16.

 What does the author of the textbook mean by saying that these Councils fulfilled a double task?

            The textbook introduces the discussion of the Ecumenical Councils with the popular — though erroneous — idea that these Councils “defined once and for all the Church's teaching upon the fundamental teachings of the Christian faith” (emphasis added). Actually, as Protopresbyter Georges Vasilievich Florovsky explains, the Ecumenical Councils defended what the Church has always known to be the truth [Bible, Church, Tradition: an Eastern Orthodox View, vol. 1 of The Collected Works of Georges Florovsky, pp. 96-97].

            In addition, the Councils worked out the Church's visible organization. The local Churches were placed under the jurisdiction of ecclesiastical provinces, and the position of the five Patriarchates was defined.