GABRIELLE EMILIE LE TONNELIER DE BRETEUIL
MARQUISE DU CHÂTELET
(1706-49)
Writings

Gabrielle Emilie le Tonnelier de Breteuil, born in Paris, 17 Dec. 1706 to a well-connected noble family, had every privilege for a little girl of her time. Her father, the baron de Breteuil was a favorite of the king, Louis XIV, and both he and her mother Anne de Froullay had relatives and friends who could help to advance the family’s interests. When she was eighteen, in 1725, they arranged for their only daughter to marry into one of the oldest lineages of Lorraine, a semi-independent duchy in northeastern France. The marquis Du Châtelet brought his title but little wealth. For the first years of her marriage, the new marquise lived a very traditional life: she bore him a daughter and two sons, ran their first household in Semur where he was the military governor, and when it was appropriate enjoyed all the pleasures of Paris: dressing elegantly, going to the theater and the opera, gambling at the houses of her noble friends.

Probably in 1733 when she was once again in Semur awaiting the birth of her second son, Du Châtelet became interested in mathematics and began to read widely in philosophy and other learned subjects. She returned to Paris to take up serious study of Descartes’ analytical geometry first with Pierre-Louis Moreau de Maupertuis and then with his colleague, the young mathematics prodigy Alexis-Claude Clairaut. From this point on, though Du Châtelet continued to care for her husband’s and children’s interests and ran the household–taking extra responsibilities when the marquis had to rejoin his troops for the wars of the 1730s and 1740s–she found time to continue reading, studying and finally writing and publishing her own works of “natural philosophy,” the equivalent to our modern “science.”

Little is known about her early education. It is likely that she was allowed to study Latin and geometry with her younger brother, but otherwise she was self-taught. By the time she published her first book, Institutions de physique (Foundations of Physics) in 1740, she had read widely in Latin, English, and Italian in fields as diverse as moral philosophy, chemistry, physics, theology, mathematics, metaphysics, natural and experimental philosophy. The essay she submitted to the 1738 Royal Academy of Sciences competition “on the nature and propagation of fire” had been published, and she had been accepted as a member of the learned Republic of Letters. She gained additional fame when she bested the executive director of the Academy of Sciences on the issue of the proper formula for kinetic energy, saw her writings on science translated into Italian and German, and was elected to the Bologna Academy of Science. Just before her death 10 Sept. 1749 from a pulmonary embolism, a consequence of her last pregnancy, she had completed a translation of Isaac Newton’s Principia and her own commentary on it, that both corrected and completed many of the Englishman’s key hypotheses proving the role of attraction in the universe. Published in final form ten years later in 1759, as part of the excitement occasioned by the return of Halley’s comet– calculating a comet’s orbit had been one of the main proofs of attraction.

The rest of Du Châtelet’s writings circulated among the learned, part of the clandestine literature of this first half of the Enlightenment. Her Discours sur le bonheur (Discourse on Happiness), a very personal exposition of what makes for our happiness– was first published in 1779 . Others exist only in manuscripts dispersed throughout libraries in France, Belgium and Russia. They include: a reworking and translation into French of sections of Bernard Mandeville’s Fable of the Bees; a massive critical commentary on the Old and New Testaments, Examens de la Bible; short essays on optics, liberty, and grammar.

Until the last decade, Du Châtelet was best known because of her two lovers: Voltaire, the French poet, playwright and philosophe, who was her companion for fifteen years, even after he took his niece as a lover; Jean-François de Saint-Lambert, the young soldier-poet with whom she fell in love in 1748. He was the father of her last child, the daughter who occasioned her death on 10 Sept. 1749.

Du Châtelet is significant not only for her writings– hers remains the only full translation of the Principia in French– but also for what her life and accomplishments tell about the possibilities for a woman of her day. She read, studied, wrote, published, and gained recognition in a learned world meant to be exclusively male. That all but her amorous life was lost to history, her writings forgotten or attributed to others, demonstrates how fragile women’s stories are and how important they are to discover and tell.

SUGGESTED READING

Judith P. Zinsser. La Dame d’Esprit: A Biography of the Marquise Du Châtelet. New York: Viking, 2006.

Judith P. Zinsser and Julie Candler Hayes, eds. Emile Du Châtelet: Rewriting Enlightenment

Philosophy and Science. SVEC [Studies on Voltaire and the Eighteenth Century] (2006:1)

Elisabeth Badinter. Les Passions intellectuelles. Paris: Fayard, 1999.

Mary Terrall.”Vis Viva.” History of Science 42 (2004): 189-209.

René Vaillot. Avec Mme Du Châtelet. 1734-1749. Edited by René Pomeau. Vol. I, Voltaire en son temps. Oxford: Voltaire Foundation, 1985-95.