Whilst working on my paper for the upcoming SBL in Baltimore (abstract here), I wrote a section which I cannot use in the paper, but would love to get some comments on. It is not about the Coherence Based Genealogical Method (CBGM) as such, but about a potential misconception of its most fancy result, the Global Stemma.
"Once we have produced a global stemma there may be an unintended side-effect for the unaware reader, which, in an ironic twist, repeats the error we have tried to avoid by doing away with the notion of text-types.
A problem in the use of text-types is that the voice of a whole group of manuscripts is reduced to a single voice, even when it is clear that, in the current state of play, there is no evidence that the whole text-type goes back to a single ancestor. To reduce manuscripts to simply being members of, say, the early Alexandrian type is simplifying a complex reality to the level of becoming only a near-truth.
However, with a global stemma a similar abuse of the constructed genealogy is possible. The error is this, that manuscripts that are not on the top layer but on the second, third or lower level, are seen as being dependent on the manuscript(s) above them and therefore can be discounted (as per Westcott-Hort). But of course, in the CBGM this is not the case, since the rationale behind the global stemma is that it only gives the closest 'potential ancestor' but not all 'potential ancestors'. I assume that many of the manuscripts on the higher levels still need the Ausgangstext (initial text) as one of their potential ancestors to explain all their variants and are therefore still independent witnesses to that initial text. Yet the danger of reduction is real: instead of falsely reducing individual witnesses to being mere members of a text-type, witnesses could be reduced to having little or no independent value because they do not have the Ausgangstext as their closest ancestor.
The main reason for this apparent misconstrual of the meaning of the global stemma is that the term 'genealogy' is employed in its own singular way — not as indicating the ancestry of the text in the strict meaning of the word, but rather as pointing to a text with a higher proportion of earlier readings. And the difference between these two is huge! The term 'genealogical relationship' as used in, say, the Introduction to the Editio Critica Maior (ECM) suggests much more than it is actually supposed to mean."