“What would it be like if…?” The subjunctive question of possibility pushes the imagination sometimes to the point of daydreams. Reading Kasper’s book could well push the imagination to wonder “What would it be like if he had been elected pope?” For people who feel a certain chill in ecumenical relations the daydream would offer the promise of spring.

That They May All Be One offers a collection of essays on ecumenical topics presented by Walter Kasper at conferences over several years. The topics suggest a clear pattern of organization exploring the current status of ecumenical dialogue and offering perspectives for future development.

Kasper highlights the need for a dialogue on ecclesiology. Different theologies of church presently complicate ecumenical understanding and prove to be a stumbling block for greater unity. Casting Ratzinger’s Dominus Jesus in the best light possible, he recognizes that precisely because of differing ecclesiologies the document becomes particularly offensive to some Christians (15-16).

Fully appreciating the ecumenical stance of the Second Vatican Council and John Paul II, Kasper outlines the ecclesiology of communio and it’s real possibilities of greater ecumenical unity. The real tension, of course, exists in holding together a horizontal communion with a vertical communion of hierarchy. Noting that “Patience is the little sister of Christian hope” the author writes of our living in an interim time and suggests several practical steps that ought to be taken in the current situation. Such steps include ecumenical exchanges with other communities as well as the ecumenical work of internal reform within the Roman Church.

In identifying significant problems in present ecumenical efforts – the Petrine ministry, the “filioque” question, and the further understanding of justification – Kasper emphasizes the need first to locate the theological issues in their own time. What questions were the theologians of that time seeking to answer? Then, as he insists, we need to translate the answers into the questions and language of our time.

Exploring the Petrine ministry as articulated by the First Vatican Council, the author proposes four hermeneutical principles: Integration within the whole context of ecclesiology; integration within the whole tradition; historical interpretation; and, interpretation according to the Gospel (141-149). Here, again, one might be struck with a “What if… we applied this kind of thought?”

The importance of ecumenical dialogue gains greater urgency in light of contemporary pluralism in thought and culture. Kasper outlines this new situation for Christianity and suggests the avoidance of naïve optimism and prophecies of doom (191). Rather than succumbing to either extreme Kasper proposes authentic hope. While some chill may indeed be in the air the author continues to hope for he knows the ecumenical task rests not merely on human desire or achievement. The work arises and is sustained as the work of the Spirit. Recognizing that “there is no realistic alternative to ecumenism” (1) God’s Spirit calls us to a church in service of truth and love (187) and thus a church of deeper unity to which we are all called.