René Descartes, widely regarded as the "Father of Modern Philosophy," reshaped the foundations of Western thought with his groundbreaking ideas. Born in 1596 in France, Descartes' quest for understanding led him to challenge long-standing beliefs and establish the method of doubt, culminating in his famous declaration, "Cogito, ergo sum" (I think, therefore I am). This biography delves into his early education at Jesuit College, his pioneering work in philosophy and mathematics, and his scientific innovations, including analytical geometry and contributions to optics. Despite personal struggles and societal resistance, Descartes’ determination to seek truth defined his legacy. This comprehensive account explores his philosophical writings, such as Meditations on First Philosophy, and examines how his work influenced the Enlightenment, laying the foundation for modern science and rational inquiry.