GIVEN THE attention devoted to Pope Pius XII and Naziism in recent years, it is salutary to be reminded that his predecessor Pius XI grappled with much the same kind of challenges and dilemmas. Indeed he did so from the very start of his reign in 1922, since Mussolini came to power just eight months after Achille Ratti, former nuncio to Poland and Archbishop of Milan, was elected as the successor to Benedict XV.Pius XI could thus have hardly had a less auspicious start to his reign. He does not get much sympathy however from David Kertzer, professor of social science and Italian at Brown University, Rhode Island, who has drawn on both Italian and Vatican sources (including the Pius XI archives opened in 2006) to tell the story of two men who both had “explosive tempers” and de