Although I know that he didn’t think of himself this way, the writer Jonathan Schell, who taught courses at Yale on non-violence and nuclear arms through 2012 and who died Tuesday night, at 70, of cancer, in his home in Brooklyn, was a luminous, noble bearer of an American civic-republican tradition that is inherently cosmopolitan and embracing.

He strengthened that two-way bridge, between republican commitments and cosmopolitan openings, not because bridge-building was his project, but because he himself was that bridge.

From his work as a correspondent for The New Yorker in the Vietnam War through his rigorous manifesto for nuclear disarmament in “The Fate of the Earth,” his magisterial re-thinking of state power and people’s power in “The Unconquerable World: Power, Nonviolence, and the Will of the People,” and his wry, rigorous assessments of politics for The Nation, Jonathan showed how varied peoples’ democratic aspirations might lead them to address shared global challenges....