“Being human is itself difficult, and therefore all kinds of settlements (except dream cities) have problems. Big cities have difficulties in abundance, because they have people in abundance. But vital cities are not helpless to combat even the most difficult of problems. They are not passive victims of circumstance, any more than they are the malignant opposite of nature.
“Vital cities have marvelous innate abilities for understanding, communicating, contriving and inventing what is required to combat their difficulties. Perhaps the most striking example of this ability is the effect that big cities have had on disease. Cities were once the most helpless and devastated victims of disease, but they became great disease conquerors. All the apparatus of surgery, hygiene, microbiology, chemistry, telecommunications, public health measures, teaching and research hospitals, ambulances and the like, which people not only in cities but also outside them depend on for the unending war against premature mortality, are fundamentally products of big cities and would be inconceivable without big cities. The surplus wealth, the productivity, the close-grained juxtaposition of talents that permit society to support advances such as these are themselves prodcuts of our organization into cities, and especially into big and dense cities.”
–Jane Jacobs, The Death and Life of Great American Cities