What is the unified theory of capitalism about? This chapter summarizes the nature of the unified theory, its epistemological justification, and its capacity to explain the functioning of the capitalist system. The unified theory has recently been presented as a new scientific endeavor in economics in several books. The present book is a kind of new volume of the series. It presents a set of essays, which seeks to further the implications of the unified theory—on explanatory and policy issues. For a new scientific endeavor, this objective seems justified. Thus, this chapter also presents the logic of the questions that underlies the set of essays.