In the Age of Enlightenment, she was a provocative figure who used all the tools at her disposal to rise to the top. But Nicola McCaskill despairs many are still unenlightened about her fascinating life.
Model Specimens is a monthly column that explores the role models who inspired today's scientists. This month, Nicola McCaskill, a science journalist and deputy editor-in-chief of Lateral, shares her love of pioneering French mathematician Émilie du Châtelet.
“If I were king, I would redress an abuse which cuts back, as it were, one half of human-kind. I would have women participate in all human rights, especially those of the mind.”
- Émilie du Châtelet
My earliest memories involve an intense desire to be a scientist. I was fascinated by the way things worked, how bugs looked under magnifying glasses, how much planets weighed (I still don’t really understand this). I read my way through my school library’s reference section. I felt sure I would go on to discover something new or explore some great uncharted territory; something would be named after me and I would win a Nobel Prize. The other small detail of my childhood convictions was that I would grow up to be a man. It wasn’t a personal gender thing, it just seemed like that’s what all the great scientists were, and I was going to be a great scientist, so.
I obviously outgrew this suspicion, but it continued to grind my juvenile gears that the lady geniuses of the science world were relegated to a single page in my library books, if that. It wasn’t until I caught a daytime re-run of a PBS documentary about Einstein’s famous equation as a teenager taking a sick day from school that I was introduced to my future beloved idol, role model, and one true love (scientifically and historically speaking). Émilie du Châtelet was a game changer to my understanding of what a woman in science could be. She was a true Renaissance woman: she had a deep and brilliant intellect, a large social circle of scientists and philosophers who held her in high regard, a long list of ex-lovers to rival Taylor Swift’s and, presumably, a killer wardrobe (she was French nobility, after all). She had everything I wanted, and she’d had it all in the exciting Age of Enlightenment, when new scientific ideas were emerging and dominating popular thought. To think that she was a real person who actually lived still thrills me.
Du Châtelet was born in Paris in 1706, the only girl of six children in a noble family. Her father was Principal Secretary and Introducer of Ambassadors to King Louis XIV, and he hosted regular salons for writers and scientists.
It’s difficult to find consistent information about du Châtelet’s life, and the details might be more mythology than fact. But it’s clear that as a young girl, Émilie was already obsessed with learning, and preferred listening in on educated visitors to playing with other children. Depending on the sources you dig up, her mother was either encouraging of her daughter’s curiosity and scepticism, or horrified by her interest in academia and sought to send her off to a convent (or perhaps both). In any case, her father recognised her talents, and allowed her to be tutored like her brothers.
Du Châtelet’s father arranged for Bernard Le Bovier de Fontenelle – the perpetual secretary of the French Académie des Sciences – to visit and discuss astronomy with Émilie at 10 years old. She was tutored in mathematics, literature and science. By 12 years old, she was fluent in German, Greek, Latin and Italian; she also played harpsichord, sang opera, and enjoyed dancing. In her teenage years, she put her mathematical prowess towards devising highly successful gambling strategies, and used her winnings to buy more books and lab equipment (she is quoted as saying that “gambling, study and greed” were the only pleasures left for older women).
After quickly proving a better student than her brothers, du Châtelet also surpassed the capabilities of her tutors, asking complicated or impossible questions and challenging her teachers (who were leading French intellectuals themselves). She was an apparently frustrating student – her ongoing argument with Samuel König regarding infinitely small measurements lead to the end of their friendship.
Émilie was a woman of many skills that went beyond the academic. She was absolutely a genius, able to carry deep conversations with the intellectual elite. She was also, by all accounts, utterly charming. Attractive, well dressed and flirtatious, she captivated scientists and scholars at parties and balls. She was also trained in riding and fencing (apparently taking on her brothers friends and usually winning) – highly unusual for a young noble woman of her time. She was completely fascinating to the people around her, and drew a lot of male attention.
At 18, Émilie’s marriage was arranged to the Marquis du Châtelet, a wealthy 34-year-old military man. The couple had three children together, and as her husband was often away from home, Émilie was free to continue studying maths and science, resuming tutoring with influential mathematicians Pierre Louis Maupertuis and Alexis Clairaut. The arrangement also left her free to have numerous affairs, which became the focus of biographers long after her death.
