Mike Davis: More than half the human race now lives in cities. Mostly in the squalor of slums and squatter cities.
Kevin Kelly: The city is a wonderful technological invention which concentrates the flow of energy and minds into computer chip-like density. In a relatively small footprint it generates a maximum of ideas and inventions. Slums are the skin of the city, its permeable edge that can balloon as it grows. Discomfort is an investment. In the favelas of Rio, the first generation of squatters had a literacy rate of only 5%, but their kids were 97% literate.