In salons, Holbach salon (TL:8), aka "Holbach Hotel", "Holbach's coterie" (Rousseau, c.1755), "philosopher's synagogue" (Diderot, c.1770), "synagogue of the atheists", "Holbach's circle" (Blum, 2011), or "philosopher's hotel" (Galiani, c.1770), was a radical enlightenment philosophical salon, held bi-weekly, during Thur and Sun dinners, in the 1750s to 1770s, at the Paris mansion of Baron Holbach, at 8 (or 10) Rue des Moulins, surrounded by his 3,000-book library, attended by about one to two dozen (or up to 50) people per meeting, original or main group shown below:
The Holbach salon, over time, attracted many of the greatest thinkers in the world, such as: Denis Diderot, Jean Rousseau, David Hume, Adam Smith, and Benjamin Franklin, to name a few; discussions tending to be themed on atheism, religion, science, philosophy, politics, morality, and the new enlightenment ideas of the encyclopedist movement.
In 1749, Baron Holbach, aged 26, returned to France from Leyden University, having completed a round education in physics and chemistry, and, after obtaining a degree or license to practice law, began to engage in Denis Diderot's Encyclopedia, e.g. contributing articles to the 1752 edition. Sometime, herein, at one of Holbach's mansions, the Holbach salon concept began to take root.
In 1754, Basile-Genevieve Aine (1728–1754), Holbach's first wife destated (died), and he closed his salon for a period of about two-years, and moved out to the country to stay with his friend Friedrich Grimm. In 1757, Holbach married his second wife Charlotte-Suzanne Aine (1733–1814), whom with he had three children, and two years later he restarted his salon meetups.
In 1759, Holbach moved into 8 or 10 Rue des Moulins (formerly known as: rue Royale Saint-Roch), Paris, a five story palace, with a 12-person to 50-person dinner table, and a 3,000-book personal library, whereat, every Thu and Sun, for a period of two decades, give or take, he hosted one of France's most famous intellectual salons, during which the greatest minds of Europe and America would come for dinner and drinking, and talk freely and openly about most philosophically taboo topics of the time. This location remained the central location for the Holbach salon for at least the next two decades.
The following are known Holbach salon meeting attendees:
|1759-1770s||Started the salon (c.1751), aiming to revive his all-night frank and open dinner debates of his Leiden student days;
something more substantial than the then-standard salons moderated by "respectable ladies", wherein polite conversation was maintained, while new literary works were read, and open conversation was largely avoided.
The Holbach salon would have officially started in this period. We can already see, in comparing Holbach, Diderot, and Rousseau, that Diderot, in his refusal to wear the wig, is already bucking social protocol, in his photo alone!
|Contributed Encyclopedia articles on music (Blom, 2011); later spent years attacking and denouncing his former friends (Spencer, 2014), e.g. his "Open Letter to Alembert" (1757), attacking Jean Alembert on music philosophy, and Emile: on Education (1762), attacking all the philosophers of the salon in group, calling them braggarts.|
|(RMS:35) French mathematician, civil engineer, philosopher, and ancient and oriental languages scholar; his “The Christian Mythology”, the fourth chapter of his Christianity Unveiled, explicitly defined Christianity as a “mythology”; Holbach employed Boulanger posthumously as one of his pseudonyms.|
|French atheist philosopher, editor, and artist; characterized a “brash evangelical atheist” (Hecht, 2003), was a friend of Baron Holbach, who in circa 1869 had begun to increasingly politicize Holbach and his views, who assisted Holbach in the classic atheist works, such as Jean Meslier, and who penned the preface to Holbach’s The System of Nature.|
|His Essay on Mind (1758), which was burned Paris, espoused atheistic, utilitarian, and egalitarian doctrines; was materialistic in its conception of the universe;
argued that a "nonreligious morality" is what really guided most people's virtues.
|Economist and abbe (Spencer, 2014)
Was supported by Voltaire; he was, supposedly. outshined by Diderot, commenting: "one simply cannot get a word in edgewise" when the philosopher [Diderot] was in full flight.
|French historian and writer;
|German-born French-language journalist, art critic, diplomat, and encyclopedia contributor; established and ran the influential Correspondance Litteraire, an intellectual newsletter that was hand-copied to avoid the censors (Spencer, 2014); was a one-man public relations office for the salon and its members; was the only man who had mastered the German language (according to Goethe).|
|Characterized as the "grandest among the guests in the first years" (Blom, 2011); noted for his for his 1745 comet impacting the sun nebular hypothesis planet formation model (later cited by Holbach in respect to the origin of earth, in respect to the origin of humans); declared that Noah’s flood had never occurred;
he attended the Holbach salon for several years, before drifting off to the salon of Marie Geoffin.
