Birth in Clermont
Blaise Pascal was born in Clermont, in Auvergne, the son of Étienne Pascal, a magistrate of the tax court.
Port-Royal Augustinianism · experimental science · 1623–1662
Blaise Pascal
Measure reason by what exceeds it.
Clermont · Rouen · Paris
Biography
The thread of a life.
Blaise Pascal was a French mathematician, experimental physicist, inventor and Christian writer. After work on conic sections, a calculating machine, the vacuum and probability, a religious experience in 1654 drew him close to Port-Royal. His Provincial Letters attack lax casuistry, and the fragments of his unfinished apology, the Pensées, probe human greatness and misery, the limits of reason and the wager.
Conics and the calculating machine
He published an essay on conic sections and then, in Rouen, designed a machine for adding and subtracting.
The vacuum and the Puy de Dôme
His New Experiments Concerning the Vacuum appeared, and the test on the Puy de Dôme tied the mercury column to the weight of the air.
Probability and the Memorial
He corresponded with Fermat on games of chance and, on the night of 23 November, recorded the religious experience of the Memorial.
The Provincial Letters
Eighteen anonymous letters defended Arnauld and satirized the moral theology of Jesuit casuists.
Death and the Pensées
Pascal died in Paris on 19 August 1662; the first edition of his Pensées appeared in 1670.
Understanding a life in depth
01Childhood, geometry and the calculating machine
Blaise Pascal was born in Clermont in 1623 into a family of magistrates; his mother died in 1626, and his father Étienne, a gifted mathematician, moved the family to Paris in 1631 and taught his children himself. Through him the young Pascal met the scholars gathered around Marin Mersenne, and in 1640 he published an essay on conic sections. In Rouen, where Étienne served as a royal tax commissioner, he designed a machine that could add and subtract, built some fifty prototypes and obtained a royal privilege for it in 1649.
02The vacuum and the authority of experiment
In 1646 the family came into contact with followers of Saint-Cyran, and Pascal turned to a more demanding religious life. In the same years he repeated Torricelli’s experiment in Rouen, published his New Experiments Concerning the Vacuum in 1647 and met Descartes in Paris that September. Against the Jesuit Étienne Noël he argued that hypotheses must answer to experiment, and in 1648 the test on the Puy de Dôme showed that the mercury column depends on the weight of the air. After his father’s death in 1651 and his sister Jacqueline’s entry into Port-Royal, he moved in worldly circles around the duke of Roannez.
03Probability, the night of fire and Port-Royal
In 1654 Pascal corresponded with Pierre de Fermat on how to divide the stakes of an interrupted game, laying foundations for the calculus of probabilities, and wrote his treatise on the arithmetical triangle. On the night of 23 November 1654 he lived through an intense religious experience, recorded in a short text, the Memorial, which he kept sewn into his clothing. He made retreats at Port-Royal des Champs, where his conversation with Isaac Le Maistre de Sacy on Epictetus and Montaigne was written down. In 1656, as Antoine Arnauld faced condemnation at the Sorbonne, he began the Provincial Letters.
04The unfinished apology and the last years
From about 1656 Pascal gathered notes for an apology for the Christian religion and presented its plan at Port-Royal, but illness slowed the work from 1659. He still took part in the contest on the cycloid in 1658, wrote on grace and, in the dispute over the formulary condemning Jansenius, took a harder line than some of his friends; his sister Jacqueline died in 1661. In 1662 he helped launch the first coaches at a fixed fare in Paris, and on 19 August he died at the home of his sister Gilberte Périer. The fragments he left were published as the Pensées in 1670.
Pascal’s theorem on conics, his arithmetical triangle and his exchange with Fermat belong to the history of mathematics and probability, and the unit of pressure bears his name. The Provincial Letters helped shape classical French prose. The Pensées were answered by Voltaire, admired and contested by Nietzsche and read by many later writers who kept their anthropology while setting aside their apologetic aim.
Sources & reference points