ゲルマン語強変化動詞および過去現在動詞Ⅳ, Ⅴ類に見られる形態的差異について: Schumacher (2005)論考の批判的考察と形態的混交説からの提案

Indo-Europeanists have so far widely accepted the idea that both the preterite tense formations of strong verbs and the present tense forms of preterite-present verbs developed out of the PIE perfect. However, class IV and V strong verbs show a long vowel in their root (e.g. *bǣr- or *bē1r- ‘carried’, *lǣs/z- or *lē1s/z- ‘collected’), whereas correponding preterite-presents reflect the original reduced grade vocalism in their root (e.g. *mun- ‘think’, *nuǥ- ‘are sufficient’). The traditional view that the PIE perfect underlies all these formations has yet to provide any satisfactory historical explanation for the conspicuous morphological difference observable between these two formation types. Although Schumacher (2005) offers a new proposal about the relevant problem in accordance with the time-honoured view, this paper points out that his ‘bigētun-Regel’ cannot adequately account for the morphological divergence at issue. Instead of the conventional interpretation of both the strong preterite and the preterite-present present tense forms having evolved from the PIE perfect alone, the current paper attempts to present a different formula, which may be called a ‘morphological conflation’ theory. This approach proposes that the preterite tense formations of strong verbs result from a mixing of the perfect and the imperfect, whilst the present tense forms of preterite-present verbs stem from an amalgamation of the perfect and the athematic present middle. It is contended that the difference in morphological conflation style has yielded the remarkable morphological differences between the two kinds of verbs under discussion.