Introduction

A program suite for doing CBGM.

Basic Terms and Procedures of the Coherence-Based Genealogical Method (CBGM)

The Coherence-Based Genealogical Method, developed by Gerd Mink at the Institut für Neutestamentliche Textforschung (INTF) in Münster, aims at a scientifically founded reconstruction of the initial text (Ausgangstext) of the New Testament tradition, i.e. a hypothesis about the text from which the manuscript transmission started. The fundamental problem posed by the nature of the New Testament manuscript tradition is known as contamination, the mutual influence of different strands of transmission on each other. Contamination renders the application of conventional stemmatics impossible, and the New Testament manuscript tradition is known to be highly contaminated. The CBGM, however, offers a cure for contamination, thanks to three essential principles distinguishing it from conventional stemmatics.

1) The CBGM does not study the genealogy of manuscripts but of the texts carried by the manuscripts, the textual witnesses. The text is the witness. 2) The CBGM does not deduce the genealogy of textual witnesses from common errors but from the genealogy of the variants by which the witnesses either agree or differ. 3) The CBGM is based on the awareness that, due to contamination, two witnesses when compared with each other both feature earlier and later, prior and posterior variants. As a rule, one of the two witnesses contains more prior variants than the other and is thus regarded as the potential ancestor of the other. At a lower number of passages, however, the descendant will contain prior variants, and this fact is taken into account systematically.

The CBGM was developed in the context of the Editio Critica Maior – Novum Testamentum Graecum (ECM).

The application requires a comprehensive, well-structured critical apparatus meeting the ECM standard. For each of the manuscripts included there is one entry at each variant passage. The apparatus of Acts, for example, contains all variants of 183 Greek witnesses at more than 7,000 variant passages.

The CBGM proceeds from the genealogy of variants to the genealogy of the witnesses containing the variants. If the editors judge a variant b as posterior to a variant a, they also make a statement about the relationship between the witnesses of a and b at one passage. Hence the following principle of the CBGM:

A hypothesis about genealogical relationships between the states of a text as preserved in the manuscripts has to rest upon the genealogical relationships between the variants they exhibit. Therefore a systematic assessment of the genealogy of these variants (displayed as local stemmata) is a necessary requirement for examining the genealogy of textual witnesses.

The relationship between two witnesses as compared at one variant passage can take four forms. 1) They are equal (01 and 02 in fig. 2). 2) They differ and have an ancestor-descendant relationship (03 and 04 are descendants of 01 and 02 in fig. 2). 3) They differ and are posterior to other witnesses but are not directly related (03 and 04 in fig. 2). 4) They differ and the relationship is unclear because the source of the variant in one of the compared witnesses is not defined (as for d in 05).

Having constructed local stemmata for each variant passage we are able to say in how many instances witness X has the prior variant as compared with witness Y at the places where they differ. As we are dealing with a contaminated tradition, there will also be a number of instances where Y has the prior variant. Finally there will be a number of unclear cases where the variants of X and Y are not directly related or it has to be left open which is the prior one. These numbers are tabulated in lists of relatives for each of the witnesses included in the apparatus.

The structure of the relatives list is explained by the Short Guide on the website <https://ntg.uni-muenster.de/acts/ph4/>. Here we focus on what is essential for this brief introduction. The first line above the table identifies the witness the list of relatives refers to: 01 as W(itness) 1 supporting variant c at the given passage and being cited at a total of 7,392 variant passages in Acts. For each of the compared witnesses (under W2 in the table) the table shows 1) how many passages W1 and W2 are equal (Eq); 2) whether W2 is a potential ancestor or descendant of W1 (W1<W2 larger or smaller than W1>W2); 3) how many passages W1 and W2 are not directly related (NoRel); 4) how many passages the relationship between W1 and W2 is unclear because the source of the variant in W1 or in W2 is not defined (Uncl).

