The Man Voltaire Killed: How an Earthquake Destroyed Leibniz's Reputation

On the morning of November 1, 1755, the churches of Lisbon were full. It was All Saints' Day, one of the most sacred feasts in the Catholic calendar, and the faithful had come to mass in numbers. At 9:40 in the morning, the earth moved.

The earthquake - one of the most powerful in European recorded history - killed somewhere between 30,000 and 40,000 people in Lisbon alone, with thousands more dying across Morocco and southern Portugal. The shaking brought down buildings. The fires that followed burned for five days. A tsunami struck the harbour within an hour of the first tremor, finishing what the earthquake had begun. Lisbon, one of the great cities of Europe, was effectively destroyed in a single morning.

Gottfried Wilhelm Leibniz had been dead for thirty-nine years. He could not read the reports. He could not respond to what came next.

Voltaire could. And he did.

The Mind That Refused Boundaries

To understand what Voltaire destroyed, you have to understand first what Leibniz actually built.

Born in Leipzig in 1646, Leibniz was, by any measure, one of the most extraordinary intellects in European history. He developed calculus independently of Newton - the priority dispute between them would define both men's later years, but the mathematics itself was genuine and original. He designed mechanical calculators that could multiply and divide. He developed the binary number system - the foundation of every computer, every digital device, every piece of software that has ever run. He made foundational contributions to formal logic that would not be fully appreciated until Frege and Russell rediscovered them two centuries later. He wrote on physics, law, history, linguistics, and theology with a depth that specialists in each field have spent generations unpacking.

He was, in a real sense, the last person in Western history who could hold the entire map of human knowledge in a single mind. A century after his death, the specialisation of disciplines had advanced so far that such a figure was no longer possible. The window had closed. He was among the last to pass through it.

And yet he left no single defining masterwork. Newton had the Principia Mathematica - one book, one monument, impossible to ignore or misplace. Kant would have the Critique of Pure Reason. Leibniz had thousands of letters, scattered manuscripts, unpublished notebooks. His ideas were distributed across the correspondence networks of Europe, brilliant and diffuse, lacking the fixed address that posterity requires.

This was the first vulnerability. The second came from the problem he chose to solve.

The Best of All Possible Worlds

In 1710, Leibniz published his Theodicy - a word he coined himself from the Greek for God (theos) and justice (dikē). The problem he was attempting to solve was ancient: if God is all-powerful, all-knowing, and perfectly good, how do we account for the existence of evil and suffering in the world?

His answer was careful, technical, and frequently misunderstood. God, Leibniz argued, faced an infinity of possible worlds - every conceivable arrangement of existence. Being perfectly rational and perfectly good, God chose to create the best one available. Not a perfect world. Leibniz was not claiming perfection. He was claiming optimality: that this world, with all its suffering and imperfection, was nevertheless the best configuration possible given the infinite constraints that govern existence. Any other world would, on balance, have been worse.

It is a serious philosophical argument. Philosophers had been wrestling with the problem of evil for centuries before Leibniz, and they have continued wrestling with it for centuries since. His contribution was taken seriously by serious people. The Theodicy was the only book he published in his lifetime, and it circulated widely across Europe.

He died in 1716, six years after its publication, largely unacknowledged. The Royal Society had sided with Newton in the calculus dispute. The Brunswick family, whose history he had spent decades promising to write without ever finishing, had little use for him in his final years. George I, who happened to be near Hanover at the time of his death, did not attend the funeral. Neither did any fellow courtier. Only his personal secretary followed the coffin. His grave went unmarked for more than fifty years.

The Theodicy remained. And in Lisbon, in 1755, it met the earthquake.

The Moment Everything Changed

For the philosophers of optimism, the Lisbon disaster was not merely a tragedy. It was an intellectual crisis.

How do you argue, with intellectual integrity, that the world is the best possible version of itself when up to 60,000 people die in a church on a holy day? When the fires burn for five days? When the tsunami takes the survivors who had run to the harbor for safety?

Voltaire felt this personally and viscerally. He had been, in earlier years, something of an optimist himself. Lisbon ended that. He wrote a long poem about the disaster within weeks - raw, angry, grief-stricken - and then, four years later, he channeled the anger into something more lasting.

