This book offers a vision of the economy as a system of structured information flow. The structuring is effected by institutions, and in particular by firms, which specialize in processing the information needed to allocate resources properly. Firms are the institutional embodiment of thevisions of individual entrepreneurs who believe that they have found a better way of allocating resources. Entrepreneurial vision is only a partial vision, however, in the sense that it does not encompass the entire economy, but only a subset of it. Free market economies encourage the exploitation of such partial visions because they encourage intermediation---it is by mediating between potential buyersand potential sellers that entrepreneurial visions are realized. A legal framework of private property, coupled with a moral framework to control the incidence of cheating, allows very sophisticated structures of information processing to emerge. These structures effect an elaborate division oflabour in the dimensions of information and control. Each firm is a small component of the overall structure of information flow. This structure is highly flexible and evolves continuously as circumstances change. Efficient adaptation is encouraged by rewarding entrepreneurs who create new firms tobe slotted into the existing structure. This vision has evolved over the last fifteen years, during which the author has researched a variety of topics connected with the theory of the firm----entrepreneurship, business culture, multinational enterprise, joint ventures and the like. In each of these areas he has identified the ways inwhich the orthodox theory of the firm needs to be modified in order to make it work properly. This book represents a major intellectual synthesis of that work.