Cirey Castle in the 18th century

Born François-Marie Arouet, Voltaire was officially born on November 21, 1694 in Paris, although he himself claimed to have been born on February 20 of the same year.
He is the son of François Arouet, notary, and Marie-Marguerite Daumart, married on June 7, 1683. From their union were born five children, of whom only three survived.

Raised by the Jesuits, Voltaire received a solid education. He developed early on a strong taste for rhetoric, theatre and literature, while also taking an interest in the sciences. The premature death of his mother on July 13, 1704, when he was only ten years old, profoundly marked his childhood.

He quickly established himself as one of the most famous French authors and as the most emblematic representative of the Enlightenment philosophy.

Voltaire profoundly marked the 18th century through his literary work as much as through his intellectual and political struggles. His outspoken positions led to a turbulent life: imprisoned in the Bastille, then exiled to England, he discovered a country he particularly appreciated. From this forced sojourn emerged, in 1734, the Philosophical Letters, in which he offered a sharp critique of French institutions in comparison to the English model. This publication led to further threats of imprisonment.

He then found refuge with his friend and mistress, the Marquise du Châtelet, who welcomed him to her château in Cirey. Voltaire resided there from 1734 to 1749, the year of Émilie du Châtelet's death. Cirey became for him a place of freedom, work, and creation, where an exceptional intellectual and scientific collaboration flourished.

While Ferney Castle is now largely associated with the last years of Voltaire's life, Cirey Castle was home to one of the greatest love and intellectual adventures of the 18th century.

Emilie du Châtelet, a major figure of the Enlightenment

When Voltaire arrived in Cirey in 1734, the château was in poor condition. Owned by the du Châtelet family, it was then poorly maintained, as Marquis Florent Claude du Châtelet, Émilie's husband, was rarely present at Cirey. A career military officer, he was commander at Semur-en-Auxois, where he carried out his duties, and seldom stayed at the property. Accounts describe a poorly maintained château, where the wind whistled in from all sides.

Upon his arrival, Voltaire deemed the château too small and ill-suited to his plans. At his own expense, he undertook significant restoration and expansion work. He had an additional wing built, now called the gallery, to house his apartments. He also commissioned a sculpted doorway dedicated to the arts and sciences, emblematic of the intellectual spirit that then pervaded Cirey. This wing and monumental doorway can still be visited today.

Outside, Voltaire and Émilie du Châtelet devoted themselves to the landscaping of the gardens. Terraces, long avenues, groves of linden trees, and plantings gradually structured the park. This work led to numerous discussions and disagreements between them, reflecting their strong personal commitment to the transformation of the estate.

Inside the castle, Voltaire set up a scientific study and ordered instruments from Abbot Jean-Antoine Nollet, a leading expert in experimental physics in the 18th century.

To nurture his passion for theatre, Voltaire also had a small performance hall installed, hidden in the attic. This theatre can still be seen today and retains three period sets, direct witnesses to Voltaire's stay in Cirey.

Theater plays a vital role in life in Cirey. Rehearsals are frequent, and performances are elaborate productions: participants dress up and wear makeup, in the style of the grand Parisian theaters. Voltaire's works are performed there, but theater is not limited to his repertoire. Émilie du Châtelet, whose education included singing lessons, also performs opera arias.

In Cirey, Voltaire continued an intense literary production. There he notably wrote Le Mondain, Discours en vers sur l'homme, the comedies Le Comte de Boursoufle and L'Enfant prodigue, as well as the tragedies Alzire, Mahomet and Mérope.

Cirey is also an important place for its interest in science. In the 1730s and 1740s, Voltaire worked to make Newtonian physics more accessible to the educated public. In particular, he published Elements of Newton's Philosophy (1738), a popular science work devoted primarily to light and gravitation, written in close connection with his correspondence with Émilie du Châtelet.

It is reported that Émilie du Châtelet discovered Newton thanks to Voltaire; in any case, academic sources emphasize that her interest in a text on Newtonian physics developed precisely at the time when Voltaire was working on his Elements, from 1736.

Finally, in Cirey, Voltaire became concretely involved in the practice of experimental physics, notably through the installation and equipping of the physics laboratory, with instruments provided by Abbé Nollet.

In Cirey, Émilie du Châtelet undertook the translation into French, from Latin, of Isaac Newton's Principia Mathematica, a fundamental work of modern physics expounding in particular the laws of motion and the theory of universal gravitation.

