Voltaire’s private life is still something of a puzzle: he invested so much energy in creating his public image that it is hard to know who there is behind the mask, or masks. There are biographies of Voltaire aplenty – but could we write a biography of François-Marie Arouet? Voltaire’s immensely rich correspondence might seem like a way of discovering the elusive ‘real’ person, but that can prove illusory: on closer inspection, the correspondence, just like all his other writings, turns out to be a vast laboratory of performances. There are, however, just a few exceptions.
We know tantalisingly little about his private life with Emilie Du Châtelet. The abbé de Voisenon tells us that she treasured the letters she had received from Voltaire and kept them bound in eight quarto volumes. Frustratingly, these seem not to have survived, and she quite possibly destroyed them before her death – surely the single greatest loss from this iconic epistolary corpus. In the case of Voltaire’s relationship with Marie-Louise Denis, on the other hand, significant numbers of genuinely personal letters have survived, though many remained in private hands until the twentieth century, and there may yet be more to be discovered. Voltaire’s relationship with his niece is therefore the most significant attachment of his life for which we have reliable documentation.
The number of known letters to Marie-Louise Denis has grown considerably over the last century. First, around a hundred letters, dating from between 1745 and 1754, came to light in the late 1930s, with the publication of the Lettres d’Alsace à sa nièce Madame Denis, edited by Georges Jean-Aubry. Already in the eighteenth century there was speculation about the exact nature of Voltaire’s relationship with his niece – were they lovers? All such lingering doubts were dispelled decisively in the 1950s, when the Pierpont Morgan Library in New York acquired some 140 letters from Voltaire to his niece, mostly dating from between 1744 and 1747. It has to be said that Voltaire’s love letters do not rank among his most subtle achievements – he sometimes writes in Italian in an attempt to relieve their tawdry banality – but they certainly leave us in no doubt about the physical nature of their relationship. Theodore Besterman published these letters in 1957, in a book beautifully produced by the Librairie Plon in Paris: the Lettres d’amour de Voltaire à sa nièce bear the surprising dedication ‘à Nancy Mitford’. In fact, Besterman had been discussing this new find of letters with Nancy Mitford over several years: she immediately sensed the fictional potential of this love triangle (Voltaire’s sexual relationship with Denis began before the death of Du Châtelet in 1749) and set to work to write up the scoop of this newly revealed ménage à trois manqué. Modern funding bodies like to encourage academics to explore ways of enhancing the outreach and impact of their scholarly discoveries, but no-one has ever done it better than Theodore Besterman. His scholarly Lettres d’amour appeared in the same year, 1957, as Nancy Mitford’s Voltaire in Love: the title was suggested to her by Evelyn Waugh, and the book was published in London by Hamish Hamilton, with a dust jacket designed by Cecil Beaton (now a collectable item in itself). Nancy Mitford’s work understandably garnered more reviews than Besterman’s, and a French translation of Voltaire in Love, Voltaire amoureux, appeared in 1959.

Now another significant collection of letters from Voltaire to his niece has surfaced, 127 autograph letters, hitherto unknown, written between 1737 and 1744. They were acquired by the Bibliothèque nationale de France in 1994 and have just appeared in an edition published by Classiques Garnier. These letters were arranged, with posterity in mind, by Marie-Louise Denis herself: she grouped them into various folders or chemises, which bear writing in her hand, and often proposed dates for the letters which were undated. The coherence of this collection is obvious: it spans the duration of her marriage to Nicolas-Charles Denis. In October 1737, Marie-Louise Mignot lost her father and became an orphan (her mother, Voltaire’s beloved elder sister Catherine, had died many years earlier). In the first letter of this collection, Voltaire sent his condolences to his niece, and advised her not to retire to a convent. Assuming willingly his role as the young woman’s protector, Voltaire set about finding her a suitable husband, and Marie-Louise quickly showed her mettle by rejecting her uncle’s choice and finding a husband of her own, the army officer Denis, whom she married in 1738. The young couple made their home in Lille, and Voltaire wrote to them both, frequently and with evident affection. Many new insights into their private life emerge from these letters, including information about Marie-Louise’s musical talents: see Nicolas Fréry’s recent blogpost here, ‘La nièce musicienne : Marie-Louise Denis et la boîte de Pandore’.

Besterman’s Lettres d’amour has as a frontispiece the beautiful oil portrait of the young Marie-Louise, then attributed to Van Loo, and now thought to be the work of Drouais (the sitter was only identified in 1921). It appears to date from around 1737, so when she is 25 years of age, just before her marriage in February 1738: perhaps the portrait was commissioned by her husband-to-be? In the new edition of Lettres inédites à Marie-Louise Denis, we produce a related image (p.52), a pastel portrait from the same period, more intimate in style, but clearly composed after the model of the oil painting. This pastel, which is in the collections of the Musée d’art et d’histoire of Geneva, was long thought to depict Charlotte de Constant, but Renée Loche has shown that the sitter is in fact Marie-Louise Denis, and that it was drawn by Marie-Louise’s younger sister, Marie-Elisabeth Dompierre de Fontaine, probably around 1737–1738. Voltaire is known to have admired her work, and this is the portrait that he would have had before him when he wrote the letters in this new volume: like the letters, it possesses a particular quality of intimacy.

After a sudden illness, M. Denis died prematurely in April 1744, and the collection closes with Voltaire writing another letter of condolence to his niece: ‘Adieu, du courage, de la philosophie. La vie est un songe, et un songe triste, mais vivez pour vos amis et pour moi qui vous aime tendrement’ (p.288). The dramatic irony here is evident, for as readers of Nancy Mitford, we know only too well how their relationship will develop. We can all now read the letters to Marie-Louise when she was a young wife, and if we want, we can try to search them for clues about the future. But perhaps it needs a novelist to do real justice to this material. Voltaire’s private life is the stuff of fiction, and possibly of epistolary fiction (think what he will do later with Paméla). Just as Nancy Mitford gave fictional shape to the truth of Besterman’s discoveries, we now need a novelist who can find the deeper truth in Voltaire’s relations with his favourite niece and her husband.
– Nicholas Cronk
The Lettres inédites à Marie-Louise Denis (1737-1744): Voltaire et sa chère nièce, edited by Nicholas Cronk, Frédéric Deloffre, Nicolas Fréry and Jacqueline Hellegouarc’h, have just been published (Paris, Classiques Garnier, 2023).