To borrow a phrase from Voltaire, the seventeenth century in European history was the century of Louis XIV, and it can be regarded as the century in which France emerged as a great power. Turning to the history of science, Alfred North Whitehead called the seventeenth century the century of genius. This century saw France contribute three mathematical geniuses: René Descartes, Pierre de Fermat, and Blaise Pascal. It is well known that Fermat was mainly interested in pure mathematics, and he is famous in particular for Fermat’s last theorem, which remained unsolved for many years until it was finally conquered at the end of the last century. Descartes and Pascal on the other hand were versatile thinkers, both of whom lived in Paris for a time, and so they became famous already during their lifetimes.