Leonardo da Vinci: The Mind That Could Not Stop

The Apprentice Who Surpassed Everyone

In 1466, the fourteen-year-old Leonardo entered the workshop of Andrea del Verrocchio in Florence.

Verrocchio ran one of the most important workshops in Italy. Painting, sculpture, goldsmithing, engineering. His bottega was a factory of Renaissance creativity. For a boy locked out of formal education, it was the closest thing to a university that existed.

Leonardo was extraordinary almost immediately. The famous story: Verrocchio asked his students to paint the angels in his Baptism of Christ. Leonardo painted one angel so luminously, with such naturalistic grace, that, according to Vasari, Verrocchio put down his brush and never painted again, "chagrined that a boy understood their use better than he did."

The story is likely embellished. But the angel is real. You can see it today in the Uffizi. It looks like it belongs in a different century than the rest of the painting.

Here is what matters more than the angel, though: Leonardo stayed in Verrocchio's workshop for years after he could have left. He was already better than his master. He stayed anyway. Not for the mentorship. For the access.

Verrocchio's workshop exposed him to anatomy, mechanics, metallurgy, optics, and mathematics. A painting commission became an excuse to study how light actually worked. A sculpture commission became an excuse to study how metal actually melted. A request for a stage set became an excuse to study how pulleys actually lifted weight.

The pattern was set. Leonardo would accept a commission. Then he would disappear into the investigation behind the commission. The patron wanted a painting. Leonardo wanted to understand painting. These are not the same thing.

1476: The Year Everything Almost Ended

Then came the accusation.

On April 9, 1476, an anonymous denunciation appeared in the tamburo, the public letter box at the Palazzo della Signoria in Florence. It accused four men, Leonardo among them, of sodomy with a seventeen-year-old named Jacopo Saltarelli.

In Florence, sodomy was punishable by death.

The charges were eventually dismissed. Florentine law required accusations to be signed, and this one was anonymous. But the two months between accusation and acquittal left a mark. Leonardo was twenty-four. He had just begun establishing himself as an independent artist. And now his name had been publicly associated with a capital crime.

Some historians suggest the accusation was politically motivated, aimed at embarrassing the Medici through their association with Leonardo. The truth is unknowable. What is knowable is what happened next.

Look at what Leonardo produced in the six years after the accusation. Two major paintings started: St. Jerome in the Wilderness, a figure in anguished self-denial alone in the desert, and the Adoration of the Magi. He finished neither. The abandoned St. Jerome is one of the most psychologically raw things he ever put on panel: the saint's body is emaciated, his face contorted, his fist beating his own chest. Whether Leonardo was painting his inner state or just painting a saint, the timing is hard to ignore.

He stopped accepting portrait commissions. He never married, never established a household. The notebooks from this period are sparser than what comes before or after. The already-reserved young artist had learned what happens when the world looks too closely at your private life.

Within six years, he left Florence entirely.

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The Letter That Changed His Life

The 1482 letter to Ludovico Sforza, Duke of Milan, is one of the most revealing documents in the history of genius.

Ten paragraphs. Nine about military engineering: portable bridges, siege machines, armored vehicles, methods for diverting waterways, cannons of "convenient and easy portability." The tenth: painting, sculpture, architecture. An afterthought.

Leonardo knew exactly what he was doing. Milan was at war. The Duke needed engineers, not artists. So Leonardo sold himself as an engineer.

But there's something deeper happening in that letter. Leonardo wasn't lying. He genuinely believed he could build these things. He had designed them in his notebooks. Bridges. Tanks. Machine guns. None of them had been built. None of them would be built in his lifetime. Several were centuries ahead of their time.

For Leonardo, the understanding was the product. Whether the bridge ever got built was almost beside the point. He understood bridges more deeply than anyone alive, and that was enough for him, even if it wasn't enough for the Duke. The patron wanted a weapon. Leonardo wanted to know how force travels through a span of timber. These are not the same hunger, and the gap between them is the story of his whole life.

