“I’ve always had a reasonably optimistic view of where we’re going, and I’ve tended to look at the positive, in terms of progress that we’re making,” he says. “Globally, the world’s in a much better situation than it’s been in past periods, despite the headlines on the war in Syria and other places where bad things are happening. There have been fewer people killed in wars, or genocides, or other forms of violence in the last decade or two than there have been in any other decade. We ought to take consolation in that.”