|On 18 Oct 1763, Hume (aged 52) visited Paris, a point in time, when most of his works were well-known and he was the toast of the town;
During which time he visited the house Holbach (aged 40) during which time a “legendary dinner party” was thrown, with about two dozen attendees, during which time Hume stated that he does not believe an atheists, because he had never seen one, to which Holbach retorted: "look around, of the eighteen seated here, 15 are atheists, and 3 have not yet made up their minds".
|Writer and defrocked priest (Spencer, 2014) Rousseau wrote about meeting him in 1748; presumed to have been at the first meetings; said to have been "never at a loss for words, and a wit that was a foil even for Diderot" (Blum, 2010); became editor of Mercure de France, an intellectual journal; wrote a treatise Voyage aux deux Indes, on political philosophy, in respect to France's dealings with the colonies and international trade.|
|Franklin and the Baron were "intimate friends" (Cushing, 1914); when he arrived at Paris, in 1776, as the congressional ambassador to the French King, was asked whether he would like to see anyone in particular, and replied: "take me to the philosophes" (Blom, 2010).|
|(IQ:150|#496) (Cattell 1000:401) English radical writer and politician (Spencer, 2014); was one of Holbach's closest friends at Leyden University, in 1745, whom he would go on "delightful evening walks" with.|
|(IQ:170|#593) (Cattell 1000:293) French economist (Spencer, 2014)|
|(Cattell 1000:633) English writer, art historian, man of letters, antiquarian and Whig politician;
|English actor, playwright, and theater manager and producer (Curran, 2012); was very-much liked by the Holbach society, both Holbach spent several months with Garrick at Hampton (Cushing, 1914).|
|Italian economist (Spencer, 2014) secretary of the Neapolitan Embassy, who spent ten years in the salons of Paris. After is return to Naples his longing for Paris led him to a voluminous correspondence with his French friends including Holbach (Cushing, 1914); argued for idea of “natural” laws in economics; but opposed the unrealistic theoretical ideas of the physiocrats and Quesnay.|
|An accomplished poet (Blom, 2011); in winter 1747 to 1748, he had an affair with Voltaire’s mistress Emile Chatelet; on 4 Sep 1749, Chatelet gave birth to his child, but then died of fever 6 days later, the child dying a year later; in 1757, Rousseau had an affair with Lambert's second woman Sophie Houdetot; he wrote several articles for the Encyclopedia, and and essay on "Luxury".|
|French explorer, geographer, and mathematician; noted for making the first maps of the Amazon region; salon attendee (Morellet, c.1785)|
|Charles-Georges Le Roy (or Leroy)||Lieutenant of the Royal Hunt; contributed Encyclopedia articles on deer, hunting, and instinct (Blom, 2011)|
|Georges-Louis Leclerc||Director of the Royal Botanical Gardens (Spencer, 2014)|
|Italian legal reformer; feted for his proposal to reform penal law along rational and proportional lines, but, as a Catholic, was scared away by the groups atheism (Spencer, 2014)|
|Irish-born English novelist and clergyman (Scott, 2010)|
|Barthez (or Barthes)||(Morellet, c.1785)|
|Venelle (or Venel)||(Morellet, c.1785)|
|Rouelle||And his disciples (Morellet, c.1785)|
|Le Chevalier de Chastellux||(Morellet, c.1785)|
|de Croismare||(Cushing, 1914)|
|de Pezay||(Cushing, 1914)|
|de Valory||(Cushing, 1914)|
|Jennifer Hecht (2004) in Doubt (pg. 352) confusingly alludes to view that Voltaire and Montesquieu were at the Holbach salon dinner when Hume in 1763 arrived, stating that he had never seen an atheist. Possibly, this was an ambiguous paragraph? Voltaire was said to have opposed the atheists of the Holbach coterie “quite bitterly when the works of Holbach and Naigeon appeared.” (Kors, 1976) Voltaire, presumably, would have attended one or more of the salon meetings; alternatively, he was “off the stage” before the Holbach salon took root (Cushing, 1914); but that he did meet Holbach in Paris in 1778 and was very cordial saying that he had long desired to make his acquaintance (Naigeon, c.1780).|
|Jennifer Hecht (2004) in Doubt (pg. 352) confusingly alludes to view that Voltaire and Montesquieu were at the Holbach salon dinner when Hume in 1763 arrived, stating that he had never seen an atheist. Possibly, this was an ambiguous paragraph? Alternatively, he was “off the stage” before the Holbach salon took root (Cushing, 1914) and non-existent when Hume (1763) arrived.|
In 2010, Rebecca Scott, while researching her book Infidels: In search of the First Evolutionists, she tracked down all the historical places proto-evolutionary ideas were discussed, from a lagoon in Lesbos where Aristotle talked about generation with his students, to the desert outside ninth-century Basra, to the police-watched houses of Paris and London in the eighteenth-century, she contacted Paris blogger Peter Olson to take some photos of the Holbach salon, inside and out, such as shown adjacent. Scott, at the end of her research, summarized the Holbach salon or "Hotel of the Philosophers" as follows:
