The marquise Emilie du Chatelet, c. 1745. Shown here with a pair of “mathematician”s dividers” (compass).
Money, breeding, and brains. If ever a girl had almost it all (except, perhaps, for beauty), it was Emilie du Chatelet, mathematical genius and respected darling of the Enlightenment Period in Europe, who matched intellects with the best in Europe – and held her own admirably.
Born in Paris on 17 December 1706 to an aristocratic family, Gabrielle Emilie le Tonnelier de Breteuil was, by virtue of her birth, destined for a life of luxury, pomp, and privilege. Women of her class and era were educated primarily in womanly skills like needlework. While their education included the basics to ensure their literacy, most of them went to convent schools only until they were fifteen or sixteen. Many were schooled at home. After that, they were expected to marry within their class, run their households, and bear aristocratic children.
But Emilie’s parents were unorthodox for their time in their approach to their daughter’s education. Her father, baron Louis Nicholas le Tonnelier de Breteuil, was a courtier of the “Sun King” (roi du soleil), Louis XIV, and also served his successor Louis XV. Her mother, Gabrielle Anne de Froullay, came from even grander stock. But both encouraged their daughter to read, study, and ask questions without restrictions. Emilie was often found in their home library, engrossed in Ovid, Cicero, Virgil, and other Roman authors.
At eighteen, Emilie made an advantageous match that would propel her further up social heights. She married Florent-Claude, marquis du Chatelet-Lomont. A man twelve years her senior, the marquis belonged to the highest ranks of nobility – the noblesse d’epee – who traced their lineage back to the ancient Franks.
Emilie’s parents (and she herself) belonged to the lesser nobility, the noblesse de robe, “those who had risen to their elite status through their service to the crown,” according to women’s historian Judith P. Zinsser, author of Emilie du Chatelet: Daring Genius of the Enlightenment, the definite biography of this remarkable woman. Her husband’s higher status conferred upon her more privileges, though her family was wealthier.
The marquis was supportive of Emilie and her activities. After bearing him three children – a girl and two boys, one of whom died young – she turned her attention to her true love, mathematics.
By all accounts, Emilie was a woman ahead for her time. While women were not given higher education during that period (mid-18th century), those with means to do so could hire tutors. Emilie relied on many mentors, les gens de lettres, the finest minds of the day – the explorer and scientist Maupertuis, the prodigy mathematician Clairaut, and the poet and playwright Voltaire.
Voltaire at age 24, by Largilliere. Born Francois-Marie Arouet, he was a French Enlightenment writer, essayist, deist, and philosopher, and the light and love of Emilie’s life.
The latter proved to be her most enduring and inspiring relationship. Marriage among aristocrats was conducted more to propagate the lineage and family lines rather than for love; men and women were expected to take lovers. So with the knowledge and consent of her husband, Emilie entered into a long and stormy affair with Voltaire, who encouraged her studies in mathematics (including the new discipline of calculus, invented by Newton and Leibniz at roughly the same time), geometry, physics, and other philosophies.
Both she and Voltaire wrote essays on the nature of fire, submitted to the Academie des sciences; hers was considered to be better written, thought out, and organized. Along the way, she discovered the works of Isaac Newton and made it her life’s work to translate his Principia Mathematica, which many scientists of the day found difficult to understand because of the complexity and novelty of many of its concepts in physics and mathematics. To date, Emilie’s edited and annotated translation remains the only full translation of this work into French.
Such was her towering intellect that she won the respect of her peers in the Republic of Letters – a world shut to women, except to those as brave and talented as she, who broke down the doors with the brilliance of her work.
Modern assessments of her work note that “although the classical mechanics of du Châtelet are not to be compared with Einstein’s concept of mass and velocity in his famous equation for the energy equivalent of matter E = mc² (where c represents the velocity of light), modern biographers and historians persist in seeing a neat accord with the principle E ? mv² first recognised by du Chatelet from over 150 years before…a correct assessment (up to a factor of 1/2) f the kinetic energy in classical mechanics.” (Wikipedia)
When Emilie’s relationship with the unpredictable and volatile Voltaire ended, she took a younger lover, poet and writer Jean Francois Saint-Lambert. She died in 1749, aged 42, of an embolism a few days after giving birth to their daughter, who lived for only a year and a half before being interred in the same tomb as her mother.
Emilie was a true Gogirl, unafraid to live her life the way she wanted. Though largely indulged by friends and family because of her genius, her privileges and rank did not cushion her from disappointments or heartaches. She made many mistakes, yet picked herself up after each one and started over, never losing sight of her goals – to increase her knowledge and the world’s through her studies and her works.