Van Doorn (2016)

• Van Doorn, Adrian. 2016. On the Gaulish influence on Breton, ms. Université de Leiden.

évaluation des arguments de Falc'hun et Fleuriot pour une influence de la langue gauloise sur le breton.

 Conclusion:
 "As we have seen in the first Chapter, not all of the arguments on the survival of Gaulish are satisfactory, either because of the interpretation of the data or because of the fact that the texts do not specifically tell us anything about the situation in Armorica. We cannot be sure that we are dealing with the Gaulish language, every time Gallica lingua is mentioned in a Latin text.
 However, when we look at the big picture, it seems plausible that Gaulish was still spoken in Armorica at the time the Bretons arrived; it was a relatively remote area, just as the Alpine regions, and the connections with Britain could very well have played a role. Therefore it is likely that there was a situation in which Gaulish could have influenced Breton.
 How are the arguments that are used by Falc'hun and Fleuriot to prove Gaulish influence on Breton constructed, and are these satisfactory and sound ? In the second Chapter, I have shown that there are some problems of argumentation in the debate. 
 Falc'hun's argument on the accent of both Gaulish and Breton cannot be used to prove Gaulish influence, because Modern Breton evidence was used instead of Old Breton data, which is anachronistic. In other cases, such as the initial h-, the clusters * xs and -tn-, -tl-, -tr- and -cr-, palatalisation and rhotacism, French is equalled with Gaulish, because there is no or little evidence from Gaulish, but this premise is not always legitimate (2.1.2, 2.1.4, 2.1.5, 2.1.7 and 2.1.8). 
 The development of sr- into fr- is not only shared by Breton and Gaulish, but also by Welsh, and is probably from an earlier stage, i.e. the Gallo-Brittonic unity, and can therefore not be used to prove Gaulish influence. In the arguments on the morphological features in 2.2, archaisms are taken as evidence for Gaulish influence.

When we take all the arguments together, we can conclude that the case for Gaulish influence on Breton is not very well-founded.

 The unexpected Breton features such as * xs > s (2.1.4) or * ū > u (2.3.1), and the metathesized form of banal (2.3.2) still have to be explained, and it is possible to do so with the help of Gaulish influence. However, we have to be aware not to use Gaulish influence as an argument that can be used whenever something is not explained otherwise, as Falc'hun seems to do quite often."