René Descartes is most commonly known for his philosophical statement, “I think, therefore I am” (originally in French, but best known by its Latin translation: "Cogito, ergo sum”). He is also attributed with developing Cartesian dualism (also referred to as mind-body dualism), the metaphysical argument that the mind and body are two different substances which interact with one another. In the mathematics sphere, his primary contribution came from bridging the gap between algebra and geometry, which resulted in the Cartesian coordinate system still widely used today.