We live life forward but understand it backward, Soren Kierkegaard observed. For Hans Küng, professor of dogmatic and ecumenical theology at the University of Tübingen and theological thorn in the papacy's side, the observation may apply equally well to theology. In fact, it may help explain why Küng has been at odds with Rome for so long.

In the foreward to [Theology for the Third Millennium], Küng acknowledges that he has never approached theology by doing a detailed analysis of how theology ought to be done. Rather, he says, challenged by ever-changing human experience, he has dealt directly with the substance of theology, trusting that his work would prove itself by eliciting both Catholic and ecumenical consensus. It is hardly surprising then that his work has not won acceptance from the Vatican, which has long been attached to doing theology a priori—shunning experiment and downgrading contrary experience.

Looking back on his theological endeavors of the past 30 years and the opposition he has encountered, Küng concludes that there has been a paradigm change in theology, a change in the basic model of explanation—one that has certainly escaped the attention of Roman Catholicism's theological gatekeepers. The author attempts to sketch what that change has involved and to “help religion perform a new critical and liberating function of both the individual and society.”

Küng begins by trying to clear up a number of classical theological conflicts left over from the Enlightenment and Reformation: conflicts between theology and magisterium, Scripture and tradition, Scripture and the church, and scriptural exegesis and dogma. He concludes in each case that it is not a matter of accepting one or the other, or of assigning priority to one, but of recognizing that none of these sources of Christian understanding is unconditionally reliable. Only God, who spoke to believers through Jesus Christ, is worthy of unreserved trust. However, Küng gives Scripture primacy as the source and measure of faith and theology in the church. His emphasis, though hardly startling, still leaves unanswered questions of how Scripture is to be understood and what emphasis church authority, tradition and theology should be given in interpreting it.

Küng devotes the core of the book to defining and discussing the implications of the apparent paradigm change in theology. He borrows the term from science and uses the work of American physicist and historian of science Thomas S. Kuhn to explain how knowledge emerges, progresses and evolves. A paradigm, he says, is “an entire constellation of beliefs, values, techniques, and so on shared by members of a given community.” Just as Kuhn finds a connection between conceptual changes in science and the replacement of one paradigm, or model of interpretation, with another, so Küng finds a similar progress and transition of knowledge in theology. When a new paradigm arises in Christian theology, however, unlike in science, it cannot completely replace or suppress the old paradigm because Christian testimony, found in the gospel, is permanent. It is common to those who accept the old paradigm and to those who advance the new, and it calls both to judgment.

After tracing the paradigm changes in the history of Christian theology and the church, Küng sketches the characteristics of the postmodern paradigm that he believes has emerged as a guide for theological understanding. From it, he says, emerges a theology that offers a thoughtful account of faith; one that is free to profess and publish its reasonable convictions; one that honors methodological discipline and church supervision; and one that is oriented toward understanding not only other Christian theologies but other cultures, religions, ideologies and sciences. Indeed, for Küng, the world of experience provides the horizon against which contemporary theology must be done. Doing theology is no longer a matter of merely applying a timeless doctrine but of translating a historical message “from the world of past experience into our present-day world of experience.”

Theology for the Third Millennium is not a book for the casual reader. Küng is not a prose stylist; his complex treatment of the subject demands careful reading and rereading. This task is made more difficult by the way most of the chapters seem to have been forged out of pieces that have appeared elsewhere. And the book is riddled with more typographical errors and copy-editing oversights than one would expect from Doubleday. Nonetheless, diligent readers will be rewarded for their efforts. In seeking to understand his own theology in retrospect, Küng also sheds light on the work of many of his colleagues, both those who agree with him and those who do not.