What are cities for? and how does it relate to their spatial form?

In this paper, we ask what cities are for, and how this relates to their spatial form. This is an issue on which space syntax so far has said nothing. It is routine to say cities exist to create contact, but this seems at least over-generalised, since cities are also often noted for their anonymity. Here we argue that cities exist to create not contact in general, but two very specific kinds of contact, and these relate to the dual form of what syntax has called the generic city – the idea that the urban grid is made up of two interlocking grids, each with its own metric and geometric properties: a foreground grid structured by and serving micro-economics, and a background grid structured by socio-cultural factors and serving mainly residence, the two being linked by a pattern of pervasive centres. These different spatial structures generate fundamental differences in social networks which in the foreground grid serve the need for morphogenesis, and in the background grid, the need for stability. The co-existence of microeconomic morphogenesis and socio-cultural stability is what the city is for, and it is both reflected in and created by the dual form of the generic city.