In the present development of the ecumenical dialogue, if one looks backwards at the text, «Unitatis Redintegratio» of the Vatican II, must take into account the decisive new approaches in the Roman Catholic theology about ecclesiastical reformation, conversion, methodology and practical suggestions. There is not always a clear distinction between , «perfect» and «imperfect» unity. The law of the context can lead to different interpretations. However, after twenty years and according to the fifth document of the joint working group, there is a clear indication of a common growth in the understanding and in the implementations of the ecumenical movement (pp. 587-596).