The spirit of the modern world has spawned two monstrous entities: the insular, autonomous Individual, and the all-grasping State, with its attendant institutions of education, the media, and the corporation. All attempts at solidarity, at community, must navigate their all-encompassing claims. The spirit of Catholicism is an altogether different spirit, as Karl Adam so brilliantly demonstrates in the republication of the eponymous work in which he seeks to identify the essence of Roman Catholicism. Adam gives particular weight to the doctrine of the Mystical Body of Christ, which he considers crucial to the problems of the present age, when mankind is desperately seeking a principle of unity and authentic community. There is a place these divinely established bonds can be found—the Church—and this locus of mankind’s spiritual unity sheds light on all of Catholic belief and practice: the Papacy, the communion of Saints, the Church Militant, Suffering, and Triumphant, the means of salvation, the necessity of the sacraments, the universality and authority of the Church, and much else. The Spirit of Catholicism is an accessible, articulate, and compelling presentation of the fundamental tenets of the Catholic faith, explaining to all—Catholic and non-Catholic alike—exactly what the Church represents. These thirteen illuminating chapters comprise one of the finest works of Catholic apologetics written in the last hundred years, and are must-reading for anyone wishing to more deeply appreciate and comprehend the riches of Catholicism.