The Ghost Map: The Story of London's Most Terrifying Epidemic--and How It Changed Science, Cities, and the Modern World

by Steven Johnson

Waste recycling turns out to be a hallmark of almost all complex systems, whether the man-made ecosystems of urban life, or the microscopic economies of the cell.

But epidemics create a kind of history from below: they can be world-changing, but the participants are almost inevitably ordinary folk, following their established routines, not thinking for a second about how their actions will be recorded for posterity. And of course, if they do recognize that they are living through a historical crisis, it’s often too late—because, like it or not, the primary way that ordinary people create this distinct genre of history is by dying.

But a family dying together, slowly, agonizingly, with full awareness of their fate—that is a supremely dark chapter in the book of death. That it continues on as a regular occurrence in certain parts of the world today should be a scandal to us all.

As soon as there were mass human settlements, waterborne diseases like dysentery became a crucial population bottleneck. For much of human history, the solution to this chronic public-health issue was not purifying the water supply. The solution was to drink alcohol.

For the first time, the law had something to say about people opting to fill their old cellars with “great heaps of turds,” as Samuel Pepys put it in a 1660 journal entry.

Initially, company representatives swore that all their water had been run through state-of-the-art filter beds at their new covered reservoirs. But reports had surfaced of some customers discovering live eels in their drinking water, which suggested that the filters were not perhaps working optimally.

Our safety depends on being able to predict the evolutionary path that viruses and bacteria will take in the coming decades, just as safety in Snow’s day depended on the rational application of the scientific method to public-health matters. Superstition, then and now, is not just a threat to the truth. It’s also a threat to national security.

However profound the threats are that confront us today, they are solvable, if we acknowledge the underlying problem, if we listen to science and not superstition, if we keep a channel open for dissenting voices that might actually have real answers.