Jane Jacobs sets out to produce an attack on current city-planning and rebuilding in America and to introduce new principles by which these should be governed. Throughout the post-war period, planners temperamentally unsympathetic to cities have been let loose on the urban environment. Inspired by the ideals of the Garden City or Le Corbusier's Radiant City, they have dreamt up ambitious projects based on self-contained neighbourhoods, super-blocks, rigid "scientific" plans and endless acres of grass. Yet they seldom stop to look at what actually works on the ground. The real vitality of cities, argues Jacobs, lies in their diversity, architectural variety, teeming street life and human scale. It is only when we appreciate such fundamental realities that we can hope to create cities that are safe, interesting and economically viable, as well as places that people want to live in.