6 Open Public Spaces and the Vita ActivaAbstract; 6.1 Introduction; 6.2 Public Sphere, Public Spaces, and Open Spaces; 6.3 Questions Concerning Systems of Open Public Spaces in Large and Medium Brazilian Cities; 6.4 Open Space Systems: Complexities and Contradictions; References; 7 Open Space Systems in Rio de Janeiro: The Public and Private Spheres Reflected in the Urban Landscape; Abstract; 7.1 Introducing Concepts; 7.2 The Environmental Question and the Pressure for Housing; 7.3 The Social Construction of Landscapes: A Theme and Its Issues