This reader is concerned with the models of organisation people carry around in their heads and with the exploration of different ways of thinking about their organizations, understanding them and diagnosing their problems. It is only concerned with significant recent writings and so traditional organization theory (bureaucracy, scientific management, closed systems, human relations approaches and contingency theories) is only dealt with briefly. The papers have been written by leading authorities in the field and the editor has synthesized their perspectives within the new approach to organizational theory by howing their levels of analysis, domains and application and connections to the wider organizational theory literature. An overview of the central thesis of the new organisational theory is given and comparison is made with the classical approach of OT.