardo’s side until the end of his life. He served as his personal assistant and secretary, wrote his letters, kept his papers in order, and preserved them after his death.]

The exact nature of the relationship between Francesco and Leonardo (whether romantic or sexual) is unknown. Nevertheless, [with his talent, his efficiency, and the constancy of his temperament, he was a devoted companion to Leonardo, much less tormented and infernal than Salai], says the author.

26.3 – Florentine interlude: battle for an inheritance

While living in Milan, Leonardo had to return to Florence to settle an inheritance dispute with his half-siblings. Since he received nothing when his father died, his beloved uncle, Francesco da Vinci, changed his will before he died. He bequeathed his estate to him.

The dispute is resolved after eight months. Leonardo returns to Milan where he is eager to resume living.

In fact, in Milan:

[Charles d’Amboise worked to create a court, like that of the Sforza, composed of painters, entertainers, scientists, mathematicians and engineers. Leonardo was the most prized of these, for he embodied all such vocations.]

[Beyond its intellectual ferment, Milan organized dazzling parades and festivities that far surpassed those of the Republic of Florence], says Walter Isaacson. And Leonardo had plenty of time to indulge his many passions (geology, water, birds, optics, astronomy, architecture, entertainment, etc.).

Chapter 27 – Anatomy, Round Two

In the lengthy chapter 27 of Leonardo da Vinci’s biography, Walter Isaacson lays out in great detail all the discoveries and work that Leonardo achieved in the fields of anatomy, as well as the way he combined them with his art. According to him:

[Anatomy shaped Leonardo’s art, but the reverse was equally true: his artistic (sculpture and drawing) and engineering skills were interdisciplinary and helped him in his anatomical research.]

All these anatomical works cannot be developed here as they are very numerous; however, here’s a compilation of them.

27.1 – His dissections

From 1508 to 1513, Leonardo da Vinci conducted his research with a young professor of anatomy, Marcantonio della Torre, who supplied him with human corpses.

According to Walter Isaacson:

[Leonardo was as skilled with a pen as he was with a scalpel. His powers of observation and visual memory enabled him to draw pictures that surpassed any anatomical treatise that had ever been published up to that point.]

Among the anecdotes mentioned by the author, one is quite peculiar: one day, Leonardo engaged in a conversation with an old man who was more than a hundred years old at the time. During this discussion, the old man explained to Leonardo that he had never been sick in his life. A few hours after their exchange, the centenarian died; he passed away peacefully without any movement or symptoms of illness. Leonardo would then dissect his corpse.

27.2 – His list of “strange” tasks

Examples of bizarre tasks that Leonardo wanted to accomplish include describing the tongue of a woodpecker (Leonardo was fascinated by the muscles of the tongue) or the jaw of a crocodile.

27.3 – His anatomical analogies

[In most of his studies of nature, Leonardo developed his theories by analogy. His quest for knowledge in all disciplines of the arts and sciences allowed him to identify recurring elements.]

As such, with regard to the human body, Leonardo da Vinci established various analogies. He compared, for example:

  • The flows and the ramifications of the human digestive, urinary, and respiratory systems with the flow of rivers, the movement of the air, and the branches of the plants.
  • The human body and machines: he paralleled the movement of muscles and the body with the mechanical rules formulated during his engineering research.

In fact:

[This interdisciplinary thinking and search for analogies was his trademark: Leonardo was the perfect embodiment of the Renaissance man but also a pioneer of scientific humanism.]

27.4 – His anatomical studies

  • Muscles and bones

Leonardo began to study human muscles initially to serve his art, but he would then continue out of pure curiosity.

  • Lips and smiles

[Leonardo was particularly interested in how the human brain and nervous system translated emotions into bodily movements. Of all these nerves and related muscles, those that control the lips are the most important to Leonardo], according to Isaacson.

  • The heart

Passionate about hydraulic engineering and fascinated by flows and liquids, Leonardo made incredible discoveries in this field. [He was one of the first to truly understand that it is the heart, and not the liver, that is at the center of the blood system], the author states. Yet his work would not be fully appreciated until centuries later.

  • The aortic valve

Leonardo da Vinci was the first to understand how the aortic valve works. This discovery would not be confirmed until modern times. Leonardo developed his hypothesis by analogy concerning the swirling of blood:

[Using his knowledge of water and air vortices, he assumed that the flow of blood spirals down the aorta… It would take anatomists 450 years to realize that Leonardo was right.]

  • The fetus

Leonardo depicted the beginning of life in an emblematic drawing found on a page of his notebooks. This drawing shows a fetus in the womb. In addition to being a good anatomical study, it [is almost sublime], according to the author, [as if it were rather a work of art.] It carries a spiritual dimension. When he made this drawing, Leonardo was studying botany. Leonardo made analogies between his botanical research and the fetus:

[Just as he made an analogy between the branching of plants and rivers and that of blood vessels, he noticed similarities between the germination of seeds and the development of human embryos. Plants have a stalk, called a funiculus, that connects the seed to the wall of its ovule until the seed is ripe, and Leonardo realized that it serves the same function as an umbilical cord.]

