What's the fate of the American Empire? Is the country in decline and destined to fall? And if so, to what extent is America mirroring the story of the Roman Empire? This week I caught up with Vanity Fair editor-at-large, Cullen Murphy, who has written extensively about the subject. The similarities are shocking — but the story is more complicated than that. Murphy presented at the 2013 IdeaFestival in Louisville.Coming up in the next episode: Can you be happy but hate positive thinking?