Book Club: The cleverest half-naked female duellist/mathematician in pre-revolutionary France

Émilie du Châtelet cares not for your social mores, and will fight you in her underwear to prove it: an extract from Katie Spalding’s ‘The Limits of Genius’.

Jonn here. I fear I rather worried the author from whose book today's post is taken, by going quiet on her for over a month. The truth is Katie Spalding's The Limits of Genius: The Surprising Stupidity of the World's Greatest Minds would make *such* a great Christmas present I was holding it back til December, in a shameless attempt to maximise impact.

Katie's book mostly tells stories which strongly suggest that the world's greatest thinkers - Albert Einstein, Marie Curie, Lord Byron - were, in fact, idiots. It also contains so many footnotes that some of them have other footnotes. Today's extract tells the story of the 18th century mathematician and physicist Emilie du Châtelet, who was just really, really cool.

Honestly, the book’s delightful, and perfect for you lot. Go buy it right now.

Gabrielle Émilie Le Tonnelier de Breteuil, Marquise du Châtelet, lived her life at full pelt. She was a mathematician, scientist, Newton fangirl, duellist and card shark, and her life stands as testament to the fact that the past sometimes really wasn’t that bad a place to be a woman, actually, so long as you had just inhuman amounts of luck, stacks of money, and an unbelievably understanding husband.

Émilie, as she was known, was born in 1706 in France, into a world barely recognisable to you or me. The country was not yet a republic or a democracy; even calling it an autocracy doesn’t really do it justice, since France at this point was less “a country” that operated under “laws” and more “a collection of nominally unified provinces” that operated under “I inherited the right to forego taxes from my father, so stop arguing, peasant”. Practically nobody was your equal; what rights you held as a subject, along with what rules you followed and even what language you spoke, didn’t come to you by virtue of being French, but from your personal mix of attributes such as occupation, hometown, and even surname.

And given all this, Émilie couldn’t really have picked a better family to be born into. Her father was a minor noble at the court of King Louis XIV who had come by his title not through heredity and tradition but by being basically as French as it’s possible to be.¹ Her mother was a convent-educated woman who knew exactly what was expected from ladies of her and her daughter’s rank. The family was rich enough to live in a four-storey house in one of Paris’s most exclusive districts, cultured enough to have their own library filled with classic literature and volumes of natural philosophy, and well-connected enough to hold regular salons, where the leading thinkers of the Académie français and Académie royal des sciences would come round to eat cake and talk about philosophy and science.

That was just as well, because even the best family in the world couldn’t save the young Émilie from her biggest weakness: being a girl. Education for women was just about barely becoming a thing at this point, and most families still agreed with the philosopher Montaigne’s judgement that “a woman was learned enough when she knew how to distinguish between her husband’s shirt and his doublet”. It was, to put it bluntly, not seen as the mark of a Proper Woman to have any education or opinions past what we nowadays expect of about a six-year-old.

Pretty much the best Émelie could have hoped for was to receive the same education as her mother: instruction on embroidery and elocution at the hands of some of Paris’s finest nuns. There is actually evidence that she attended one of these schools, and there’s also evidence that she wasn’t particularly impressed by it, in the form of her first intellectual project: a translation into French of Bernard Mandeville’s banned satirical text The Fable of the Bees.

“I feel the full weight of the prejudice which so universally excludes us from the sciences … there is no place where we are brought up to think,” she wrote* in the introduction to the book. “I am convinced that many women are either unaware of their talents for lack of education, or that they bury them … for lack of intellectual courage. I experienced this myself, which confirms it.”²

Well, Émilie wasn’t having any of that in her own life. And so, when it came time for her to be presented at court to find a husband, she hatched a plan. While the other young ladies at court were busy practising the special Versailles tippy-toe walk and curtseying backwards in a corset so painfully restrictive that they had to train for days before they were tough enough to withstand it in public, Émilie was … well, most likely doing the same, in all honesty; that shit was hard, and this was a time when being “not like the other girls” was more of an accusation than a compliment.³ But that wasn’t all she was practising, is the point.

