A traffic screen sees a bottleneck; a care home sits on the corner. With Weaver, Jacobs, a Japanese traffic experiment, the streets of Datça and Ashby's law: is a city a machine to tune, or an order to tend?

Louis Wirth's four words — large, dense, permanent, heterogeneous — tested at Çatalhöyük, Göbekli Tepe and Uruk: is a city its stone, or a pattern of strangers who depend on one another?