Blaise Pascal

Blaise Pascal was a French mathematician, physicist, inventor, philosopher and Catholic writer who lived from 1623 to 1662. A child prodigy educated by his father, a tax collector in Rouen, he wrote a significant treatise on conic sections at the age of 16 and later corresponded with Pierre de Fermat on probability theory, work that strongly influenced the development of modern economics and social science. In 1642 he began pioneering work on calculating machines, known as Pascal's calculators or Pascalines, establishing him as one of the first two inventors of the mechanical calculator. He made important contributions to the study of fluids and clarified the concepts of pressure and vacuum, generalizing the work of Evangelista Torricelli; the SI unit for pressure is named for him. In 1646 he and his sister Jacqueline identified with the Catholic movement known by its detractors as Jansenism, and following a religious experience in late 1654 he began writing influential works on philosophy and theology, including the Lettres provinciales, set in the conflict between Jansenists and Jesuits, and the Pensees, which contains Pascal's wager, a probabilistic argument for belief in God. He also wrote an important treatise on the arithmetical triangle and, between 1658 and 1659, on the cycloid and its use in calculating the volume of solids. He died in Paris at the age of 39 after several years of illness.