When we deal with cities we are dealing with life at its most complex and intense. Planners are guided by principles derived from the behaviour and appearance of suburbs, tuberculosis sanatoria, fairs and imaginary dream cities - from anything but cities themselves.

The notion - and I tell you this one even worries me that it extends into New Urbanism - the notion of the shopping center [as] a valid kind of downtown. That's taken over. It's very hard for architects of this generation even to think in terms of a downtown or a center that is owned by all different people, with different ideas.

Cities never flourish alone. They have to be trading with other cities. My new hypothesis shows why. But also in trading with each other they can't be in too different stages of development, and they can't copy one another.

The more successfully a city mingles everyday diversity of uses and users in its everyday streets, the more successfully, casually (and economically) its people thereby enliven and support well-located parks that can thus give back grace and delight to their neighborhoods instead of vacuity.

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.

The notion that you could discard the old world and now make a new one. This is what was so bad about Modernism.

To science, not even the bark of a tree or a drop of pond water is dull or a handful of dirt banal. They all arouse awe and wonder.