Profile: Listening to Money Talk

It isn't easy interviewing British historian Niall Ferguson. One very simple Q. can elicit 10 solid minutes of A. Ferguson gallops from an explanation of the differences between the economies of imperial Britain and nasdaq America to the corrupt fortune Prime Minister William Gladstone made from his investments in Egypt in the 19th century and on to Ferguson's own loathing of sport-utility vehicles. "The fact that family cars are becoming trucks," says the Calvinist-reared Scot, "is a grotesque expression of what the U.S. economy is doing."

Some clever, loquacious people are said to think in paragraphs, but Ferguson...