Summary: "Territorial" theories argue that spatial design can only play an important role in society by virtue of there being a "correspondence" between spatial zones and social identities. In this paper it is argued that "structured non-correspondence" can also play a positive social role, with quite different consequences for spatial design. To the extent that a system works on non-correspondences it functions more probabilistically. It relies on numbers and frequencies of events which take place to reproduce a statistically stable global system, rather than on the formal clarity of its structure. This gives non-correspondence systems a robustness which highly structured systems do not possess. They can thus tolerate much more local disorder and yet be reproducible
