Blaise Pascal (/pæˈskæl, pɑːˈskɑːl/; French: [blɛz paskal]; 19 June 1623 – 19 August 1662) was a French mathematician, physicist, inventor, writer and Christian philosopher. He was a child prodigy who was educated by his father, a tax collector in Rouen. Pascal’s earliest work was in the natural and applied sciences where he made important contributions to the study of fluids, and clarified the concepts of pressure and vacuum by generalising the work of Evangelista Torricelli. Pascal also wrote in defence of the scientific method.

In 1642, while still a teenager, he started some pioneering work on calculating machines. After three years of effort and 50 prototypes, he built 20 finished machines (called Pascal’s calculators and later Pascalines) over the following 10 years, establishing him as one of the first two inventors of the mechanical calculator.

Pascal was an important mathematician, helping create two major new areas of research: he wrote a significant treatise on the subject of projective geometry at the age of 16, and later corresponded with Pierre de Fermat on probability theory, strongly influencing the development of modern economics and social science. Following Galileo Galilei and Torricelli, in 1646, he rebutted Aristotle’s followers who insisted that nature abhors a vacuum. Pascal’s results caused many disputes before being accepted.

In 1646, he and his sister Jacqueline identified with the religious movement within Catholicism known by its detractors as Jansenism. His father died in 1651. Following a religious experience in late 1654, he began writing influential works on philosophy and theology. His two most famous works date from this period: the Lettres provinciales and the Pensées, the former set in the conflict between Jansenists and Jesuits. In that year, he also wrote an important treatise on the arithmetical triangle. Between 1658 and 1659 he wrote on the cycloid and its use in calculating the volume of solids.

Pascal had poor health, especially after the age of 18, and he died just two months after his 39th birthday.

Inventions and Discoveries

In 1642, inspired by the idea of making his father’s job of calculating taxes easier, Blaise Pascal started work on a calculator dubbed the Pascaline. (German polymath William Schickard had developed and manufactured an earlier version of the calculator in 1623.) The Pascaline was a numerical wheel calculator with movable dials, each representing a numerical digit. The invention, however, was not without its glitches: There was a discrepancy between the calculator’s design and the structure of French currency at the time. Pascal continued to work on improving the device, with 50 prototypes produced by 1652, but the Pascaline was never a big seller.

In 1648, Pascal starting writing more of his theorems in The Generation of Conic Sections, but he pushed the work aside until the following decade.

At the end of the 1640s, Pascal temporarily focused his experiments on the physical sciences. Following in Evangelista Torricelli’s footsteps, Pascal experimented with how atmospheric pressure could be estimated in terms of weight. In 1648, by having his brother-in-law take readings of the barometric pressure at various altitudes on a mountain (Pascal was too poor of health to make the trek himself), he validated Torricelli’s theory concerning the cause of barometrical variations.

In the 1650s, Pascal set about trying to create a perpetual motion machine, the purpose of which was to produce more energy than it used. In the process, he stumbled upon an accidental invention and in 1655 Pascal’s roulette machine was born. Aptly, he derived its name from the French word for “little wheel.”

Overlapping his work on the roulette machine was Pascal’s correspondence with mathematical theorist Pierre de Fermat, which began in 1654. Through their letters discussing gambling and Pascal’s own experiments, he found that there is a fixed likelihood of a particular outcome when it comes to the roll of the dice. This discovery was the basis of the mathematical theory of probability, with Pascal’s writings on the subject published posthumously.

Although the specific dates are uncertain, Pascal also reportedly invented a primitive form of the wristwatch. It was an informal invention to say the least: The mathematician was known to strap his pocket watch to his wrist with a piece of string, presumably for the sake of convenience while tinkering with other inventions.


  • We know the truth, not only by the reason, but also by the heart.
  • I have made this letter longer than usual because I lack the time to make it shorter.
  • Men never do evil so completely and cheerfully as when they do it from religious conviction.
  • All men’s miseries derive from not being able to sit in a quiet room alone.
  • Kind words do not cost much. Yet they accomplish much.
  • Do you wish people to think well of you? Don’t speak well of yourself.
  • Men despise religion. They hate it and are afraid it may be true.
  • To have no time for philosophy is to be a true philosopher.
  • The eternal silence of these infinite spaces fills me with dread.
  • In faith there is enough light for those who want to believe and enough shadows to blind those who don’t.