Cities, complexity and beyond

Two notions form the title of this handbook – cities and complexity. The first, cities, refers to a form of settlement and way of life that emerged some 5500 years ago and since then has proved to be among the most stable institutions created by humans. Cultures, empires, states and political regimes rose and fell while cities adapted to all transformations and continued to exist. The twenty-first century is to a large extent the Age of Cities: cities have become the most dominant form of human settlement and way of life as more than half the world’s population live in cities. The study of cities can be traced back to antiquity, for example, to first-century bc Vitruvius and his ten books on architecture – De architectura. However, a starting point of the modern study and science of cities can be seen in Johann Heinrich von Thünen’s (1826 [1966]) The Isolated State that opens with ‘Imagine a very large town at the centre of a fertile plain’. Similarly to cities, notions of complexity can be traced back to antiquity, to ancient philosophy – ‘no man ever steps in the same river twice, for it’s not the same river and he’s not the same man’, wrote sixth-century bc philosopher Heraclitus of Ephesus and with this sentence preceded a basic property of complexity – ‘far from equilibrium’, namely, that complex systems are always changing, never at rest. However, the complexity we are dealing with here is much younger, referring to a set of theories that started to appear in the 1960s in order to study open and complex systems that exhibit phenomena of selforganization, chaos, and so on. With the exception of Humberto Maturana’s Autopoiesis theory (Maturana and Varela 1973), these founding complexity theories were first developed in the material sciences (physics, chemistry, and so on) closely linked to thermodynamics: Prigogine’s dissipative structures (Prigogine and Stengers 1985) which started from the notion of entropy with close association to fluid dynamics (for example, Bénard’s convection), Haken’s (1983) synergetics that commenced from the phenomenon of light amplification by stimulated emission of radiation (LASER), chaos theory of Lorenz (1972) and Feigenbaum (1983), Mandelbrot (1983) who expanded the Cantor (1883) set from the nineteenth century into the fractal theory of today, and more. For further details see Chapter 2 in this volume. In association with the appearance of the above founding complexity theories a link was made with the study of cities. First as a metaphor to convey the distinction between a complex system that is open to its environment and a classical material system that is closed to it. ‘The classical formulation [of entropy] due to Clausius refers to isolated systems exchanging neither energy nor matter with the outside world’, said Nobel Laureate Prigogine (1977) in his Nobel lecture; and then he asked and answered: ‘Are most types of “organizations” around us of this nature? ’, [that is, characterized by thermodynamic equilibrium? ]. ‘[T]he answer is negative. Obviously in a town, in a living system, we have a quite different type of functional order. ’ This link to ‘a town’ did not come out of the