This book offers a critical survey of religious change and its causes in eighteenth-century Europe, and constitutes a challenge to the accepted views in traditional Enlightenment studies. Focusing on Enlightenment Italy, France and England, it illustrates how the canonical view of eighteenth-century religious change has in reality been constructed upon scant evidence and assumption, in particular the idea that the thought of the enlightened led to modernity. For, despite a lack of evidence, one of the fundamental assumptions of Enlightenment studies has been the assertion that there was a vibrant Deist movement which formed the intellectual solvent of the eighteenth century. The central claim of this book is that the immense ideological appeal of the traditional birth-of-modernity myth has meant that the actual lack of Deists has been glossed over, and a quite misleading historical view has become entrenched.