René Descartes (1596–1650) is the most important French philosopher who ever lived and, arguably, among the top five philosophers of all time. He is known as “the father of modern philosophy” in part because of the influence he continues to exert over the way the discipline is practiced. But he was much more than a philosopher; he was a universal genius whose writings range over anatomy and physiology, astronomy, biology, epistemology, ethics, mathematics, medicine, metaphysics, meteorology, music, optics, psychology, and physics. There is a very long tradition of Cartesian studies but over the past thirty years there has been an explosion of academic works devoted to Descartes’ ideas, and the rate of production is accelerating. An insatiable appetite for all things Cartesian is being fed by a steady diet of new monographs, guidebooks, biographies, anthologies of essays, translations, journal articles, and other scholarly works. One of the primary aims of this volume is to help the reader digest this vast literature, while also introducing him or her to the breadth of Descartes’ thought.

The Cambridge Descartes Lexicon is more like an encyclopedia or a compendium than a traditional dictionary, both in its scope and in its content. Many of the entries are fairly lengthy, especially those devoted to important subject terms such as “Cogito Ergo Sum,” “Free Will,” “God,” “Human Being,” “Idea,” “Law of Nature,” and “Representation.” Most of the subject entries are also “scholarly” in the sense that they introduce readers to debates in the secondary literature. The authors of these entries sometimes present these debates without defending their own views, but in many cases they take an interpretive stand. Authors of overlapping entries were encouraged to stake out opposing positions (see, e.g., “Body,” “Individuation,” and “Substance”). The result is that by reading just a few pages readers can familiarize themselves with almost any given scholarly dispute and get a sense of the arguments and textual evidence for various interpretations.

In perusing the Lexicon, readers will find articles on all of the familiar topics, such as “Certainty,” “Clarity and Distinctness,” “Doubt,” “Dualism,” “Geometry,” “Knowledge,” “Method,” and “Mind,” as well as entries on several unexpected and perhaps unfamiliar topics such as “Language,” “Physico-Mathematics,” “Rosicrucian,” and “The Stampioen Affair.”