The motive for the publication of this code of decretals is thus stated by the authors themselves:
Many good Christians are reduced to silence, and compelled to bear the sins of others against their own better knowledge, because they are unprovided with documents by which they might convince ecclesiastical judges of the truth of what they know to be the law; seeing that though what they allege may be altogether right, yet it is not heeded by the judges unless it be confirmed by written documents, or by recorded decisions, or made to appear in the course of some known judicial proceeding.
The object of the compilation may be found also in these words:
We have likewise inserted the decretal epistles of certain apostolic men—that is, of Clement, Anacletus, Evaristus, and others who are their successors, indeed as many as we have been able to find, down to Pope Sylvester; after these
we have annexed the rest of the decretals of the Roman prelates down to Gregory the Great, together with certain epistles of that pontiff; in all which, by virtue of the dignity of the Apostolic See, resides an authority equal to that of the councils; so that, the discipline of the ecclesiastical order being thus by our labours reduced and digested into one body of law, the holy bishops may be instructed in the entire "rule of the fathers"; and thus obedient ministers and people may be imbued with spiritual precedents, and be no longer deceived by the practices of the wicked. For there are many who by reason of their wickedness and cupidity bring accusations against the priests of the Lord, to their great oppression and ruin. Therefore the Holy Fathers did institute laws, which they called holy canons, which, however, the evil-minded have often made the instruments of unjust charges, or even possessed themselves of the goods of the innocent.
The canons were insufficient to meet the evils of the day. Some remedy must be found of equal if not greater authority. The decretals of the Roman Pontiffs were seized for this holy purpose. Many such decretals were known to the Church. But there was a fatal hiatus of two centuries and a half after the founding of the See of Peter. That chasm must be bridged over by documents which would prove that the divine headship of Peter was consciously exercised by all his successors. With such indisputable evidence the supremacy of Rome would be established beyond question, and the entire hierarchy would be benefited. The ascendancy of the Church over the state would be established. Papal sovereignty would be acknowledged. Episcopal independence of secular control would be secured.
The sources of the Isidorian Decretals, now
satisfactorily determined, were: the writings of the Church Fathers, particularly Rufinus (d. 410); the works of Cassiodorus (b. 470); Jerome's Vulgate; the Liber Pontificales; the general theological literature down to the ninth century; various collections of laws like Breviarium Alaricianum, the Lex Visigothorum, and the Frankish capitularies; the genuine archives of the Church like papal letters and decretals, Church canons, and minutes of Church councils; the correspondence of Archbishop Boniface (d. 754); and the forgeries.
Before this collection appeared there had been several others formed in the Western Church:[330:1]
1. Dionysius Exiguus, a Scythian, who lived at Rome as a monk in the sixth century, made a collection of the fifty Apostolic Canons; decrees of the Eastern and African Church councils from 375 to 451; and letters of Popes from 314 to 498. This collection was used by Charles the Great as a basis in part for the Frankish laws.