[In the following review, Galvin criticizes Küng's Christianity for “the thin description of the essence of Christianity, the general aversion to high Christology (even in John) and to trinitarian theology, the reticence in speaking of soteriology, and the frequent glossing over of complex issues through rhetorical questions and appeal to simplistic alternatives [which] prevent the work from achieving its objective of fostering deeper understanding of the Christian faith.”]

This massive volume[, Christianity,] is but the second of a planned trilogy. Preceded by Judaism and soon to be followed by Islam, it is part of a grand project, supported by the Bosch Jubilee Foundation and the Daimler-Benz Fund, for promoting world peace by fostering peace among religions through an interreligious dialogue rooted in investigation of each religion's foundation. Yet even the trilogy will not complete the project, for Küng reserves for a future work a treatment of the Church in non-European areas and a full presentation of his proposals for Christianity's future. Accordingly, apart from a systematically important but brief account of the essence of Christianity, the present volume is largely devoted to an analysis of Christianity's history.

K[üng]'s basic thesis is relatively simple. Freely adapting Thomas Kuhn's conception of paradigm shifts to the exigencies of his historical material, he argues that Christianity's essence, which can never exist in pure form, has been embodied over the course of Christian history in five distinct paradigms, each of which originated in a particular historical-cultural context, and most of which have survived to the present, despite having been superseded in later situations by a new paradigm. Since the specifics of a given paradigm do not pertain to the essence of Christianity, such elements ought not to be sources of division among Christians or of conflict with other monotheistic religions.

As K[üng] understands it, the essence of Christianity lies in its concentration on the person of Jesus Christ, crucified but raised to eternal life with God. Though always in danger of compromising monotheism, obscuring openness to the activity of God's Spirit outside the Church, and degenerating into sterile preoccupation with dogmatic formulas, concrete and practical orientation on Christ constitutes Christianity's specific identity amid the vicissitudes of its history.

The bulk of the book presents the five paradigms which K[üng] detects in the history of Christianity. K[üng] does not seek to be exhaustive, but to locate the emergence of each paradigm, provide information about its major exponents, and diagnose its chief strengths and weaknesses. This approach allows him to range widely and yet be selective in choosing historical topics for examination.

At the origin, closest in time and apparently also in spirit to Jesus, stands the apocalyptic paradigm of early Jewish Christianity, which combined faith in Jesus as the Messiah with continued observance of Mosaic ritual law. Enmeshed in conflict with other tendencies within Christianity even in the New Testament period, Jewish Christianity survived the destruction of Jerusalem but receded from clear historical view in the centuries which followed. The only paradigm unable to maintain its existence to the present, it nonetheless offers resources for interreligious dialogue with Jews and Muslims because of its uncompromising fidelity to monotheism.

The rival and immediate successor to Jewish Christianity, the ecumenical Hellenistic paradigm of Christian antiquity, also originates in the New Testament period. Inaugurated by Paul, it reaches its theological heights in Origen and continues to exist to this day in the Christian East. Responsible for developing a fixed rule of faith, a New Testament canon, and a monarchical episcopate, it tends to shift emphasis from concrete orientation on Christ to speculative theological questions and is inclined to identify its embodiment of Christianity with the essence of the faith.

Even greater problems in this regard are detected in the third paradigm, that of medieval Roman Catholicism. Developing theologically from Augustine through its peak in Aquinas to contemporary Roman theology, and marked from Leo I through the Gregorian Reform to Vatican I by increasing claims on behalf of the papacy, this form of Christianity has also lasted to the present, though not without compromise of the basic message of the gospel. The fourth paradigm, that of the Reformation, is discussed with particular focus on Luther; while presented in more sympathetic terms as a long-overdue prophetic reform of Western Christianity based on the priority of the Word of God, it is also criticized for tendencies toward fragmentation into a variety of churches and for periodic reliance on civil authorities.

The final paradigm is that of modernity, originating in the 17th century but fully developed only in later political, philosophical, economic and cultural revolutions. Exemplified theologically by Schleiermacher, this paradigm represents a needed rethinking of Christianity in a new age, but is often weakened by excessive stress on reason, uncritical belief in progress and ominous tendencies toward nationalism. The need thus arises for a sixth paradigm, of a contemporary ecumenical nature, which K[üng] finds foreshadowed by Pope John XXIII and Vatican II but thwarted by subsequent reactionary developments within Catholicism. Sketching the outline of that paradigm—likely, one suspects, to hark back to Jewish Christianity with its relatively low Christology and undeveloped ecclesial structures—is a task for a future volume.

Written in an irenic spirit, K[üng]'s book is intended for a wider public, and persevering readers will enhance their knowledge of church history. In view of the wide range of the work, K[üng]'s reliance on secondary literature and on his earlier publications is inevitable. But the thin description of the essence of Christianity, the general aversion to high Christology (even in John) and to trinitarian theology, the reticence in speaking of soteriology, and the frequent glossing over of complex issues through rhetorical questions and appeal to simplistic alternatives prevent the work from achieving its objective of fostering deeper understanding of the Christian faith. The tone of the book is lowered by its carping at anything associated with Pope John Paul II. That there is more to the essence of Christianity than is claimed here undoubtedly complicates Christian dialogue with Judaism and Islam, but an interreligious consensus in which at least one party is unable to recognize its own faith would be of very limited value.