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.

New ideas must use old buildings

This is something everyone knows: A well-used city street is apt to be a safe street. A deserted city street is apt to be unsafe.

Today barbarism has taken over many city streets, or people fear it has, which comes to much the same thing in the end.

Whenever and wherever societies have flourished and prospered rather than stagnated and decayed, creative and workable cities have been at the core of the phenomenon. Decaying cities, declining economies, and mounting social troubles travel together. The combination is not coincidental.

All through organized history, if you wanted prosperity you had to have cities. Cities are places that attract new people with new ideas.

In wretched outcomes, the devil is in the details.