In the ninth century, a series of elaborate forgeries were written under the pseudonym of Isidore Mercator, which are now known as the Pseudo-Isidorian Decretals (or simply the False Decretals). Among these documents are over 100 letters ostensibly written by popes and bishops in the early church, in which these popes and bishops repeatedly quoted works written centuries after their lifetimes.
Everett Ferguson indicates that this was no small thing:
This collection became the most influential forgery in the history of the Roman Catholic church. It became the basis of the claims for the papal monarchy in the later Middle Ages. (Church History, 18.IV.B)
This is obviously a sensitive subject, and doubly so because the gradual discovery of the fraud occurred during the Reformation period, during which the RCC faced broader challenges to its authority. Nonetheless, I'm hoping that it's possible to politely probe the influence of these documents on the medieval church.
One particular point of disagreement I seem to have uncovered relates to the decretals' impact on the Decretum Gratiani (or Concordia discordantium canonum), an important 12th-century collection of canon law. Wikipedia seems to downplay their impact on Gratian's work, not listing the False Decretals as one of his sources, and saying that his work "ended the immediate influence of the False Decretals" (source).
At the same time, the Catholic Encyclopedia notes that "many fragments" of the false decretals "are to be found in the 'Decretum' of Gratian."
Thus I'd like to limit my query here to the impact of the Pseudo-Isidorian Decretals on Gratian's Decretum. Ways of viewing "impact" might include:
- the percentage of Gratian's text that, directly or indirectly, comes from the False Decretals
- the percentage of Gratian's supporting references that ultimately come from the False Decretals
- any instances of statements or rules that Gratian rests solely or primarily on the False Decretals
Note that I am framing this as something that is, at least theoretically, objectively answerable. I'm specifically not asking how much of Gratian's text ought to be kept or discarded, for example, nor do I care how Catholics and Protestants have defended or attacked the legitimacy of Gratian's collected canons. Instead, I'm interested in a textual analysis of the use (intentional or unintentional) of the Pseudo-Isidorian Decretals in the Decretum Gratiani.