Club de l'Entresol
The Club de l'Entresol (French pronunciation: [klœb də lɑ̃tʁəsɔl], Mezzanine Club) was a think-tank, club and discussion group founded in 1724 by Pierre-Joseph Alary and Charles-Irénée Castel de Saint-Pierre on the English model for free discussion of political and economic questions. It met every Saturday, between 5:00 and 7:00 p.m., at the home of président Hénault, in place Vendôme in Paris, and was named after the mezzanine there where Alary had an apartment.
It was frequented by 20 of the finest forerunners of the Age of Enlightenment, with regular attendees including Montesquieu, Helvétius, the marquis d'Argenson, Andrew Michael Ramsay, Horace Walpole and Viscount Bolingbroke. It was exclusively male, though other unofficial attendees include Madame du Deffand and the future Madame de Pompadour.
Having got wind of the club's possibly dangerous doctrines, particularly its opposition to mercantilism and Physiocracy, Louis XV shut it down in 1731. Its closure was also due to pressure from Cardinal Fleury, who had considered its conversion into an academy but finally decided on its closure since it was too critical of his administration.
Nick Childs, A Political Academy in Paris 1724–1731: The Entresol and Its Members. Studies on Voltaire and the Eighteenth Century. Oxford: Voltaire Foundation, 2000. xi + 289 pp.