Blaise Pascal was born in Clermont, France in 1623.  His father, a local judge in Clermont, moved to Paris in 1631 to pursue his own intellectual interests in the sciences as well as to better the education of his only son.  Blaise Pascal revealed his intellectual promise at a young age.  He began with the study of languages and was restricted from the study of mathematics in particular. His father's injunction aroused his curiosity, and Pascal began to secretly study geometry during his recreational times.  He began to discover some of the properties of figures such as the sum of the angles of a triangle are equal to two right angles.  His father, taken aback with his son's display of ability, gave him a copy of Euclid's 'Elements' which he eagerly read and mastered.

At the age of fourteen Pascal was admitted to the weekly meetings of Roberval, Mersenne, Mydorge, and other French geometricians (from which ultimately sprang the French Academy).  At sixteen he wrote an essay on conic sections; at eighteen he constructed the first arithmetical machine (which he further improved in 1649).  During this approximate time, Blaise Pascal began to correspond with Pierre Fermat, revealing a shift in attention to analytical geometry and physics.

After a three year hiatus in the study of religion, Pascal returned to his scientific and mathematical research.  Much of his scientific research consisted of studies done on the pressures exerted by gases and liquids.  Around 1653 he invented the arithmetical triangle.  Pascal's arithmetical triangle gives the coefficients of the expansion of a binomial and can be used to find the numbers of combinations of 'm' things taken 'n' at a time.  Pascal is perhaps best known as a mathematician in connection with his correspondence with Fermat in 1654 in which he laid the principles of the theory of probability.  This theory and correspondence arose from a problem involving a two-player game.  Pascal's last mathematical work was that on the cycloid curve in 1658.

After a life-threatening accident in 1654, Pascal again turned to religion.  He was so shaken by his experience with death that he wrote an account of the accident on a small piece of parchment and hung it near his heart to constantly remind him.  He made an oath to 'abandon the world' and, subsequently, moved to Port Royal where he later died in 1662.  Blaise Pascal's incessant studying had done much damage to his health.  From the age of fourteen or fifteen he suffered from insomnia and acute dyspepsia.  Physically worn-out by his studies, Pascal met death while honoring
his oath.  Applying probablility theory to spiritual life, Pascal believed that it was worth while to be 'religious' given the expectation and value of the promise of eternal happiness.  This came to be known as "Pascal's Wager."

Author: Clarence L. Terry

References:
Text Reference:
'A Short Account of the History of Mathematics' (4th edition, 1908) by W.W. Rouse Ball.

Web Reference:
http://www.maths.tcd.ie/pub/HistMath/People/RBallHist.html