In the early 1980s, two Catholic theologians—Karl Rahner and Heinrich Fries—offered a proposal of their own for the unity of the church. It provoked widespread discussion after its publication under the title Unity of the Church: An Actual Possibility. Eight theses lay out the conditions for church unity. They are (briefly summarized):
Thesis one states that the basic truths of Christianity as expressed in the Holy Scriptures and the Apostles’ and Nicene-Constantinopolitan Creed are to be binding for any future one church.
Thesis two states that no confessional statement that is binding for any one church is to be explicitly rejected by the others, nor is any confessional statement of any one church to be imposed on the others. This applies especially to Roman Catholic teaching that has not achieved dogmatic status and ethical questions as well.
Thesis three states that churches can maintain their same structures and overlap in territory as they have previously.
Thesis four states, in two parts, that a) all participating churches recognize the sense and right of the petrine ministry of the Roman pope as the concrete guarantee of the unity of the church in truth and love, and b) the pope on his side commits expressly to recognize and respect the independence of the participating churches. He will make use of his teaching authority in a way that is equivalent to a common council of the whole church.
Thesis five states that all participating churches will have bishops as the head of the various jurisdictions.
Thesis six states that the participating churches will exist in a mutual brotherly exchange in all their dimesions of church life.
Thesis seven states that, without any prejudice about the legitimacy of the ministerial offices that have existed in the divided church up till the present, from now on all ordinations will take place with prayer and the laying-on of hands in such a way that their recognition presents no difficulty for the Roman Catholic church.
Thesis eight states that between the individual participating churches there will be pulpit-and-altar fellowship.