The essays in this volume form a commentary on Descartes' Meditations. Following the sequence of the meditational stages, the authors analyze the function of each stage in transforming the reader, to realize his essential nature as a rational inquirer, capable of scientific, demonstrable knowledge of the world. There are essays on the genre of meditational writing, on the implications of the opening cathartic section of the book on Descartes' theory of perception and his use of skeptical arguments; essays on the theory of ideas and their role of Descartes' reconstructive analytic method; essays on the proofs for the existence of God, on the role of the will in the formation and malformation of judgments; and the essays on the foundations of the science of extension and on Descartes' account of the union of mind and body.