Today would have been the late urban activist and writer Jane Jacobs' 100th birthday, and the concepts she introduced into the public lexicon are no less relevant in New York City than they were before she decamped from her beloved Greenwich Village to Toronto in 1968.
Jacobs' seminal book, "The Death and Life of Great American Cities," has shaped conversations about development and gentrification in the Big Apple since its publication in 1961.
That text rested on her own observations of and experiences in New York and advocated for the inclusion of local expertise in city planning.
Below are the key concepts and expressions in Jacob's book, brought to light with the help of Peter Laurence, author of a new biography called "Becoming Jane Jacobs."
In "The Death and Life of Great American Cities," Jacobs compares the innate order of cities, forever in flux, to "an intricate ballet in which the individual dancers and ensembles all have distinctive parts which miraculously reinforce each other and compose an orderly whole."
Jacobs described her own Greenwich Village block on Hudson Street as "the scene of an intricate sidewalk ballet," in which her part first thing every morning was putting out her garbage can.
But contrary to the "myth that Jane Jacobs was this housewife who sat on the stoop on Hudson Street and just watched the city go by," as Laurence put it, the writer actually spent most days working at the Time-Life building in Rockefeller Center.
Eyes on the street
In Jacobs' opinion, a thriving city was one where residents felt safe in public spaces among strangers.
And for that to happen, "there must be eyes upon the street, eyes belonging to those we might call the natural proprietors of the street," she wrote in her 1961 masterwork.
The more "eyes upon the street," the more witnesses and deterrents to crime.
"It’s a decentralized form of surveillance," Laurence explained. "We need policing in some fashion. If you have eyes on the street, you need less state-sponsored policing.”
One way to keep "eyes on the street," Jacobs maintained, was to construct and preserve mixed-use buildings, which juxtapose public space, like sidewalks and ground-floor retail, and private apartments.
By comparison, "housing projects led to built-in unsafety," Laurence said, because its residents were working during the day and there were no "eyes on the street" to monitor the passageways between buildings.
Jacobs' idea of "mixed-use" development was a paradigm shift away from ideas commonly held by urban planners in the first half of the 20th century, who would put a business district in one part of the city and all the residences in another, Laurence said.
In Jacobs' model, urban residents would work, shop and play all within the same block.
"In our American cities, we need all kinds of diversity, intricately mingled in mutual support," Jacobs wrote in "Death and Life." For the urban activist, mixed-use development was only one kind of diversity.
Jacobs was also thinking of social, racial and income diversity, Laurence said.
"These are rather overlooked parts of her work, because she's writing before the Civil Rights Act and at a time where housing is still segregated" by income brackets.
Jacobs maintained that neighborhoods accrued more "social capital" the longer its residents lived there. If neighborhoods were to govern themselves, they needed to be familiar with locals' habits to know what was normal behavior and what was suspicious.
Though she often gets credit for coining the phrase "social capital," Laurence said she simply popularized it.
Jacobs called for most city blocks to be short because they were pedestrian-friendly. She opposed urban planning trends that accommodated cars, which were already clogging the streets of New York City by the 1940s and advancing suburban sprawl across the country.
Jacobs supported the preservation of old buildings, including those that were "low-value" and "rundown," because she argued that new construction hiked up rental prices, warding off businesses and nonprofits with limited budgets.
"If a city area has only new buildings, the enterprises that can exist there are automatically limited to those that can support the high costs of new construction," she wrote. "New ideas," tested out with low overhead costs, "must use old buildings."
When Jacobs called for high concentration, or density, of people to support the economic growth, prosperity and vitality of cities she was also referring to the concentration of activities and ideas.
She believed that a city was, according to Laurence, a "highly packed, concentrated form of the exchange of ideas."
The 24-hour city
New Yorkers may be used to calling 311 with their complaints about noisy nightlife, but Jacobs believed that it was good to have a bar on your block, because it meant there were "eyes on the street" in the evening.
Her own block was home to the White Horse Tavern, which continues to serve patrons to this day.