SUMMARY
If systems comprise interrelated parts that interact and mutually influence one another, then a city can be considered a system. This article argues that cities are complex adaptive systems comprising of numerous components and subsystems that through their interactions create novel behaviours including high levels of self organisation. This view of the city as system differs from the so-called systems view of planning which viewed cities as relatively simple systems that can be controlled. As complex adaptive systems cities are able to respond to their environments demonstrating emergent behaviour that is an attribute of the system as a whole. Examples of other complex adaptive systems provide lessons for city development such as the need for constant growth and change if stagnation and death are to be avoided. As too much control can stifle the growth of complexity, the emphasis should rather be creating the appropriate rules and enabling community involvement.