Paris has always sought and known how to shape its present to envisage the future. Its forward path is clearly outlined, and even if things proceed in stops and starts, the city remains generously open in its search for ways to combine its densely stratified past with new and complex horizons. In this time of transition, the Grand Paris project has cast everything into question, opening everything up to debate and reflection. Yet the city remains the central focus of ideas on the future. The fact that Paris achieves this feat of constant metamorphosis at different scales, in different ways and across many different districts is, we think, highly significant. It is a city able both to adopt a topical approach in the manner of acupuncture, or to conduct major surgery on wide, once vital urban swathes that changes in society, production and the city’s role have side-lined.