If Tim Keller is someone to read for political philosophy, what about urban design and planning? It turns out that much Christian reflection on the city is similar to Christian thought about government and society — it is pietistically utilitarian. The city or politics are ways to evangelize or carry out God’s will for me and others, not a common arena of human life that relies on the sorts of human inquiry that may involve both sides of the antithesis.

Here is one of Tim Keller’s typical briefs for the city:

social scientists tell us that across the whole planet there are at least 5 million people moving into cities from the countryside every month. The number of churches per capita in the country and towns dwarfs the number of churches in cities. People are moving to cities with fewer places of gospel witness for the population, and that situation is worsening by the day. For example, New York City will be gaining a net of 1 million people over the next 25 years. That’s bigger than Charlotte, North Carolina. Yet will we be planting as many new churches here as there are churches in Charlotte? Probably not.

So put the balance like this: we need churches everywhere there are people—but the people of the world are moving into cities much faster than the church is. Jesus told us to go into the world to make disciples (Matt 28:18–20). If we fail to go where the world is going, then we aren’t heeding our Lord’s command. Certainly we must never insist that everyone should do city ministry, nor that gospel ministry in one place is intrinsically better than in another, but we shouldn’t shrink from emphasizing city ministry as never before.

Don’t romanticize or demonize or shrug at the city. Love the city, as Christ loved you.

Treat cities like a mission field.

But if you are going to transform a city with a gospel ecosystem, you may need to read urban designers and planners. And if you read the history of the cities, you may encounter a less than onward-and-upward understanding of the city. Cue James Howard Kunstler:

The city is perhaps the greatest cultural artifact of the long-running human project, which now faces an array of predicaments at a larger scale than at any previous inflection point in our history. These include population overshoot, the fossil-fuel quandary, competition over dwindling resources, an unsound banking system, climate uncertainty, and much more. These dynamics are expressing themselves currently in political disorders and cultural hysterias, and the anxiety over what happens next appears to be driving us crazy. . . .

The urban metroplexes of the U.S. have assumed a scale and complexity of operation that cannot be sustained in the coming disposition of things. They will contract substantially. Some of them in especially unfavorable locales—Tucson, Miami, Houston—may disappear altogether, but the rest will have to become a lot smaller and the process is liable to be messy as various groups fight over who gets to inhabit the districts that retain value: for example, riverfronts and original urban cores. This will occur against the backdrop of more generalized political disorder and the failures of national government, especially where fiscal management is concerned. State governments, too, may be broke and impotent. (That implies a devolution of political power from the grand scale to the local level, where decisions and action will matter.)

Cities that are overburdened with skyscrapers and megastructures face an added degree of failure. These buildings will never be renovated in the coming era of resource and capital scarcity. Professional observers like Krieger’s colleague, Edward Glaeser of Harvard’s Kennedy School of Government (author of Triumph of the City, 2011), is exactly one of those who expects only more-bigger-higher-denser cities in the years ahead. That will be another disappointment for the wishful-thinking techno-narcissists of this land. More likely we will see skyscrapers and megastructures convert from being assets to liabilities in very short order. We may not even have the financial mojo to pay for their disassembly and the salvage of their modular materials.

The places in our country that stand a chance to carry on are the very places that have gone through the most catastrophic failure and disinvestment the past 50 years: the small towns and small cities that are scaled to the capital and resource realities of the future—especially the ones that have a meaningful relationship to food production. Many of these places lie along America’s inland waterway system (the Ohio, Mississippi, Missouri, Great Lakes, including the Hudson River estuary and the Erie and Champlain Canals). As the trucking system collapses, we will have to move more things by boat. The conventional futurists don’t even see this coming.

But you don’t read about this side of the city when you see descriptions of gospel ecosystems:

When a gospel movement is underway, it may be that the Body of Christ develops to the point that a whole city tipping point is reached. By that I mean the moment when the number of gospel-shaped Christians in a city reaches critical mass. The Christian influence on the civic and social life of the city—on the very culture—is recognizable and acknowledged. That means between 10 and 20 percent of the population.

. . . In New York City, some groups have a palpable effect on the way life is lived when their numbers reach at least 5 to 15 percent and when the members are active in public life. . . . In other words, something is going on in New York that goes beyond one church, one network, or any one denomination. It goes beyond any particular race or ethnic group. It’s a movement.

We’re a long way from getting to the place we need to be, a city tipping point, when 10 to 20 percent of the population goes to those churches, and you begin to realize that the whole city, the whole culture is going to change because of the impact of Christians in a place like New York.

That’s what we’re after. It takes a movement to reach a city, and that’s more than just planting a church, or even seeing your denomination growing.

Someone needs to ask, what will remain of the city when the movement arrives?