It has been usually interpreted that the axis on which the philosophy of Descartes is centered is the search for truth in the form of a metaphysical certainty, allowing the safe foundation of knowledge. This paper questions that reading, arguing that the Cartesian epistemological proposal represents an instrument to improve the conduction of the subject in the vicissitudes of ordinary life, concluding with a sense of certainty, whose fallible status will guide his actions in the world.