How many atheists at d’Holbach’s table?

On the 23rd of August 1763 d’Holbach has read – this is what he tells him –Hume’s “valuable works” and declares the “strongest admiration” for his genius, the “highest idea” of his person, and the “strongest desire” of getting acquainted with “one of the greatest philosophers of any age, and of the best friend[s] to mankind”. On the 17th of October Hume arrives in Paris; after a few days he meets d’Holbach, and Diderot reports their conversation: “the English philosopher thought to say to the Baron that he did not believe in atheists, that he never saw any. The Baron said to him: ‘Monsieur, Count exactly how many we are here.’ We were eighteen. The Baron added: ‘It is not unhappy that we can count fifteen of them at the first stroke. The other three do not know what to think about it.’” The anecdote was first published in Diderot’s Correspondence (1830), then in Romilly’s Memoirs (1840) (a slightly different version) and in Burton’s Life of Hume (1846). It soon became a sort of common place in among those who ascribe to Hume a “true religion”. It is reported by famous biographers (Burton, Greig, and Mossner) and scholars (Laird, Kemp Smith, Livingston, Gaskin, Garrett, and Yoder) as a confirmation that, unlike d’Holbach, Hume was not an atheist and never called himself such; sometimes as a confirmation that he was a theist, or a deist, or a believer in God as a probable intelligent cause of order in the universe. An anecdote, however founded, is not a good foundation for an argument; yet it can tell us many other things. What happened exactly at d’Holbach’s table? In 1775, Hume writes a memorandum for his nephew Josey who is going to Paris: he should drive to the Faubourg Saint-Germain, “a Creditable Place – Hume says – at which I have known several of my Friends to lodge”; and he should visit Baron d’Holbach: his house, as Hume declares two years earlier, used to be “a common receptacle for all men of letters and ingenuity”.