Does the lack of evidence mean that aliens don’t exist? Why does an unproven mathematical hypothesis have profound consequences? Are humans capable of grasping the nature of divinity? Is it ethical to give a patient a placebo? Why do people persist in demonstrably false beliefs like flat earth theory? Should someone want to know when they will die?

George G. Szpiro examines these questions and many others, offering an engaging and witty tour of what we can learn from ignorance. In a series of fast-paced chapters, he unravels problems ranging across science, mathematics, law, economics, politics, religion, psychology, and philosophy—some esoteric, others drawn from everyday life. Ignorance comes in many forms, Szpiro shows. Some questions are only temporarily unsolved; others are inherently unanswerable. Sometimes authorities keep answers from us, for good or ill. Often our assumptions and biases keep us from overcoming our ignorance, and occasionally we choose to remain ignorant—for surprisingly rational reasons.

Ultimately, Szpiro argues, ignorance is not purely negative. It can motivate the pursuit of learning and wisdom—as long as we acknowledge it. Presenting sophisticated topics in an accessible way, this book shows how ignorance sheds light on the nature of knowledge.