The term 'FIRST CARTESIAN' refers to the French philosopher and mathematician Rene Descartes (1596-1650). He is often referred to as the father of modern philosophy and is best known for his philosophical work, Discourse on the Method, which laid the foundation for the scientific method. He is also credited with developing the Cartesian coordinate system, which is a system of coordinates used in geometry and algebra. This system is still widely used today.