Augustine of Hippo’s magnum opus The City of God is one of the greatest works of the Western intellectual tradition—so powerful, in fact, that one could argue all of Christian theology has been a series of footnotes to Augustine. Written during the transition from antiquity to the rise of Christianity, it is one of the key texts in defining our ethical framework into the 21st century. Yet even serious readers can be intimidated by a book that spans over 1,000 pages.