There are a few things to note about Émilie du Châtelet’s name before we begin. She was known as Gabrielle-Émilie Le Tonnelier de Breteuil prior to her marriage, but Voltaire and others began calling her simply Émilie after her marriage. It’s worth noting that she published under the pen name “Madame la Marquise du Chastellet” because her husband was the Marquis de Chastellet. Voltaire introduced the “Châtelet” spelling, which has since become the norm. We will refer to her as “Émilie” until her marriage, and then as “du Châtelet” afterward.
Louis Nicolas Le Tonnelier de Breteuil was the father of Émilie. A member of Louis XIV’s court at Versailles, he had a home in Paris as well as a large estate in Touraine. [6] and [8] refer to him as a:-
… a charmer in his youth… fashionable but slightly ridiculous … nobody liked him very much …
Before she died, he married his cousin, Marie Anne le Fèvre de Caumartin, who had been transferred to a convent because she was pregnant. Émilie’s mother, Gabrielle Anne de Froulay, was raised in a convent by his second wife. “Studious and disciplined” is how [10] describes her. A position at Court, which he retained until Louis XIV’s death in 1715, led Le Tonnelier de Breteuil to marry her in 1697. This was the point at which he retired to his mansion in Paris with a view of the Tuileries gardens. His wife and five children, one of which being Émilie who was just nine years old when they moved in, lived there. They occupied the lower levels of the house, while the upper floors were occupied by the rest of the family.
Voltaire wrote in his Éloge historique de Madame la Marquise du Châtelet (see [9]):-
From her most tender childhood, her mind was nourished by reading good authors in more than one language. She started a translation of the Aeneid and I have seen several sections of this filled with the spirit of the author. Later she learnt Italian and English; Tasso and Milton were as familiar to her as Virgil. She made less progress in Spanish, because she was told that there is only one famous book in that language and that this book is frivolous.
In his Mémoires Voltaire wrote (see [9]):-
Her father … made her learn Latin, which she knew as well as Mme Dacier; she knew the finest passages of Horace, Virgil and Lucretius by heart; all the works on philosophy by Cicero were familiar to her. Her dominant taste was for mathematics and philosophy.
Her cousin, Mme de Créqui (who was jealous of Émilie and claimed she was four years older than she was, so is almost certainly unduly cruel in her description) wrote this description of the teenage Émilie (see for example [6]):-
My cousin Émilie was three or four years younger than I, but five or six inches taller … . She was a colossus in all her limbs – a marvel of strength and a prodigy of clumsiness. She had terrible feet and formidable hands.
It is rather remarkable that, in addition to the academic lessons provided by private tutors, Émilie was given lessons in fencing, riding, and gymnastics. This may have been an attempt by her parents to have her overcome her clumsiness and also to use up some of the excess energy she possessed. One might also wonder why she studied mathematics but this must be due at least in part to the fact that M de Mézières, a family friend, encouraged her. Every night Émilie’s parents entertained guests in their Paris house and she would have seen mathematicians like Bernard de Fontenelle there frequently. Most of all, however, mathematics was a subject Émilie loved.
When she was sixteen years old Émilie was introduced to the Court at Versailles by her father. She loved the glamour and extravagant life there. She was married on 20 June 1725 to the Marquis Florent-Claude Chastellet. He was a military man who was made governor of Semur-en-Auxois in Burgundy. After the marriage du Châtelet spent time in Semur-en-Auxois but she also lived in Paris and a number of other places. Her husband spent most of his time on garrison duties which meant that he spent long periods away from his wife. Their first child was a daughter, Françoise Gabriel Pauline, born on 30 June 1726, while their second child was a son, Louis Marie Florent, born on 20 November 1727. Du Châtelet’s father died in 1728 and after that she made a number of visits to her mother at Créteil. In April 1733 a second son was born but he died in September 1734. Before this, however, du Châtelet had met Voltaire.
