Sometime in mid-July 1518, in the city of Strasbourg, a woman stepped into the street and started to dance.
She was still dancing several days later. Within a week about 100 people had been consumed by the same irresistible urge to dance. The authorities were convinced that the afflicted would only recover if they danced day and night.
So guildhalls were set aside for them to dance in, musicians were hired to play pipes and drums to keep them moving, and professional dancers were paid to keep them on their feet. Within days those with weak hearts started to die.
By the end of August 1518 about 400 people had experienced the madness. Finally they were loaded aboard wagons and taken to a healing shrine. Not until early September did the epidemic recede.
This was not the first outbreak of compulsive dancing in Europe. In fact, there had been as many as ten dancing epidemics before 1518, one in 1374 engulfing many of the towns of modern day Belgium, north-eastern France and Luxembourg.
The 1518 case is simply the best documented and by a richer variety of sources than its predecessors. It was not the first, though it was almost certainly the last to occur in Europe.
How do we explain this bizarre phenomenon? A popular idea has been that the dancers had ingested ergot, a psychotropic mould that grows on stalks of rye. But this is highly unlikely. Ergotism can trigger delusions and spasms, but it also typically cuts off blood supply to the extremities making coordinated movement very difficult.
It's also been suggested that the dancers were members of a heretical cult. This is also improbable because contemporaries were certain that the afflicted did not want to dance and the dancers themselves, when they could, expressed their misery and need for help. What's more, there was no suggestion of treating these people as heretics.
The other main contender is that this was an outbreak of mass hysteria. This is far more plausible, especially because in 1518 the poor of Strasbourg were experiencing famine, disease and spiritual despair on a scale unknown for generations.
But in itself this theory doesn't explain why the people danced in their misery.
3. set aside駁回
My explanation rests on the fact that the dancers were in a trance state; otherwise they would have been unable to dance for such lengths of time.
We know that the trance state is more likely to occur in people who under extreme psychological distress, and who believe in the possibility of spirit possession. All of these conditions were satisfied in Strasbourg in 1518.
The city's poor were suffering from severe famine and disease. And, crucially, we also know they believed in a saint called St. Vitus who had the power to take over their minds and inflict a terrible, compulsive dance.
Once these highly vulnerable people began to anticipate the St. Vitus curse they increased the likelihood that they'd enter the trance state. And once in it, they acted out the part of the accursed: dancing wildly for days at a time. So the epidemic, I argue, was a result of both desperation and pious fear.
The dancing plague died out because the supernaturalist beliefs that fed it gradually disappeared. In the short run, cities like Strasbourg were no longer susceptible because they became Protestant during the Reformation and spurned the saint worship on which the dancing plague depended.
In the long run, the fervent supernaturalism of the medieval world had to make way for the rise of modern science and rationality. The dancing madness was effectively starved out of existence. Even so, half a millennium later it still serves as a reminder of the ineffable strangeness of the human brain.