Ecrasez l’infâme! Voltaire’s rallying cry against fanaticism resonates with new force today. Nothing suggests the complex legacy of the Enlightenment more than the struggle of superstition, prejudice, and intolerance advocated by most of the Enlightenment philosophers, regardless of their ideological differences. The aim of this book is to undertake a reconsideration of the controversies surrounding the questions of religion, toleration, and fanaticism in the eighteenth century through an examination of Rousseau’s dialogue with Voltaire. What come to light from this confrontation are two leading and at times competing world views and conceptions of the place of the engaged writer in society.