Blaise Pascal (June 19, 1623 – August 19, 1662) was a French mathematician, physicist and religious philosopher. His contributions to the natural sciences include the construction of mechanical calculators, considerations on probability theory, studies of fluids, and clarification of concepts such as pressure and vacuum. Following a profound religious experience in 1654, Pascal abandoned mathematics and physics for philosophy and theology.
In honor to his scientific contributions, the name pascal has been given to a unit of pressure and to a programming language, as well as to many mathematical concepts.
Born in Clermont-Ferrand, Puy-de-Dôme, France, Blaise Pascal lost his mother at the age of three. His mathematician father, Étienne Pascal (1588–1651), brought him up. Blaise Pascal was the brother of Jacqueline Pascal (1625–1661).
Contributions to science
At age 16, Pascal produced a treatise on conic sections which, among other things, included an important original result now known as Pascal's theorem. At age 18 he constructed a mechanical calculator capable of addition and subtraction (the Zwinger museum, in Dresden, Germany exhibits one of his original mechanical calculators).
In 1650, suffering from frail health, Pascal retired temporarily from mathematics. However, in 1653, his health recovered and he wrote Traité du triangle arithmétique in which he described a convenient tabular presentation for binomial coefficients, the "arithmetical triangle", now called Pascal's triangle.
His notable contributions to the fields of the study of fluids (hydrodynamics and hydrostatics) centered around the principles of hydraulic fluids. His inventions include the hydraulic press (using hydraulic pressure to multiply force) and the syringe. He clarified concepts such as pressure (for which his name has been given to the SI unit of pressure) and vacuum.
In 1654, prompted by a friend interested in gambling problems, he corresponded with Fermat on the subject, and of that collaboration was born the mathematical theory of probabilities. He later used a probabilistic argument, Pascal's Wager, to justify belief in God and a virtuous life.
Theology and philosophy
Following an accident at the Neuilly bridge where the horses plunged over the parapet but the carriage miraculously survived in 1654, Pascal abandoned mathematics and physics for philosophy and theology.
In this new field, Pascal gained fame for his attack on casuistry, a popular ethical method used by Catholic thinkers in the early modern period, (especially the Jesuits). Pascal denounced casuistry as the mere use of complex reasoning to justify moral laxity. His writings on this subject, a defense of the Jansenist Antoine Arnauld, appeared as the Lettres provinciales, or "Provincial Letters." This work incensed King Louis XIV of France who ordered in 1660 that the book be shredded and burnt.
Pascal's most influential theological work, the Pensées, was yet unfinished by his death, but a version of his notes for that book appeared in print in 1670, eight years after, and it soon became a classic of devotional literature.
Pascal died in Paris on August 19, 1662 and is buried there in the St. Étienne-du-Mont cemetery.