In all of them there was unauthentic matter, accepted as if its pseudo-authorship or pseudo-source were genuine. But in the stormy times of the ninth century following the death of Charlemagne, the method of argument through forged authority was exceptionally creative. It produced two masterpieces which won universal acceptance. The first was a collection of false Capitularies ascribed to Charlemagne and Louis the Pious, and ostensibly the work of a certain Benedictus Levita, deacon of the Church of Mainz, who worked in the middle of the century. Far more famous and important was the book of _False Decretals_, put together and largely written, that is forged, about the same time, probably in the diocese of Rheims, and appearing as the work of Saint Isidore of Seville. This contained many forged letters of the early popes and other forged matter, including the Epistle or “Donation” of Constantine; also genuine papal letters and conciliar decrees. These false collections were accepted by councils and popes, and formed part of subsequent compilations. From the tenth century onward many such compilations were made, all of them uncritical as to the genuineness of the matter taken, and frequently ill-arranged and discordant. They were destined to be superseded by the great work in which appears the better methods and more highly trained intelligence developing at the Bologna School in the first part of the twelfth century. Its author was Gratianus, a monk of the monastery of St. Felix at Bologna. He was a younger contemporary of Irnerius and of Peter Lombard. Legend made him the latter’s brother, with some propriety; for the compiler of those epoch-making _Sentences_ represents the same stage in the appropriation of the patristic theological heritage of the Middle Ages, that Gratian represents in the handling of the canon law. The Lombard’s _Sentences_ made a systematic and even harmonizing presentation of the theology of the Fathers in their own language; and the equally immortal _Decretum_ of Gratian accomplished a like work for the canon law. This is the name by which his work is known, but not the name he gave it. That appears to have been _Concordia discordantium canonum_, which indicates his methodical presentation of his matter and his endeavour to reconcile conflicting propositions. The first part of the _Decretum_ was entitled “De jure naturae et constitutionis.” It presents the sources of the law, the Church’s organization and administration, the ordination and ranking of the clergy, the election and consecration of bishops, the authority of legates and primates. The second part treats of the procedure of ecclesiastical courts, also the law regulating the property of the Church, the law of monks and the contract of marriage. The third part is devoted to the Sacraments and the Liturgy.