Voltaire first met du Châtelet while she was still a child for he had been one of the many guests at their parents dinner parties. They met again on one of the first occasions that du Châtelet went out after the birth of her second son. She had already had a number of lovers which was the custom of the time for someone of her status. One lover was Maupertuis who was teaching her mathematics around the time that she met Voltaire. However, she quickly developed a strong relationship with Voltaire and he found in her someone (almost certainly the only woman in France) with whom he could discuss the philosophical and scientific topics which interested him. For example Terrall writes in [18] that du Châtelet was:-
… the only French woman of her time seriously to develop her talent for mathematics and physics.
Voltaire had just returned from England, and the two shared a belief that to understand the world one must apply reasoning to scientific evidence. They also both were firmly convinced of the truth of Newton‘s world view which at that time was unpopular in France.
How could a woman like du Châtelet participate in scientific discussions? The meetings of the Académie des Sciences in Paris were the focus of discussions on research topics but these were not open to women. The other places where discussions took place were the cafés of Paris but again women were not allowed to enter them. On one occasion in 1734 she tried to go into the Café Gradot to discuss mathematics with Maupertuis. This Paris café was the most famous as a meeting place of the top mathematicians, astronomers and physical scientists and it was the café where Maupertuis and other mathematicians spent many hours in debate. Du Châtelet, however, was prevented from entering on the grounds that women were not admitted but she was not one to allow convention to dictate what she might do. A week later she appeared at the Café Gradot again, this time dressed as a man. It was not an attempt to fool people, just to make a statement on what she believed was a ridiculous rule. She was allowed in and served by the management, much to Maupertuis‘ amusement.
In May 1734 Voltaire and du Châtelet attended the wedding of the Duc de Richelieu (who had been another of du Châtelet’s lovers). Days later Voltaire was forced to hide for a couple of months after a warrant was issued for his arrest because of his pro-English, anti-French writings. After that he went to live at Cirey, which was the remote house owned by du Châtelet’s husband. Voltaire wrote (see for example [9]):-
I found in 1733 a young lady who felt more or less as I did, and who resolved to spend several years in the country to cultivate her mind, far from the tumult of the world. It was the marquise Du Châtelet, the woman who in all France had the greatest disposition for all the sciences. … Seldom has so fine a mind and so much taste been united with so much ardour for learning; but she also loved the world and all the amusements of her age and sex. Nevertheless she left all this to go and bury herself in a dilapidated house on the frontiers of Champagne and Lorraine, where the land was very fertile and very ugly. She beautified the house, to which she added pleasant gardens. I built a gallery, in which I created a very fine collection of scientific instruments. We had a large library.
Du Châtelet’s husband does not seem to have been unhappy at this arrangement, for he certainly benefited from Voltaire spending large amounts of money improving the house and estate, and frequently the three were at Cirey together. Hénault, after visiting Cirey, wrote about the life du Châtelet and Voltaire lived there (see for example [3]):-
Émilie’s father was Louis Nicolas Le Tonnelier de Breteuil. He was an official at the Court of Louis XIV at Versailles with property in Paris and also land in Touraine. He is variously described ([6] and [8]) as:-
… a charmer in his youth… fashionable but slightly ridiculous … nobody liked him very much …
His cousin, Marie Anne le Fèvre de Caumartin, was sent to a convent when Le Tonnelier realised she was pregnant and he married her three days before she died. His second wife, Gabrielle Anne de Froulay who was Émilie’s mother, was brought up in a convent. She is described in [10] as “studious and disciplined”. Le Tonnelier de Breteuil married her in 1697 and settled down after buying a position at Court which he held until Louis XIV died in 1715. At this stage he retired to his big house in Paris overlooking the Tuileries gardens. Le Tonnelier de Breteuil lived there with his wife and five children, one being Émilie who was about nine years old when they moved in. They lived on the ground floor while other members of the family lived on the floors above.
Voltaire wrote in his Éloge historique de Madame la Marquise du Châtelet (see [9]):-
From her most tender childhood, her mind was nourished by reading good authors in more than one language. She started a translation of the Aeneid and I have seen several sections of this filled with the spirit of the author. Later she learnt Italian and English; Tasso and Milton were as familiar to her as Virgil. She made less progress in Spanish, because she was told that there is only one famous book in that language and that this book is frivolous.
