This book surveys the historical and theological foundations of the ecumenical movement and the role of dialogue in the churches' commitment to manifest their unity in a full and visible way. Angelo Maffeis takes these foundations as they emerge in multilateral and bilateral settings of interchurch encounter. Special attention is given to conciliar ecumenism and to the dialogues to which the Roman Catholic Church is partner. Delineating the nature of dialogue and shaping its structure, Maffeis considers the conditions for authentic dialogue and an ecumenical theology that sustains the reception of ecumenical findings. This book includes a bibliography of select sources pertinent to the ecumenical movement in general and ecumenical dialogue in particular.