The city constitutes a remarkable and highly contested topic within the field of social sciences. There is literally not a single human theme that could not be related and imagined within the framework of the urban: sex and crime, production and reproduction: of power, hierarchy, poverty, life course and so forth. Paradigm shifts abound: from structuralist to cultural turns and from political economy approaches to phenomenology. The main challenge, however, seems to go unanswered. It is sex in the city, poverty in the city, immigrants in the city, but what is meant by the city other than an all-purpose nostrum for societal problems? I will briefly describe this confusion as a point of departure to offer some conceptual ideas of how to constitute the city as a scientific object of knowledge. My frame of reference will be what is labelled the 'spatial turn' in social sciences. The two main objectives are (1) to conceptualize the city as a particular space-structuring form of sociation and (2) to identify and qualify some features of this spatial form (Berking, H., 2008. Stadte lassen sich an ihrem Gang erkennen wie Menschen. In: H. Berking and M. Low, eds. Die Eigenlogik der Stadte. Frankfurt am Main: Campus). Since there are different and differentiated spatial forms of sociation to analytically grasp the city's distinctive spatial form is a precondition for reconstructing its internal symbolic order as a world in its own right. The key issues will be 'density' or more precisely 'densification' and 'doxa', the latter referring to what is called the natural attitude to the world, the pre-reflexive or tacit knowledge of everyday life (Lebenswelt).
