Pascal never took an IQ test — the first one appeared 243 years after his death. The ≈195 is Catharine Cox's 1926 estimate, one of her highest, driven by extraordinarily well-documented childhood precocity.
The maths his father kept from him
Born in Clermont-Ferrand on June 19, 1623, Pascal lost his mother Antoinette at three and was educated at home by his father Étienne, a tax official and amateur mathematician. Étienne planned to hold back mathematics until his son was older.
By the family's account — both Étienne and his sister Gilberte wrote about it — Blaise worked out a good part of Euclid's geometry on his own, calling circles “rounds” and lines “bars”. His father dropped the ban and gave him the books.
At sixteen he presented his Essay on Conics to Marin Mersenne's Paris circle. It contained what is now called Pascal's theorem; Descartes at first refused to believe a sixteen-year-old had written it.
Education: never a school, always a circle
Pascal never attended a school or university. His education ran on his father's method and on the scientific salons of Paris and Rouen — each dial one stage.
Home lessons built on general principles first: languages and grammar before mathematics, which was held back until he was 15.
Attended the weekly Paris gatherings of mathematicians around Marin Mersenne with his father, from about 12.
Absorbed the projective geometry of Desargues, the direct source of his work on conics.
His father's tax post in Rouen turned him to practical calculation — and led to building the calculating machine.
Repeated the Italian's barometer experiments with Pierre Petit — self-directed physics training.
Two bonesetters treating his father introduced the family to Jansenist writings — the start of his theological education.
Each number, the sum of two above
Known in China since Yang Hui in the 13th century, the triangle takes Pascal's name for his systematic 1654 exposition, which came out of the Fermat correspondence on the “problem of points”. Switch views to see what hides inside.
Row n holds the number of ways to choose k items from n. Row 11: 1, 11, 55, 165, 330, 462…
From a mountain to a unit of pressure
Months after his probability letters with Fermat, Pascal had an intense religious experience. He recorded it on a small parchment he kept sewn into his clothing for the rest of his life — the Mémorial — and withdrew from active science.
He aligned himself with the Jansenist community at Port-Royal and wrote the eighteen anonymous Provincial Letters (1656–57) defending Antoine Arnauld against the Sorbonne — still a founding text of French prose. His last project, a defence of Christianity, was left as about 1,000 fragments, published in 1670 as the Pensées; they include Pascal's wager, one of the earliest uses of expected-value reasoning in philosophy. He died on August 19, 1662, aged 39, of causes still debated.
The rest of the collected works
Beyond the triangle, the vacuum experiments and the Pensées: the treatises, contests and one very practical invention.
His first report on vacuum experiments, before the mountain test.
Pascal's law of fluid pressure and the principle of the hydraulic press; published 1663.
The problem of points — how to split stakes in an unfinished game — founding probability theory.
On definitions, proof and persuasion; an influence on the Port-Royal Logic.
Challenged Europe's mathematicians to solve problems on the cycloid, then published his own solutions.
Writings on grace and free will from the Jansenist side.
Launched the first public omnibus service in Paris, weeks before his death.
“The heart has its reasons which reason knows nothing of.”
“Man is but a reed, the most feeble thing in nature; but he is a thinking reed.”
“I have made this letter longer than usual, only because I have not had the time to make it shorter.”
Timeline
Reading the ≈195
Cox scored documented childhood precocity, and Pascal's — recorded by both his father and his sister Gilberte — is among the most striking in her sample. The same method underrates people with thinly documented childhoods. It is a retrospective estimate, not a measurement.
Sources
- Cox, C. M. (1926). The Early Mental Traits of Three Hundred Geniuses. Stanford University Press
- Pascal, B. (1640). Essai pour les coniques
- Pascal, B. (1657). Les Provinciales
- Pascal, B. (1670). Pensées
- Pascal, B. & Fermat, P. (1654). Correspondence on probability
- Pascal, G. — memoir of Blaise Pascal by his sister Gilberte
- Mesnard, J. (1965). Pascal et les Roannez. Desclée de Brouwer
- Connor, J. (2006). Pascal's Wager. HarperOne