I have often been the victim of SWOT analysis – away-days with colleagues where we are forced to reflect on Strengths and Weaknesses, Opportunities and Threats. It often leads to lots of self-congratulatory wishful thinking but occasionally unearths something more profound. As I prepared for a recent conference on non-Catholics in Rome after 1870 I found myself using a kind of SWOT analysis: France stood defeated and Germany was united; Rome had fallen, the Pope was a prisoner in the Vatican and had lost his temporal power. But he had also been declared infallible by the First Vatican Council.