This weekend I finished reading Steven Johnson‘s The Ghost Map: The Story of London’s Most Terrifying Epidemic — and How It Changed Science, Cities, and the Modern World. A recounting of nineteenth-century London’s battle with cholera, it proved to be one of those books so riveting I could not bear to put it down.
It is at bottom an etiology of error — uncovering how mistaken beliefs about the causes of disease take hold, thrive, and persist, with disastrous consequences for public health. It considers important questions:
The history of knowledge conventionally focuses on the breakthrough ideas and conceptual leaps. But the blind spots on the map, the dark continents of error and prejudice, carry their own mystery as well. How could so many intelligent people be so grievously wrong for such an extended period of time? How could they ignore so much overwhelming evidence that contradicted their most basic theories? These questions, too, deserve their own discipline — the sociology of error.
This book delivers as well a message of optimism about intellectual courage and unblinkered vision — how two men struggled to cast off bad ideas and pursue better ones — ideas that ultimately led to the defeat of a deadly disease.
For anyone fascinated by human judgment and cognition, this book offers a reminder, rooted in history, of the importance of the second glance, of the ability to see anew.