At that time [90th in Lagos], if you drove through the city, you drove through a foreground that always seemed to be incredibly dramatic and incredibly agonised - smoking, burning, incredible compression. In the first year we stayed on the ground and went everywhere. But then in order to discover whether this was the whole story, we rented a helicopter. And we began to understand that this is not chaos but a highly modern system that had been abandoned, then at some point went into reversal, then slowly came out of it.

The real thing we tried to look at is what happens to a society when the state is absent. At that point, the state had really withdrawn from Lagos; the city was left to its own devices, both in terms of money and services. That, by definition, created an unbelievable proliferation of independent agency: each citizen needed to take, in any day, maybe 400 or 500 independent decisions on how to survive that extremely complex system.

But now sustainability is such a political category that it's getting more and more difficult to think about it in a serious way. Sustainability has become an ornament.

Nigeria [in 1990] was all rumour, an unbelievable amount of rumour - largely about crime and almost mythical manifestations of evil.

I'd say that my profession ends where architectural thinking ends - architectural thinking in terms of thinking about programs and organizational structure. These abstractions play a role in many other disciplines, and those disciplines are now defining their 'architectures' as well.

The architecture per se isn't at fault. The more important factor, in my view, is the political neglect of these areas, which have essentially been cut off from other neighborhoods.

The Grid makes the history of architecture and all previous lessons of urbanism irrelevant. It forces Manhattan's builders to develop a new system of formal values, to invent strategies for the distinction of one block from another. The Grid's two-dimensional discipline also creates undreamt-of freedom for three-dimensional anarchy. The Grid defines a new balance between control and de-control in which the city can be at the same time ordered and fluid, a metropolis of rigid chaos.