"On Populist Reason" is a book by the political theorist Jan Zielonka that explores the nature of populism in contemporary politics. It examines how populist movements arise in response to perceived failures of traditional political systems and the role of public sentiment in shaping political discourse. The book argues that populism is not merely a reactionary force but a complex phenomenon that reflects deeper societal issues. Zielonka analyzes the strategies used by populist leaders to connect with their audiences and the implications of these movements for democracy and governance in Europe and beyond.