Contrary to the “populist linguistic purism” of Remy de Gourmont, who believed in a “native” and primal language, as well as in a literature that “does not receive neither borrow anything” (Roussin), Proust moulds his novel in a “gloriously impure, lumberfilled” linguistic matter (Malcolm Bowie). Proust’s idea of language is radically opposed to the nationalist ideology that penetrated into the late Nineteenth century France. To the Cratylism of Ramuz, of Remy de Gourmont, and eventually of Céline, Proust opposes the « age of things » that his hero struggles to understand, and in which the impurity of the living becomes style. Instead of representing a risk of “contamination”, some « winged and throbbing colonies of precious insects” (Swann’s Way) feed in the Recherche the acacias of the Bois de Boulogne, whilst nourishing the French language, that Proust does not fear to make “stranger” to his readers. This essay aims at finding and understanding the literary and political significance of such an esthetics of language, that still represents, in this 21st Century of localisms and nationalistic simplifications, a challenge and a provocation.