Whoever would write about a modern pope labours under serious handicaps. The public utterances of the popes are veiled by a conventional language that most effectually muffles their personality. In the action of the Roman See upon the universal Church during the time they are its bishop, it is not by any means easy to disentangle the part of the pope and the part of the high official whose trained mind is the papal instrument. Convention, again, seals the mouths of those who could speak about the personal reactions of the pope whether to the personalities who cross his path or to the crises of his reign. And once the pope is dead interest shifts rapidly to his successor. In the reign of that successor, in the press of business and of actuality that absorbs the high officials of the Curia from the moment of the new pope’s election, there is little leisure left for the composition of memoirs by those who really knew the pope who has died. The portrait of a pope has thus to be built up from scanty materials indeed, and the most promising of these, from the biographical artist’s point of view, are only too often sadly lacking in authenticity. If Pius XI had been a letter writer as industrious as Queen Victoria, if he had kept a diary, and if there were any chance of these documents seeing the light, then we might, some one might, at some future day, be in a position really to analyse his personality in the best French manner, and set his greatness before the world with the skill of a Gainsborough or a Goya. As it is . . .