This work began around 1745 and occupied Émilie du Châtelet until the end of her life in 1749. The translation was not limited to a simple passage from Latin to French: it was accompanied by an important apparatus of commentary and mathematical explanations intended to make complex concepts, then little known in France, understandable.

After Émilie du Châtelet's death, the manuscript was entrusted to scholars in her circle. A first partial publication appeared in 1756, under the direction of the mathematician Clairaut, with a preface by Voltaire. The complete edition was published in 1759, under the title *Principles mathématiques de la philosophie naturelle*, translated into French by Madame la marquise du Châtelet.

This translation remains today the standard French version of Newton's Principia and constitutes one of Émilie du Châtelet's major contributions to the history of science. It made the Château de Cirey a central location for the dissemination of Newtonian thought in 18th-century France.

Written between 1744 and 1746, the Discourse on Happiness is a personal philosophical text by Émilie du Châtelet, written at the Château de Cirey. Unlike her scientific works, this text was not intended for publication and was only circulated after her death.

In this work, Émilie du Châtelet explores the conditions for human happiness. She addresses themes such as the pursuit of pleasure, the use of reason, the role of the passions, the importance of intellectual work, and freedom of thought. She asserts, in particular, that happiness rests on knowledge, the exercise of the mind, and inner independence.

The Discourse on Happiness stands out for its direct and accessible tone. Émilie du Châtelet adopts a clear, sometimes lively, writing style that makes the text particularly enjoyable to read. It offers a rare glimpse into the philosophical thought of a woman in the 18th century, at a time when this type of reflection was almost exclusively dominated by male authors.

Published posthumously in 1779, this text reveals another facet of Émilie du Châtelet: beyond the renowned scientist, it highlights a philosopher attentive to existential questions and the human condition. Thanks to the modernity of its reflections, the Discourse on Happiness remains a frequently read and discussed text today, whose ideas retain a genuine relevance.

Although their passionate love gradually gave way to a deep friendship, Voltaire and Émilie du Châtelet never truly parted ways. At the age of forty-two, Émilie became pregnant by her last lover, the poet Jean-François de Saint-Lambert. She died from complications of childbirth in 1749.

At the last minute, she managed to complete the translation of Newton's treatise and send it to the King's Library. Voltaire then took charge of its publication. Deeply affected by her death, he left the Château de Cirey, which he had described as "earthly paradise."

Little Adélaïde, born to Émilie du Châtelet and Saint-Lambert, was recognized by the Marquis du Châtelet. Despite this, she died in 1751, still a child, in the arms of her wet nurse.

After the death of Emilie du Châtelet in 1749, her husband, the Marquis, carefully maintained the château. When he in turn died in 1765, their son, Louis-Marie-Florent, Duke of Châtelet, became lord of Cirey.

The Duke of Châtelet married Diane Adélaïde de Rochechouart in 1752. They had no children, but he and his wife maintained an almost filial relationship with their niece Diane Adélaïde de Damas, daughter of the Duchess's sister, whom they designated as the heir of Cirey.

The revolution accelerated events. The Duke and Duchess of Châtelet were guillotined in 1794.

Diane Adélaïde de Damas, who became Countess of Simiane through her marriage, inherited Cirey earlier than expected. However, the property was declared national property and sold off in lots.

Then begins the fight of Adelaide of Simiane to retake Cirey.

Françoise d'Issembourg du Buisson d'Happoncourt, wife of Graffigny, was born in Nancy in 1695 and died in Paris in 1758. Author of the famous novel Lettres d'une Péruvienne, published in 1747, she established herself as one of the most influential women of letters of the 18th century.

A friend of Voltaire, she spent extended periods at the Château de Cirey between 1738 and 1739, invited by the philosopher and the Marquise du Châtelet. While this stay ended in conflict, it left an exceptional record: Madame de Graffigny documented life at Cirey almost daily in her extensive correspondence. She described with great precision the château's inhabitants, the interior decoration, theatrical activities, scientific instruments, and the daily life of this important center of the Enlightenment.

This account, rich in observations and anecdotes, is today a valuable source for understanding the castle and the intellectual life that unfolded there. It allows us to reconstruct Cirey as closely as possible to its historical reality.

Long forgotten, like Emilie, particularly in the 19th and 20th centuries, Madame de Graffigny is now experiencing a true rediscovery. In 2026, *Letters from a Peruvian Woman* will be added to the curriculum.

"Literature of ideas" of the early French baccalaureate exam — one more reason to (re)discover the Château de Cirey, where she stayed.