“ explores the myriad ways in which ‘not-knowing’ affects our lives, sometimes for good, sometimes for ill.”—Michael Dirda, Throughout history, every age has thought of itself as more knowledgeable than the last. Renaissance humanists viewed the Middle Ages as an era of darkness, Enlightenment thinkers tried to sweep superstition away with reason, the modern welfare state sought to slay the “giant” of ignorance, and in today’s hyperconnected world seemingly limitless information is available on demand. But what about the knowledge lost over the centuries? Are we really any less ignorant than our ancestors?   In this highly original account, Peter Burke examines the long history of humanity’s ignorance across religion and science, war and politics, business and catastrophes. Burke reveals remarkable stories of the many forms of ignorance—genuine or feigned, conscious and unconscious—from the willful politicians who redrew Europe’s borders in 1919 to the politics of whistleblowing and climate change denial. The result is a lively exploration of human knowledge across the ages, and the importance of recognizing its limits.