Cartesian Philosophy is a school of thought founded by the French philosopher René Descartes in the 17th century. It emphasizes the importance of reason and doubt as tools for acquiring knowledge. Descartes famously stated, "Cogito, ergo sum," meaning "I think, therefore I am," which highlights the certainty of one's own existence as a starting point for understanding reality. This philosophy also explores the distinction between the mind and body, known as dualism. Descartes argued that the mind is a non-physical substance, while the body is physical. This separation has influenced various fields, including psychology, science, and metaphysics, shaping discussions about consciousness and existence.