Biological metaphors for the city abound in daily use. You may live close to an “arterial” road or in the “heart” of a metropolis. You may work in one of the city’s “nerve centres” or exercise in a park described as the city’s “lungs”.
The ready use of such metaphors indicates an underlying naturalism in our thinking about the city. Naturalism is a belief that a single theory unites natural and social systems.