The letter worked. Ludovico brought Leonardo to Milan. He would stay for seventeen years.

Seventeen Years in the Fortress

Milan was where Leonardo became Leonardo.

Not because he painted The Last Supper. Not because he designed the canal system. Not because he organized elaborate court festivals with mechanical lions and flying stage effects. But because Milan gave him something Florence never had: a patron who let him investigate.

Ludovico Sforza wanted spectacle, engineering, prestige. Leonardo wanted to understand. For seventeen years, these desires overlapped enough to keep both men satisfied.

The bronze horse is the most heartbreaking example. Ludovico commissioned a massive equestrian statue of his father. Leonardo spent over a decade on it. Not sculpting, but studying. He dissected horses. He filled notebooks with horse anatomy. He designed revolutionary casting techniques for a statue that would stand twenty-three feet tall.

Then the French invaded. Ludovico's soldiers melted the bronze into cannons. The horse was never cast. Leonardo's notebooks survived. The investigation was complete, even if the product never existed.

The Rival Who Finished Everything

When Leonardo returned to Florence around 1500, a twenty-five-year-old sculptor named Michelangelo Buonarroti was becoming the most famous artist in Italy. Their rivalry is the most revealing contrast in the history of art.

Michelangelo was everything Leonardo wasn't: brusque, unkempt, obsessively focused, and a compulsive finisher. He completed the Sistine Chapel ceiling. He completed the David. He completed the Pietà. Leonardo, twenty-three years older and infinitely more versatile, finished almost nothing. The two men despised each other.

The most reliably sourced confrontation comes from the Codice dell'Anonimo Gaddiano. Leonardo and his companions were walking through Florence when a group reading Dante asked him to explain a passage. Michelangelo happened to be passing. Leonardo, perhaps genuinely deferring, said they should ask Michelangelo, who was known as a Dante expert. Michelangelo took it as a sneer and fired back: "Explain it yourself, you who made a design of a horse to be cast in bronze, were unable to cast it, and for shame abandoned it."

The insult landed because it was true. Leonardo had abandoned the horse. He had abandoned the Adoration of the Magi. He would abandon the Battle of Anghiari, the massive wall painting commissioned in direct competition with Michelangelo's Battle of Cascina for the same hall in the Palazzo Vecchio. Neither painting survived, but the commission itself tells the story: Michelangelo left because the Pope summoned him to Rome. Leonardo left because his experimental paint technique failed. One was pulled away by demand. The other was defeated by investigation. He had tried to reinvent fresco painting, and the paint melted off the wall.

When Michelangelo's David was completed in 1504, Leonardo served on the committee deciding where to place it. He suggested hiding it in a courtyard. Then he sketched the figure and redesigned it as a Neptune. Even in admiration, he couldn't resist turning someone else's finished work into raw material for his own investigation.

The 7,200 Pages No One Was Meant to Read

Leonardo's notebooks are the interior of his mind, laid open.

Thirteen thousand pages originally. About 7,200 survive. They contain the most extraordinary range of inquiry ever produced by a single human being: anatomical drawings more accurate than anything produced for another three centuries. Designs for flying machines, submarines, solar concentrators, calculators. Studies of water flow, optics, botany, geology, cartography. Architectural plans. Fables. Jokes. Grocery lists.

All written backwards. Left-handed mirror script, running right to left across the page, so that you need a mirror to read it naturally. The practical reason: Leonardo was left-handed, and writing in this direction prevented his hand from smearing the ink. He could write normally when he chose to. His letters to patrons run left to right like everyone else's.

But the practical explanation doesn't cancel the psychological one. A man who was accused of a capital crime for his private life, who never published his findings, who kept his intellectual work in notebooks no one else could casually read. This man literally wrote so the world couldn't easily look over his shoulder. Whether that was conscious intent or a happy accident of left-handedness, the effect was the same: a layer of privacy built into the act of writing itself.

The notebooks reveal a mind operating on a principle most people cannot sustain for five minutes: pure curiosity, applied to everything, with no concern for output.

