Steven Johnson
Emergence is the idea that independent agents following simple rules can, en masse, exhibit complex, seemingly directed behavior. The classic example of emergence is the ant colony.
Emergence is a fascinating concept. It not only explains parts of the natural world but can be applied to the development of man-made systems.
Unfortunately, once Steven Johnson gets past ants, his book degenerates into generalization. He talks about theories of brain function and city development while almost totally ignoring more concrete examples from the artificial life field. In the final chapters he finds emergence everywhere, and his heated superficial prose is reminiscent of the dot com hype of a few years ago: vague claims and little substance. Sadly, Johnson is no Steven Levy.