The entrepreneurial investors of the time just want to repeat themselves indefinitely and don't know when to stop. You can't do that. And so finally the housing boom, or the auto boom, or whatever it is that's been carrying things along, runs out of customers.

Cities need old buildings so badly it is probably impossible for vigorous streets and districts to grow without them.... for really new ideas of any kind--no matter how ultimately profitable or otherwise successful some of them might prove to be--there is no leeway for such chancy trial, error and experimentation in the high-overhead economy of new construction. Old ideas can sometimes use new buildings. New ideas must use old buildings.

Traffic congestion is caused by vehicles, not by people in themselves.

Backward cities, or younger cities, or newly forming cities in supply regions, have to develop to a great extent on one another's shoulders. This is one of the terrible things about empires.

Neighborhoods built up all at once change little physically over the years as a rule...[Residents] regret that the neighborhood has changed. Yet the fact is, physically it has changed remarkably little. People's feelings about it, rather, have changed. The neighborhood shows a strange inability to update itself, enliven itself, repair itself, or to be sought after, out of choice, by a new generation. It is dead. Actually it was dead from birth, but nobody noticed this much until the corpse began to smell.

The trouble with paternalists is that they want to make impossibly profound changes, and they choose impossibly superficial means for doing so.

As in the pseudoscience of bloodletting, just so in the pseudoscience of city rebuilding and planning, years of learning and a plethora of subtle and complicated dogma have arisen on a foundation of nonsense.