The public space of democracies is constructed in a context that is marked by the digital transformation of the economy and society. This construction is carried out primarily through deliberation. Deliberation informs and guides both individual and collective action. To shed light on the concept of deliberation, it is important to consider the rationality of choice; but what type of rationality is this? References to economic reason are at once widespread, crucial and controversial. This book therefore deals with arguments used by individuals based on the notions of preferential choice and rational behavior, and also criticizes them. These arguments are examined in the context of the major themes of public debate that help to construct the contemporary public space: "populism", social insurance, social responsibility and environmental issues. Economic Reason and Political Reason underlines the importance of the pragmatist shift of the 2000s and revisits, through the lens of this new approach, the great utilitarian and Rawlsian normative constructs that dominated normative political economics at the end of the 20th century. Alternative approaches, based on the concept of deliberative democracy, are proposed and discussed.