The " false writings " referred to in the text include also the Pseudo-Isidorian Decretals, together with other forgeries. The Pseudo-Isidorian Decretals are certain fictitious letters ascribed to early popes from Clement( A. D. 100) to Gregory the Great( A. D. 600), incorporated in a ninth century collection purporting to have been made by " Isidore Mercator." The name " Pseudo-Isidorian Decretals " has been in use since the advent of criticism in the fifteenth century.
Pseudo-Isidore took as the basis of his forgeries a collection of valid canons called the Hispana Gallica Augustodunensis, thus lessening the danger of detection, since collections of canons were commonly made by adding new matter to old. Thus his forgeries were less apparent when incorporated with genuine material. The falsity of the Pseudo-Isidorian fabrications is now incontestably admitted, being proved by internal evidence, investigation of the sources, the methods used, and the fact that this material was unknown before 852. Historians agree that 850 or 851 is the most probable date for the completion of the collection, since the document is first cited in the Admonitio of the capitulary of Quiercy, in 857.
The author of these forgeries is not known. It is probable that they emanated from the aggressive new church party which formed in the ninth century at Rheims, France. It is agreed that Bishop Hincmar of Rheims used these decretals in his deposition of Rothad of Soissons, who brought the decretals to Rome in 864 and laid them before Pope Nicholas I.
Among those who challenged their authenticity were Nicholas of Cusa( 1401-1464), Charles Dumoulin( 1500-1566), and George Cassender( 1513- 1564). The irrefutable proof of their falsity was conveyed by David Blondel, 1628.
An early edition is given in Migne Patrolgia Latina, CXXX. For the oldest and best manuscript, see P. Hinschius, Decretales Pseudo-Isidorianiae at capitula Angilramni( Leipzig, 1863). Consult The New Schaff-Herzog Encyclopedia of Religious Knowledge( 1950), vol. 9, pp. 343-345. See also H. H. Milman, Latin Christianity( 9 vols.), vol. 3; Johann Joseph Ignaz von Doellinger, The Pope and the Council( 1869); and Kenneth Scott Latourette, A History of the Expansion of Christianity( 1939), vol. 3; The Catholic Encyclopedia, vol. 5, art. " False Decretals," and Fournier, " Etudes sure les Fausses Decretals," in Revue d ' Historique Ecclesiastique( Louvain) vol. 7( 1906), and vol. 8( 1907).
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