René Descartes: (March 31, 1956 - February 11, 1650) : French philosopher, mathematician, scientist and writer.

The French mathematician and philosopher Descartes is sometimes called the father of modern philosophy and one of the first proponents of the scientific method. He is considered the cofounder of analytical geometry, along with Fermat, thus preparing the way for the invention of the calculus; one of the appendices of his book Discourse de la méthode is entitled La géométrie and contains his contribution to the subject.

After the French postal service issued the above stamp in honour of Rene Descartes, sharp eyes noticed that the title of Descartes' most famous book was wrong. Thus a second stamp was issued with the correct title. The book in question, Discourse on Method, appeared in 1637. In it Descartes rejected traditional Aristotelian philosophy, outlining a universal system of knowledge that was to have the certainty of mathematics. He first adopted a skeptical view of everything, seeking "clear and distinct" ideas that any rational person could not doubt. One of these is his famous statement, "I think, therefore I am." For Descartes, method was analysis, going from self-evident truths step-by-step to more distant and more general truths.

Descartes wrote his Geometry as an application of his method; it was published as an appendix to the Discourse. His attempts to unify algebra and geometry influenced the creation of what became coordinate geometry, and influenced the development of calculus by Newton and Leibniz in the next generation.