This book examines one of the most remarkable political myths of the modern era. The image of a Jesuit conspiracy against state, society, and modern civilization haunted the imaginations of European liberals for most of the nineteenth century. This book examines the operations and structures of this conspiracy theory in one of its main centres of influence: France. It examines the functions which the Jesuit myth performed in nineteenth-century French politics, and provides a detailed analysis of its thematic development, rhetorical strategies, and internal tensions. The book relates the influence of anti-Jesuit beliefs to the Jesuits' own position in nineteenth-century society and religious and political life; but its major contribution is to show how the myth expressed the deeper anxieties and served the broader mental needs of French liberals and republicans in an age of political instability. At the cost of encouraging mistrust and intransigence in French politics, the Jesuit myth played an important part in forging the political identity of the moderate French Left. In an innovative Conclusion, the author also places the Jesuit myth in the large context of long-term evolutions in the character and significance of conspiracy theories as an ingredient in modern political mentalities