7,000 Pages of Genius: Inside Leonardo’s Notebooks
Mirror-written, scattered across the world, and once sold for $30.8 million: the most valuable notebooks ever kept.
Leonardo da Vinci finished perhaps fewer than twenty paintings in his lifetime. He left behind something arguably greater: roughly 7,000 surviving pages of notebooks — and scholars believe that may be only half of what he wrote. They are, page for page, the most valuable documents ever produced by a single human hand.
What is in them
Everything. Anatomical dissections decades ahead of medical science — including the first accurate depictions of the human spine and studies of the heart's valves that cardiac surgeons still cite with admiration. Flying machines, parachutes and an aerial screw. War engines and diving suits. Studies of turbulent water that fluid dynamicists regard as observationally correct. Grocery lists, debts, the names of models. Plans for treatises on painting, water and anatomy that he never assembled.
All of it written right-to-left in his famous mirror script — most likely, scholars note, simply because he was left-handed and it kept the ink from smudging, though it also conveniently discouraged casual readers.
Where they are
After his death in 1519, Leonardo's pupil Francesco Melzi guarded the papers; after Melzi died, they scattered. Today the surviving material is bound into codices spread across Milan (the 1,100-page Codex Atlanticus), Windsor Castle, Paris, Madrid — where two codices were rediscovered only in 1965 — Turin, London and Seattle. That last address matters: in 1994, Bill Gates bought the 72-page Codex Leicester for $30.8 million, still the highest price ever paid for a book or manuscript at auction. He has since exhibited it publicly around the world and had it digitised.
"Learning never exhausts the mind."
— Leonardo da Vinci
The tragedy of the notebooks
Here is the painful counterfactual. The notebooks contain correct or prescient accounts of erosion and deep time, the heart as a pump, friction laws, and powered flight's basic problems — almost none of it published in his lifetime or for centuries after. Had the anatomical studies alone been printed in the 1500s, medicine might have advanced by a century. Instead, science had to rediscover what a Florentine artist had already drawn. Genius unpublished, it turns out, is genius delayed.
His paintings tell the opposite story — maximum impact from minimum output. The Mona Lisa draws millions of visitors a year, and his Salvator Mundi sold in 2017 for $450.3 million, the most expensive painting ever auctioned.
<iframe width="560" height="315" src="https://www.youtube.com/embed/0JnLnXE5vqM" title="5 Hidden Things About Leonardo Da Vinci To Blow Your Mind" frameborder="0" allowfullscreen loading="lazy"></iframe>Watch: 5 Hidden Things About Leonardo Da Vinci To Blow Your Mind
The pages still working
The notebooks are not finished teaching. Engineers have built working machines from his drawings — his self-supporting bridge and his robot knight have both been reconstructed successfully — and in 1967 the two lost Madrid codices surfaced in Spain's National Library after four centuries, adding 700 pages overnight. Scholars consider it entirely possible that more pages are still waiting in Europe's uncatalogued archives.
The verdict
We call polymaths "Renaissance men" because of him, and our ranking of history's greatest multi-field minds still puts him first. But the notebooks add a warning label to the legend: Leonardo's endless curiosity came with an inability to finish, publish and ship. The most valuable pages ever written are also history's most expensive lesson in the difference between knowing and telling.
Frequently Asked Questions
How many pages of Leonardo's notebooks survive?
Roughly 7,000 pages, bound into codices held in Milan, Windsor, Paris, Madrid, Turin, London and Seattle — perhaps half of what he originally wrote.
Why did Leonardo write in mirror script?
Most scholars think the left-handed Leonardo simply avoided smudging ink by writing right to left; it also discouraged casual readers.
Who owns the Codex Leicester?
Bill Gates, who bought it in 1994 for $30.8 million — still the record auction price for any book or manuscript.