Celebre pour ses travaux d'economie politique ainsi que pour son activite diplomatique, Ferdinando Galiani (1728-1787) incarne un type singulier de 'philosophe', s'attribuant et reniant cette appellation en fonction des contextes. Bien que refusant de construire un systeme ordonne d'idees, Galiani produit un savoir philosophique qui accompagne et enrichit ses projets politiques. Situee au carrefour de l'histoire, de la litterature et de la philosophie, cette monographie etudie ainsi le parcours de Galiani en mesurant la finalite sociale et politique de sa production philosophico-litteraire, et en saisissant son identite de 'philosophe' entre Naples et Paris. Quelles influences ces deux milieux socioculturels ont-ils eu sur sa pensee et sur sa carriere? Cette interrogation constitue le coeur d'une analyse souhaitant reconsiderer conjointement les contextes napolitain et parisien, ou les termes de 'philosophe et de 'filosofo se chargent de significations, de pratiques et d'emplois differencies. A l'aune des discours, des pratiques et des representations que cet auteur construit tout au long de sa vie, ce livre inscrit Galiani dans la dimension concrete du travail philosophique, en etudiant sa maniere de vivre en philosophe, la ou les batailles philosophiques, les succes editoriaux et la gloire cohabitent sans antagonisme avec des inquietudes d'ordre materiel, des craintes concernant sa reputation ou encore des echecs. --- Famous for his works on political economy as well as for his diplomatic activity, Ferdinando Galiani (1728-1787) embodies a singular type of 'philosopher', attributing and denying himself this designation according to the context. Although he refused to construct an ordered system of ideas, Galiani produced a philosophical knowledge that accompanied and enriched his political projects. Situated at the crossroads of history, literature and philosophy, this monograph studies Galiani's career by measuring the social and political purpose of his philosophical-literary production, and by establishing his identity as a 'philosopher' between Naples and Paris. What influences did these two socio-cultural milieus have on his thought and his career? This question constitutes the core of an analysis that aims to simultaneously reconsider the Neapolitan and Parisian contexts, where the terms 'philosophe and 'filosofo take on different meanings, practices and uses. In the light of the discourses, practices and representations that this author constructed throughout his life, this book places Galiani in the real dimension of philosophical work, studying his way of life as a philosopher, where philosophical battles, editorial successes and fame coexist without conflict with material worries, fears about his reputation or even failures.