Susan Jacoby examines a new American cultural phenomenon that clashes with the nation's heritage of Enlightenment reason and modern scientific knowledge. She critiques an anti-rationalist landscape, from pop culture to 'junk thought,' fostered by mass media, religious fundamentalism, and a credulous public. Jacoby argues that America's addiction to infotainment distinguishes this age of unreason from past anti-intellectual outbreaks, leading to a decline in reading and a rise in illiteracy. This impassioned book challenges Americans to confront the painful truth about the costs of abandoning reason.