27.5 – Lost influence

Once again, Leonardo made little effort to share all his knowledge. His intention to publish the findings of all his anatomical studies was undermined by his disinterest in organizing his notes into a collection.

In the end, Leonardo’s passion for knowledge always prevailed:

[The treasure trove of treatises he did not publish is testament to the unusual nature of his motivations. He wanted to accumulate knowledge for himself and for his own pleasure, rather than to make a name for himself as a scholar or to advance humanity.]

Chapter 28 – The World and Its Waters

In this chapter of the biography of Leonardo da Vinci, Walter Isaacson details all the discoveries of the scientific genius concerning the world and the waters.

28.1 – The microcosm and the macrocosm

At the same time that he was studying the human body, Leonardo was also probing the body of the Earth. As usual, he made analogies between the two. Here is what Leonardo wrote in one of his notebooks comparing the microcosm and the macrocosm:

[Man has been called by the ancients a ‘lesser world’, and indeed the term is well applied. Seeing that if a man is composed of earth, water, fire, and air, this body of earth is similar. While man has within himself bones as a stay and framework for the flesh, the world has stones which are the supports of earth. While man has within him a pool of blood wherein the lungs as he breathes expand and contract, so the body of the earth has its ocean, which also rises and falls every six hours with the breathing of the world; as from the said pool of blood proceed the veins which spread their branches through the human body so the ocean fills the body of the earth with an infinite number of veins of water.]

For Leonardo, this relationship between microcosm and macrocosm has a spiritual component. This mystical link between man and the earth is reflected in many of his masterpieces.

Moreover, as he considered the earth as a living organism, Leonardo also explored how it ages and evolves. He came to realize that nature possesses two traits that at times seem to oppose each other: a unity that is found in its recurring patterns and analogies, but also in its infinite and marvelous variety.

28.2 – Water

One of Leonardo’s notebooks – the Leicester Codex – shows in a fascinating way the extent to which Leonardo sought to understand the causes and effects that govern our cosmos, [from our muscle biomechanics to the movement of the planets, from the flow of our arteries to that of rivers.]

For Leonardo, the most fundamental force on earth and in our bodies lies in the movement of fluids, and in particular, water. This is why hydrodynamics was central to all his interests, whether artistic, scientific, or technical.

In this section, Walter Isaacson develops, in detail, all of Leonardo da Vinci’s studies concerning water. What fascinated him above all, in the dynamics of water, was how it could be disturbed: diversions, whirlpools, dissipation, and vortexes. Among many discoveries, Leonardo understood, for example, that vortices also occur in the air (spiral). He also made an analogy between the concept of waves and emotions, which also propagate in the form of waves (waves of emotion).

28.3 – The revised and corrected analogy

The author insists here on Leonardo’s capacity to question himself and his open-mindedness. [This ability to let go of preconceived ideas is the key to his creativity], contends the author.

By way of example, Walter Isaacson tells us that Leonardo da Vinci easily abandoned the seductive idea of the analogy between the circulation of water on earth and the circulation of blood in the human body when he realized that his analogy between the macrocosm (the earth) and the microcosm (man) was erroneous.

28.4 – Geological phenomena, astronomy, and the blue sky

In this part of the book “Leonardo da Vinci – The Biography“, Walter Isaacson highlights all the demonstrations and discoveries of Leonardo da Vinci in geology and astronomy.

  • Geological phenomena of erosion and fossilization

The author states that Leonardo was two centuries ahead of his time on this subject.

  • Astronomy

Decades before Copernicus and Galileo, before discovering that the sun did not revolve around the Earth, Leonardo had already understood that:

  • The sun “is immobile”.
  • The Earth “is only one of many cosmic bodies, and not necessarily the central one”.
  • The moon “does not emit light but reflects the light of the sun” (a person on the Moon would see that our planet reflects light in the same way).

Leonardo intended to write a treatise on astronomy, but this work would never see the light of day.

  • The blueness of the sky

Leonardo pondered this ordinary and banal question that no one had asked themselves since childhood, but to which the greatest geniuses, from Aristotle to Leonardo da Vinci, via Newton, Rayleigh and Einstein, had tried to provide an answer: why is the sky blue? Leonardo [considered many explanations and finally found a solid and essentially correct one]: [The azure that we see in the atmosphere is not its specific color. The atmosphere owes its blue color to the particles of moisture which capture the luminous rays of the sun], wrote the scientist in his notebooks.

Chapter 29 – Rome

29.1 – Villa Melzi

In 1512, to escape political unrest (wars in Italy led by France), Leonardo decided to leave Milan. He moved 30 kilometers away to the comfortable family home of his student and adopted son, Francesco Melzi, aged 21. At the Villa Melzi, Leonardo could indulge his varied passions in complete peace of mind.

29.2 – Portraits of Leonardo

During his stay in Villa Melzi, surrounded by those who practically made up his family, Leonardo entered his sixties.

Walter Isaacson’s portrayal of the 60-year-old Leonardo is based on portraits and sketches drawn by Leonardo himself. Many of them depict a distinguished, aging sage with long, curly hair, and a drooping beard.

The most famous and beautiful of all these portraits is, according to Walter Isaacson, the Portrait of a Man in Red Chalk.