A typical page might contain a study of how the muscles of the jaw connect to the skull, followed by a note about buying black stockings, followed by a sketch of how water behaves when it falls from a height into a pool, followed by a reminder to ask a mathematician about squaring a circle.

He wrote to-do lists for his own curiosity. One surviving list includes: "Describe the tongue of the woodpecker." Not for a commission. Not for a treatise. Just because he wanted to know.

"Nature is the source of all true knowledge. She has her own logic, her own laws, she has no effect without cause nor invention without necessity."

He intended for the notebooks to be published. They never were. Not during his lifetime. Not for centuries after. The most comprehensive record of human curiosity ever assembled sat in trunks, passed between collectors, slowly dispersed across Europe.

What is Leonardo da Vinci's personality type?

Leonardo da Vinci is an Enneagram Type 5, The Investigator

The evidence isn't subtle. Across sixty-seven years, the same four behaviors repeat at the scale of genius.

• He treated his own attention as a scarce resource and guarded it. From his retreat after the sodomy accusation, to his decades of working alone, to his final years in a French manor with only two companions, Leonardo consistently chose observation over participation. He gave the world contact in small, selective doses, then withdrew.
• He gathered understanding instead of sharing it. The notebooks weren't communication. They were accumulation. He filled 13,000 pages with the most extraordinary range of inquiry ever produced by one person and organized none of it for anyone else to read.
• The task was never the task. Every commission became cover for something deeper. The patron wanted a painting; Leonardo wanted to understand how a human face holds emotion at the moment of betrayal. The patron wanted a horse statue; Leonardo wanted the complete anatomy of the horse. He kept paying himself in comprehension while his clients went unpaid in product.
• He lived in his mind and forgot he had a body. Vasari called him "lovable" and a "sparkling conversationalist" who could not deliver on commitments. The charm was real; so was the withdrawal. He forgot to eat. He kept a fractured sleep schedule of brief naps because sustained sleep felt like time stolen from thinking.

And the investigation was never neutral or detached. He didn't just study anatomy; he drew it more beautifully than any anatomist ever had. He didn't just observe light; he painted it with a technique so fine that modern scientists needed X-ray fluorescence to measure the layers. The understanding had to be accurate and his own, original, unmistakably his — and that stubbornly personal streak is what kept the most knowledgeable man alive from ever being a mere cataloguer. (More on the wing that supplies that streak in the rabbit hole below.)

The Man Who Kept a Thief for Twenty-Five Years

In 1490, a ten-year-old boy named Gian Giacomo Caprotti entered Leonardo's household in Milan.

Leonardo nicknamed him "Salaì," meaning "Little Devil." Within days, the boy was stealing. Leonardo's notebook entry is precise: "Thief, liar, obstinate, glutton." He catalogued Salaì's offenses with the same detached accuracy he applied to anatomical studies. How much he stole. What he broke. How much his father would need to reimburse.

He kept the boy for twenty-five years.

The daily reality of that relationship is documented in Leonardo's own hand, and it reads like a ledger of exasperation that never once considers the obvious solution. Salaì stole from guests. He broke things. He ran up clothing bills that Leonardo meticulously recorded: four pairs of hose, a cloak lined with green velvet, twenty-four pairs of shoes over one period. Leonardo bought him silk doublets and recorded the cost to the lira. On the same page, he might note that Salaì had stolen again. Then he designed him a costume for a court pageant.

Salaì grew into a mediocre painter, a persistent thief, and Leonardo's most constant companion. He modeled for St. John the Baptist and Bacchus, the most sensuous figures Leonardo ever painted. Leonardo left him half a vineyard in his will.

The Salaì relationship reveals something the notebooks don't: the man who understood everything about the human body could not apply that understanding to his own emotional life. He kept a thief because the thief needed him. He catalogued the stealing with clinical precision and then paid for another pair of hose.

He could analyze any system except the one running inside himself. He could dissect a human heart and draw it more accurately than anyone for three centuries. He could not account for his own.

