This article deals with the importance of the epistolary exchange between Leibniz and Fontenelle. Our knowledge of their correspondence is still incomplete, but Fontenelle’s critics emphasize the importance of his relationship with Leibniz. Despite no complete edition of the Leibniz-Fontenelle correspondence having yet been published, it is possible to consult the original manuscripts in Bodemann’s collection. The Ritter-Katalog includes four of Leibniz’s unpublished letters and different versions of an important letter written on 7 April 1703. The article deals with these unpublished manuscripts, in particular on two of them, which provide important information. The first, dated 6 January 1703 and never previously analyzed, reveals a fundamental engagement with metaphysical issues through focusing on the notion of substance, the laws of motion and related problems. The second, dated 7 April 1703 and in three different unpublished versions, continues his detailed and intense discussion of motion. The unpublished manuscripts show the difficulties faced by Leibniz in the draft texts and the importance he attached to Fontenelle’s opinion given that he sent him the texts on his metaphysics and dynamics.
Keywords: Leibniz, Fontenelle, correspondence, epistolary, manuscripts, metaphysics, dynamic