Although the characters drawn always look older than Leonardo actually was (perhaps he drew himself as he imagined himself to be, the author speculates), these mysterious portraits bear a strong resemblance to Leonardo. Therefore, the preponderance of experts are near certain that he was indeed the subject, thus confirming the image we have of the master:

[Taken together, these drawings and paintings seal the image of Leonardo as the icon of a bearded genius and a noble Renaissance scholar, who was simultaneously spirited, absent-minded, passionate, and melancholic.]

29.3 – In Rome

In 1513, Leonardo left Milan for Rome.  This was a new experience. He had never lived there prior.

Leonardo moved with Francesco Melzi, Salai, and three other relatives, to the elegant summer palace of the pope, the Belvedere, on the heights of Rome, where apartments were allotted to him. He would stay there for three years.

The building housed the favorites of Pope Leo X and his brother Julian de Medici. The latter was passionate about art and science, and it was he who suggested to Leonardo that he come to Rome. As a result, and thanks to Julian’s patronage, Leonardo had a large household of assistants and students. Despite the tempting demands of art-hungry patrons, Leonardo had no desire to paint and therefore did not paint. He preferred to study the rare plants in the palace gardens and was interested in mirrors at that time. Fascinated by the manufacturing process of concave mirrors, he decided to produce them for the wardrobes of the pope and Julian.

[The place was ideal for him. Slightly out of the way and isolated, but home to a court of artists and scientists, the Belvedere and its gardens blended grand architecture with natural wonders, including a menagerie, a botanical garden, orchards, and a fishpond.]

One day while accompanying Pope Leo to Bologna, Leonardo met the new king of France, Francis I. As Julian’s influence was beginning to wane, a new opportunity would arise for Leonardo…

Chapter 30 – Pointing the Way

Here, Walter Isaacson expands on the many questions that arose around two paintings. These were done late in life more out of personal passion than in response to a commission. These two paintings are:

  • The Portrait of Saint John the Baptist.
  • The Angel of the Annunciation and Angel Incarnate.

Chapter 31 – The Mona Lisa

The 31st chapter of Walter Isaacson’s biography of Leonardo da Vinci is devoted entirely to Leonardo’s most famous painting: The Mona Lisa.

31.1 – The climax

Leonardo da Vinci began painting the Mona Lisa after returning from his service with Borgia in 1503. After that, he never stopped working on the painting. The Mona Lisa followed the master to Florence, Milan, Rome, and then to France, where he added further touch-ups until 1517. However, Leonardo never delivered the portrait and never received payment for it:

[The painting would be found in his workshop at the time of his death. It is therefore logical to consider Mona Lisa as his late career work and to see it, in every one of its details, as the culmination of a life dedicated to perfecting the ability to combine art and nature.]

Walter Isaacson quotes Kenneth Clark to highlight the artist’s talent in the famous Mona Lisa portrait:

[The science, the pictorial skills, the obsession with nature, the psychological insight are all present and so perfectly balanced that we are hardly aware of them at first glance.]

In particular, it shows:

  • The complexity of human emotions marked by the mystery of a suggested smile.
  • The link between our nature and the universe that surrounds us. Two landscapes are intertwined, says the author: [that of the soul of Mona Lisa and that of the soul of nature.]

The author mentions here another painting: the Portrait of Ginevra de’ Benci, posing in front of a river, the bust of three quarters. This portrait, begun at the very beginning of Leonardo’s career, in Verrocchio’s studio, bears a striking resemblance to the Mona Lisa, which he undertook forty years later. The difference between the two works, however, highlights Leonardo’s progress as a painter, but above all the maturity he had acquired as a scientist, philosopher, and humanist.

31.2 – The commission

The Mona Lisa is a portrait of a 24-year-old woman, Mona Lisa, whose real name was Lisa del Giocondo (“Mona” is a contraction of Madonna, Madame in French). It was her husband, Francesco del Giocondo, who commissioned Leonardo to paint her.

At that time, the painter rejected the incessant pleas of Isabella Este, a much richer and more prominent patron. He was also very busy with his scientific research and was reluctant to pick up a brush. So, why did Leonardo accept this commission? According to Walter Isaacson, he was probably persuaded because he was a client of his father, a friend of the family. Above all, he agreed to paint the Mona Lisa because he was interested in her mysterious air and her charming smile. The icing on the cake: the seductive Mona Lisa is neither a famous noblewoman nor the mistress of a nobleman. [Without having to cater to the whims or respecting the instructions of a powerful client], this allowed him complete freedom to paint this portrait as he so wished.

31.3 – But is it really Lisa?

Many mysteries and controversies surround the Mona Lisa painting. Walter Isaacson points out two grey areas:

  • Here, he discusses another plausible version attributed to the Mona Lisa painting: it is indeed Mona Lisa, but the portrait could have been commissioned not by her husband but by Giuliano de’ Medici, who could have had a Shakespearean relationship with Lisa. Walter Isaacson tells how Julien, as a teenager, could have been the lover of the beautiful Lisa and therefore wanted this portrait. This version would explain why Leonardo da Vinci never delivered the portrait of his wife to Francesco.
  • Some people believe that there are in fact two distinct paintingsMona Lisa and La Gioconda (in Italian). The author explains the ins and outs of this controversy, linked to writings at the time of his death. If this hypothesis were correct, then it would mean that Mona Lisa would not be Mona Lisa. Nevertheless, the author of the biography of Leonardo da Vinci, who has studied the artist’s life in depth and all his notebooks, is categorical: for him, there is no doubt that the Mona Lisa is indeed Mona Lisa, Lisa del Giocondo.

