In 1962, the leading French economist François Perroux prefaced the first volume of the critical edition of Marx’s work in the Bibliothèque de La Pléiade, an edition directed by Maximilien Rubel. A year later, Perroux published an essay titled Industrie et création collective. In this essay he contrasted the fecundity, notably for the present, of Saint-Simon’s thought rather than Marx’s. These intellectual conversations from Marx to Saint-Simon revealed Perroux’s main intellectual sources and the core vision of his intellectual project.