The table is organized by the percentages of agreement (Perc) by default (and can be reorganized according to the user). These percentages indicate the degree of pre-genealogical coherence of the witnesses under comparison, while their genealogical coherence is shown by the figures under W1<W2 and W1>W2. As mentioned above, W2 is considered a potential ancestor of W1, if W1<W2 is larger than W1>W2. In this case a ranking number corresponding to the percentage of agreement (Perc) appears under NR. According to fig. 3, A is the first, 81 the fifth potential ancestor of 01. The figures under W1<W2 and W1>W2 show the relative strength of the textual flow leading from prior variants in W1 to posterior variants in W2.

All diagrams in Coherence and Textual Flow displayed below the local stemma of the selected passage derive from tables like the one in fig. 3. The ECM editors use the textual flow diagrams of the module Coherence in Attestations as a starting point when assessing the quality and coherence of attestations. The textual flow diagrams show the witnesses with a range of potential ancestors, which is defined by the connectivity attributed to a variant by the user[1]_. The potential ancestors within the connectivity range are either part of the same attestation or they support another variant. In our example all the potential ancestors outside the attestation of c support a. This is a strong argument for assessing a as prior to c.

The term potential ancestor was coined in view of the final procedure of the CBGM, the construction of the global stemma. A global stemma will be composed of optimal substemmata for which only stemmatic ancestors are used. Stemmatic ancestors are those which are necessary for explaining the text of a witness. The text of a witness is regarded as explained if it can be deduced completely by agreement with or posteriority to the variants in the ancestors.

In the context of the CBGM the term stemma is restricted to the local stemma of variants and the global stemma, the final account of the genealogy of all witnesses that are necessary for explaining the development of the text from its earliest to its latest incarnations. By contrast, diagrams dealing with witnesses and their potential ancestors are called textual flow diagrams or TFDs.

The construction of the global stemma is work in progress. There are two CBGM modules geared towards the global stemma: Optimal Substemma (OS) and Minimum Set Cover (MSC). OS checks a range of up to 15 potential ancestors for optimal combinations to explain the text of a witness. More than 15 and the Webserver may become overstrained. MSC reaches out to a larger number of potential ancestors but does not check all possible combinations in a given range. So again, the result is only an approximation to an optimal substemma. An optimal result would only be yielded by a method that includes all combinations of all potential ancestors. In the near future we hope to be able to find help with developing OS software for utilizing a HPC cluster.

References

Novum Testamentum Graecum – Editio Critica Maior, ed. by the Institute for New Testament Textual Research, Münster.

Vol. III Acts of the Apostles, ed. Holger Strutwolf, Georg Gäbel, Annette Hüffmeier, Gerd Mink, and Klaus Wachtel. Part 1: Text, Part 2: Supplementary Material, Part 3: Studies, Stuttgart: German Bible Society 2017. ISBN 978-3-438-05614-6

Vol. IV Catholic Letters, ed. Barbara Aland, Kurt Aland†, Gerd Mink, Holger Strutwolf, and Klaus Wachtel. Part 1 Text, Part 2 Supplementary Material, 2nd revised edition, Stuttgart 2013, ISBN 978-3-438-05606-1 and 978-3-438-05607-8.

Gerd Mink: The Coherence-Based Genealogical Method (CBGM), Introductory Presentation. <http://egora.uni-muenster.de/intf/service/downloads_en.shtml>

Short Bibliography on the CBGM <http://egora.uni-muenster.de/intf/projekte/gsm_lit_en.shtml>

The program suite consists of:

  1. a web client,

  2. an API server, and

  3. a set of scripts to manipulate the CBGM database.

Web ClientjavascriptAPI ServerpythonScriptspythonDatabasepostgres

Overview of the program suite

The web client runs in the browser.

The API server can manage multiple databases. Each book and phase gets its own database.

The scripts can be run manually on the VM to manage the whole CBGM process, that is:

  • importing new books,

  • doing the CBGM (passing from one phase to the next),

  • and eventually updating the apparatus.