Blaise Pascal was a French mathematician, physicist, and religious philosopher. Pascal's earliest work was in the natural and applied sciences. His important contributions to these fields include the construction of mechanical calculators, the study of fluids, and clarification of concepts such as pressure and vacuum by expanding the work of Evangelista Torricelli. Pascal also lent his pen to the defense of the scientific method. In mathematics, Pascal did groundwork in projective geometry, writing a significant treatise on the subject at the age of sixteen. In correspondence with Fermat beginning in 1654, Pascal helped establish probability theory. His ideas in this area have had major ramifications in economics and the social sciences. Following a mystical experience in late 1654, he fell away from mathematics and physics and devoted himself to reflection and writing about philosophy and theology. This period was characterized by the composition of his two most famous works, the Lettres provinciales and the Pensées. (Read more...)