A World Lit Only By Fire is William Manchester's attempt to write a book of popular history defending the increasingly unpopular view among historians that the medieval world was culturally, religiously, and technologically backward. This world was destroyed by the blossoming of confidence in reason and the progress of art, literacy, astronomy, geography, and theology. The book is divided into three chapters. The first chapter introduces Manchester's conception of the medieval mindset. The second chapter includes a lengthy discussion about how this mindset was continuously challenged by a number of individuals and movements. Finally, the last chapter explores in detail the adventure of Ferdinand Magellan whom Manchester believes shattered the medieval mind and heralded the coming of modernity.