In his Mémoires Voltaire wrote (see [9]):-
Her father … made her learn Latin, which she knew as well as Mme Dacier; she knew the finest passages of Horace, Virgil and Lucretius by heart; all the works on philosophy by Cicero were familiar to her. Her dominant taste was for mathematics and philosophy.
Her cousin, Mme de Créqui (who was jealous of Émilie and claimed she was four years older than she was, so is almost certainly unduly cruel in her description) wrote this description of the teenage Émilie (see for example [6]):-
Émilie’s father was Louis Nicolas Le Tonnelier de Breteuil. He was an official at the Court of Louis XIV at Versailles with property in Paris and also land in Touraine. He is variously described ([6] and [8]) as:-
… a charmer in his youth… fashionable but slightly ridiculous … nobody liked him very much …
His cousin, Marie Anne le Fèvre de Caumartin, was sent to a convent when Le Tonnelier realised she was pregnant and he married her three days before she died. His second wife, Gabrielle Anne de Froulay who was Émilie’s mother, was brought up in a convent. She is described in [10] as “studious and disciplined”. Le Tonnelier de Breteuil married her in 1697 and settled down after buying a position at Court which he held until Louis XIV died in 1715. At this stage he retired to his big house in Paris overlooking the Tuileries gardens. Le Tonnelier de Breteuil lived there with his wife and five children, one being Émilie who was about nine years old when they moved in. They lived on the ground floor while other members of the family lived on the floors above.
Voltaire wrote in his Éloge historique de Madame la Marquise du Châtelet (see [9]):-
From her most tender childhood, her mind was nourished by reading good authors in more than one language. She started a translation of the Aeneid and I have seen several sections of this filled with the spirit of the author. Later she learnt Italian and English; Tasso and Milton were as familiar to her as Virgil. She made less progress in Spanish, because she was told that there is only one famous book in that language and that this book is frivolous.
Voltaire wrote in his Éloge historique de Madame la Marquise du Châtelet (see [9]):-
From her most tender childhood, her mind was nourished by reading good authors in more than one language. She started a translation of the Aeneid and I have seen several sections of this filled with the spirit of the author. Later she learnt Italian and English; Tasso and Milton were as familiar to her as Virgil. She made less progress in Spanish, because she was told that there is only one famous book in that language and that this book is frivolous.
In his Mémoires Voltaire wrote (see [9]):-
Her father … made her learn Latin, which she knew as well as Mme Dacier; she knew the finest passages of Horace, Virgil and Lucretius by heart; all the works on philosophy by Cicero were familiar to her. Her dominant taste was for mathematics and philosophy.
It is rather remarkable that, in addition to the academic lessons provided by private tutors, Émilie was given lessons in fencing, riding, and gymnastics. This may have been an attempt by her parents to have her overcome her clumsiness and also to use up some of the excess energy she possessed. One might also wonder why she studied mathematics but this must be due at least in part to the fact that M de Mézières, a family friend, encouraged her. Every night Émilie’s parents entertained guests in their Paris house and she would have seen mathematicians like Bernard de Fontenelle there frequently. Most of all, however, mathematics was a subject Émilie loved.
When she was sixteen years old Émilie was introduced to the Court at Versailles by her father. She loved the glamour and extravagant life there. She was married on 20 June 1725 to the Marquis Florent-Claude Chastellet. He was a military man who was made governor of Semur-en-Auxois in Burgundy. After the marriage du Châtelet spent time in Semur-en-Auxois but she also lived in Paris and a number of other places. Her husband spent most of his time on garrison duties which meant that he spent long periods away from his wife. Their first child was a daughter, Françoise Gabriel Pauline, born on 30 June 1726, while their second child was a son, Louis Marie Florent, born on 20 November 1727. Du Châtelet’s father died in 1728 and after that she made a number of visits to her mother at Créteil. In April 1733 a second son was born but he died in September 1734. Before this, however, du Châtelet had met Voltaire.
