Abstract
Three basic ideas characterize the Weltanschauung of the Enlightenment: Reason, Nature, and Progress. These three clusters of ideas interact and explain the process of social change and material progress. It can be achieved by ‘social engineering’ from above or by reform from below. In the 19th century USA and England, the ‘laissez‐faire’ principle strove to bring about economic growth, freedom, and social justice from below. The Soviet Union, China, and the ‘new’ countries in Africa and Asia are striving to bring about modernization from above. In Myrdal's view the ongoing population explosion precludes the gradualist, ‘laissez‐faire’ approach, and he insists on the interventionist approach to assure progress. In his view, only intelligent planning can change and improve social institutions quickly.