Collective intelligence and cities, more than an urban metaphor

If cities are complex adaptive systems (John Holland, 1995), their functioning and all interactions among their own internal structures could use as possible models plural examples starting from our neuronal system till the immune one. This comparison has to deal with the complexity, which those systems have in common, but it is also based on their prompt responsiveness to stimulations coming from external context, that systems must metabolize in order to evolve and mutate into “something else”. Success of cities and languages (meaning survival and an optimized way of functioning and developing) is therefore crucially based on the capability of reacting to a constant changing environment whether this is shaped by social, economical, ecological and cultural agents. The next challenge should be then to “identify and build new common goals” safeguarding pluralism and heterogeneity as basic elements of a “collective intelligence”, our greatest resource.