Blaise Pascal (June 19, 1623, Clermont-Ferrand – August 19, 1662, Paris) is a French mathematician, physicist, inventor, writer and Catholic philosopher.

A child prodigy educated by his father, a Tax Collector in Rouen, Pascal's earliest work is in the natural and applied sciences where he makes important contributions to the study of fluids, and clarifies the concepts of pressure and vacuum by generalizing the work of Evangelista Torricelli.

Pascal also writes in defense of the scientific method.

In 1642, while still a teenager, he starts some pioneering work on calculating machines, and after three years of effort and 50 prototypes he invents the mechanical calculator.

He builds twenty of these machines (called the Pascaline) in the following ten years.

Pascal is a mathematician of the first order.

He helps create two major new areas of research.

He writes a significant treatise on the subject of projective geometry at the age of sixteen, and later corresponds with Pierre de Fermat on probability theory, strongly influencing the development of modern economics and social science.

Following Galileo and Torricelli, in 1646 he refutes Aristotle's followers who insist that nature abhors a vacuum.

His results cause many disputes before being accepted.

In 1646, he and his sister Jacqueline identify with the religious movement within Catholicism known by its detractors as Jansenism.

His father dies in 1651.

Following a mystical experience in late 1654, he has his "second conversion", abandons his scientific work, and devotes himself to 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 this year, he also writes an important treatise on the arithmetical triangle.

Between 1658 and 1659 he writes on the cycloid and its use in calculating the volume of solids.

Pascal has poor health especially after his eighteenth year and his death comes just two months after his 39th birthday.