ABSTRACT
The cities always served human societies. They are part of infrastructures and tools we make to confront the challenges of nature and to manage living within societies. However, in contrast to well-designed tools and machines, cities are collective ‘tools’, whose many features simply emerge rather than being carefully planned. City economies, ecologies, agglomeration characteristics, and innovative capabilities, for instance, can be classed among their emerging features; properties that arise from multiple combinations and innumerable individual choices and practices of the city’s population rather than being a result of central control and design.
