Rene Descartes was a French philosopher, mathematician, and scientist who is widely regarded as one of the most influential thinkers of all time. He is best known for his philosophical work, which laid the foundation for modern Western philosophy. He is also credited with developing the Cartesian coordinate system, which is still used in mathematics today. Descartes is often referred to as the 'Father of Modern Philosophy' and his famous phrase, 'I think, therefore I am, ' is one of the most well-known philosophical statements in history.