Two works from the father of modern philosophy. In Discourse on Method, he formulated a scientific approach comprising four principles, including to accept only what reason recognizes as "clear and distinct." In Meditations, he explores the mind/body distinction, the nature of truth and error, the existence of God, and the essence of material things. Unabridged republication of Discourse and Meditations from The Philosophical Works of Descartes, Cambridge University Press, 1911.
Here's a sample of other books in this Dover category
The Geometry of René Descartes by René Descartes The great work that founded analytical geometry. Includes the original French text, Descartes' own diagrams, and the definitive Smith-Latham translation. "The greatest single step ever made in the progress of the exact sciences." — John Stuart Mill.
Tractatus Logico-Philosophicus by Ludwig Wittgenstein In his proposal of the solution to most philosophic problems by means of a critical method of linguistic analysis, Wittgenstein sets the stage for the development of logical positivism. Introduction by Bertrand Russell.
