In this book, Karl Adam seeks to identify the "spirit" or essence of Roman Catholicism. He 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. Its thirteen illuminating chapters comprise one of the finest works of Catholic apologetics written in the last 100 years, and are must-reading for anyone wishing to more deeply appreciate and comprehend the riches of Catholicism.