Voltaire and Émilie du Châtelet found love with each other in 1733. Émilie was the intelligent daughter of Louis Nicolas le Tonnelier de Breteuil. Through an arranged marriage, she had become the wife of an army man named Marquis Florent-Claude du Châstellet-Lomont. He was frequently absent and considered dull, formal, and cold. In comparison to her husband’s dullness, formality, and coldness, Émilie was dramatically passionate, and the first time she fell head-over-heels in love it was not with her husband but instead when she was smitten by a French Don Juan named the Count of Guébriant, who unfortunately thought of her as one more notch on his bedpost.
The Marquise du Châtelet (a name derived from Voltaire who changed Châstellet to Châtelet) was highly gifted and adept at learning languages. She was also passionate about studying educational subjects, such as mathematics, which she studied from Moreau de Maupertuis, a member of the Academy of Sciences. Thus, when Voltaire met Émilie, he was enchanted by her intellect, fell in love with her, and wrote her a romantic poem:
- “…Why did you only reach me so late?
- What happened to my life before?
- I hunted for love, but found only mirages
- I found only the shadow of our pleasure.
- You are a delight
- You are tender
- What pleasure I find in your arms.”
Although Voltaire might have been captivated by the green-eyed, 26-year-old, Émilie may have had one major flaw – an unappealing appearance. One person who provided a less than flattering description of her was Madame du Deffand, a French hostess and patron of the arts. She claimed the Marquise had “fat arms and legs, enormous feet and a very small head with a pointed nose and a shapeless mouth containing few teeth and those decayed.” However, the French Rococo portraitist Maurice Quentin de La Tour, who painted Émilie, depicted a studious but pleasant looking woman.
Whether her appearance was lacking or not, Voltaire could not have been more smitten and an intimate relationship with her began almost immediately. Their relationship soon resulted in Parisians doing a lot of tongue wagging and Émile aided them. She was married and instead of being discreet, she openly expressed her passion for Voltaire by kissing him full on the lips anywhere, anytime.
The Marquise owned an estate called Cirey. As appearances were crucial, Voltaire thought it might be the perfect escape from Parisian gossipers. Unfortunately, Cirey had been severely neglected and Émilie had no money. To remedy the situation, Voltaire used his money hoping to transform it into a haven and the couple settled there in 1736. While there, they developed a strict work regime that they enforced even when guests visited.
Among the passions Voltaire and Émilie du Châtelet shared was a love for science and sometimes they collaborated or competed against one another. One competition they entered separately was the 1738 Paris Academy contest related to writing an essay titled, The Propagation of Fire. Both their entries attempted to disprove the theory that fire was a material substance, neither won, but they did receive honorable mentions. Their essays were published, along with other winners and the first place winner, the Swiss mathematician, physicist, astronomer, logician, and engineer, Leonhard Euler.
In 1740, King Frederick II of Prussia requested Voltaire come and visit, and another request was issued to Voltaire in 1743. Voltaire naively thought that he could influence the Enlightened Despot, and, so, he went and stayed for several weeks. Émilie was unhappy about Voltaire’s absence and his visit with Frederick. She was an emotional woman, and over the years, Voltaire and Émilie du Châtelet had quarreled frequently and passionately. These arguments caused stress to their relationship and resulted in Voltaire often leaving for months at a time. His absences did not mean he didn’t care, but the constant fighting and separations over the years reduced their relationship to shambles.
Voltaire and Émilie du Châtelet even continued to remain in a committed platonic relationship when he became interested in another woman. The new woman was his fat and rosy-cheeked niece, Marie Louise Mignot. She was the daughter of Voltaire’s beloved sister Marguerite-Catherine and her husband, Pierre-François Mignot. When Pierre-François died in 1737, Voltaire had helped his 26-year-old niece marry an army supply officer named Nicholas-Charles Denis. After the marriage, Voltaire and his niece, now known as Madame Denis, continued to exchange affectionate letters.
When Madame Denis’s husband unexpectedly died in 1744, she found herself living with her sister and brother-in-law in Paris. By then Voltaire’s letters were sexual, and because Voltaire had learned over the years the problems gossip could cause, he wrote his letters in Italian to avoid nosy servants gossiping. Voltaire’s explicit sexual letters were not unwelcome. “No matter that he was her uncle: such relationships were not uncommon, and if marriage was intended … one could even apply to the Pope for special permission” One contemporary historian noted that the letters about “Mme Denis’s bottom seems to have been a particular joy. And the champion of free speech was unabashed when it came to conveying the nature of any physical malfunction that might stand – or not – between them … Voltaire Almighty was not, after all, omnipotent.” When he received acceptance of his letter, he took his chubby-cheeked niece in as his housekeeper and companion, and she remained with him until the day he died.
In 1748, despite his relationship with his niece, Voltaire and Émilie du Châtelet continued their relationship. He traveled with her to Lunéville where she met Jean François de Saint-Lambert, a French poet, philosopher, and military officer. Passion ruled Émilie’s soul, and despite the handsome Marquis de Saint-Lambert being ten years younger than 42-year-old Émilie, she fell wildly, madly, passionately in love. When Voltaire learned of the affair, he was both grieved and indignant. However, he soon got over it and said as much in letter to her.
The following months found the effervescent Émilie besotted with the Marquis de Saint-Lambert. Every moment she was distracted by him and every moment apart seemed unbearable. Despite being in her forties, Émilie soon became pregnant and delivered a healthy girl four days before the princesse de Lamballe was born in Turin, Italy. Émilie named the new baby Stanislas-Adélaïde Du Châtelet. It initially appeared as if the birth went well on 4 September, but it did not because Émilie developed puerperal fever and died six days later.
When Voltaire learned Émilie had died, he was beyond distraught. He did not want to part with her even in death and was completely heartbroken. The famous nineteenth-century Scottish essayist, historian, and philosopher, Thomas Carlyle, wrote about Voltaire’s sorrowful reaction:
At length … [Voltaire], absorbed in deep grief, left the room, and with difficulty reached the main door of the Castle, not knowing wither he went … he fell down at the foot of the outer stairs, and near the box of a sentry, where his head came on the pavement. His lackey, who was following … tried to lift him. At this moment M. de Saint-Lambert, retiring by the same, also arrived; and observing M. de Voltaire in the situation, hastened to assist the lackey. No sooner was M. de Voltaire on his feet, than opening his eyes, dimmed with tears, and recognising M. de Saint-Lambert, he said to him, with sobs and the most pathetic accent: “Ah, my friend, it is you that have killed her!” Then, all of a sudden, as if he were starting from a deep sleep, he exclaimed … “Eh! mon Dieu! Monsieur, de quoi vous avisiez-vous de lui faire un enfant?” They parted hereupon, without adding a single word; and retired to their several apartments, overwhelmed and almost annihilated by the excess of their sorrow.
-  Bodanis, David, Passionate Minds, (New York, Three River Press, 2006, p. 66.
-  A. J. Ayer, Voltaire (New York: Random House, 1986), 14–15.
-  Pearson, Roger, Voltaire Almighty: A Life in Pursuit of Freedom. (New York: Bloomsbury Publishing, 2005), p. 188.
-  Ibid.
-  Thomas Carlyle, The Modern British Essayists (Philadelphia: A. Hart, 1852), 154–55.