- “Although there is no plaque to distinguish this house from any other eighteenth-century town house in Paris, this house at number 8, Rue des Moulins (then the Rue Royale-Saint Roch), was the centre of the French Enlightenment. Nicknamed the Hotel of the Philosophers or the Synagogue, it belonged to the Baron Holbach, a wealthy French-German intellectual and a passionate atheist, who ran a salon for the radical intelligentsia of Paris every Thursday and Sunday from 1759 to 1789. He had an excellent chef, a dining table that seated fifty, a library of over 3,000 volumes, and a large number of paintings by France's leading artists. Rousseau, Diderot, Buffon, Galiani, Grimm, Marmontel, Naigeon, Saint-Lambert, Suard all passed through these doors. Diderot rarely missed a gathering. Foreign intellectuals such as Adam Smith, Laurence Sterne and Horace Walpole had dinner here during their visits to France. The house was under police surveillance. The very first book of atheism was written here - System de La Nature – by Baron Holbach himself. Early evolutionary ideas were discussed across his table. The leading members of the Encyclopedie met here. With these people for company Diderot published Rève de d'Alembert.”
- — Rebecca Scott (2010), Infidels: In search of the First Evolutionists
Inside the salon, as the story goes, they wrote the books, e.g. Christianity Unveiled (1761), System of Nature (1770), while outside the salon the police burned them, when printed, or sometimes the hangman burned the books, with a noose around them, like a mock hanging.
The following are quotes:
- “The first time that Hume found himself at the table of Holbach, he was seated beside him. I don't know for what purpose the English philosopher took it into his head to remark to the Baron that ‘he did not believe in atheists’, and ‘that he had never seen any’. The Baron said to him: ‘count how many we are here’. We are eighteen. The Baron added: ‘It isn't too bad a showing to be able to point out to you fifteen at once: the three others haven't made up their minds’.”
- “There is the Rue Royale-Saint Roch! All the decent and clever people in Paris gather there. To find the door opened to you, it is not enough to have a title or to be a savant; one must also be good. It is there that exchange is secure. It is there that history, politics, finance, belles-lettres and philosophy are discussed. It is there that men esteem each other enough to contradict each other. It is there that the true cosmopolitan is found.”
- — Denis Diderot (c.1780), Oeuvres (10:378-79)
- “Holbach, more than Voltaire, more than Diderot, is the father of all the philosophy and all the anti-religious polemics at the end of the eighteenth and the first half of the nineteenth century.”
- — Auguste Faguet (c.1895), Publication 
- “The coterie holbachique was a unique "radical" force in the thought of the eighteenth century, but this is a curious harmony, for there is no agreement upon the com-position of the coterie, or upon the precise significance of its presence in Paris. The primary reason for this is that the coterie holbachique early became the subject of a myth that passes still, in part or in whole, for the truth.”
- — Alan Kors (1975), “The Myth of the Coterie Holbachique” (pg. 573) 
- “The flourishing of radical philosophy in Baron Holbach's Paris salon from the 1750s to the 1770s stands as a seminal event in Western history. Holbach's house was an international epicenter of revolutionary ideas and intellectual daring, bringing together such original minds as Denis Diderot, Laurence Sterne, David Hume, Adam Smith, Ferdinando Galiani, Horace Walpole, Benjamin Franklin, Guillaume Raynal, and Jean-Jacques Rousseau.”
- “D'Holbach's scholarly activities began in earnest in 1744, when his uncle sent him to the University of Leiden. Around this time Leiden was internationally renowned as one of the most progressive and enlightened educational establishments in Europe. It is noteworthy that La Mettrie's radically materialist The Human Machine was published in that city in 1747, while d'Holbach was still studying there. Yet of greater significance seems to be the contact he made there with several Englishmen, including John Wilkes and Mark Akenside, who encouraged and influenced his philosophical development. His profound understanding of English philosophy, theology and literature is clear from his later writings, and he even translated Akenside's pantheistic poem Pleasures of Imagination: a Poem in Three Books (1744) into French in 1759. During the course of his education d'Holbach became fluent in French, German, English, Italian and Latin, and by his death he had amassed a private library containing some 2,956 editions. This education was life-long, as his wealth allowed him to dedicate himself to learning, collecting, discussing, writing and publishing free from either poverty or the dependency on patronage that troubled so many of his contemporaries. Once re-established in Paris after his university days, d'Holbach held a philosophical salon on Thursdays and Sundays in the Rue Royale, and periodically entertained at Madame d'Aine's Château de Grand-Val at Sucy-en-Brie. At these gatherings, he cultivated friendships and relationships with many of the most important thinkers of his time, amongst them Denis Diderot, Melchior Grimm, Jean-Francois Marmontel, Guillaume-Thomas Raynal, Adam Smith, Lawrence Sterne, David Garrick and Ferdinando Galiani.”
