Blaise Pascal was a French physicist, mathematician, philosopher, and inventor. A child prodigy, Pascal's work on projective geometry, at the age of 16 is commendable. He is one of the earliest inventors of the mechanical calculator, which he did when he was still a teenager. His work on probability theory influenced the development of social science and modern economics.
Seventeenth-century French mathematician Pierre de Fermat was also a qualified lawyer. Remembered mostly for his contribution to number theory, probability, calculus, and analytic geometry, he was also known for his proficiency in six languages, including Greek and Latin. One of his major works, Introduction to Loci, was released posthumously.
French Catholic priest and astronomer Pierre Gassendi is remembered for his efforts to reconcile atomism with Christian ideals and for his anti-Aristotelianism. His studies included research on Epicurean philosophy. Apart from observing the transit of Mercury, he also studied the speed of sound and horizontal momentum.
One of the founders of projective geometry, French mathematician Girard Desargues began his career as an architect and an engineer, designing several private and public buildings in Paris and Lyon and also a project for lifting water. Eventually he became associated with a group of Parisian mathematicians and undertook researches on perspective and geometrical projections, publishing several papers on it.