Title: Regulae ad directionem ingenii (Rules for the Direction of the Mind)
(I use an English translation in Great Books of the Western World – 1952)
Published: 1626–1628. Regulae ad directionem ingenii (Rules for the Direction of the Mind). Incomplete. First published posthumously in Dutch translation in 1684 and in the original Latin at Amsterdam in 1701 (R. Des-Cartes Opuscula Posthuma Physica et Mathematica). The best critical edition, which includes the Dutch translation of 1684, is edited by Giovanni Crapulli (The Hague: Martinus Nijhoff, 1966).
From Wikipedia: Descartes has been often dubbed as the father of modern Western philosophy, the philosopher that with his sceptic approach has profoundly changed the course of Western philosophy and set the basis for modernity. The first two of his Meditations on First Philosophy, those that formulate the famous methodic doubt, represent the portion of Descartes’ writings that most influenced modern thinking. It has been argued that Descartes himself didn’t realize the extent of his revolutionary gesture. In shifting the debate from “what is true” to “of what can I be certain?,” Descartes shifted the authoritative guarantor of truth from God to humanity. (While the traditional concept of “truth” implies an external authority, “certainty” instead relies on the judgment of the individual.) In an anthropocentricrevolution, the human being is now raised to the level of a subject, an agent, an emancipated being equipped with autonomous reason.