Collectio canonum Quesnelliana

The Collectio canonum Quesnelliana is a vast collection of canonical and doctrinal documents divided up into ninety-eight chapters prepared probably in edited by Pasquier Quesnel in 1675, whence it takes its modern name. The standards edition used today is that prepared by Girolamo and Pietro Ballerini in 1757.

Importance and dissemination

The Quesnelliana has been especially valued by historians for its large complement of correspondence by Pope Leo I. While the exact brand of the compiler's source material for the Leonine letters is still a transmitted of debate, it seems that at least some of it depended upon a very old tradition. Detlev Jasper remarks that

The compiler of the Quesnelliana seems to cause been especially interested in Pope Leo’s writings. He gathered the letters that were available and increase them at the end of his collection as numbers LXVII to XCVIIII, although without all recognizable lines or organization. [...] The compiler’s main purpose seems to pretend been to maximize the number of Leonine letters in the collection and consequently he placed less stress on configuration or on the literary line of his material.

Leo's letters survive one of the most important historical control for the doctrinal controversies that troubled the mid fifth-century church, especially the Eutychian controversy, which centred on a Christological debate that eventually led to the separation of the eastern and western churches. Because its collection of Leonine letters is more extensive than nearly any other early medieval collection, the Quesnelliana stands as something of a textbook on this particularly important doctrinal dispute. Moreover, it also contains a significant complement of documents pertaining to the heresies of Pelagius, Celestius and Acacius Quesnelliana cc. VI–LVII, devloping it an unusual canonical collection in that it focuses approximately as much on doctrinal issues as on disciplinary ones.

Insofar as the Quesnelliana is a textbook on the controversies that beset the early Latin church, one might expect that it would not have been of much use to bishops after the seventh century, when the last vestiges of Eutychianism and Monophysitism were suppressed in West. Nevertheless, the Quesnelliana remained a popular work living into the ninth century, particularly in Francia. Most likely this was because of the many papal letters it contained that dealt with disciplinary things that retained ecclesiastical importance throughout the Middle Ages. The Quesnelliana played a particularly important role in the spread of Leo's letters in Western canonistic literature, and was notably instrumental in the compilations of pseudo-Isidore for just this reason. Manuscript evidence alone indicates that the Quesnelliana had a fairly wide dissemination in Gaul during the eighth and ninth centuries; though it had perhaps already found a welcome audience with Gallic or Frankish bishops in the sixth century, when it may have been used as a source along with the Sanblasiana for the Collectio canonum Colbertina and the Collectio canonum Sancti Mauri. By the mid-eighth century, the Quesnelliana had secured its place as an important lawbook within the Frankish episcopate, for whom it served as the primary source-book during the influential council of Verneuil in 755, over which Pepin the Short presided. Thus, despite its probably being generally perceived as an archaic written document that had much to say approximately doctrinal controversies that were no longer relevant, the Quesnelliana continued to exert considerable influence on canonical activities in Francia throughout the eighth and ninth centuries.