Rousseau and Abbé Etienne Condillac dined en piquenique sometime in 1745 or 1747. The date is uncertain because Rousseau is careless with dates related to the incident twenty years after in Confessions.
Hard up and living in Paris in the rue Saint-Denis, Rousseau sometimes shared the expense of dining. He writes that when Condillac came to dine with him, they dined en piquenique, “il venait quelquefois diner avec moil tête à tête en piquenique.” The sharing custom was primarily Parisian and recognized in Gilles Ménage’s dictionary in 1694 as an established custom. Rousseau’s use of the term suggests its common practice fifty years after.
The menu is not given. However, Rousseau preferred a vegetarian diet (mainly white foods) and wine.
* Étienne Bonnot de Condillac (aka Abbé Condillac) was a French philosophe. About the time Rousseau remembered this incident, Condillac had completed Essai sur l’origine des connaissances humaines, Essay on the Origin of Human Knowledge.
See Jean Jacques Rousseau The Confessions (VII, 1769/1782)
Je m’étais aussi lié avec l’abbé de Condillac, qui n’était rien, non plus que moi, dans la littérature, mais qui était fait pour devenir ce qu’il est aujourd’hui. Je suis le premier peut-être qui ai vu sa portée, et qui l’ai estimé ce qu’il valait. Il paraissait aussi se plaire avec moi; et tandis qu’enfermé dans ma chambre, rue Jean-Saint-Denis, près l’Opéra, je faisais mon acte d’Hésiode, il venait quelquefois dîner avec moi tête à tête en pique-nique. Il travaillait alors à l’Essai sur l’origine des connaissances humaines, qui est son premier ouvrage. Quand il fut achevé, l’embarras fut de trouver un libraire qui voulût s’en charger.
I had also become acquainted with the Abbé de Condillac, who was nothing, no more than myself, in literature, but who was made to become what he is to–day. I am perhaps the first who has seen his significance, and who has esteemed him for what he was worth. He also seemed to be pleased with me; and while shut up in my room in the Rue Jean–Saint–Denis, near the Opera, I was performing my act of Hesiod, he sometimes came to dine with me tete–a–tete on a picnic. He was then working on the Essay on the Origin of Human Knowledge, which is his first work. When it was finished, the difficulty was to find a bookseller who would undertake it.
See Jean Jacques Rousseau The Confessions (VII, 1769/1782), http://gallica.bnf.fr/services/engine/search/sru?operation=searchRetrieve&version=1.2&query=%28gallica%20all%20%22j.%20j.%20rousseau%20the%20confessions%22%29