W. C. Sellar and R. J. Yeatman’s comic history of England, 1066 and All That, talks about nineteenth-century British Prime Minister W. E. Gladstone’s efforts to solve the Irish Question—the puzzle of what to do with rebellious Ireland, which was then part of the United Kingdom. According to Sellar and Yeatman, every time that Gladstone got close to an answer the Irish changed the question. Over the last couple of days, a new Irish question has stymied Brexit negotiations between the United Kingdom and the EU: how to deal with the border between the Republic of Ireland, which