A lot of modern life depends on forms of care that do not require intimacy.

Contracts, insurance, markets, public goods, due process, and standardized rules extend cooperation beyond the boundaries of family, friendship, and tribe.

That is the subject of Stranger Ethics.

General rules get harder when they cost insiders

• Does a neighborhood get to exclude newcomers in the name of community?

• Is mutual aid still admirable when help depends on being liked?

• When does preservation become incumbent privilege?

• Should sympathetic people get exceptions that unsympathetic people would not?

• Who bears the costs of labor standards, accessibility rules, family obligations, and bureaucratic discretion?

These are questions about what happens when rules meant to apply broadly collide with the interests of people already inside.

Cities are the obvious laboratory

Strangers share housing, transit, commerce, public space, infrastructure, risk, and government at enormous scale. Cities make visible both the institutions that let strangers cooperate and the pressures to reserve their benefits for insiders.

I live in New York City, and you might too. A question New Yorkers encounter every day is what we owe one another when we are not friends, family, or comrades.