31.4 – Analysis of the Mona Lisa portrait

Walter Isaacson provides a detailed and meticulous description of the Mona Lisa. He discusses:

  • The eyes of the Mona Lisa

In many of Leonardo’s other portraits, the subject’s eyes seem to follow the viewer as he/she moves. Although Leonardo was not the only one to create this effect, it is so closely associated with him that it is known as the “Mona Lisa” effect.

[Stand in front of the work and the subject is looking at you; move from side to side and its gaze always seems to be pointed directly at you.]

  • The smile of the Mona Lisa

The smile of the Mona Lisa is, according to Walter Isaacson, the most mystical and captivating element of all. [Never in a painting have movement and emotion, the cornerstones of Leonardo art, been so intertwined], declares the author. Then, he specifies that [at the time when he was perfecting the smile of Lisa, Leonardo spent his nights in the depths of the morgue.]

[It was in the morgue that Leonardo da Vinci, fascinated by the anatomy of the face, sought to understand how the smile is formed. He removed the skin of many corpses in order to study muscles and nerves. Leonardo analyzed the possible movements of each part of the face. He researched the origin of each of the nerves controlling each facial muscle.]

Moreover, thanks to his studies of optics, Leonardo realized that:

[When we look at an object directly, it appears sharper. When we look at it with peripheral vision, from the corner of the eye, the same object appears a little blurred, as if it were further away. Thanks to this knowledge, Leonardo was able to create an elusive smile, which evades the viewer wishing to see it more than he/she can.]

After discussing copies of the Mona Lisa and various debates (such as whether to proceed with a cleaning of the original to reveal new discoveries and restore it to its full splendor), Walter Isaacson concludes, regarding the Mona Lisa:

[The Mona Lisa became the most famous painting in the world not only because of media hype and happenstance but also because viewers were able to establish a deep emotional connection with it… Lisa, sitting on her balcony against the backdrop of geological eternity, symbolizes Leonardo’s profound meditation on the meaning of the human condition.]

Chapter 32 – France

32.1 – Last trip

[Leonardo spent a large part of his career looking for patrons who were unconditionally paternalist, encouraging and indulgent, at least more so than his own father had generally been towards him.]

We realize that [up to that point, none of Leonardo’s benefactors had been up to the task.]

However, it was during his trip to Bologna in 1515, alongside Pope Leo X, that Leonardo met his last and most devoted patron: Francis I, the new king of France. The 21-year-old king has just succeeded his father-in-law Louis XII. He was a great admirer of Leonardo da Vinci. He collected his works.

After this meeting, Francis I, encouraged by his mother, Louise of Savoy, kept inviting Leonardo to come to France.

Just at that time, Julien de Medici died. Leonardo had a complicated relationship with the rest of the Medici family (“The Medici created me and destroyed me”, he wrote cryptically in one of his notebooks). He therefore accepted the invitation of the king of France.

Leonardo was 64 years old when he left Rome, with his companions, to join the king’s court. It was the first time he had left his country. He knew that this trip would probably be his last. On the way, the convoy stopped in Milan where Salai decided to stay. He moved into the house and vineyard that Leonardo had received from Ludovico Sforza. Salai would visit Leonardo until his death. Battista de Villanis, Leonardo’s new servant, who accompanied them, [quickly replaced him in Leonardo’s heart.] Melzi, as for him, continued the road with Leonardo.

32.2 – Francis I

Leonardo da Vinci and Francis I: “teachers of each other”

King Francis I was a great, charismatic, and courageous man. He was also a good person, who was civilized and cultured (his mother was also very civilized). He was a lover of the Italian Renaissance and wanted to spread it in France.

Francis I also possessed the same devouring thirst for learning [in fields as varied as those that fascinated Leonardo da Vinci.] He loved poetry, music, literature, science, mathematics, geography and history. He could speak Italian, Latin, Spanish, and Hebrew.

[He was sociable and a lover of women, with a dashing appearance and a reputation as a graceful dancer, a great hunter and a powerful wrestler. After spending a few hours each morning on state affairs, he would ask to be read the great authors of ancient Rome and Greece. He would also put on plays and shows at night. Leonardo was a perfect recruit for his court.]


[Francis proved to be the ideal patron for Leonardo. He admired the master unreservedly, never pestered him to finish his paintings, encouraged his love of engineering and architecture, encouraged him to put on shows and fantasies, provided him with a comfortable home and paid him a regular salary. Leonardo was given the title of “first painter, engineer and architect to the king,” but his value to the king was his intelligence, not his production. Francis had an insatiable thirst for knowledge, and Leonardo was the best source of empirical knowledge in the world. He could educate the king on virtually any subject, from how the eye works to why the moon shines. In turn, Leonardo learned from this elegant and erudite young monarch.]

