Adam Smith and Karl Marx recognized that the best way to understand the economy is to study the most advanced practice of production. Today that practice is no longer conventional manufacturing: it is the radically innovative vanguard known as the knowledge economy.

"Specialise!" is the advice often given by career advisers, school teachers and the like. David Epstein takes the opposite position: In an ever more specialised, highly complex world, it pays to have good old-fashioned broad common knowledge in as many areas as you take interest in, both in terms of intellectual curiosity and professional success. To have a decent grasp of various aspects of life means to be able to discern the links between them, thus developing a better understanding of how our world works and what drives events as they unfold.