This book scrutinizes the mysterious power of rumors and seeks to analyse it philosophically, examining along the way some key moments of our cultural history concerning rumors, from Shakespeare and Cervantes to Gogol and Kafka. It also underlines the fact that, although rumors are as old as humankind, the advent of the internet and social media has raised the spreading of rumors to an entirely new level, to the point where we could speak of the rumorization of the social. The more communication there is, the more the social fabric threatens to fall apart - and the more urgent it becomes to find strategies to counteract this.