A city is also made of the intentions, desires, gestures and acts that fill it with other movement and cover it with different rhythms. To observe it in its streets and obstacles, to unveil it where it opens and closes up, to act performatively on the city is, at the same time, to confirm and transform it, to traverse and probe it, to surpass and transcend it, to preserve and disturb it. It is to impart an instability to its stability, an ephemerality to its continuity, a departure to its permanence, a metamorphosis to its form. Performance art is a praxis: we transform ourselves by transforming, we become what we are and what we are not. This is what preoccupies Ana Pais, a theatre critic, professor and researcher, and the editor of Performance in the Public Sphere.