Rene Descartes born on March 31, 1596 in La Haye, France.
He is known for his most famous observation, "I think; therefore, I am." He was considered to be the Father of Modern Philosophy because his approach was very different from the current studies applied in his time.
In mathematics, he had the following contributions:
1) introduced Cartesian geometry, which incorporate algebra
2) introduced the law of refraction