When distance and convenience sets in; the small, the various and the personal wither away.

What is more dramatic, even romantic, than the tumbled towers of lower Manhattan, rising suddenly to the clouds like a magic castle girdled by water? Its very touch of jumbled jaggedness, its towering-sided canyons, are its magnificence.

I have been dwelling upon downtowns. This is not because mixtures of primary uses are unneeded elsewhere in cities. On the contrary they are needed, and the success of mixtures downtown (on in the most intensive portions of cities, whatever they are called) is related to the mixture possible in other part of cities.

No neighbourhood or district, no matter how well established, prestigious or well heeled and no matter how intensely populated for one purpose, can flout the necessity for spreading people through time of day without frustrating its potential for generating diversity.