Résumé
Among the protagonists of the Vienna Circle, Otto Neurath appears to be the one who mentions the Enlightenment the most. Together with Hans Hahn and Rudolf Carnap, their 1929 manifesto presented their view as a “scientific world-conception” understood as a “spirit of Enlightenment and anti-metaphysical factual research”. His leading role regarding this topic can be explained by his wide range of interests in the history of philosophy, his views on the historical roots of their thought and, most importantly, by his growing focus on the idea of unity of science and especially his big editorial project of the International Encyclopedia of Unified Science.As the main editor of the 18th century Encyclopédie and a leading figure of the French Enlightenment, Denis Diderot could be the main source of inspiration. But in Neurath’s writings, Diderot has fewer mentions than Voltaire, D’Alembert, Condillac or Rousseau. Evidence tends to show that Neurath started to read Diderot more closely in the late 1930s. Especially in 1938, when he wrote articles about his views on encyclopedism, around the publication time of the International Encyclopedia of Unified Science first volume. This paper aims to reconstruct Neurath’s reading of Diderot, linked with the elaboration of their new encyclopedia.I would like to demonstrate that before the 30’s, Neurath seems to know only vague elements of Diderot’s thinking, even during the elaboration of the International Encyclopedia of Unified Science when he takes encyclopedism as an epistemological model and the French one as a renewed inspiration. This analysis will be based on Neurath’s mentions of Diderot and his Encyclopédie before 1935.Then I would like to reconstruct Neurath’s reading of Diderot’s works around 1938, when he became more aware of their proximity and explicitly revendicates his heritage for their new encyclopedia. My analysis will be based on Neurath’s notes of his reading of Diderot’s philosophical works (still in his exile library kept at the Wiener Kreis Gesellschaft). And the similar arguments he made in the “Unified Science as Encyclopedic Integration” (1938). But also, in some letters to R. Carnap and R. Schappire found in the archives (kept at the Österreichische Nationalbibliothek).Finally, I would argue that the main parallel that could be made between Neurath and Diderot is their similar attitudes. Both on a theoretical and a practical level emerging from different problems and historical contexts. As “polymaths” engaged in society, the driving force of the groups and projects they initiated.