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The Sweetest Death He Ever Studied

Late in his career, an old man approached Leonardo in a hospital in Florence. He was over a hundred years old. He told Leonardo he felt nothing wrong with his body except weakness. A few hours later, the man died.

Leonardo dissected him immediately.

Not out of callousness. Out of the purest curiosity a human being has ever expressed toward death. The old man had described his death as painless, "so sweet a death," and Leonardo needed to know why. What was the mechanism? What did the body do differently when it died gently instead of violently?

He found the answer in the arteries. Thickened walls, reduced blood flow to the organs. The centenarian had died of what we would now call atherosclerosis. Leonardo described it accurately enough that researchers didn't improve on his findings until the twentieth century.

"Every evil leaves pain in our memory except the supreme evil, death, which destroys this memory along with our life."

The dissection captures Leonardo's entire relationship with existence. Other people experienced the old man's death as a loss. Leonardo experienced it as a question. And questions, for him, were the only currency that mattered.

He dissected perhaps thirty human corpses in his lifetime. He worked at night in monastery hospitals, by candlelight, peeling back layers of muscle and fat on bodies that were rapidly decomposing. The smell must have been extraordinary. The drawings he produced were extraordinary too: the most accurate anatomical illustrations in history, depicting the circulatory system, the musculature, the fetal position in the womb, the mechanics of the shoulder joint.

None of it was published. The notebooks went into trunks. Three hundred years later, when anatomists finally caught up to where Leonardo had been, they didn't know he had already been there.

"He Begins by Thinking of the End Before the Beginning"

Pope Leo X said this about Leonardo in 1514, and it is the most perceptive thing anyone ever said about him.

Leonardo didn't procrastinate the way most people procrastinate, through avoidance or laziness. He procrastinated through understanding. And the people who paid him left a paper trail of exasperation.

Isabella d'Este, Marchioness of Mantua, pursued Leonardo for six years trying to get a single painting out of him. She sent agents. She wrote letters. Over twelve thousand of her letters survive, and the Leonardo thread reads like someone trying to pin down smoke. He had made a chalk portrait of her in 1499. She spent the next four years begging for a painted version. She eventually gave up on specifics and told him to paint anything he wanted, any subject at all. He never delivered.

Her agent in Florence, Fra Pietro da Novellara, reported back in April 1501 with the most accurate diagnosis anyone ever wrote of Leonardo: his "mathematical experiments have absorbed his thoughts so entirely that he cannot bear the sight of a paintbrush." The man commissioned to paint was too busy understanding to paint.

The Last Supper had eyewitnesses. Matteo Bandello, a novice at Santa Maria delle Grazie, watched Leonardo work and left a firsthand account: "He would arrive at an early hour, climb up onto the scaffolding, and start working. Sometimes he would stay there from dawn until sunset, not once setting down his brush. On other occasions, he would go for two, three or four days without taking up his brush, but spending one or two hours a day standing before the work, arms folded, scrutinizing and assessing the figures in his mind." Bandello also saw Leonardo dash across Milan in the midday heat to add a single brushstroke, then leave.

The Mona Lisa took twenty years. He carried it with him from Florence to Rome to France, adding translucent layer upon translucent layer of sfumato, the technique he described as painting "without lines or borders, in the manner of smoke." Modern X-ray fluorescence analysis has measured those layers at one to two micrometers thick. A human hair is seventy. He applied them with his fingers, not brushes. No brush strokes are detectable. Twenty to thirty layers of near-invisible paint, each dried for weeks or months before the next was applied. No one has successfully replicated it in five hundred years. He never delivered the painting to anyone. He was still working on it when he died.

The Virgin of the Rocks was commissioned with a seven-month deadline. He finished it twenty-five years later.

"Art is never finished, only abandoned."

He didn't abandon work because he lost interest. He abandoned it because completion meant the investigation was over. What the patron experienced as unreliability, Leonardo experienced as having learned enough to ask the next question.

