TCS Daily

Women, Lepers, and Jews!

By Todd Seavey - May 7, 2003 12:00 AM

Who needs science when you've got basic human intuition? To lots of people, that sounds about right.

An employee of a popular organic restaurant recently told me she doesn't need to sort through lots of studies about whether man-made chemicals such as pesticides are causing disease. It's just "common sense" to be afraid of such things, she said. To others, it's "common sense" that vaccines are dangerous.

Before setting science aside, though, it's worth asking how good humanity's track record with intuition and "common sense" is. After all, a health fear (or a cure) seen as reasonable by the public today might one day be regarded as lunacy if the data don't bear out the intuition. Or so history suggests.

Europe in the so-called Renaissance is a good place to start. Faced with the very real threat of the Black Death (bubonic plague), a modern, science-minded person might start systematically keeping track of who lived, who died, what the likely causes were, and what, if anything, could be done to decrease the odds of death. Tragically, then as now, frightened people had a tendency to adopt any theory that promised to give them some purchase on the chaos around them. To put it harshly, they made stuff up, often based loosely on ancient Greek ideas about illness being caused by imbalances in bodily humors (my thanks to MIT computer research scientist Chuck Blake for collecting some of these examples).

  • Blaming the plague on evil vapors, they kept fires burning all day to ward off the disease, reportedly burning down such huge swaths of forest and choking the air with so much smoke that birds fell from the sky.

  • Women, lepers, and - can you guess? - Jews were sometimes scapegoated as the causes of the infestations. Occasionally, doctors themselves were blamed for causing the plague and were chased from town, which must have been a particularly odd sight, since doctors in that day often wore creepy, penguin-like "protective" costumes with conical, beak-like face masks. I might be tempted to chase my doctor from town, too, if he dressed like that.

  • Of course, even if it wasn't airtight, a protective face mask made a bit more sense than some of the other disease-fighting measures of the day, such as spreading a mixture including the salt from human urine on bread and eating it.

  • Some families began their day with trips to the town latrine to breathe deeply of the noxious fumes, on the theory that this would keep other, more dangerous fumes out of the lungs.

  • Incense made of rose petals was burned in amounts large enough to cause respiratory problems (though that may have inadvertently driven away some rats and the fleas they carried, the real source of the disease).

  • Numerous holy relics were sold as protection, including what must have been several tons worth of the True Cross. Whole religious movements and new saints arose for the primary purpose of warding off the plague.

It would all be laughable if not for the fact that such confusion contributed to the deaths of about one third of Europe's population in just four years. Safest were the royals, who often simply barricaded themselves in their castles until outbreaks died down. The only monarch who had the misfortune to perish - and not even be widely remembered for it - was Alfonso the Magnanimous, king of Aragon and Sicily in the mid-fifteenth century.

Two centuries after Alfonso's demise, Europeans had worked out a complex system of quarantine, which helped contain plagues even when their causes remained mysterious. Science was making progress. It is worth noting, though, that during the period when the Black Death was at its worst, in the fourteenth and fifteenth centuries, dawning science was sometimes accompanied by an increase rather than decrease in superstitions and quack remedies. Once people think they're getting a handle on health problems, they may become overeager for new medications and inventions and thus accept them uncritically.

Similarly, the pseudo-scientific claims of our own day - whether from anti-chemical scaremongers or alternative medicine promoters - are rarely presented as completely at odds with mainstream science. Rather, they are presented with just enough of a scientific veneer to make people feel comfortable switching off their skepticism and running on intuition and instinct - figuring out what "sounds plausible" instead of what is true.

People are most prone to make intuitive leaps when they're desperate or panicked (I'll argue in an upcoming speech that chemicals have been targeted for such paranoia, one of the topics under discussion at conference this week in London on public panics).

If summoned via time travel to stand before a tribunal of future historians and asked how we could have believed some of the stupid things we believe in our own day, I suggest we have lots of hard data on hand, not just "common sense."

Todd Seavey is a Phillips Foundation Journalism Fellow, edits for the American Council on Science and Health, and is working on a book entitled "Conservatism for Punks."

TCS Daily Archives