René Descartes (1596–1650) was a French philosopher, mathematician, and scientist — known as the Father of Modern Philosophy. He introduced rationalism and famously said “I think, therefore I am” (Cogito, ergo sum). His ideas shaped modern science and logic.René Descartes (1596–1650) was a French philosopher, mathematician, and scientist — known as the Father of Modern Philosophy. He introduced rationalism and famously said “I think, therefore I am” (Cogito, ergo sum). His ideas shaped modern sc