To Marshall Berman, the long platforms and barrel-vaulted ceilings of the Washington, D.C., subway system feel like a “theater of absurdity and cruelty.” The professor of political theory and urbanism ...

Imagine you are inside a cave, chained with others and facing a blank wall. All you can see are shadows cast against the wall from the light outside. Plato tells this story in “The Republic”: “Imagine ...