Émilie didn’t plan on just being seen by the King in an absurd dress and demurely waiting to see which man she caught the eye of was the poshest. Even at her young age, she knew the realities of life in the 18th century: her education, her freedom to climb trees and fence and read books and discuss natural philosophy with the secretary of the French Académie des Sciences – all of that came to her purely through her father’s generosity. Most of the other girls her age – even the King’s own daughters – couldn’t read or write, let alone pen a faithful translation of Virgil from the original Latin into contemporary German⁴. And so finding the right husband – the man who would take sole ownership of her from her dad – was quite literally a life-changing decision. She needed to make sure she attracted the right sort of guy.

So she did what any one of us would do in that situation: she stripped down to her underwear and challenged the head of the King’s household guards to a duel.

You can imagine that, to Jacques de Brun, the chief guardsman in the maison militaire, this demand for a sword fight from a barely dressed teenage girl must have been rather baffling. It also can’t have been a very tempting offer for the seasoned professional soldier: either you lose, in which case what are you doing in your job, really, or else you win and… kill a child? Which would, you’d think, put a bit of a downer on the party, at the very least.

But for reasons we can only speculate on, de Brun accepted the challenge, and luckily for both parties, it was a draw. At which point, Émilie put down her sword, picked up her copy of Descartes’s Analytic Geometry, and left.

It was, honestly, a hell of a flex. And it worked: by showing the men at court what a self-confident, accomplished, intellectually curious – all of which was to say: terrible – wife she would be, she successfully bought herself two more years of singledom.

She didn’t waste that time. She collected maths books and lab equipment for science experiments, and since her parents wouldn’t pay for them she simply learned to count cards and gambled for money to buy them herself.

Eventually, Émilie did marry – she never really had the choice to stay single forever – at the ripe old age of 18. These days, getting married at 18 might make your parents despair at how young you are to be making such a big decision, but Émilie’s parents were probably worried about her aging out of the marriage pool, so it probably came as a relief to all involved when the Marquis Florent-Claude du Chastellet-Lomont,⁵ an easygoing army officer who was literally twice her age, showed an interest in her.

Despite the age gap, Florent-Claude was, given the time and place, the perfect match for Émilie. Sure, there were certain wifely duties she was expected to deliver on – and deliver she did, first in 1726 with the birth of Françoise-Gabrielle-Pauline, then a year later when she gave birth to Louis Marie Florent, and finally in 1733 with the birth of Victor-Esprit – but once the family’s lineage was secured, Florent-Claude pretty much just went off on military campaigns and left Émilie to do whatever she wanted.

And what Émilie wanted to do was incredibly scandalous. Émilie wanted to study maths.

Now a distinguished lady, she hired some of the leading mathematical minds in the country to tutor her – the kind of people who today have their own theorems and equations named after them. When her teachers met to discuss philosophy and science at the Café Gradot, where women were barred entry unless they were sex workers, she walked straight in after them to join the discussion. And sure, she was kicked out almost immediately, but you know what she did? She had a tailor knock up a men’s suit for herself and started attending the Café in drag.

And then, Émilie met her two greatest and most enduring loves: first, a writer and satirist twelve years her senior named François-Marie, and second, Isaac Newton.

Now, you’ve probably heard of Isaac Newton – and if you haven’t, then please, read up on him, because he was a complete weirdo. Émilie wrote many mathematical and scientific books and treatises throughout her life – she was actually the first woman to ever be published by the Parisian Academy of Sciences – but her magnum opus was to be a French translation of Newton’s Philosophiae Naturalis Principia Mathematica. This being Émilie, her version was not only a complete translation, but also included a sort of “beginner’s guide” section, modern updates and commentaries on Newton’s theories, and importantly, a translation of theorems and proofs from Newtonian to continental mathematical notation.

