In his Tradition and Authenticity in the Search for Ecumenic Wisdom, Thomas Langan argued that the close interaction of traditions in today's society calls for methodical critical appropriation of the beliefs fostered by the principal traditions. He also promised to demonstrate by example how such appropriation could be accomplished. In The Catholic Tradition, Langan successfully fulfills that vow by showing how a tradition—the Catholic—has shaped his own outlook.

In this comprehensive study, Langan examines the history of the Catholic Church and the origins of its teachings since the Church's conception. Although committed to the Catholic religion, Langan does not obscure the Church's failings as he lays out the fundamentals of the Catholic faith.

He provides insight into the great Christological councils, discusses the differences in the spiritualities of East and West, and portrays the crucial roles that the pope and bishops played during the Middle Ages. He incorporates the thought of Augustine, Aquinas, and medieval Catholicism as he traces the rise and decline of Christian Europe, the great issues raised by the reform: priesthood, the Eucharist, spirituality, and Church structure.

Satan has no greater triumph, Langan asserts, than when Catholics, who are recipients of the Good News of God's universal love, allow selections from their tradition to be turned into sectarianism and ideology. This balanced history of the Church as human reality faces such perversions squarely. But despite betrayals by its own across the centuries, the Catholic tradition, with its origin at Sinai, remains the oldest and largest extant religious institution.

In a last section Langan offers a unique overview of the church's present situation, its strengths and weaknesses, the new movement and the challenge of the "new evangelization."