Drawing upon his thirty years experience of teaching ecclesiology, the author tries to identify some developments and paradigm shifts he recognizes as having influenced theological reflection on the Church in Roman Catholic, Orthodox, Anglican, and Protestant contexts. He contrasts the present-day situation of Catholics to the isolationist doldrums that characterized the post-Modernist and pre-Vatican II eras. The impact of the Faith and Order Commission of the World Council of Churches was already notable when Catholics belatedly began to participate in ecumenical dialogue. Various advances in ecclesiology can be identified, especially the use of 'communion' ecclesiology. Negatively, the achievements of ecumenical exchanges are little known by the faithful and rarely cited by church leaders. Canonical regulations especially affecting eucharistic hospitality do not take into consideration the doctrinal consensuses that have emerged. A select bibliography is appended.