The September 11 attack on the World Trade Center in lower Manhattan is viewed as an assault on many things: U.S. foreign policy in the Middle East, freedom and democracy, an immoral way of life. Indeed, the attack becomes a kind of projective test for identifying concerns each of us may have already held. Not surprisingly then, architects, planners and other urbanists see it as an assault on the city. That is, as an assault physically on the recent forms it takes of tall buildings, open spaces, and dense networks of mass transit and socially and psychologically on experiential qualities that are intrinsic to urban life. This presentation will describe two of those qualities, openness and uncertainty, that this author and others hold dear. It will suggest how they have been both celebrated and threatened over the last decade or so, how we need to withstand the recent assault upon them, and the difficulties and the advantages of doing so.