This article describes the social and linguistic processes underlying the formation of political language in France from the end of the Middle Ages to the nineteenth century. The author emphasizes the close relationship between the evolution of political language, as it can be traced through the many editions of dictionnaires and grammaires, and novel forms of sociability, from the medieval notion of friendship to revolutionary civism. The eighteenth century is considered a crucial moment in this process, given that during that period the thinkers of the Lumières, in their effort to harness civil society through language, forged the notion of a space of universal communication among men as a precondition for the invention of a political language specific to contemporary democracy.