How did one earthquake change the way Europe thought?
On the morning of 1 November 1755, All Saints’ Day, the churches of Lisbon were full. At around half past nine the ground began to shake. The earthquake is now estimated at magnitude 8.5 to 9.0, and it is still the most destructive in European history.
Stone churches and houses swayed and collapsed on the people inside. Survivors ran to the open ground by the river, the safest place they could think of. Within the hour, a tsunami several metres high came up the Tagus and swept the waterfront. Meanwhile the candles lit for the holy day had started fires all over the city, and they burned for five days.
Nobody knows exactly how many people died. The United States Geological Survey puts it at about 60,000, roughly a quarter of the city. King José I survived only because he was staying at a palace outside the city. For the rest of his life he was afraid of being inside buildings, and he lived in a grand tent.
That was the disaster. What makes it worth remembering is what people did with it afterwards.
The question nobody could avoid
In 1755, many educated Europeans believed, in one form or another, that the world was arranged by a good God and that, seen from high enough, everything was for the best. The philosopher Leibniz had argued that this was “the best of all possible worlds”. The English poet Alexander Pope had written “Whatever is, is right.”
Then a Catholic capital was flattened on a holy day, with its people at prayer.
Voltaire, the most famous writer in Europe, answered in 1756 with a long poem on the disaster of Lisbon. His question was simple: what had the children crushed in their mothers’ arms done to deserve it? Three years later he went further. In Candide (1759), his hero lives through the Lisbon earthquake in the company of Dr Pangloss, a tutor who keeps insisting that all is for the best while everything around him goes wrong. The book was a comedy, and a devastating one.
Jean-Jacques Rousseau wrote back to Voltaire in August 1756 with a different point, and it may be the most modern thing anyone said about Lisbon:
Nature did not construct twenty thousand houses of six to seven stories there, and if the inhabitants of this great city had been more equally spread out and more lightly lodged, the damage would have been much less and perhaps of no account.
In other words, the earthquake was natural, but a good part of the catastrophe was man-made. People who study disasters today still start from that idea.
And in Königsberg, a young philosopher named Immanuel Kant published three essays in 1756 trying to explain what causes earthquakes. His answer (hot gases in underground caverns) was wrong. But he was looking for a natural cause instead of a divine one, and that was the right question.
Thirteen questions
In Lisbon itself, the response was led by the king’s minister, Sebastião José de Carvalho e Melo, later known as the Marquis of Pombal.
He is often credited with the famous answer to the king, “Bury the dead and heal the living.” He probably did not say it. Historians give the words (in a longer version that ends “and close the ports”) to another nobleman, the Marquis of Alorna. It is a good story. It just belongs to someone else.
What Pombal certainly did was stranger, and more lasting. On 26 January 1756 he sent the bishops of the kingdom a questionnaire with thirteen questions, to be passed to every parish priest. At what time did the earthquake begin? How long did it last? Did the sea rise or fall first? What happened to the wells and springs? There was no question about sin, and no mention of God. More than six hundred parishes replied.
It was an attempt to collect facts about an earthquake from across a whole country, and many consider it the beginning of modern seismology.
The rebuilding followed the same spirit. The old lower town was replaced with the Baixa: straight streets on a grid, buildings of the same height, and inside their walls a flexible wooden frame, the gaiola pombalina (the “Pombaline cage”), designed to bend when the ground shakes instead of breaking.
Sources
- USGS, Today in Earthquake History (1 November) · earthquake.usgs.gov
- Hakai Magazine, The Earthquake That Brought Enlightenment · hakaimagazine.com
- Lisbon Quake, The inquiry into the Lisbon earthquake · lisbonquake.com
- Lisbon Quake, The King’s Ministers (on the Marquis of Alorna) · lisbonquake.com
- Poème sur le désastre de Lisbonne · en.wikipedia.org
- Rousseau, Lettre à M. de Voltaire (18 August 1756), original edition · archive.org
- Kant’s earthquake essays, discussed in The Lisbon earthquake and the scientific turn in Kant’s philosophy · researchgate.net
- Gaiola (construction) · en.wikipedia.org
- Atlas Obscura, Carmo Convent Ruins · atlasobscura.com