How can historians measure and analyse the fluctuations of trust and civic feeling? In spite of the remarkable success enjoyed by Yann Algan and Pierre Cahuc’s La société de défiance, the book’s argument is based on a very fragile opposition between the Third Republic, seen as the golden age of trust, and bureaucratic state intervention established at the end of the Second World War. In this article, Nicolas Delalande shows how slight and ideologically biased the authors’ historical arguments are.