During his pontificate and the years of influence that preceded it, Benedict XVI was often stereotyped as an arch-traditionalist, but his next-to-unprecedented decision to abdicate the papal throne may be one of the most striking concessions to modernity a recent pope has made. His statement of resignation basically acknowledges as much, citing the realities of “today’s world, subject to so many rapid changes and shaken by questions of deep relevance for the life of faith” as a particular reason why greater “strength of mind and body” than he now possesses is required of the successor to Saint Peter. These lines are an implicit nod not only to the particular challenges facing his pontificate, but also to the vast changes that mass media and global travel have...