Neurath’s Reading of Diderot: Theoretical and Practical Models, Echoes of Similar Attitudes

Among the many intellectual roots of Otto Neurath’s thought, the Enlightenment is a crucial reference, but the significance of the French Enlightenment (Lumières) remains largely unexplored. Neurath, however, consistently engaged with this tradition, and within it, Denis Diderot emerges as a key figure. Evidence of Neurath’s reading of Diderot spans decades, from early mentions of his literary works to his encyclopedic writings, up to annotations of Diderot’s Letter on the Blind found in his exile library. Diderot’s encyclopedism—classification without a rigid system, collaborative nature, evolving structure, and the social relevance of this endeavor—deeply resonated with Neurath’s scientific world-conception and his view of unified science. More than a passing reference, Diderot’s encyclopedism provided both an epistemological and editorial model for Neurath’s International Encyclopedia of Unified Science. In this article, I analyze Neurath’s explicit references to Diderot to reconstruct this reception: the ways of referencing, their timeline, his manner of approach, the motivations underlying Neurath’s interest, and their meaning. I outline a shared intellectual attitude, committed to an empirical, critical, and antidogmatic approach to knowledge across disciplinary boundaries. This rapprochement between Neurath and Diderot illuminates an unexamined but foundational connection between the Lumières and logical empiricism.