- — Mark Curran (2012), Atheism, Religion, and Enlightenment in Pre-Revolutionary Europe (Pg. 24) 
- Rue des Moulins (Paris) (French → English) – Wikipedia.
- Olson, Peter. (2010). “Hotel of the Philosophers”, BlogSpot, Sep 19.
- Blom, Philipp. (2011). A Wicked Company: Holbach’s Salon and the Forgotten Radicalism of the European Enlightenment (Amz) (open conversation, pg. 55; guests, pg. 56). McClelland.
- Diderot statute – r/Sculpture.
- Cushing, Max. (1914). Baron d’Holbach: a Study of Eighteenth Century Radicalism in France (PhD dissertation) (txt) (salon, pg. #; Plato and Aristotle [Platon et des Aristote], pg. #). Alexandria.
- Spencer, Nick. (2014). Atheists: the Origin of the Species (pg. 104). Bloomsbury.
- Nicolas Boulanger – Hmolpedia 2020.
- Jacques Naigeon – Hmolpedia 2020.
- Jean-Francois Marmontel – Wikipedia.
- Diderot, Denis. (1784). Oeuvres, Volume Five, Correspondence (pg. 465). Publisher.
- Marmontel, Jean. (c.1780). Memoires (pg. 214). Mercure, 2000.
- Marie Goeffrin – Wikipedia.
- (a) Hume, David. (1932). The Letters of David Hume, Volume One (editors: J.Y.T. Greig) (pg. 491). Oxford.
(b) Blom, Philipp. (2010). A Wicked Company: Holbach’s Salon and the Forgotten Radicalism of the European Enlightenment (Amz) (pg. 137). McClelland, 2011.
- Hume-Holbach dinner party anecdote – Hmolpedia 2020.
- Durant, Will. (1965). The Story of Civilization, Volume Nine: the Age of Voltaire (pgs. 695-96). Simon.
- (a) Walpole, Horace. (1846). The Letters of Horace Walpole, Volume Four (pg. 226). Bentley.
(b) Walpole, Horace. (1846). The Letters of Horace Walpole, Volume Six (pg. 370). Bentley.
(c) Blom, Philipp. (2010). A Wicked Company: Holbach’s Salon and the Forgotten Radicalism of the European Enlightenment (Amz) (pg. 137). McClelland, 2011.
- Williams, Elizabeth. (2017). A Cultural History of Medical Vitalism in Enlightenment Montpellier (pg. #). Routledge.
- Curran, Mark. (2012). Atheism, Religion, and Enlightenment in Pre-Revolutionary Europe (pg. 24). Publisher.
- Kors, Alan. (1976). D’Holbach Coterie: an Enlightenment in Paris (pg. 124). Princeton, 2015.
- Scott, Rebecca. (2013). Darwin’s Ghosts: In Search of the First Evolutionists (Holbach, 5+ pgs; Saint Roch, 2+ pgs). Bloomsbury.
- (a) Diderot, Denis. (1765). “Letter to Sophie Volland” (WS), Oct 6.
(b) Anon. (2015). “Le bon David: Meets 15 Atheists”, Rodama 1789, Blogspot, Nov 8.
- Durant, Will. (1965). The Story of Civilization , Volume Nine, the Age of Voltaire (pg. 713). Simon and Schuster.
- Kors, Alan. (1975). “The Myth of the Coterie Holbachique” (abs), French Historical Studies, 9(4):573-95.
- Kors, Alan. (1976). D’Holbach Coterie: an Enlightenment in Paris. Princeton, 2015.
- Zaretsky, Rob. (2006). “Hume and Humility”, Engines of Our Ingenuity, Episode 2173.
- Radu, Kenneth. (2012). “Review of: a Wicked Company”, LindaLeith.com, Feb 3.
- Anon. (2019). “Baron d’Holbach Brought Back to the Mother Land by a Joyous Sett” (Ѻ), Voltaire Foundation, Aug 6.
- D’Holbach’s Coterie – Wikipedia.