Buildings die, said Toyo Ito in a lecture in 1997. And when they die, cities move; they grow, they digest and excrete and even, sometimes, in the imagination of Ron Herron, they get up and move - but that is only when they are determined on self-preservation.
'Cities on the Move' celebrates the indeterminacy of the city over the determinacy of architecture, the idea that a city is more than the sum of its parts, but that each part is a vital constituent. Trade, rot and sleaze are as much a part of it as transport, education and healthcare; all belong, interact and create a version of reality. Value judgements, argues exhibition co-designer Rem Koolhaas, are dangerous because they impose irrelevant norms onto a phenomenon which neither knows nor needs them. As far as possible, the city becomes a self-referential and self- sustaining body of activities.
The exhibition has already visited Vienna, Bordeaux, New York and Copenhagen; it will go on to Helsinki. But it has a special resonance with the Hayward Gallery. Not only do its various spaces lend themselves to a meaningful division into sections termed Street, Building, Commerce, Protest and Decay, but Koolhaas' design re-uses components from the Patrick Caulfield and 'Addressing the Century' exhibitions (the latter designed by Zaha Hadid). Their strange familiarity recalls the dislocated near-recognition that true urbanites feel when they visit a different city for the first time - a street plan of Shanghai shows the river following a similar course to that of the Thames in London - just as the situation of the Hayward itself raises huges issues about redundancy and preservation of buildings, of transition and memory.
Rarely can there have been such a close affinity between exhibited and exhibiting. Indeed, one almost feels that the deterministic indeterminacy of the Hayward Gallery is the lurking paradigm from which Koolhaas and his colleagues have put together the exhibition; that the means pre-suppose the ends. Nor can there have been an exhibition which takes as its subject so explicitly the city, rather than the architecture of the city.
Architecture, like art, weaves in and out of the social processes which the exhibition describes, without ever defining them. It surfaces in the extraordinary sculptures which resemble those given to Malaysian businessmen to commemorate a successful initiative, or in the remodelled 'tuk-tuk' (a motor rickshaw), and becomes explicit in videos of Foreign Office Architects' Yokohama Teminal, Kansai Airport or Rogers' Korean communications tower. Yet architecture is dragged under again in panels from Liu Thai-Ker of rsp Architects, or Wang and Ouyong's presentation of the Hang Seng Bank in Hong Kong: 'the building is designed to take full advantage of the waterfront location'. This is precisely where Koolhaas demands suspension of value judgement; the implications of taking that statement at face value are much more interesting, and lead to far more serious perceptions, than getting on a North London high-horse about what 'architecture' is.
Architecture surfaces, too, in the arrangement of the inflatable toys on the market stands in the sections on commerce and decay, but only in a subsidiary role. Decay, a simulation of a red-light district, has something of the feel of Madame Tussaud's chamber of horrors, except that the waxworks have naked breasts. Above all loom Lee Bul's giant inflatable women, which the attendants encouraged visitors to blow up. I made my excuses and left. The section on protest offered the chance to catapult oranges at figures in a film projected onto a wall, but it seemed relatively tame compared to either the nature of protests in South East Asia, or the enormity of what inhabitants have to protest about.
The Pacific Rim will, of course, dominate the world: its destiny is only moderately delayed by the global economic crisis of the last two years. While the baggage of occidental value judgements lends a certain scepticism to the quality of architecture and the urban environment which such rapid development produces, it's there and it's real - a mix of the incredibly good and incredibly bad.
Jeremy Melvin is a writer and teacher