« La boussole des Souverains » : l’application du Droit des gens de Vattel dans la diplomatie du xviiie siècle

Emer de Vattel (1714-1767), the jurist from Neuchâtel, published his Droit des gens ou Principes de la loi naturelle appliqués à la conduite et aux affaires des Nations et des Souverains in 1758. The book was a great success both in constitutional and international law. Vattel was considered an authority on international law during the eighteenth and nineteenth centuries. As Charles Fenwick has shown, Vattel’s book was used by tribunals, in speeches before legislative assemblies, and in the correspondence of executive officials. The book was also a manual for students, a reference work for statesmen and a text from which political philosophers drew inspiration.The Droit des gens was immediately translated into English in 1759, a year later into German, into Spanish in 1774 (even though this edition was never published due to the Inquisition), and finally into Italian in 1781. Through these translations and re-printed editions, Vattel’s work played an important role: the resulting theory of his internationalist doctrine, the identification of a State’s sovereignty, independence, and equality have become basic notions of international law. The aim of the present article is to reconstruct the historical and cultural context in which Vattel lived and worked, to investigate the juridical discourse on diplomacy in his Droit des gens, and finally to scrutinize the use of Vattel’s work in eighteenth-century diplomacy