What is a nation? A familiar and a strange idea, I know what it is until someone asks me. “A nation is the same people living in the same place” says Leopold Bloom in James Joyce’s Ulysses, “or also living in different places”. Joyce himself left Ireland for good in 1912 when Dublin was still in the United Kingdom and he never took Irish citizenship. Does that make him really a British – rather than an Irish – writer? The idea is provocative, but then ideas of nation often are. When De Gaulle declared himself to have “a certain idea of France” he implied that his idea of France had a unique grandeur to it, tacitly recognizing that there was no single idea France whilst asserting that his was the best. Just as no nation thinks of itself in the same way as its neighbours (although all correctly think they are exceptional), so no two citizens of any country think identically about it. There are as many ideas of France as there are people who think about France, and as many Englands as the...