The Most Talented Person Who Ever Lived Had a Completion Problem

Leonardo da Vinci left behind approximately 7,200 pages of notebooks. They contain designs for flying machines, submarines, tanks, solar-powered industrial systems, anatomical drawings more accurate than any produced for the next three hundred years, studies of water flow, botanical illustrations, mathematical proofs, architectural plans, and shopping lists.

He completed fewer than twenty paintings in his entire life.

This is the central paradox of Leonardo, and it is not a minor biographical footnote. It is the key to understanding how his mind worked. He was not lazy. He was so interested in everything that finishing any one thing meant stopping the investigation, and stopping was physically painful to him. His notebooks are full of sentences that begin "I shall continue tomorrow" — and tomorrow he was drawing the musculature of a horse or designing a canal system or dissecting a human eye.

The Illegitimate Son Who Couldn't Go to University

Leonardo was born in 1452 in Vinci, Tuscany, the illegitimate son of a notary. Because he was illegitimate, he was barred from university and from most of the professions open to educated men. This accident of birth turned out to be the most consequential thing that ever happened to him.

Without a university education, Leonardo was not trained in Latin, Scholastic philosophy, or Aristotelian science. He did not inherit the intellectual framework that constrained virtually every other educated European of his era. Instead, he learned by looking. He called himself a "disciple of experience" and insisted that observation was superior to book learning — a position that was radical in the fifteenth century and is obvious now only because people like Leonardo won the argument (Walter Isaacson, Leonardo da Vinci, 2017).

He dissected more than thirty human corpses, at night, in hospital basements, drawing what he saw by candlelight. His anatomical drawings of the heart, the spine, the fetus in the womb, and the vascular system were not surpassed until the invention of medical imaging. He drew the aortic valve so accurately that a British surgeon in 2005 used Leonardo's drawings to develop a new surgical technique.

The Notebooks Are the Masterpiece

Most people know Leonardo for the Mona Lisa and The Last Supper. These are extraordinary works. But the notebooks are the real masterpiece — the most complete record of a human mind in action that has ever existed.

They are written in mirror script, right to left, possibly because Leonardo was left-handed and found it more natural, possibly as a mild encryption. They move without warning from hydraulic engineering to the physics of light to observations about why the sky is blue to sketches for a painting commission he would never finish.

The flying machines did not fly. The tank was never built. The canal system was never completed. The giant bronze horse — the largest equestrian statue ever attempted — was never cast because the bronze was repurposed for cannons. The Battle of Anghiari, which would have been his largest painting, was abandoned when his experimental fresco technique failed.

None of this diminishes what he accomplished. It reveals the cost of a mind that could not stop questioning. Leonardo did not finish things because finishing required accepting limitations, and his mind recognized no limitations. He saw connections between anatomy and architecture, between water flow and hair curl, between the flight of birds and the fall of leaves, and each connection opened ten new questions (Martin Kemp, Leonardo da Vinci: The Marvellous Works of Nature and Man, 2006).

He died in 1519 in France, reportedly in the arms of King Francis I. His last notebook entry was a geometry problem. He was still working on it.