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 do not carry over to the artificial systems of human society. (Thus)…the…disbelief always expressed by (my) architecture students (about)…medieval cities as marvelously patterned systems that had mostly just “grown” in response to myriads of individual decisions. To my students a pattern implied a planner… The idea that a city could acquire its pattern as “naturally” as a snowflake was foreign to them.

Herbert Simon (1981). The Sciences of the Artificial, p 33