Towards an urban evolutionary theory. — Urban theories and especially urban economic theories adopt a static conception of cities (for instance central place theory or agglomeration economies theory). As a result their explanation of the urban phenomena neglect their genesis and urban change. Therefore, possibilities of prediction are reduced. To deal with cities which are complex objects, urban theory has to integrate dynamics and history. We propose here the premisses of an urban evolutionary theory, including self-organization processes. A few elements of this theory can be borrowed from dynamic models inspired by physical or biological theories of self-organization, but they have to be complemented by some specific social and spatial pr...