The Collected Works of Spinoza provides, for the first time in English, a truly satisfactory edition of all of Spinoza's writings, with accurate and readable translations, based on the best critical editions of the original-language texts, done by a scholar who has published extensively on the philosopher's work. This first volume contains Spinoza's single most important work, the Ethics, and four earlier works: the Treatise on the Emendation of the Intellect, the Short Treatise on God, Man, and His Well-Being, Descartes' "Principles of Philosophy," and Metaphysical Thoughts. Also included are Spinoza's letters from the periods when these works were being written. The elaborate editorial apparatus—including prefaces, notes, glossary, and indexes—assists the reader in understanding one of the world's most fascinating, but also most difficult, philosophers. Of particular interest is the glossary-index, which provides extensive commentary on Spinoza's technical vocabulary. A milestone of scholarship more than forty-five years in the making, The Collected Works of Spinoza is an essential edition for anyone with a serious interest in Spinoza or the history of philosophy.