What does it mean to say that the Apostle Peter-and each of his successors-is kepha, the rock on which Christ has built His Church? Could this rock ever be allowed to crumble, without the Church herself crumbling? Can a successor of Peter fail in his office, or even in his faith, without negating the Church's indefectibility? What are the nature-and limits-of the pope's infallibility and primacy? Has the role of the supreme pontiff sometimes been exaggerated or distorted? Today questions like these are asked with greater urgency than ever, owing to the pontificate of Pope Francis. In Super Hanc Petram, Fr Lanzetta answers them with balance, realism, and confidence in Divine Providence. Lanzetta investigates Pope Francis's sources, leitmotifs, methods, and goals, examining the return of nominalism and pragmatism, the elevation of pastoral care over doctrine, the proclamation of a mercy that severs charity from truth, the substitution of "a people on the move" for "the mystical body" and of a panreligious humanistic fraternity for the salvific Christian mission, the inversion of hierarchy by synodality, the selective use of Vatican II as an impetus for "paradigm shifts," an evolutionary vision of doctrinal development driven by sociological-cultural theories, and the supplanting of eschatology by ecology. Pastors, theologians, laity, converts, non-Catholics interested in the Church and her relationship with modernity-all will find Fr Lanzetta's study valuable for the light it sheds on the age-old office of the papacy and on the tempestuous reign of its most recent incumbent.