Encyclical of Pope leo xiii, dated June 20, 1896, formulating the pope's teaching on the unity and unicity of the Church. The first lines express Leo's concern for the return to the "fold" of "sheep that have strayed," the fold being "under the guardianship of Jesus Christ, the chief Pastor of souls." The encyclical understands unity as the oneness of the Catholic Church with Jesus Christ, and therefore reunion as the return of all Christians to the Catholic Church.
The encyclical has no internal divisions, though paragraphs have been numbered by most translators (16 in Claudia Carlen, The Papal Encyclicals ). The text is easily divided into five parts, with an introduction and a conclusion: the visibility of the Church (3–5), the unity of the Church (6–7), the Magisterium (8–9), the divine society (10–12), the Roman Pontiff and the bishops (13–15). Parts one and two give a strongly Christocentric picture of the visible Church, which is based on the doctrines of the Incarnation and Redemption. The documentation is Scriptural, chiefly Pauline, and, more abundantly, patristic. Parts three and four explain the Catholic understanding of the patristic doctrine as it had developed through the Middle Ages and the Counter-Reformation, with a strong emphasis on the task and responsibility of the bishops and popes to teach the true doctrine and the corresponding duty of all believers to accept all the doctrines without exception. That the Church is thus constituted as a "divine society" was a popular notion in the ultramontane party in its arguments with Gallicanism before and after Vatican Council I. Part five draws the logical conclusions regarding the necessity and the divine authority of papal and episcopal government, though evidently without the nuances that were to be brought in by Vatican II with its emphasis on the collegiality of the episcopate. In n.15 Pope Leo teaches that bishops who "deliberately secede from Peter and his successors" thereby lose all jurisdiction, thus indirectly and presumably unintentionally throwing doubt on the ecclesiality of the Orthodox Churches. He goes on to assert that the pope's "power over the episcopal college" is "clearly set forth in Holy Writ." The conclusion is an appeal to all those who believe in Christ to "obey" the pope's "paternal charity."
The doctrine of Satis cognitum, commonly labelled "unionism," in contrast with the ecumenism of Vatican Council II, took no account of the theological insights of the school of Tübingen or of the thought of Cardinal John Henry Newman. Nonetheless, it inspired and encouraged devotion to the unity of the Church and the reunion of the Churches. Unionism began to be abandoned with the start of the ecumenical movement at the Missionary Conference of Edinburgh in 1910, by the formation of the World Council of Churches in 1948, and by the subsequent commitment of the Catholic Church to the restoration of Christian unity as explained in the conciliar decree Unitatis redintegratio of Vatican II, and in the encyclical Ut unum sint of John Paul II (May 25, 1995).
Bibliography: Latin text: Acta Sanctae Sedis 28, 708–739. English text: c. carlen, ed., The Papal Encyclicals 1878–1903 (Ann Arbor, Mich. 1990) 387–404.
[g. h. tavard]