Joseph Capizzi, an expert on Saint Augustine, delves into Augustine's concept of the two cities - earthly and city of God. The discussion covers themes of love, moral communities, church and secular world intertwining, societal justice, legitimate kingdoms, and more. They also explore philosophical perspectives on judgment, ignorance, necessity, societal issues like politics, justice, and ethical considerations around war and torture. The conversation contrasts sacrifices made by Romans for earthly glory with those required for the kingdom, and explores the relationship between faith, suffering, virtue, love, and citizenship within a historical context.