For a number of years, those interested in recovering women's thought have known about Princess Elisabeth, a seventeenth-century correspondent and friend of Descartes whose questions provoked the philosopher to think more seriously about ethics and the passions. Up to now, only a few of her letters have found their way into print. This volume includes translations of all of Elisabeth's extant letters to Descartes, as well as of other materials relevant to understanding her philosophical perspective and her life. Nye has supplemented the translations with a running commentary on the historical, biographical, and intellectual context of the letters.