The specific and novel aspect of this two-volume foundational work compared to other introductions to ecumenism lies in its practice-oriented conception. The contributions in the volumes are authored by a multilateral team of ecumenical theologians with experience and focus in religious education and didactics. The first volume offers fundamental contributions to central ecumenical questions in 15 chapters. The range of topics includes the presentation of historical developments and denominational information, the discussion of classical controversial issues (sacraments, understanding of the church and ministry, ethics), and the practical fields of the conciliar process, confessional cooperative religious education, and local ecumenical work. Since Volume 1 is self-contained, it is suitable for both self-study and...