Much of [Derrick] Bell’s scholarship rejected dry legal analysis in favor of allegorical stories. In books and law review articles, he presented parables about race relations, then debated their meaning with a fictional alter ego, a black professor named Geneva Crenshaw, who forced him to confront the truth about the persistence of racism in America.

One of his best-known parables is “The Space Traders,” which appeared in his 1992 book, “Faces at the Bottom of the Well: The Permanence of Racism.” In the story, as Mr. Bell later described it, creatures from another planet offer the United States “enough gold to retire the national debt, a magic chemical that will cleanse America’s polluted skies and waters, and a limitless source of safe energy to replace our dwindling reserves” in exchange for one thing: its black population, which would be sent to outer space. The white population accepts the offer by an overwhelming margin.