Francis I, “completely in love” with Leonardo

The two men grew fond of each other and spent much time together. Francis offered Leonardo a comfortable salary, no matter how many paintings he produced. He provided him with the small red-brick manor house of Le Cloux (now called Le Clos Lucé) in the Loire Valley. The residence was built in the heart of a hectare of gardens and vineyards. It was connected to the castle of Amboise, where François I lived, by a 500 meter tunnel. 

32.3 – The visit of Antonio de Beatis

Walter Isaacson recounts the visit of Cardinal Louis Aragon, whom Leonardo welcomed in 1517, accompanied by the 40 members of his retinue. Among them, Antonio de Beatis wrote about the visit in his diary. Leonardo is portrayed as [the most eminent painter of the time], admired by his contemporaries. The old man is, according to him, comfortably settled in his manor, [brooding over the paintings he loves and exhibiting them like personal treasures.] He suffered from paralysis of his right hand. He could no longer paint but continued to draw and teach, notably in Melzi. 

32.4 – Romorantin

The king offered Leonardo one last mission: to design a new complex of cities and palaces for the royal court in the village of Romorantin, 80 kilometers from Amboise.

This mission was perfect for Leonardo. It offered him the opportunity to give free rein to several of his passions: architecture, urban planning, hydraulics, engineering, and even the organization of festivals and shows.

However, the project was eventually abandoned in 1519 (the year of Leonardo’s death). The king decided instead to build his new castle at Chambord, still in the Loire Valley.

32.5 – Drawings of a flood

Walter Isaacson presents the 16 drawings of a flood by Leonardo da Vinci during his latter years in France.

These drawings, intended to be exhibited or to accompany the reading of an apocalyptic tale, have, according to the author, a unique artistic power. Alternating between reality and fantasy, they are [the product of the fevered and frenzied imagination] of the genius.

In these drawings, Leonardo describes the apocalyptic flood and the emotions of the men confronted with the unleashing. It contains meticulous depictions of the currents and whirlpools that form in the water when it is diverted.

[The drawings of the flood conjure up the Genesis story, a subject treated by Michelangelo and many other artists over the years. Leonardo chose to look at it differently by making no mention of Noah and to go far beyond the biblical tale by adding Greek and Roman gods to the fray.]

At no point in his writings or drawings depicting the flood does Leonardo mention the wrath of God. Rather, he expresses his belief that chaos and destruction are linked to the power of nature.

32.6 – The end

His will

About a month before his death, Leonardo began to put his affairs in order. He had his will drawn up by a notary.

The author specifies the wishes mentioned by Leonardo da Vinci in this will. The most noteworthy are:

  • His half-brothers: Leonardo bequeathed them a substantial sum of moneyand the property he had inherited from his uncle Francesco, [thus likely settling the dispute between them], the author contends.
  • Francesco Melzi: as a legally adopted son, he was Leonardo’s de facto heir. He was appointed executor of the will and received most of the estate.
  • Battista de Villanis, his last servant and companion: he received water rights and half of the vineyardgranted to him in Milan by Ludovico Sforza, as well as all his furnishings and household utensils.
  • Salai: Leonardo, who had distanced himself from Salai, left him the other half of the Milanese vineyard. However, true to his reputation, Salai managed to obtain a number of copies of Leonardo’s paintings, and even a few originals such as the Mona Lisaand Leda and the Swan.

The death of Leonardo da Vinci

Leonardo da Vinci died at the age of 67, on May 2, 1519.

The image of Leonardo’s death has been painted by many admiring artists.

Leonardo da Vinci – The Biography” shows here, as an example, the famous painting by Jean-Auguste-Dominique Ingres, entitled Death of Leonardo da Vinci: the painting represents Leonardo expiring in the arms of the king. This scene is a possibility, the author explains, but not attested.

[Here is the final scene, sublime and worthy of the character: Leonardo curled up on his deathbed, snuggled in the arms of his powerful and generous patron, in his comfortable home, surrounded by his favorite paintings.]

Leonardo was buried in the church of the Château d’Amboise, which was demolished in the early 19th century. What are likely his remains, found 60 years after the demolition, are buried under a funerary slab in the chapel of Saint-Hubert adjoining the castle. 

Chapter 33 – Conclusion

33.1 – Genius

A genius, but not a superman

For the author of the biography of Leonardo da Vinci, there is no doubt that Leonardo da Vinci is a genius:

[At this point, I hope you will agree that Leonardo was a genius, one of the few figures in history who unquestionably deserves that title or, to be more precise, earned it.]

However, the works left unfinished by Leonardo da Vinci demonstrate that he was not, however, superhuman. For the author, this prevalent and distinctive characteristic of Leonardo da Vinci says a lot about the artist:

  • First, that he much preferred to take on the challenge of conception rather than the task of accomplishment.
  • Second, that he was driven by the changing world, and he liked it.
  • And finally, that hesaw his art, engineering, and treatises as a dynamic process that could always be improved as new knowledge was learned and applied.

Walter Isaacson calls Leonardo da Vinci a genius for several reasons. Leonardo da Vinci, he says, [foresaw what innovators would conceive centuries after him.]

