Definition
"Concordia Discordantium Canonum" is Latin for "the harmony of the discordant canons." It is the original title of the foundational text of medieval canon law compiled by the Italian monk Gratian around 1140–1151 A.D. The work systematically reconciled conflicting ecclesiastical rules, councils, papal decrees, and patristic writings into a single organized body of church law. The text is far more commonly known as the Decretum Gratiani, or simply the Decretum. It became the cornerstone of the Corpus Juris Canonici — the authoritative collection of Roman Catholic canon law that governed ecclesiastical courts across Western Europe for centuries.
The title itself describes the method: Gratian did not simply compile conflicting canons but attempted to resolve their contradictions through analysis and commentary, producing a harmonized synthesis. That methodological ambition distinguished the Decretum from earlier canonical collections and gave it lasting doctrinal authority.
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Common Confusion
The term is frequently encountered in two forms: "Concordia Discordantium Canonum" (the standard spelling) and "Concordia Disgordantium Canonum" (a variant appearing in some historical editions and secondary sources, including Black's 2nd Edition Supplemental). The "Disgordantium" spelling is a transcription error or archaic variant — not a distinct work. Researchers encountering either form in historical sources are looking at the same text. Similarly, the Decretum Gratiani and the Concordia Discordantium Canonum are one and the same document; using one title does not signal a different recension or edition.
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Why It Matters in Research
Researchers working in ecclesiastical law, medieval legal history, or the history of jurisprudence will encounter this title and its variants across a wide range of corpus materials. Several navigational points matter:
**Title variation is a real trap.** Historical sources — including legal dictionaries of the 18th and 19th centuries — render both the Latin title and Gratian's name inconsistently. "Grattan," "Gracian," and "Gratianus" all appear. "Discordantium" and "Disgordantium" coexist. Cross-referencing under Decretum Gratiani will often retrieve materials that the full Latin title does not.
**Dating varies across sources.** Black's 2nd Edition places the compilation at A.D. 1151. Modern scholarship generally dates the Decretum to approximately 1140, with later recensions. When a source gives 1151, it is likely following older secondary authority. Neither date should be treated as authoritative for anything beyond identifying the work.
**Canon law in common law jurisdictions.** English ecclesiastical courts operated under canon law derived partly from the Decretum well into the post-Reformation period, and certain doctrines — testamentary jurisdiction, marriage law, defamation of clergy — carried canonical concepts into common law development. Researchers tracing the origins of these doctrines may need to move between the canonical and common law corpus.
**The Decretum as interpretive text, not enacted law.** Unlike a statute or papal bull, the Decretum was a private scholarly compilation. It acquired authority through use and adoption, not formal promulgation. This matters when evaluating how historical sources treat it: references to it as "law" reflect its functional authority, not a legislative act.
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Historical Dictionary Support
Black's 2nd Edition Supplemental gives a brief but accurate entry, identifying the work as "a collection of ecclesiastical constitutions made by Grattan, an Italian monk, A.D. 1151" and noting the common name Decretum Gratiani. The entry is representative of how 19th-century American legal dictionaries treated canon law sources: functionally accurate, but thin. The date, the spelling of Gratian's name, and the characterization as a "collection" (rather than a harmonizing synthesis) are all typical period simplifications.
Historical legal dictionaries do not, as a class, engage with the Decretum's internal structure — the division into the Distinctiones, Causae, and the De Consecratione — which matters for anyone using the text directly. They also do not address the Ordinary Gloss (the Glossa Ordinaria of Johannes Teutonicus and Bartholomaeus Brixiensis), which is inseparable from how the Decretum was read and applied in practice. For substantive engagement with the text itself, historical dictionaries are a starting point only.
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Jurisdictional Note
Canon law as a living legal system applies within the Roman Catholic Church, which continues to operate under the 1983 Code of Canon Law — a text that superseded the Corpus Juris Canonici (including the Decretum) for most purposes. The Concordia Discordantium Canonum retains relevance in historical and comparative legal research, and in ecclesiastical courts operating under older canonical traditions.
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