"Cities over the world face complex and rapidly evolving challenges. Ranging from climate, to poverty, economic downturns and demographic shifts, cities now need to confront an unprecedented array of issues. Addressing them requires ingenuity and versatility, whether in policymaking, investment decisions or everyday livelihoods. At the Flexible City Symposium of the Oxford Programme for the Future of Cities, we seek to re-think the city, in theory and practice to confront these challenges" (www.theflexiblecity.org).