06-25-2025

A digital treasure: Medieval books meet innovative technology

A rooster finds a gemstone in the manure, but would prefer a grain of oats. According to this opening story, the Bernese Dominican monk Bonerius called his collection of fables "The Gemstone" around 1350 and thus wished for readers who were more interested in spiritual values than sensual pleasures. Almost 700 years later, this work is now the subject of an innovative digital project. Funded by the German Research Foundation DFG, the KU is working together with the Heidelberg University Library on a new digital edition of this first German collection of fables conceived as a complete work.

The fables of the ancient Greek author Aesop were a real hit with the public in the Middle Ages. "The success of a text is measured by how many surviving copies there are of it", explains Dr. Christina Patz from the Research Center for Medieval Religious Literature, who is coordinating the project at the KU. For Bonerius's work, there are an impressive 38 textual witnesses, including manuscripts and two prints from the Gutenberg era. Albrecht Pfister from Bamberg took a financial risk in 1461 when he published the "Edelstein” (Gemstone), not only the first printed German book, but also the very first book illustrated with woodcuts. His courage was apparently rewarded, as he published a second edition just one year later – a strong indication of the collection's popularity.

The morals of some fables may seem strange today, but they provide fascinating insights into the mindset of people in the Middle Ages, says German philologist Christina Patz: "It is precisely in fables that social values are reflected with astonishing clarity. There is no better way to look into people's heads and hearts than by reading what they read." She sees preserving such literary testimonies for posterity and making them accessible as an important task of early German literary studies. "These texts are part of our history and therefore our identity."

According to his epilog, the "Gemstone" originally comprised one hundred fables, but only a codex burnt in Strasbourg in 1870 contained all of them. Before book printing, it was common practice to copy books, with each scribe or client selecting according to their own ideas. Some texts have only survived four times, while others have survived 30 times. "If we look at the entire tradition, we can find the hundred fables and, in simple terms, puzzle them together into one edition", says Patz. The last person to attempt this was Franz Pfeiffer in 1844. However, he was only aware of 17 textual witnesses, around 45 percent of today's tradition. Pfeiffer's approach was also different from today: "By comparing textual witnesses, he thought he could reconstruct the original text, which he saw attested in only four of the sources." He also singled out various verses as alleged "patchwork".

In this way, he created the rather unique reality of a "polished gemstone" – but with one major drawback, as Christina Patz explains: "Today, it is no longer state of the art to editorially aim at a hypothetical original text that is not attested in any surviving form." Instead, according to the leading manuscript principle, one relies on textual witnesses that offer the best and most complete text according to the criteria of chronological and linguistic proximity to the author. Pfeiffer's editorial "art form" was nevertheless the basis for dealing with Boner's work for more than 180 years due to a lack of alternatives.

"The resulting new edition will present a less polished, but historically more genuine gemstone", says Prof. Dr. Gerd Dicke. The former professor of Early German Literature at the KU, who has been retired since 2022, is head of the DFG-funded project. He took on the complex task of researching the authoritative textual witnesses himself. In addition, he also specifically identified more recent, reduced and linguistically simplified editorships, which make up the bulk of the collection. Another preliminary step was the digitalization of the manuscripts and prints in the Virtual Library of Heidelberg University Library, whose "heiEDITIONs" platform is setting standards in the development of an infrastructure for digital editions in the German-speaking world.

Gemstone2 — Depiction of the ancient fable writer Aesop in the Latin-German "Edelstein" manuscript Munich around 1450.

Over the past few months, the project team has now transcribed a total of nine editorially relevant text witnesses using the AI-based text recognition software "eScriptorium". They were then converted into a format for virtual visualization by specially developed processing programs at Heidelberg University Library that follows the internationally valid standards of the "Text Encoding Initiative" (TEI) in literary studies. In this way, the textual witnesses can not only be used digitally in the most faithful form of transmission, but can also be juxtaposed synoptically, i.e. with exact verse accuracy. "This makes it possible to understand what changed in terms of content and language over the course of the text's history", explains Christina Patz. The digital facsimiles can also be switched on synoptically: "This is a considerable added value of the digital presentation form, which makes it possible to get an overview of the range of all manifestations of the Gemstone", emphasizes Gerd Dicke. Also to be included in the synopsis is the collection text edited on the basis of three manuscripts, in which the language has been carefully standardized and minor errors corrected. Orthographic and dialectal variants – such as lewe, löuwe or lœwe – have been "normalized" - löwe (lion) – thus making the collection text searchable and linkable to Middle High German dictionaries.

The first phase of the DFG-funded project will be completed at the beginning of 2027 and the "Edelstein" will be digitally accessible in all its surviving versions, as well as comparable and searchable in the text-historically central variants. In a planned second funding phase, the sources of the "Edelstein" texts - Latin school manuscripts and Dominican sermon manuals - will be catalogued and annotated. There are also plans to systematically process the rich pictorial tradition of around 1350 illustrations.

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