The Invisible Hand: Unplanned Order
We have become accustomed to the idea that a natural system like the human body or an ecosystem regulates itself. To explain the regulation, we look for feedback loops rather than a central planning and directing body. But somehow our intuitions about self-regulation without central direction do not carry over to the artificial systems of human society. I retain vivid memories of the astonishment and disbelief always expressed by the architecture students to whom I taught urban land economics many years ago when I pointed to medieval cities as marvellously patterned systems that had mostly just “grown” in response to myriads of individual decisions. To my students a pattern implied a planner in whose mind it had been conceived and by whose fiat it had been implemented. The idea that a city could acquire its pattern as “naturally” as a snowflake was foreign to them. They reacted to it as many Christian fundamentalists responded to Darwin: no design without a Designer!
Herbert A. Simon, Economic Rationality: Adaptive Artifice