There is good reason to be ambivalent about the usefulness of general considerations in linguistic reconstruction. As a heuristic device, a theoretical framework can certainly be helpful, but the negative potential of aprioristic considerations must not be underestimated. E.g., there is a whole range of phenomena which receive a natural explanation when we assume that glottalization is ancient in Germanic. The methodological question is: why have scholars been reluctant to identify the vestjysk stød with the English glottalization as a historical reality which may have been inherited from the proto-language? The role of general linguistics is to provide an idea of what can be expected in linguistic development, not by theoretical reasoning but by inspection of what actually happens.