There was a Pope Leo who saved Rome from Attila the Hun. And a Pope Leo who worked miracles and toured Europe fighting corruption. But presumably neither of them was uppermost in the thoughts of the mild-mannered administrator Robert Prevost, who has just become the 267th Pope, when he chose the name Leo XIV. It seems likelier that he was identifying himself with the last Leo: the thirteenth, who reigned from 1878 to 1903, about whom almost nobody has a bad word to say, and whose most celebrated act was the earth-shaking encyclical Rerum Novarum.
Rerum Novarum decisively condemned two then-dominant schools of thought—class-warfare socialism and laissez-faire capitalism—and at the same time laid out a humane, reasonable alternative. It is, even today, a thrilling read.