And [what makes Leonardo a genius, what distinguishes him from those who are only extraordinarily intelligent], the author  affirms, is:

  • His creativity, his ability to apply imagination to intellect.
  • The ease with which he could combine observation with fantasy: this enabled him to make [unprecedented leaps to connect the visible with the invisible.]
  • His universal nature: there are many other thinkers who were deeper or more logical, more pragmatic, but none were as creative in so many different fields. Many geniuses are geniuses but in specific disciplines (like Mozart in music or Euler in mathematics for example).

[Leonardo was a genius, but he represented much more: he embodied the quintessence of universal thought, a man who sought to understand all of creation, including our place within it.]

33.2 – Learning from Leonardo

Walter Isaacson ends his conclusion by listing all that he believes we can learn from the great humanity and genius of Leonardo.

[Leonardo was not only a genius, but also a being of great humanity – eccentric, obsessive, playful, and easily distracted, which rendered him more accessible. He was not gifted with a kind of mastery that is completely inconceivable to us. No. He was a self-taught man who single-handedly carved his own path to his genius. So, although the rest of us could only dream of having such talent, we can learn from him and try to be more like him. His life is full of lessons.]

And so here is what Walter Isaacson says Leonardo’s life teaches us:


Curiosity is truly Leonardo da Vinci’s most distinctive and incredible trait. He was interested in everything, all the time. His journey emboldens us to learn voraciously as well – not necessarily out of utility, but rather as an end in itself, out of pure pleasure.

Child-like wonder

Many of us stop questioning everyday phenomena when we become adults. We may appreciate the beauty of a blue sky, but we no longer question why it is blue, for example. Leonardo, on the other hand, was always amazed.

To observe

Leonardo had this incredibly acute faculty of observation.

To start with the details

In order to observe something attentively, Leonardo wrote in one of his notebooks that one must proceed step by step, [starting with the smallest detail.]

To imagine the unimaginable

Leonardo’s first activity during his formative years was to make actors appear, to stage performances and plays.

Leonardo’s activities throughout his life allowed him to cultivate his great creativity. The staging of all these shows, for example, led him to mix theatrical ingenuity and fantasy. Thus, he developed a combinatorial creativity: he could [see birds flying, but also angels; lions roaring, but also dragons.]

To go down ”rabbit holes”

Leonardo da Vinci delved into every subject he studied. His notebooks are full of notes that show the pleasure he took in getting to the bottom of things (for example, there are 169 attempts to square the circle, 730 results on the flow of water, a list of 67 words describing different types of water movements, the measurements of each of the segments of the human body and the calculation of their proportional relationships, etc.).

To let yourself become distracted

Leonardo’s passionate quests led him to stray down parallel paths. Leonardo studied in depth all the subjects that caught his attention. For Walter Isaacson, it was clearly this posture that fostered the multiple connections he made between things.

To respect facts

When he had an idea in mind, Leonardo da Vinci tested it by experiment.  If his experiment showed that his theory was not correct, then he abandoned it and looked for a new one. Leonardo was a precursor because this approach, which is lost today, became common a century later, with Galileo and Bacon.

To procrastinate

In fact, when he procrastinated, Leonardo did not do nothing: his method consisted in gathering, at first, all the facts and all the possible ideas. Then, only after this step, he simmered this set of ingredients. To illustrate this idea, Walter Isaacson quotes Leonardo da Vinci here addressing the Duke of Milan:

[Creativity requires time for ideas to marinate and intuitions to gel. Men of lofty genius sometimes accomplish the most when they work least], he explained, [for their minds are occupied with their ideas and the perfection of their conceptions, to which they afterwards give form.]

On the other hand, Leonardo da Vinci was a perfectionist. Therefore, he would prefer to abandon a project rather than make something “just good enough.

[Until his death, he would take masterpieces such as Saint Anne and the Mona Lisa with him on each of his trips, with the idea that he would always have to add a new brushstroke.]

According to Walter Isaacson, Leonardo da Vinci knew that [true artists value beauty, even the beauty of invisible parts.]

The author then invites us to do as Leonardo da Vinci: sometimes it is a good idea not to deliver a product until it is perfect.

To adopt a visual way of thinking

Unable to formulate equations and abstract mathematical concepts, Leonardo had no choice but to visualize them. He therefore adopted a visual way of thinking for his studies of proportions, his rules of perspective, his calculation of reflections from concave mirrors, and his methods of changing a shape without changing its size.

To avoid a silo mentality

Leonardo’s approach blurred the lines between science and art. According to Walter Isaacson:

[Leonardo was a free spirit who strolled cheerfully through all the disciplines of the arts, sciences, engineering, and humanities. With his knowledge of how light hits the retina, he shaped the perspective of The Last Supper, and on the page where he drew his anatomical views of the dissection of the lips, he sketched the smile that would reappear in Mona Lisa. He knew that art is a science and that science is an art.]

To not become complacent

The author invites us to imagine ourselves creating something totally inconceivable (as Leonardo did with his flying machine, the diversion of the Arno River) or solving an insolvable problem (as Leonardo did with squaring the circle). It is a way to blur the lines between imagination and reality.

