Sir Isaac Newton (1642-1727) left a voluminous legacy of writings. Despite his influence on the early modern period, his correspondence, manuscripts, and publications in natural philosophy remain scattered throughout many disparate editions. In this volume, Newtons principal philosophical writings, including excerpts from the Principia and the Opticks and a corrected translation of De Gravitatione, are collected in a single place. This newly expanded second edition of Philosophical Writings contains new excerpts from Newtons earliest optical writings, some of his unpublished reflections on the interpretation of Scriptural passages that concern the Earths motion, and his correspondence with important figures in his day, including the theologian Richard Bentley, the mathematician Roger Cotes, and the philosopher G. W. Leibniz. The excerpts show in depth how Newton developed a number of highly controversial views concerning space, time, motion and matter and then defended them against the withering criticisms of his contemporaries.