The Rue Saint-Guillaume is a narrow street off the Boulevard Saint-Germain. If it does not seem quite fashionable then it is only because it is too central in Paris ever to go out of fashion. There are some interesting shop windows, and some stretches of the street are quiet. There are more people in the street than cars, and students are hanging around the entrance to Sciences Po, among them the politicians and political journalists of France’s future. For the time being they are waiting for a lecture to begin, for friends to show up, or passing the time of day with other students before they disperse. Next door, in a building that is much like any other, there is a large secured door or gate that opens, on the rare occasions when it does open, into a low space that gives into a courtyard surrounded by five-storey buildings. It feels more open than the street, and quieter. Across the cobbles there is the facade of the Maison de Verre: plate glass floor-to-ceiling on the ground floor, and above that the whole wall is an uninterrupted screen of glass blocks, a grid of compact squares. 1