Spatial and environmental planning is an essential feature of all but the very simplest of societies. Its form and role and the principles on which it should be based, however, have become increasingly controversial questions. In this important book Patsy Healey draws on a wide range of new thinking in social, political and spatial theory to provide a framework for planning which is rooted in the institutional realities of our increasingly fragmented societies but designed to foster communication and collaborative action. The second edition includes a major new chapter assessing recent developments in theory and practice.