Émilie was involved with several intellectuals and aristocrats, and was described as a passionate lover (once almost driven to suicide after a split, then vowing to never be so invested in a man again). She was the only intellectual woman in France at the time, and – in combination with her reputed social charms and captivating sexuality – this made her a popular lady. By far, her longest and highest profile affair was with the famous and controversial philosopher Voltaire, who admired her intelligence and encouraged her to pursue her scientific studies. They were open about their relationship, and lived together at her husband’s country estate (the Marquis du Châtelet was apparently entirely tolerant of Émilie’s dalliances, and occasionally stayed with them). They collected over 20,000 books there, and conducted experiments to explore fire, optics and gravity.
Du Châtelet and Voltaire collaborated and competed on their scientific work. Often disagreeing with each other’s conclusions, in 1737 they both anonymously entered a contest by the Académie des Sciences to explain fire. Émilie’s paper, Dissertation sur la nature et la propagation du feu, predicted infrared radiation (discovered in 1800 by William Herschel). And while neither of the two won the competition, they both received honourable mentions and were published, making Émilie the first woman ever to be published by the academy.
This was no small thing – the French Academy of Science did not allow women to publish, speak, or even attend their meetings. Almost 200 years later, they turned down Nobel Prize winner Marie Curie’s membership application, stating that women were not permitted. But somehow, Émilie’s inclusion did not seem particularly exceptional. She personally knew almost all the scientists in France – she had discussed ideas with them, had dinner with them, danced with them, and earned their respect. She was already considered a central figure within the community of scientists and academics in France, which was the dominant source of intellectual ideas throughout Europe at the time. So her publication was strangely uncontroversial, despite being highly unusual.
Émilie became fascinated by the work of Isaac Newton, and helped Voltaire pen a simplified explanation of Newton’s theories – Elémens de la philosophie de Newton – in 1738. Dissatisfied with children’s books at the time, she also wrote a book for her 13-year-old son, Institutions de Physique, in 1740, which explained new and complicated science and philosophy (including the new and important field of calculus).
Despite her admiration for Newtonian physics, Émilie found herself in disagreement with Newton (and with Voltaire) when it came to the mathematics of energy. Newton – along with conventional wisdom at the time – believed that energy was mass multiplied by velocity (E=mv), but du Châtelet’s experiments contradicted this. Inspired by Leibniz, she dropped brass objects into soft clay, measuring the depth of the impact. When the weight was doubled, the depth should double, too – but it trebled. She therefore argued that while energy can be transferred, momentum is conserved (that is, it cannot be lost to friction); and that energy was actually an object’s mass multiplied by its velocity squared (E=mv2).
This big idea was taken to public debate (a dramatic event for scientists in the 1700s, without an equivalent today). With absolute conviction, Émilie argued for her equation against one of France’s leading scientists, Jean-Jacques d’Ortous de Mairan, the Permanent Secretary of the academy. She was also arguing against the accepted truth of the time, the opinion of her lover Volaire, and the work of her idol Newton. Again, a woman had never debated a scientist of the leading science institution of the nation (and none ever have since). But Émilie was a unique, yet ubiquitous presence within her world, and the debate was not recorded as some major first for women in mathematics – it was simply a major debate on an important question, leading scientists to take sides (mainly the side of de Mairan, with the traditional view).
The issue was not resolved by the debate, but Émilie’s argument drew attention to the area, shifting theoretical physics into the experimental. The data that came in from experiments replicated over and over were clear: she was right. Newton, and most of the scientists throughout Europe, were wrong. Her results were later used by Euler and Lagrange to come up with formal frameworks to understanding mechanics. The findings were also key to Einstein’s famous theory of relativity (E=mc2).
Du Châtelet and Voltaire both had other affairs, and ultimately separated after 15 years (some sources suggest Voltaire was humiliated by Émilie’s sophisticated understanding of Newtonian maths, which he couldn’t follow but believed to be perfect). Voltaire took up with his own niece, Émilie with the poet and philosopher Jean François de Saint-Lambert, but the two remained close friends.
Émilie’s writing extended beyond maths and science. She translated The Fable of the Bees, a poem about economics, and added a preface arguing for the education of young women to allow them to take part in the arts and sciences. She also wrote her Discours sur le Bonheur (Discourse on Happiness), a philosophical essay explaining her personal sources of happiness – gambling, love, and above all, study. She described learning as the only source of happiness that did not rely on other people, and considered education the sole path to success for women, writing: “Learning is the only way to acquire glory for half of humanity, yet it is precisely this half which is deprived of the means of education, rendering impossible such a taste of glory.”
