Blaise Pascal

Blaise Pascal was born in 1623 in Clermont, Auvergne. His mother died when he was three; his father Étienne, a tax official and amateur mathematician, educated him at home — and, wanting him to master languages first, forbade mathematics. The boy, according to his sister Gilberte, rediscovered Euclid’s first thirty-two propositions by himself, drawing with charcoal on the floor. At sixteen he wrote a treatise on conic sections that impressed Descartes; at nineteen he invented the Pascaline, a mechanical calculator; his experiments on the vacuum and atmospheric pressure (having his brother-in-law carry a barometer up the Puy de Dôme in 1648) refuted the Aristotelian horror of the vacuum; with Fermat he founded the mathematics of probability (1654), prompted by a gambler’s question.

The night of fire

On the night of 23 November 1654, from about half past ten until half past midnight, Pascal had an overwhelming religious experience. He recorded it on a parchment — the Memorial — which he sewed into the lining of his coat and carried until his death:

FIRE. God of Abraham, God of Isaac, God of Jacob, not of the philosophers and scholars. Certitude. Certitude. Feeling. Joy. Peace… Joy, joy, joy, tears of joy.

He associated himself with Port-Royal, the convent at the centre of Jansenism — a rigorous Augustinian movement emphasizing grace and human corruption, in conflict with the Jesuits. His Provincial Letters (1656–57), satirical letters attacking Jesuit casuistry (the art of finding excuses for sin), are masterpieces of French prose.

He spent his last years planning an Apology for the Christian Religion, aimed at sceptics and libertines, but grew ever sicker; he died in 1662 at thirty-nine. The notes he left — some thousand fragments, on scraps of paper cut and threaded together — were published as the Pensées (“Thoughts”, 1670). See Pensées.

The human condition

Pascal’s portrait of human beings is one of the most penetrating ever written. We are suspended between two infinities — the infinitely large and the infinitely small: “The eternal silence of these infinite spaces terrifies me.” We are a paradox:

What a chimera, then, is man! What a novelty, what a monster, what a chaos, what a contradiction, what a prodigy! Judge of all things, feeble earthworm; repository of truth, sewer of uncertainty and error; the glory and the refuse of the universe!

The thinking reed

Man is only a reed, the weakest in nature, but he is a thinking reed. It does not take the whole universe in arms to crush him; a vapour, a drop of water, is enough to kill him. But even if the universe were to crush him, man would still be nobler than what kills him, because he knows that he is dying… All our dignity consists, then, in thought.

Diversion

I have often said that the sole cause of man’s unhappiness is that he does not know how to stay quietly in his room.

Kings, hunters, gamblers, soldiers all seek diversion (divertissement) — not the hare, but the chase — to avoid thinking about their mortality and misery. Pascal’s analysis of distraction has never seemed more modern.

The Wager

Pascal addresses the sceptic who says reason cannot decide whether God exists. Very well — but you must bet; you are already embarked. Weigh the outcomes:

“If you win, you win everything; if you lose, you lose nothing. Wager, then, without hesitation that He is.” And if you cannot make yourself believe? Act as believers do — take holy water, have Masses said: “this will make you believe naturally, and stupefy you” (vous abêtira).

The Wager is the first application of decision theory. Objections: the “many gods” problem (which God should you bet on?), the impossibility of believing at will, and the suspicion that a God who rewards self-interested belief is not worth worshipping. See the argument in the Argument Library.

The heart

The heart has its reasons which reason does not know. (Le cœur a ses raisons que la raison ne connaît point.)

The “heart” for Pascal is not emotion but intuitive knowledge — we know first principles (space, time, motion, number) by the heart, not by demonstration. Reason’s last step is to recognize that there are infinitely many things beyond it.

Influence

Pascal stands at the source of Christian existentialism: Søren Kierkegaard, Dostoevsky, Unamuno, Gabriel Marcel. Nietzsche admired him as the most instructive victim of Christianity. T. S. Eliot called the Pensées the work of “a man of the world among ascetics, and an ascetic among men of the world”. Every modern discussion of decision under uncertainty passes through his wager.