Henri Le Saux, OSB (1910-1973), known in India as Swami Abhishiktânanda, is a well known pioneer of the interreligious dialogue in the contemporary Catholic Roman Church. This work is an introductory investigation of the ecclesiastic and ecclesiastical foundations of this dialogue. It suggests that Abhishiktânanda s ecclesiology is well-founded not only in the monastic tradition, but also in the theological work of the Second Vatican Council.