To create for yourself, not just your patrons

Leonardo da Vinci did not want to depend on anyone and was free to create. Case in point:

[The very powerful and wealthy Marquise Isabella d’Este begged him, but Leonardo would not paint her portrait. However, he did paint the portrait of a silk merchant’s wife, named Lisa. He did it because he wanted to, and he continued to work on it for the rest of his life, without ever sending it to his client.]

To collaborate

[Genius is often thought of as the prerogative of loners who, entrenched in their garrets, are struck by creative enlightenment], writes Walter Isaacson. While this idea may be somewhat true, it is not true of Leonardo da Vinci.

Many of the artist’s creations are in fact the result of collaborations (such as the Madonna of the Rocksthe Madonna with Spindle and many other paintings). So much so that it is difficult to know who painted what on these paintings. Another example is the Vitruvian Man. This drawing is nothing more and nothing less than [the fruit of sharing ideas and sketches with friends.]

Lastly, Leonardo’s theatrical works as well as his best anatomical studies were all produced in partnership (teamwork at the court of the Sforza castle as far as the shows are concerned and in partnership with Marcantonio della Torre as far as anatomical research is concerned).

According to the author of Leonardo da Vinci’s biography:

[Genius is born with the intelligence of an individual. It requires a singular vision, but its realization often involves working with others. Innovation is a team sport. Creativity is a collective endeavor.]

To make lists of odd things

The to-do lists Leonardo kept are a testament to his immense curiosity about subjects as unlikely as they are varied.

To take notes exclusively on paper

Walter Isaacson encourages us to write down our thoughts in notebooks:

[Five hundred years later, Leonardo’s notebooks stand to amaze and inspire us. Five decades from now, our own notebooks, will still be there to amaze and inspire our grandchildren, which is not the case with our tweets and Facebook posts.]

To remain open to the mystery

Finally, for Walter Isaacson, Leonardo da Vinci teaches us that [not everything has to be clear-cut or precisely defined.] Let’s leave room for some mystery in our lives.


The book “Leonardo da Vinci – The Biography” includes an epilogue that contains:

  • Information that the author has learned and passes on to us regarding the tongue of the woodpecker, before adding:

[I thought that after reading this book, like Leonardo who once wrote “Describe the tongue of the woodpecker” in one of his eclectic and strangely inspiring to-do lists, you might like to know more about the tongue of the woodpecker. Just out of curiosity. Out of sheer curiosity.]

  • Information about Leonardo’s notebooks: the author lists their names, and for each, where they are located, who owns them, and whether they can be consulted.
  • Dozens of pages of sources used by the author and notes to complete the already extremely well-documented account.

Conclusion of “Leonardo da Vinci – The Biography” by Walter Isaacson

An extremely well-researched book

Walter Isaacson’s biography of Leonardo da Vinci is probably the most dense (nearly 600 pages) and documented (nearly 50 pages of notes and sources) that exists. It is also absolutely captivating.

Three points are worth highlighting.

The narrative and journalistic talent of Walter Isaacson

The author skillfully reconstructs the life story of Leonardo da Vinci.

The book reads like a novel with a touch of journalism, in chronological and thematic form.

As the chapters progress, Walter Isaacson takes the reader on an extraordinary journey into the heart of the Italian Renaissance. It is a compelling narrative, filled with detailed anecdotes, all sourced and extremely well-documented. Isaacsons‘ flowing and pleasant writing style makes it easy to read, so much so that the 600 pages fly by.

A complete biography, supported by recent discoveries

This book provides a comprehensive overview of the scope of Leonardo da Vinci’s genius, from his origins to his death.

Walter Isaacson’s biography of Leonardo da Vinci draws on the most recent findings on the subject. It recounts the events that marked the life of the master, the context in which he lived, his research, his collaborations, his ideas, his works, his approach. Walter Isaacson’s biography is essentially based on the 7,200 pages of notes written by Leonardo da Vinci in his notebooks. However, it also takes into account the testimonies of his time, other biographies, and research on the artist’s life.

This book is a deep dive into the mind and creative process of Leonardo da Vinci.

The quality of the illustrations and appendices

The book “Leonardo da Vinci – The Biography” contains many good illustrations. It begins and ends with a number of highly relevant appendices. Throughout the pages, the author notably includes:

  • Extracts from Leonardo’s notebooks(sketches, drawings, notes, etc.).
  • Photos and detailed analyses of his major paintings.
  • A historical and biographical picture
  • A summary of the key figures in Leonardo’s life.
  • A list of information concerning the artist’s notebooks,

How Walter Isaacson’s biography of Leonardo da Vinci can benefit you

Knowledge and rich general culture

Walter Isaacson’s biography is a very long read, but contains very little repetition. It leads us from discovery to discovery throughout the chapters. Not only does the book shed light on how Leonardo da Vinci made his mark on the history of humanity, art, and science, but it also enriches us with all of Leonardo’s explorations.

All in all, it is a reading that educates us on many levels: with what we learn in scientific, artistic, technical, or historical matters.

