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The Law Library’s Canon Law Collection

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The following is a guest post by Dario Ferreira, Senior Legal Information Analyst at the Law Library of Congress.

In addition to the laws of different countries, the Law Library also collects books and documents relating to the legal systems and codes of different religions.  For example, the Law Library is a great source of information on canon law.

The Code of Canon Law is extraordinary in that it covers the entire Catholic population, regardless of the geographical location.  One out of every six or seven people of this planet and one out of four people in the United States are subject to its provisions.  The Law Library has in its collections an enormous amount of history and information relating to this body of ecclesiastical law.

Who is the authority behind the law?  The productive sources of the law for the universal Church are the Pope, the ecumenical councils, and the Roman congregations.  The instrumental sources of the law are the Bible and tradition, and the collection of documents that contain the legal provisions enacted by the legislative authority of the Church.

Title page of the 1591 edition of the Decretum Gratiani (Source: Library of Congress Prints and Photographs Division)

The Law Library holds an extensive canon law collection, containing approximately three thousand volumes, a good number of them written by the most renowned canon experts over the last eight centuries.  In 1981, the Library published a book entitled The Canon Law Collection of the Library of Congress to inform readers about the existence of this little known collection.  The collection has continued to grow since the guide’s publication.

The strength of the collection are the works of important Church figures of the seventeenth and eighteenth centuries, and manuscripts and early editions of the sources of ecclesiastical law of the Roman Catholic Church.  These works comprise ninety-eight percent of the collection.  Through the centuries there were numerous attempts to organize the Church’s many and diverse laws.  The most famous compilation was the work of Gratian, a twelfth-century Camaldolese monk, whose Concordia Discordantium Canonum (Concordance of Discordant Canons, also known as the Decretum Gratiani) appeared around 1140 AD.  The Library of Congress possesses many editions of this work.

While the Decretum Gratiani was of great importance, it didn’t have official character.  As noted above, other collections followed.  Some of those compiled by papal authority were known as Liber Extra, Liber Sextus, and the Liber Septimus.  In 1437, the Council of Basilea (1431-1449) applied the heading Corpus Juris Canonici to these works and the Decretum Gratiani.

The Law Library holds many editions of the Corpus Juris Canonici, which is a fundamental and essential source for the study of canon law.

Although there were many compilations over the centuries, an official codification of canon law had to wait until 1917.  On May 27, 1917, Pope Benedict XV solemnly promulgated  in his Constitution, Providentissima Mater Ecclesia, the first Codex Juris Canonici (Code of Canon Law), which become effective for the universal Church a year later.  In 1983 Pope John Paul II promulgated the second official Code of Canon Law.  The Law Library has an autographed copy of the text of this new code in its Rare Book Collection.

Since 1908, canon laws have been promulgated by their publication in the official gazette, Acta Apostolicae Sedis, which is also contained in the canon law collection of the Law Library of Congress.

Comments (9)

  1. It is wonderful that the Law Library of Congress draws attention to canon law and its history. Nice photo of the 1591 Decretum! A pity, though, that the notice seems underresearched, which is a pity when the post comes from a library. Even Wikipedia will tell you that no scholar any longer believes that Gratian was a Camaldolese monk. The Constitutiones Clementinae (or the Clementines, for short) was sometimes called Liber septimus in the Middle Ages, but there are few, if any scholars to use that name today (and why does the link go to a treatise on architecture?). And is the famed Swiss city no longer Basel in English?

    • Thank you for your comment – we really appreciate that an expert on canon law found our blog interesting! We’ve now removed the link that we inadvertently included. Thanks also for highlighting the fact that in this subject area there are differences in opinion and changes in terminology over time.

  2. The Catholic University of America in Washington, D,C., publishes the “History of Medieval Canon Law”, edited by Kenneth Pennington and Wilfried Hartmann. In 2008 appeared the volume “The History of Medieval Canon Law in the Classical Period, 1140-1234. From Gratian to the Decretals of Pope Gregory IX” [LoC link This volume is currently the handbook on this subject. In it you can also find details about the first use of the book title “Corpus Iuris Canonici” in the sixteenth century.

  3. In global law terms and Human Rights law terms, can you help with a search for the law on nuns, charity and the dowry land given to God.

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