Gratian’s Decretum: Sources and Influence
This field of inquiry is hampered by ignorance of the compiler’s identity and the existence of manuscripts with abbreviated or variant versions of the text, not represented by Winroth’s two recensions. One of these is the manuscript St. Gall, Stiftsbibliothek, 673 (=Sg), which some have argued contains the earliest known version (borrador) of the Decretum.[12] However, other scholars have argued that it contains an abbreviation of the first recension, expanded with texts taken from the second recension.
Gratian’s Sources
Gratian’s sources included Roman law, the Bible, the writings of (or attributed to) the Church Fathers, papal decretals, and the acts of church councils and synods. In most cases, Gratian did not obtain this material from a direct reading of the sources, but rather through intermediate collections. Thanks to the research of modern scholars—in particular, Charles Munier, Titus Lenherr, and Peter Landau—we now know that Gratian made use of a relatively small number of collections in the composition of most of the Decretum. These are:
- Anselm (II) of Lucca’s canonical collection, originally compiled around 1083 and existing in four main recensions: A, B, Bb, and C. Peter Landau suggests that Gratian probably employed a manuscript containing an expanded form of recension A, which he calls recension A’;
- The Collectio tripartita attributed to Ivo of Chartres, usually thought to date to 1095;
- The Panormia of Ivo of Chartres, also usually dated to 1095, although several scholars have argued for a later date and some even question Ivo’s authorship;
- Gregory of St. Grisogono’s Polycarpus, completed sometime after 1111;
- The Collection in Three Books, composed sometime between 1111 and 1139, though dated by some to around 1123;
- The Glossa ordinaria to the Bible.
Other sources are known to have been used in the composition of particular sections of the Decretum:
- Isidore of Seville’s Etymologies for DD. 1-9 (the so-called Treatise on Laws);
- Alger of Liège’s Liber de misericordia et iustitia for C. 1;
- The Sententiae magistri A. for the De penitentia and some other sections.
Effect
Gratian himself named his work Concordia Discordantium Canonum—”Concord of Discordant Canons.” The name is fitting: Gratian tried to harmonize apparently contradictory canons with each other by discussing different interpretations and deciding on a solution. This dialectical approach allowed for other law professors to work with the Decretum and to develop their own solutions and commentaries. These legalists are known as the decretists.
These commentaries were called glosses. Editions printed in the 15th, 16th, or 17th centuries frequently included the glosses along with the text. Collections of glosses were called “gloss apparatus” or Lectura in Decretum (see also glossator). Systematic commentaries were called Summae. Some of these Summae were soon in circulation as well and obtained the same level of fame as the Decretum itself. Early commentators included Paucapalea and Magister Rolandus. The most important commentators were probably Rufin of Bologna (died before 1192) and Huguccio (died 1210). Less well-known was the commentary of Simon of Bisignano, which consisted of the Glosses on the Decretum and the Summa Simonis.
Peter Lombard borrowed and adapted from the Decretum when discussing penance in his Sentences.