Candide was published in 1759. It was an immediate sensation.

The detail that sharpens the tragedy into something almost unbearable: Leibniz published the Theodicy in 1710. He died in 1716. The Lisbon earthquake was 1755. Candide was 1759. He had been dead for forty-three years before Voltaire put him on trial. He never knew the earthquake was coming. He never knew what would be done with his argument. He never had the chance to speak.

What Voltaire Actually Did

Dr. Pangloss - the character Voltaire created as his stand-in for Leibniz - is not a philosopher. He is a fool. He repeats the mantra "all is for the best in the best of all possible worlds" as a kind of tic, an automatic response that fires regardless of what is happening around him. War, disease, earthquake, rape, murder: Pangloss absorbs each catastrophe and recites his formula. The joke is that nothing can penetrate the optimism. The joke is that the optimism is indistinguishable from stupidity.

It is one of the most devastating pieces of satire in the Western literary tradition. Candide is brilliantly written, propulsively paced, and ruthlessly funny. As a work of literature, it is close to flawless.

As a philosophical engagement with Leibniz, it is a fabrication.

Voltaire did not argue against what Leibniz actually said. He argued against a caricature - Leibniz's careful, hedged, technical argument stripped of its context, its qualifications, its actual content, and replaced with the blithering of a comic buffoon. The distinction Leibniz had drawn - between a perfect world and the best available world - was simply discarded. The Pangloss who insists everything is wonderful is not the Leibniz who wrote that evil exists and must be accounted for. They share a phrase. They share nothing else.

Voltaire knew this. He was too intelligent not to. The decontextualization was deliberate - a rhetorical choice, not a misunderstanding.

The damage was permanent. "Panglossian" entered the language as an adjective for naive, reflexive optimism. Leibniz's name, for the educated general public, became attached to a fictional idiot who couldn't see suffering in front of his face. The most technically sophisticated theodicy in the philosophical tradition was reduced to a punchline - and the punchline proved stickier than the argument.

The Man Who Couldn't Defend Himself

Every other significant target of Voltaire's satire could respond or had living defenders. Leibniz had neither, in the moment that mattered.

The calculus dispute had already done its work in the English-speaking world. The Royal Society's verdict against him - delivered, with grotesque impropriety, by a committee Newton himself had largely controlled - had left his mathematical reputation tarnished in the country where Newton's influence was strongest. Now Voltaire finished the work in France, in the language of the European intellectual elite, with a weapon far more effective than any scholarly commission: a story that made people laugh.

Between them, Newton and Voltaire had bracketed the man. The mathematician who had independently arrived at one of the most important discoveries in the history of science was cast as a plagiarist. The philosopher who had attempted one of the most ambitious syntheses of reason and theology was cast as a fool. The actual Leibniz - precise, restless, brilliant, difficult, endlessly curious - disappeared between the two caricatures.

He had no monument to point to. No Principia. No single fixed address for his ideas. The letters sat in archives. The manuscripts went unpublished. The man himself was forty-three years in the ground.

What Remains

The irony that the post has been building toward is this: the work survived anyway.

The calculus Leibniz developed is the calculus mathematicians actually use - his notation, not Newton's, became standard. The binary system he described in 1703 is the foundation on which every computer ever built has run. The formal logic he pioneered was rediscovered by Frege and Russell in the nineteenth and twentieth centuries and became the basis of analytic philosophy. The monadology is still read, still argued over, still generating philosophical papers.

The achievements Voltaire never touched outlasted the caricature he created - but only in specialist circles. In the wider culture, the caricature held. Most people who encounter Leibniz at all encounter him first as Pangloss, as the butt of a joke about earthquakes and optimism, before they encounter him as the man who built the mathematical infrastructure of the modern world.

The tragedy is not that Leibniz was forgotten. Forgotten figures can be rediscovered; archives can be opened; reputations can be rebuilt. The tragedy is that he was replaced - the real man substituted by a fictional fool, the substitution executed with such genius that it has held for two and a half centuries.

He tried to reconcile God and evil. An earthquake he never saw was used to destroy him. He never got to say a word in his own defense.

Gottfried Wilhelm Leibniz is part of the Architects of Reason collection - portraits of the seventeenth-century minds whose ideas built the modern world.

Explore the collection....