ABSTRACT
This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book presents a method to explore rationality with the help of argumentation analytical tools, as initiated by Toulmin. It explores expressive rationality first, as it is the most under-explored aspect of rationality. The book explains the social rationality behind publicly debated decisions, where decision makers and their critics refer mainly to socially shared norms, principles and values as sources for legitimation. It analyses decision-making debates that exchange good reasons to act. Instrumental rationality has been central to economists' understanding of rationality for a long time. The book also explores how decisions that are mainly based on instrumental-rational considerations can be challenged or supported by social- and expressive-rational arguments. It illustrates how can expressive, social and instrumental rationality influence each other. The book proposes questions that help to identify the irrationalities, to support decision makers and their advisers in better addressing them.