And I want to be clear here: this was a massive undertaking. We tend to forget it now, because of how we’re taught about Isaac Newton And The Physicist’s Apple in primary school, but there was a time when the Principia was the most cutting-edge physics known to anybody in Europe. Newton’s ideas had been out for decades already when Émilie began her work, but there was a reason nobody had tried to do what Émilie was doing. Anybody even attempting such an undertaking would need to be fluent in Latin, geometry, algebra, calculus, and physics; they would need to be up to date on all English and continental scientific developments since Newton; they would need to be a good communicator, with an instinct for coming up with intuitive explanations of complex ideas; and most of all, they would need to be actually interested in spreading Newton to Europe. Basically, they would have to be Émilie du Châtelet.

And then there was François-Marie. You’ve probably heard of him, too, believe it or not – but not as François-Marie Arouet. You almost certainly know him by his penname – Voltaire. He was one of the very few men in Émilie’s life who saw her for the genius she was – you know, rather than a sort of The Amazing Sentient Sex Object sideshow act – and their love affair lasted almost the entirety of her adult life.

“No woman was ever more learned than she was,” Voltaire would later write. “For a long time she moved in circles which did not know her worth and she paid no attention to such ignorance. … I saw her, one day, divide a nine-figure number by nine other figures, in her head, without any help, in the presence of a mathematician unable to keep up with her.”

And like everything Émilie did (and Voltaire did too, for that matter) their affair completely shocked society. Not because Émilie was married – taking a lover was pretty much expected behaviour in those days, since marriage was more about securing family alliances than spending your life with The One. But you were expected to have some discretion, goddamnit. You were supposed to maintain standards.

Well, if you haven’t already guessed, the woman who at 16 was willing to strip down to her petticoats and challenge a professional fighter to a duel rather than play the role society wanted to force her into was, now married and in charge of her own life⁶, not interested in the social mores of her prudish peers. She straight-up moved Voltaire into her country home, where they lived essentially as husband and wife – but like, a really cool rich intellectual husband and wife who spent all their time writing satires and having sex and doing maths.

“That lady … I look upon as a great man,” wrote the loved-up Voltaire. “She understands Newton, she despises superstition and in short she makes me happy.”

And if you’re wondering whether Émilie’s husband might have noticed that there was some dude living in his house with his wife, the answer is yes, and he was totally fine with it. Seriously. In fact, since the house was a bit neglected and Voltaire was spending his own money doing it up, Florent-Claude actively encouraged his living there. Why not, you know? Free renovations!

Portrait by Maurice Quentin de la Tour. Image: Wikipedia/public domain.

But all good things come to an end, and Voltaire ultimately fell in love with somebody else – his own niece, as it happens, which really seems to be a theme with the men in this book. Émilie, too, moved on, to a toyboy poet named Jean François de Saint-Lambert.

And then, tragedy struck. She got pregnant.

It was 1749, and Émilie was 42 years old. She knew that giving birth would be a death sentence. Her translation of Newton had already taken four years of her life, and now she started working 18-hour days in a desperate bid to finish it before she died. Voltaire would later write that “her one thought was to use the little time she thought that remained to complete the work she had undertaken and so cheat death of stealing what she considered was part of herself”.

In September 1749, she gave birth to a daughter, Stanislas-Adélaïde. In quintessential du Châtelet style, the newborn was “laid on a quarto book of geometry,” according to Voltaire, who, along with Florent-Claude and Jean François, was present for the birth. It was kind of like Bridget Jones, I guess, only more so.

Émilie was still making last-minute changes to her translation of Newton right up until she died, six days later, due to complications from childbirth. It took ten years for her work to be published, but to this day it remains the standard French translation of the Principia.