The Final Fortress

In 1516, at sixty-four, Leonardo accepted an invitation from Francis I of France. He packed his notebooks, his paintings (including the unfinished Mona Lisa), and traveled across the Alps with Salaì and his most devoted pupil, Francesco Melzi.

Francis installed him in the manor of Clos Lucé, near the royal château at Amboise, connected to the king's own residence by an underground passage. He gave Leonardo a generous pension of 700 gold écus and a title: "First Painter, Engineer and Architect of the King." He asked for almost nothing in return except conversation. Francis called Leonardo mon père, my father.

Here is the most interesting test of the Five thesis: what happens when a Five gets unlimited freedom? No commissions to dodge. No priors complaining about deadlines. No patrons demanding delivery. Just a king who wanted to listen.

Leonardo did not spiral. He designed an entire city. The Romorantin project was his most ambitious engineering vision: a royal residence with canals diverted from a Loire tributary, water mills, irrigated farmland, sewers, connected suburbs. It was never built. The region was plagued by malaria. But the plans are extraordinary, a mind finally free to design at the scale it always thought at. He also influenced the design of the double-helix staircase at Chambord, two intertwined staircases where people ascending and descending can see each other but never meet. It is the most Leonardo thing ever built by someone else.

His right hand had become crippled, likely from a stroke. He could no longer paint. But he could still draw with his left hand, still write, still think. When Antonio de Beatis visited him in October 1517 as part of a cardinal's entourage, Leonardo proudly showed his paintings and notebooks, though he acknowledged the paralysis had ended his painting life.

In his final years, he produced studies of deluges, apocalyptic drawings of water destroying the world, churning vortices of black chalk spiraling across the page. They are simultaneously scientific (extending his lifelong study of fluid dynamics) and deeply personal. Not illustrations of the Biblical flood. Meditations on the power of natural forces to overwhelm everything human beings construct. The work of a mind that had spent sixty years studying water, now free to imagine what water could do if nothing held it back.

He made his will on April 23, 1519. He left his notebooks to Melzi. He left the vineyard and half his property to Salaì. He requested sixty poor men carry candles at his funeral, the same precision he brought to everything else. Even dying had a design.

He died on May 2, 1519. The famous story, that he died in the arms of Francis I, was invented by Vasari fifty years later. Francis's own diary suggests he was miles away.

It doesn't matter. What matters is what Leonardo left: the notebooks. The fifteen paintings. The anatomical drawings. The flying machines. The canal designs. The studies of light. The understanding.

He had spent sixty-seven years collecting the world inside his mind. The fortress was complete. What no one could take from the bastard son of Vinci, no one ever did.

The Productive Procrastination of History's Greatest Mind

Here is what the Enneagram resolves about Leonardo that nothing else does.

The standard narrative calls him a procrastinator. The ADHD researchers claim him as one of theirs. The art historians lament the paintings he never finished. The engineers wish he'd built his machines.

They are all describing the same thing from the outside.

From the inside, from the interior of a Five, the picture is different. Leonardo didn't fail to finish. He succeeded at understanding. The painting was never the point. The understanding behind the painting was the point. The bronze horse was never the point. The anatomy of the horse was the point. The military machines were never the point. The physics of force and motion were the point.

His notebooks are the most productive procrastination in human history. The work of a mind that treated completion as a kind of death — because when you finish, you stop investigating. And when you stop investigating, you stop being alive in the only way that matters to a Five.

On his deathbed, he reportedly lamented that he "had offended God and humanity in not having worked at his art as he should have." If he said it, he was wrong. He worked at his art more deeply than any human being has ever worked at anything. He just couldn't stop working at it long enough to call it done.

The question Leonardo's life asks is the question every Five eventually faces: Is understanding the world the same as living in it?

He bought caged birds in the Florentine market and released them. Then he stood there in the street, watching how they flew. He also refused to eat meat, which was extraordinary in Renaissance Italy, where vegetarianism was considered borderline heretical. The Italian explorer Andrea Corsali, writing from India in 1516, compared the vegetarian Gujarati Hindus to "our Leonardo da Vinci," who would not allow any living thing to be harmed. In his notebooks, Leonardo wrote: "Does nature not produce enough simple food to satisfy you?"

