Blaise Pascal

By Emeka Obi

He was the greatest might-have-been in the history of science — a prodigy who remade two fields before breakfast, so to speak, and then abandoned both for God. Blaise Pascal, born in Clermont in 1623, was publishing mathematics at sixteen: his Essay on Conic Sections contained Pascal's theorem, still taught today, and by nineteen he had built a working mechanical calculator — the Pascaline — to help his father with tax computations, the first calculating machine to reach production. At twenty-three he entered the most dramatic scientific controversy of the age: the nature of the vacuum.

The Aristotelians insisted nature abhors a vacuum; Torricelli's mercury tube suggested otherwise. Pascal, frail and brilliant, organized the decisive experiment: in 1648 his brother-in-law Florin Périer carried a mercury barometer up the Puy de Dôme while a control tube stayed at the base. The column fell as they climbed — the air had weight, it pressed, and its pressure diminished with altitude. The vacuum was real; the atmosphere was an ocean of air, and men lived at its bottom. The unit of pressure, the pascal, bears his name.

Then, in a single burst of correspondence with Pierre de Fermat in 1654, he founded the mathematics of chance. The problem of points — how to divide stakes in an interrupted game — led them to the calculus of probabilities: expectation, the binomial coefficients of Pascal's triangle, the first rigorous treatment of uncertainty. Insurance, statistics, quantum mechanics: all descend from those letters.

And then the night of November 23, 1654 — the Memorial, the mystical experience he sewed into his coat lining — turned him. Pascal gave science up for Jansenist theology, writing the Provincial Letters, which Voltaire called the first work of French prose genius, and the Pensées, fragments on faith and human wretchedness assembled after his death. He died in 1662 at thirty-nine, in pain, having reconciled the geometer and the mystic in a single tormented soul. The wager that bears his name — that reason itself counsels betting on God — is the most famous argument in the philosophy of religion, and it was written by a man who had weighed the air.

Impact on civilization

Pascal gave the world two foundations at once: the experimental proof of atmospheric pressure and the vacuum, which destroyed the Aristotelian horror vacui and opened the way to pneumatics, steam power, and meteorology; and the calculus of probability, which turned uncertainty itself into a mathematical object and underlies modern statistics, insurance, finance, and quantum theory. The Pascaline pioneered mechanical computation. And the Pensées made him the patron saint of everyone who has felt the tension between reason and faith — the scientist as theologian, proving the two hungers can live in one mind.