In the centuries since her death, Émilie du Châtelet has mostly been remembered as either “Voltaire’s girlfriend”, or “Newton’s translator”. Neither does her justice. She was a woman who wanted us to “be certain of who we want to be;” to “choose for ourselves our path in life, and let us try to strew that path with flowers”. She was a scientific genius at a time when it was remarkable that she could even read. And most of all, she was a scholar, willing to fight for the right to study maths and science.

With a sword, in her underwear, if necessary.

Katie, a glorious line in her bio tells me, "spent ten years of her life studying maths, which is just about the upper limit on how much maths you can do before people start actively avoiding you at parties". You can buy The Limit's of Genius (British version) or Edison's Ghosts (American) from Amazon, Waterstones or direct from Hachette.

1. Louis Nicolas Le Tonnelier de Breteuil, Émilie’s father, was … just the worst, to be honest. He was the youngest son in an extremely high-achieving family; his father had bought himself a minor provincial judicial title and worked his way up to one of the most senior offices in the kingdom, and his brothers held important positions in the army, navy, church, and the royal court.

Louis Nicolas, on the other hand, was basically the Van Wilder of the 17th century, in that he partied hard with daddy’s money well past the age where most people would have graduated and settled down, ruined a few women’s lives, and would probably be completely forgotten by now if not for the star he bequeathed the world (yes, the part of Émilie will be played by Ryan Reynolds in this metaphor). He probably would have got banished from court if it wasn’t for the fact that Louis XIV was also, in many ways, just the absolute worst, and the two got on like a maison en feu.

At 29, Louis Nicolas was given the title of “Reader to the King”, a job which had literally zero responsibilities but some of the best benefits available, like respectfully watching the King take a whizz or put his hair on for the day. They both had a penchant for knocking up inappropriate women*, which led Louis Nicolas to be sent by the king on several conveniently timed “diplomatic missions” until the various scandals had died down. Eventually, at the age of 49, he met Gabrielle Anne de Froulay, the 27-year-old daughter of a well-established Posh family and technically the sister of his aunt, married her, and had Émilie and her five brothers.

*[A SUBSIDIARY FOOTNOTE WITHIN THE FOOTNOTE] Although it could be argued that for Louis XIV there were no inappropriate women. He was married to Maria Theresa of Spain from the age of 22, but that didn’t stop him from taking 13 mistresses who bore him at least 16 illegitimate children. Not only was this not scandalous, it was a time honoured tradition: the maîtress-en-titre, or chief mistress to the king, had been a semi-official position at court for centuries by the time Louis took the throne.

Louis Nicolas, however, was a cad even by – and in some ways, especially by – the standards of the time. Before he’d hit 30 he had already provoked the ire of his family by secretly marrying his own cousin who promptly had a baby and then died. Then, a few years later, he started an affair with Anne Ferraud, a Parisian writer who was a decade his junior and fully married to somebody else. She fared arguably slightly better than her predecessor: her husband formally separated from her and refused to accept paternity of the child she bore, and she was sent by royal order to a convent. She lived there for four years, during which time she wrote a wildly successful novel about a young married woman who has a scandalous affair with an older man that proves to be her undoing. She did finally have the last laugh though, outliving Louis Nicolas by 12 years and being remembered for her totally-not-based-on-real-life writing for even longer than that.

2. It should be noted that Mandeville did not write this. “Translation” in these days was less about faithfully conveying the meaning of a work originally created in another language and more about just kinda riffing on the general ideas contained inside it, it seems.

3. These days, of course, it’s enough to get a starring role in your own vaguely problematic young adult fiction series about post-capitalism vampires or something.

4. She didn’t actually do this, but the thing is that she totally could have.

5. A note on the Marquis’s name here: Lomont refers to the side of the family he came from, you can ignore it, and du Chastellet is equal to du Châtelet. Basically there were a whole bunch of spelling reforms that happened in the mid-1700s, so when the pair were married they had one surname – Chastellet – but by the end of Émilie’s life the standard spelling was Châtelet.

6. Or at least as much as you could be in 18th century France.