The kindness was real. But so was the observation. He could never separate the two. He could never just set something free without studying how it moved through the air. He could never just love someone without cataloguing their flaws in a notebook. He could never just paint a woman's face without spending twenty years trying to capture the exact way a smile exists and doesn't exist simultaneously.

He has been dead for five hundred years and we are still finding things in those notebooks. Did he leave them unfinished, or did he leave them open — knowing that the investigation, like the man, was never meant to end?

🐇 Enneagram Rabbit Hole: Wings, Subtypes & Connecting Lines for Leonardo da Vinci

For the Enneagram nerds. Skip if you're not deep into the system: the rest of the analysis stands on its own.

Leonardo da Vinci's Wing: 5w4

The record leans 5w4 over 5w6. A 5w6 ("The Problem Solver") tends to attach its hoarded knowledge to a discipline, an institution, or a body of authority — building a defensible position inside a known system. Leonardo did the opposite. He refused universities he was barred from anyway, never published, and rendered anatomy and light more beautifully than they had ever been rendered because accuracy alone never satisfied him; the work had to be unmistakably his. That fusion of investigation with a stubborn, melancholic aestheticism — the 4 wing's signature — is why he drew a dissected shoulder like a devotional object and chased the impossible smoothness of sfumato for twenty years. The flood drawings at the end of his life, scientific and grief-soaked at once, are the 4 wing speaking plainly. More on how wings shade a core type.

Leonardo da Vinci's Instinctual Subtype: sp/so

He reads self-preservation-dominant. The self-pres Five guards a private fortress: a small, controlled habitat with minimal demands, where energy goes to the inner world rather than the social one. The mirror-script no one could read over his shoulder, the household kept to two or three companions, the polyphasic sleep that fenced off thinking time, the retreat into work after the 1476 accusation — all of it is the self-pres instinct minimizing intrusion. The social instinct runs second and shows in his court life: he charmed dukes and a king, staged pageants, played the "sparkling conversationalist." The one-to-one instinct is faintest, surfacing mainly in the few intense, asymmetrical bonds he kept for decades (Salaì, Melzi). Background on instinctual subtypes.

Stress and Growth Arrows

Under stress, Fives take on the scattered, over-committed quality of Type 7 — chasing one fascinating thread after another without landing. This is Leonardo's "never finished anything" pattern read from the inside: a single page might run from jaw muscles to a grocery note to the physics of falling water to squaring the circle, each genuinely begun, none seen through. Isabella d'Este chasing one painting for six years, the Virgin of the Rocks finished twenty-five years late, the bronze horse studied for a decade and never cast — that is the 5-to-7 spread, appetite for the next question overrunning the discipline to close the last one. In growth, Fives move toward Type 8: stepping out of the head and into decisive, embodied action in the world. The rare moments Leonardo did this are telling — the 1482 letter that boldly sold him to Milan, the Romorantin city he designed at full scale for Francis I, the centenarian he dissected within hours of the man's death. When the fortress door opened outward, the understanding briefly became force.

Counterarguments: Why Leonardo da Vinci Might Not Be Type 5

The strongest alternate case is Type 4: the melancholy, the aestheticism, the deathbed lament that his work "did not reach the quality it should have," the conviction that everything had to be original. But the 4 organizes life around feeling and identity — who am I, why am I different — while Leonardo organized his around the impersonal question of how the world works; his emotion ran through investigation, not the reverse. A Type 9 case rests on the withdrawal and the avoidance of conflict, but the 9 merges and goes along to keep the peace, whereas Leonardo withdrew to concentrate — the fortress of a knower, not the numbing-out of a peacemaker. What would change our mind: evidence that the unfinished work stemmed from a 4's "it isn't beautiful or true to me yet" perfectionism rather than a 5's "the investigation taught me what I needed and moved on." The notebooks point to the second — he abandoned the painting precisely because the understanding behind it was complete.