For some reason the YouTube algorithm has been sending me videos of my old lectures: a recent lecture at Penn on ornament, a 2002 Toronto ideacity talk on Palladio, a 2013 talk at McGill University on architecture,and a talk about the history of the chair at the New York School of Interior Design. In 2011 I gave a lecture at the National Building Museum in Washington, DC. The occasion was the publishing of Makeshift Metropolis, a book about the ideas—good and bad—that have influenced the planning of our cities over the twentieth century. The four big ideas I talked about were: the City Beautiful movement; the garden city; Le Corbusier’s Ville Radieuse; and Jane Jacob’s idea of the humanist city. My main thesis was that American cities are driven by demand rather than supply, that is, by what people want rather than what city planners and architects suggest. I still think that’s true.