The life lessons of a man of genius

Leonardo da Vinci’s life is so exceptional that it is impossible not to come away with valuable insights.  A truly passionate and curious polymath, Leonardo da Vinci was interested in everything that could enrich his knowledge. He knew how to build bridges between disciplines.

In his last chapter (conclusion), Walter Isaacson lists all that the man and his approach can teach us. For this purpose, the author analyzes the human aspect of Leonardo da Vinci. He refers to his qualities which, when joined together, produced a genius, but also speaks of his failings.

Leonardo da Vinci was a man of geniuswho was passionateself-taughtmarginalextremely curious, imaginative and creative. He was an artist, a scientist, an engineer, an innovator (and much more), who was able to compensate for his lack of conventional education with a keen sense of observation and tenacious desire to experiment. He was also a man who knew how to assume his own uniqueness (illegitimate child, left-handed, homosexual man, vegetarian). His strength ultimately came from compensating for his so-called weaknesses.

A demanding but very inspiring read

Walter Isaacson’s biography of Leonardo da Vinci is a fabulous read for anyone interested in the life of this man, but also for anyone who is passionate about extraordinary lives. It’s a long book but definitely worth the effort of reading. The author is sure to grab your attention right from the start…

Strong points:

  • A very well-written book, part novel and part documentary journalism, which transports the reader into the world of the Italian Renaissance, its arts, and its geniuses.
  • A very inspirational book: through the beautiful people we discover, the open-mindedness, the artistic and philosophical freedom of the time, and of course through the incredible life of Leonardo da Vinci.
  • Surprising discoveries on the scientific, pioneering, and innovative genius of Leonardo da Vinci.
  • Illustrations that make the book a valuable compendium of Leonardo’s life, beyond a simple biography.

Weak point:

  • Aside from the length of the book, which may discourage some readers, I cannot honestly think of any weaknesses to point out.

My rating : Leonardo da Vinci - The Biography by Walter Isaacson Leonardo da Vinci - The Biography by Walter Isaacson Leonardo da Vinci - The Biography by Walter IsaacsonLeonardo da Vinci - The Biography by Walter IsaacsonLeonardo da Vinci - The Biography by Walter IsaacsonLeonardo da Vinci - The Biography by Walter IsaacsonLeonardo da Vinci - The Biography by Walter IsaacsonLeonardo da Vinci - The Biography by Walter IsaacsonLeonardo da Vinci - The Biography by Walter Isaacson

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The handy guide to The Biography of Leonardo da Vinci

The first known works of Leonardo da Vinci listed by Walter Isaacson in his book:

  1. The Warrior
  2. The Aerial Screw
  3. The Landscape of the Arno Valley
  4. Tobias and the Angel
  5. The Baptism of Christ
  6. Annunciation and Madonnas

Frequently Asked Questions (FAQ) about the book, The Biography of Leonardo da Vinci

1. How has the book The Biography of Leonardo da Vinci by Walter Isaacson been received by the public?

Considered the most creative genius in history, The Biography of Leonardo da Vinci has been a great success with the public and has become a best-seller. Drawing on thousands of pages of his notebooks and the most recent discoveries made by historians, Walter Isaacson takes us on a quest to uncover a genius, fueled by a passionate curiosity, an uncanny power of observation, and a boundless imagination.

2. What has been the impact of Walter Isaacson’s The Biography of Leonardo da Vinci?

This book has had a huge impact on many modern-day geniuses. Being a one-of-a kind creator, innovator and observer with remarkable imagination, talent and curiosity, Leonardo da Vinci has been a source of inspiration for many in the artistic, scientific, and technical fields.

3. For whom is The Biography of Leonardo da Vinci intended?

This book is for entrepreneurs, scientists, artists, creators, innovators, inventors, and the gifted. It is also a thrilling book for anyone interested in the life of Leonardo da Vinci.

4. What makes Leonardo da Vinci a genius according to Walter Isaacson?

Walter Isaacson calls Leonardo da Vinci a genius for several reasonsLeonardo da Vinci, he says, [foresaw what innovators would conceive centuries after him.]

5. What can we learn from Leonardo da Vinci according to Walter Isaacson?

According to Walter Isaacson, Leonardo was not only a genius, but also a being of great humanity – eccentric, obsessive, playful, and easily distracted, which rendered him more accessible.

The qualities of Leonardo da Vinci’s success versus the qualities of failure

Qualities of Leonardo da Vinci’s success Qualities of failure
Curiosity Lack of curiosity
Child-like wonder Indifference
Respect for facts Disregard for facts
Attention to detail Negligence
Imagination Lack of imagination

Who is Walter Isaacson?

Walter Isaacson

Walter Isaacson was born on May 20, 1952 in New Orleans, Louisiana. Following his studies at the Isidore Newman School in New Orleans, Walter Isaacson received his doctorate in History and Literature from Harvard University. An author and biographer, he is the president and CEO of the Aspen Institute.

He has written the biographies of many internationally recognized figures, including Leonardo da Vinci, who was a creative, innovative, imaginative, talented, and inquisitive individual, an exceptional observer, and an inspiration to younger generations, especially those in the artistic, scientific, and technical fields. He is also the author of biographies of Henry Kissinger, Benjamin Franklin, Albert Einstein, Steve Jobs, etc.

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