"Descartes merely implicates conventionally that his 'sum' follows from his 'cogito'" -- H. P. Grice

H. P. Grice, “Descartes on clear and distinct perception’ -- Descartes, René (1596–1650) French philosopher and mathematician, regarded as the father of modern philosophy, born at La Haye. Descartes rejected the methods and assumptions of scholasticism and sought to set knowledge on a firm basis by demanding certainty in the justification of our beliefs. His philosophical system, based on his method of systematic doubt, accepted nothing as true that could not be clearly and distinctly perceived to be true. He held that for each of us the first indubitable truth is “I am thinking, therefore I exist” (Latin cogito ergo sum). Descartes’s focus on the primacy of epistemology shaped subsequent understanding of the nature of the philosophy. Since doubt is an imperfect state, he inferred the existence of God as a Perfect Being. Cartesian dualism argues that mind and body are distinct substances and that a human being is a union of an extended body and a thinking mind. The relation between mind and body remains a basic question in philosophy of mind. His rationalism, search for certainty and conception of mind have also influenced phenomenology and other movements in modern European philosophy. Descartes’s philosophy is best understood in relation to his contributions to the emerging modern science of his time. His major works include Discourse on the Method (1637), Meditations on First Philosophy (1641), Principles of Philosophy (1644), and The Passions of the Soul (1649). He died in Stockholm while tutoring