Wikipedia
The Encyclopédistes were a members of the Société des gens de lettres, a French writer's society, who contributed to the development of the Encyclopédie from June 1751 to December 1765 under editors Denis Diderot and Jean le Rond d'Alembert. The composition of the 17 volumes of text and 11 volumes of plates of the Encyclopédie was the work of over 150 authors belonging, in large part, to the intellectual group known as the philosophes. They promoted the advancement of science and secular thought and supported tolerance, rationality, and open-mindedness of the Enlightenment.
More than a hundred encyclopédistes have been identified. Still, as Frank Kafker has shown, the encyclopédistes were not a unified group, neither in ideology nor social class. Below some of the contributors are listed in alphabetical order, by the number of articles that they wrote, and by the identifying "signature" by which their contributions were identified in the Encyclopédie.
Beyond the known collaborators – at least in name – many articles are not signed and certain authors expressed a desire to remain anonymous. Other authors, Allard or Dubuisson for example, remain a mystery to us. Moreover, the sporadic research into the quotations, borrowings, and plagarisms in the Encyclopédie – the illustrations as well as the text – illuminate a group of "indirect" collaborators.
"Among some excellent men, there were some weak, average, and absolutely bad ones. From this mixture in the publication, we find the draft of a schoolboy next to a masterpiece." — Denis DiderotA machine-generated and incomplete list of authors sorted by number of posts can be found at the project ARTFL. There are list by frequency and by letter.