René Descartes (31 March 1596 – 11 February 1650) was a French philosopher, mathematician, and scientist. A native of the Kingdom of France, he spent about 20 years (1629–1649) of his life in the Dutch Republic after serving for a while in the Dutch States Army of Maurice of Nassau, Prince of Orange and the Stadtholder of the United Provinces. One of the most notable intellectual figures of the Dutch Golden Age, Descartes is also widely regarded as one of the founders of modern philosophy.
One of Descartes’s most enduring legacies was his development of Cartesian or analytic geometry, which uses algebra to describe geometry. Descartes “invented the convention of representing unknowns in equations by x, y, and z, and knowns by a, b, and c“. He also “pioneered the standard notation” that uses superscripts to show the powers or exponents; for example, the 2 used in x² to indicate x squared. He was first to assign a fundamental place for algebra in our system of knowledge, using it as a method to automate or mechanize reasoning, particularly about abstract, unknown quantities.