Born in England and raised in Ghana, Appiah is half English and half African. And perhaps because of this, he’s fascinated with the concept of identity, and the power it wields over people. But rather than wage identity politics, Appiah encourages us instead to be good global citizens, interested in and accepting of each other. In short, cosmopolitan. But also, at least a little bit “contaminated”… Appiah’s written a book on the subject: it’s called Cosmopolitanism: Ethics in a World of Strangers.