My Grandfather’s Son, the memoir of US Supreme Court justice Clarence Thomas, was published this week. It is the inspiring tale of Mr Thomas’s rise from a shack without indoor plumbing in segregated Georgia. It is also a look back in anger at the allegations of sexual harassment brought by Anita Hill in 1991 that nearly derailed his nomination. “There is nothing this committee, this body, or this country can do to give me my good name back,” he said at the time. He was right. His judicial achievements ever since remain under that cloud. Yet even if all Ms Hill’s allegations had been provably true, it would have been unclear what Mr Thomas was guilty of, aside from making a few ill-considered remarks.

Since then, the price of sexual-harassment litigation has mounted along with its reach. Similar allegations from Paula Jones nearly cost the country its elected president in 1999. Last week, in the biggest case involving sexual harassment since the Clinton impeachment, a jury found the Madison Square Garden corporation liable for $12m in a case against Isiah Thomas (no relation), the Hall-of-Fame basketball player and coach and president of the New York Knicks. The verdict, against which MSG plans to appeal, showed that the public understanding of sexual harassment is dangerously vague. What is it? Coercion? Linkage of advancement to sex? “Unwanted sexual advances”? Without clear guidelines, sexual harassment becomes a licence for freelance social engineering.