Often referred to as simply the Discourse on the Method, this work is frequently cited as one of the most important to appear during the Enlightenment era. It discusses the best means through which those in search of knowledge can approach the world, and the practice of science, as a means of attaining true and definitive insight. The Discourse on Method is influential chiefly for its contribution to science, having inspired many famed scientists toward their own discoveries over the centuries.

Descartes instructs the reader to doubt everything, and to use this universal doubt as a starting point from which to approach a problem. In addition to matters of science, Descartes discusses his personal, religious beliefs. In addition to his Method, Descartes also explains certain social and personal beliefs such as obeying the laws and statutes of his country and prioritising self-advancement over the achievement of material wealth or fortune.

Famous for including the much-quoted phrase "Je pense, donc je suis" - "I think, therefore I am" - the Discourse on Method today stands as a crucial cornerstone of countless educational courses on philosophy.