The Coherence-Based Genealogical Method – What is it about?
- Elements of a genealogical hypothesis are not the manuscripts but the states of the text that they convey and that may be far older than the respective manuscript. The text with its respective state will be referred to here as witness, not the manuscript.
- A hypothesis is called a stemma if it links witnesses or variants genealogically. For a hypothesis about a genealogical connection not only the connection itself but its quality is relevant. This quality has to be documented by adequate data. This complexity is integrated into this understanding of stemma. Consequently, a stemma in the sense of a graphical connection of witnesses is merely a simplified representation of a stemma in the more complex sense.
The process of transmission of the New Testament texts resulted in a high degree of contamination.
This is due to the fact that again and again the copies of the texts do not entirely rest on a single master copy. Indeed, it appears as if the number of contamination acts, which resulted in a mixture of different states of text, were on average rather slight from one generation of copying to the next. The high degree of contamination among the preserved states of text is due to the multitude of copying processes and the large number of lost text states—particularly among those text states that belong to an earlier stage of the textual history.
At the same time the possibility must be taken into account that identical variants appear in texts which otherwise are quite different from one another, and that they have emerged repeatedly by coincidence, without any process of contamination.
Any hypothesis on the textual history and genealogy thus must be arrived at by means of a method that does justice to both aspects: contamination and coincidental repeated emergence of variants. In this process a problem typical for a highly contaminated textual tradition must be mastered, namely, that one witness when compared with any other contains both variants that are younger, and older, than those of the other witness.
The Coherence-Based Genealogical Method is based on the following assumptions: In a textual tradition where all the copies have survived and where the source, or (in case of contamination) the sources, are also known, as well as the origin of every reading in every copy, the genealogical interrelationships between all the variants at any place of variation must appear in a global stemma of the witnesses as genealogical relationship between coherent fields of relationships between witnesses.
Conversely, the relationship between each descendant and its ancestor, or (in case of contamination) at least a subset of relationships between it and its ancestors, should appear at any place of variation, namely as the relationship between witnesses sharing the same variant there, or as the relationship between witnesses between which a change of the variant took place which supports the ancestor-descendant relationship. Since every descendant may be an ancestor in relationship to other witnesses, chains of coherencies are formed within attestations. These chains help to find out about unique or multiple emergence of variants. Chains of coherencies connect attestations of different variants where a change of text took place between witnesses.
Thus, the coherencies of witnesses within a global stemma are linked in the way presented to the coherencies of witnesses at given places of variation. The relation among the witnesses at any given place of variation is compatible with their relation within a global stemma. As the attestation of variants appears within a stemma as a coherent field, the relations of the entire attestation of any given variant with the entire attestation of any other variant, and, by consequence, the relation of the variants itself are compatible with the global stemma at any place of variation.
From this emerges a connection of local stemmata of variants to a global stemma of witnesses.
In a real context a large proportion of the witnesses is generally lacking. Consequently, the relation between the states of text of the existing witnesses can only be the subject of a genealogical hypothesis. It cannot be the objective of such a hypothesis to reconstruct in detail historical processes. That is impossible. Rather it is the objective to find the structure which interprets in the most straightforward way the genealogical relations between the available states of text and which is not falsified at any place of variation.
Such a structure is highly complex, but it is made up from structures of lesser complexity. In this context one can draw advantage from the fact that there exists the connection between local stemmata of variants and a global stemma of the witnesses as explained above. This relation is also valid for the elements of a global stemma, substemmata, which show the relation of a descendent with its hypothetical ancestors.
A textual tradition as a whole is characterised by internal coherence, while the relations among the individual states of text are determined by coherencies of different type and quality. Due to the development of states of text from prior ones to posterior ones there emerges in the tradition a general textual flow which the individual witnesses must be placed in. The relative position of any individual witness to any other can also be determined by studying the parameters of the textual flow. The study of coherencies (and particularly chains of coherencies) and the analysis of the textual flow are of primary importance.
In this context, different classes of coherence exist:
pre-genealogical coherence. Based solely on the conformity of variants, it can be established objectively. A strong pre-genealogical coherence exists between witnesses with a high degree of conformity. It is a criterion for the likelihood that variants might have—on account of their witnesses—a genealogical relation at all. Also, the lack of pre-genealogical coherence points to the coincidental multiple emergence of variants.
The study of pre-genealogical coherence is an important means to establish provisional local stemmata of variants. It makes it possible to generate negative genealogical statements with a high degree of objectivity. Moreover, the entire methodological reservoir of textual criticism must be brought to bear on the construction of stemmata of variants. The local stemmata that emerge in that way may be incomplete (as some relations between variants or even all relations in entire passages cannot be determined), and they are provisional, because genealogical relations between variants cannot at first be based on genuine genealogical witness-related data.
genealogical coherence. This emerges from the degree of conformity and the predominant directions of the textual flow among the witnesses, and it presupposes pre-genealogical coherence and a first establishment of local stemmata of variants. The stemmata of variants lead to the first witness-related genealogical data. The predominant direction of the textual flow between witnesses depends on all conclusions that can be drawn about the genealogical relations of its variants. It enables the determination of potential ancestors for each witness. The higher the degree of conformity between them and the descendent, the stronger the genealogical coherence.
The resulting genealogical coherence makes an iterative process possible, in the course of which local stemmata and, by consequence, the resulting genealogical coherence, are revised again and again.
stemmatic coherence. It represents the definitive stemmatic connection in an optimal substemma which—not being falsifiable at any place—explains in the most straightforward way the origin of a text (i.e. normally by looking at its sources of contamination). Stemmatic coherence presupposes genealogical coherence; yet, witnesses which are genealogically coherent on account of the values of the textual flow are not automatically stemmatically coherent (e.g. if they are not necessary as ancestors in an optimal substemma).
The analysis of the genealogical coherence and of the textual flow already enable the representation of predominant textual flows in a stemma-like graph with respect to the strength of the textual flow and its directional stability. These representations thus depict the genealogical coherencies of a higher degree and they give a reasonable prediction for a stemma which offers stemmatic coherencies. However, for the determination of stemmatic coherence and the creation of optimal substemmata which consist of the smallest possible combination of necessary ancestors and which constitute in their entirety the global stemma, it must be ascertained whether the variants contained in the textual flow from one potential ancestor are contained within the textual flows from other potential ancestors, and whether, in the case of a lower degree of conformity of a potential ancestor, there are variants which require, or at least suggest, stemmatic coherence.
The Coherence-Based Genealogical Method does not create stemmata in an automatic way, but it derives genealogical structures from findings (the results of collations) and their assessment in the light of textual criticism, controlled by means of an iterative process, the rules of which are oriented on a model of the textual tradition. The Coherence-Based Genealogical Method makes no textual decisions. It merely reveals an image of the tradition which emerges from a text-critical philological study of all the variants. The iterative process of the method helps the text-critical philological hypotheses to confirm their plausibility.