This book, drawn from his PhD dissertation, studies the way subjective beliefs get modelled in game theory, asset pricing, and monetary economics. In particular, he provides explicitly mathematical foundations for common prior assumptions about nature in repeated games and asset pricing. He also recasts the explanatory power of subjective beliefs in monetary economics. Thus, in economies with rational agents, the common prior assumption has strong learning foundations in repeated game theory. In asset pricing, even though the learning foundations have been clearly identified, commonly accepted heuristic explanations may be flawed. Dr. Leoni dismisses the importance of subjective, and possibly irrational, beliefs in explaining the failure of banking systems. Levratto, N., & Stanziani, A. (Eds) 2010. Le Capitalisme au Futur Antérieur—Crédit et Spéculation en France, Fin XVIIIè-Début XXè Siècles. Brussels: Editions Bruylant.