René Descartes

René Descartes (1596–1650), French philosopher, mathematician, and scientist, is often hailed as the father of modern philosophy. His method of radical doubt sought certainty by questioning all assumptions, culminating in the famous dictum Cogito, ergo sum (“I think, therefore I am”). Descartes emphasized reason as the foundation of knowledge, distinguishing mind from body in his dualism, which shaped metaphysics and psychology. He advanced mathematics through analytic geometry, linking algebra and geometry, and contributed to optics and physics. His Meditations on First Philosophy remains a cornerstone of Western thought, inspiring rational inquiry, scientific progress, and debates on consciousness, existence, and truth.

Cogito, ergo sum. But I could not possibly exist with the nature I actually have, unless there really is a God