Voltaire first met du Châtelet while she was still a child for he had been one of the many guests at their parents dinner parties. They met again on one of the first occasions that du Châtelet went out after the birth of her second son. She had already had a number of lovers which was the custom of the time for someone of her status. One lover was Maupertuis who was teaching her mathematics around the time that she met Voltaire. However, she quickly developed a strong relationship with Voltaire and he found in her someone (almost certainly the only woman in France) with whom he could discuss the philosophical and scientific topics which interested him. For example Terrall writes in [18] that du Châtelet was:-
… the only French woman of her time seriously to develop her talent for mathematics and physics.
Voltaire had just returned from England, and the two shared a belief that to understand the world one must apply reasoning to scientific evidence. They also both were firmly convinced of the truth of Newton‘s world view which at that time was unpopular in France.
How could a woman like du Châtelet participate in scientific discussions? The meetings of the Académie des Sciences in Paris were the focus of discussions on research topics but these were not open to women. The other places where discussions took place were the cafés of Paris but again women were not allowed to enter them. On one occasion in 1734 she tried to go into the Café Gradot to discuss mathematics with Maupertuis. This Paris café was the most famous as a meeting place of the top mathematicians, astronomers and physical scientists and it was the café where Maupertuis and other mathematicians spent many hours in debate. Du Châtelet, however, was prevented from entering on the grounds that women were not admitted but she was not one to allow convention to dictate what she might do. A week later she appeared at the Café Gradot again, this time dressed as a man. It was not an attempt to fool people, just to make a statement on what she believed was a ridiculous rule. She was allowed in and served by the management, much to Maupertuis‘ amusement.
In May 1734 Voltaire and du Châtelet attended the wedding of the Duc de Richelieu (who had been another of du Châtelet’s lovers). Days later Voltaire was forced to hide for a couple of months after a warrant was issued for his arrest because of his pro-English, anti-French writings. After that he went to live at Cirey, which was the remote house owned by du Châtelet’s husband. Voltaire wrote (see for example [9]):-
I found in 1733 a young lady who felt more or less as I did, and who resolved to spend several years in the country to cultivate her mind, far from the tumult of the world. It was the marquise Du Châtelet, the woman who in all France had the greatest disposition for all the sciences. … Seldom has so fine a mind and so much taste been united with so much ardour for learning; but she also loved the world and all the amusements of her age and sex. Nevertheless she left all this to go and bury herself in a dilapidated house on the frontiers of Champagne and Lorraine, where the land was very fertile and very ugly. She beautified the house, to which she added pleasant gardens. I built a gallery, in which I created a very fine collection of scientific instruments. We had a large library.
Du Châtelet’s husband does not seem to have been unhappy at this arrangement, for he certainly benefited from Voltaire spending large amounts of money improving the house and estate, and frequently the three were at Cirey together. Hénault, after visiting Cirey, wrote about the life du Châtelet and Voltaire lived there (see for example [3]):-
I also stopped at Cirey. It is a rare sight. The two of them are there alone, plunged in gaiety. One writes verse in his corner, the other triangles in hers. The architecture of the house is romantic and surprisingly magnificent.
Du Châtelet’s husband does not seem to have been unhappy at this arrangement, for he certainly benefited from Voltaire spending large amounts of money improving the house and estate, and frequently the three were at Cirey together. Hénault, after visiting Cirey, wrote about the life du Châtelet and Voltaire lived there (see for example [3]):-
I also stopped at Cirey. It is a rare sight. The two of them are there alone, plunged in gaiety. One writes verse in his corner, the other triangles in hers. The architecture of the house is romantic and surprisingly magnificent.
Let us end this biography by quoting again from Voltaire’s Preface (see for example [19]):-
No woman was ever more learned than she was, yet no one deserved less than she did to be called a blue-stocking. She only ever spoke about science to those from whom she thought she could learn; never did she discuss it to attract attention to herself. She was not ever seen gathering around her those circles which wage battles of the mind, where one sets up a kind of tribunal and passes judgement on one’s century – which then in its turn judges you most severely. 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.