Rene Descartes
Arguably, the most famous philosophical quote ever – I think, therefore I am (cogito ergo sum), which is considered to be the foundation of the Modern Philosophy and thought, belongs to the French philosopher Rene Descartes (31 March 1596 – 11 February 1650). Renatus Cartesius (his Latinized name) was as well a prominent and influential mathematician and scientist, who is the founder of the Cartesian coordinate system, praised as the first systematic bridge between geometry and algebra.