I enjoyed reading this book because I’ve only ever thought of emergence in terms of a mind emerging from neuronal connections in the brain. I have never considered cities to be emergent because I never saw anything crazy coming out of them. I couldn’t think of a complex system arising from a city. There didn’t seem to be anything smarter than the city components. The Manchester example was really interesting because it showed that a city could become very organized without someone planning it. Manchester’s useful organization just happened over time. What still sort of confuses me is that this great organized city didn’t just happen on its own; people were there to build it and interact with each other, which is what made the city was it is today, so how can one call a city emergent if, overall, people were responsible for its layout?
Being fascinated with the brain, I was disappointed that the book did not discuss the brain that much. I thought the mind was the ultimate example, but Johnson focused more on ants, cities, and computers. I guess maybe those topics are more accessible to the common person, and brain jargon might have lost a lot of interest. He did hint at free will near the end of the book, but it was more about free will in The Sims, which admittedly was interesting because I love The Sims; however, I was hoping for more insight into human free will, though I suppose you would need a book in itself to cover that topic.
I think that, with the cities idea, they may not have emerged totally on their own, of course; but, since humans created them, they emerge the same way that humans did, gradually growing more complex and expanding over time as humans did, less as an entity, more intertwined with the human race. Of course, a city that did NOT evolve with the people that live in it would be much harder to believe . . .