 The French religious history of the nineteenth century was summarized by him in "un siècle de l'Eglise de France" (1901).He contributed notable works of religious psychology in his celebrated books, "Le doute et ses victimes" (1865), and "La foi et ses victoires" (1881-83).His "Espérance" (1892) throws much light on the beginnings of the contemporary religious revival among intelligent Frenchmen at the end of the nineteenth century; his "L'évangile du pauvre" (1905) appeared opportunely during a period of social unrest.