Abstract: The great obsession of the nineteenth century was, as we know, history: with its themes of development and of suspension, of crisis and cycle, themes of the ever-accumulating past, with its great preponderance of dead men and the menacing glaciation of the world. The nineteenth century found its essential mythological resources in the second principle of thermodynamics. The present epoch will perhaps be above all the epoch of space. We are in the epoch of simultaneity: we are in the epoch of juxtaposition, the epoch of the near and far, of the side-by-side, of the dispersed. We are at a moment, I believe, when our experience of the world is less that of a long life developing through time than that of a network that connects points and intersects with its own skein. One could perhaps say that certain ideological conflicts animating present-day polemics oppose the pious descendents of time and the determined inhabitants of space. Structuralism, or at least that which is grouped under this slightly too general name, is the effort to establish, between elements that could have been connected on a temporal axis, an ensemble of relations that makes them appear as juxtaposed, set off against one another, implicated by each otherthat makes them appear, in short, as a sort of configuration. Actually, structuralism does not entail a denial of time; it does involve a certain manner of dealing with what we call time and what we call history. Yet it is necessary to notice that the space which today appears to form the horizon of our concerns, our theory, our systems, is not an innovation; space itself has a history in Western experience and it i s not possible to disregard the fatal intersection of time with space. One could say, by way of retracing this history of space very roughiy, that in the Middle Ages there was a hierarchic ensemble of places: sacred places and profane places; protected places and open, exposed places; urban places and rural places (all these concern the real life of men). In cosmological theory, there were the supercelestial places, as opposed to the celestial, and the celestial place was in its turn opposed to the terrestrial place. There were places where things had been put because they had been violently displaced, and then on the contrary places where things found their natural ground and stability. It was this complete hierarchy, this opposition, this intersection of places that constituted what could very roughly be called medieval space: the space of emplacement.