Despite arguing against Newton’s ideas and proving him incorrect, she still considered his new approach to mathematics – calculus – to be the future. Calculus presented a new way of thinking about maths, which Émilie believed was critical to understanding physics. But even in the 1700s, calculus was hard, and Newton’s landmark work – Principia Mathematica – was written in English, making it difficult for French academics to gain a deep understanding of his complex principles. With her multilingual fluency and her mathematical mastery, du Châtelet set about translating the work into French. She included her own commentary, proofs and notes.
In 1749, Émilie fell pregnant with Saint-Lambert’s child. At 42 years old, she knew what this meant – a death sentence – and she worked furiously to complete her translation of the Principia. She finished days after giving birth, but died just one week later (her daughter did not survive infancy). Her translation of Newton’s work was published 10 years later, and is considered her greatest achievement – it’s still the standard French translation today. Émilie’s early death was a tragedy felt in both the science and social circles. Voltaire, who was with her at her death, apparently collapsed from grief and took a long time to recover.
It wasn’t long before du Châtelet’s work was disparaged and forgotten. Even as her insights became mainstream science, it was difficult for people to believe a woman had uncovered them, and their origin was often lost. For modern science historians, who have revised the works of many great women scientists and helped promote them as role models, Émilie is still an obscure and somewhat problematic figure. She’s seen as more of a curious anomaly than a serious scientist; her sexual life is considered her defining feature, in a way it never is for promiscuous male intellectuals who also have multiple affairs. Many people didn’t want to talk about, or promote in schools, a woman who they felt slept her way to the top of science.
The term ‘patriarchal bargain’ emerged in the 1980s to describe the way women can conform to sexist norms to gain their own power. It’s a ‘strategy’ that nearly every woman does in some way, individually manipulating the system for their benefit, but leaving the system itself intact. It’s been used to describe, for example, the way professional business or sportswomen might pose for sexy photos to gain attention or money. Of course, as women we’re generally damned if we do, damned if we don’t – such tactics can easily backfire.
Émilie is often remembered as someone else’s mistress, lover or student; she made no secret of her passion for love, her sexuality or her affairs. But these attributes were also what made her the only woman fully accepted by the science community – otherwise entirely male – of her time. It was her charm and connections that secured her a place at the table, but her feminine wiles also lead to the devaluation of her contribution to science. It’s a kick in the teeth that survives beyond her death and into her legacy: Émilie’s love affairs have proven to be more inspiring to many biographers than her actual work.
As I grew older, and became drawn to a career in the media rather than the lab, the idea of patriarchal bargaining shifted to the front of my mind. I wanted to be successful without feeling like I was selling my soul; I also wanted to wear lipstick and pretty dresses without being read as a ditz that didn’t belong. It’s hard to know how to play the game when the game is constantly playing you.
For me, Émilie du Châtelet represented an alternative approach, developed and perfected in the 1700s. Wear the dress. Read the books. Love passionately. People might think you’re smart, or dumb, or slutty, or whatever. What’s important is what you actually do. “Let us be certain of who we want to be,” she wrote. “Let us choose for ourselves our path in life, and let us try to strew that path with flowers.”
It can be extraordinarily difficult for women in science – or any traditionally male-dominated field – to negotiate the gap between how we see ourselves, and how we’re seen by others; the difference in how we want to be understood, and how we’re actually perceived. Ideas and attitudes about women still drive us to self-doubt, imposter syndrome, and to leave our chosen careers.
Voltaire famously described her as “a great man whose only flaw is that she is a woman.” Even a genius polymath with more passion and ideas than time is remembered in terms of her inability to conform to narrow gender roles. But Émilie didn’t view being a woman as a flaw; she only wished that it wasn’t a barrier to further study.
Unusual for her time, and for ours, Émilie du Châtelet knew what she was about. She understood better than anyone her own value as a great mind of The Enlightenment, she knew she belonged within the intellectual elite, and she knew how she wanted to be remembered.
“Judge me for my own merits, or lack of them, but do not look upon me as a mere appendage to this great general or that renowned scholar, this star that shines at the court of France or that famed author. I am in my own right a whole person, responsible to myself alone for all that I am, all that I say, all that I do. It may be that there are metaphysicians and philosophers whose learning is greater than mine, although I have not met them. Yet, they are but frail humans, too, and have their faults; so, when I add the sum total of my graces, I confess that I am inferior to no one.”
- Émilie du Châtelet
Edited by Tessa Evans and Jack Scanlan