<論説>「帝紀」・「旧辞」成立論序説

Abstract

今日、『古事記』の原資料である「帝紀」・「旧辞」の完成時期を、天武朝以降に求めるのが通説的理解である。しかし、『古事記』序文からは、天武による「帝紀」・「旧辞」の撰録・討覈の実施は読み取れず、また、『古事記』における王統譜の改作時期を天武朝以降に求める見解もその論証過程には不備が確認され、両書が『記』に直結する形に纏められた時期は、天智朝以前に遡及させなければならないといえる。 それを前提とし、主として『古事記』の王統譜を分析することで、現存諸史料には確認されない、息長氏・ワニ氏・尾張氏等の継体擁立氏族を主体とした、舒明朝における修史事業の存在を抽出した。その修史事業において、息長氏などは継体との関係を密接化させ、尊貴性を明確化させるために種々の系譜を創作したのだが、決してそれら氏族だけにメリットがあったと解釈すべきではない。修史事業参画氏族が、敏達―押坂彦人大兄―舒明という敏達王系と血縁関係を有していることに着目すれば、それら氏族出自の后妃を六世紀以降の王統の直接的祖である継体に至る王統譜上に添加し、その所生皇子などが即位するという事象を複数例造作することは、舒明即位の正統性を顕在化させることに結び付くのである。これを踏まえれば、舒明朝の修史事業とは、舒明の意向に立脚して推進された王権主導の事業であったことが判明する。

It has been generally accepted that the Teiki ("Imperial Chronicles") and Kyuji ("Ancient Dicta"), the source materials for the Kojiki, were compiled during and after the reign of Emperor Tenmu (reigned 673-86). From the preface to the Kojiki, however, it cannot be ascertained that the research and compilation of the Teiki and Kyuji were done by Tenmu. Furthermore, the process was flawed by which it was determined that after Tenmu's reign the imperial lineages were recast in the Kojiki. In fact, it was before the reign of Emperor Tenji (reigned 661-72) that the two works were compiled in a form that directly links them on the Kojiki. On this premise, mainly by analyzing the imperial lineages in the Kojiki, the existence of a historical compilation project in the court of Emperor Jomei (reigned 629-641) can be discerned, though it cannot be confirmed in extant sources. Central to the project were familial groups supporting Emperor Kitai (reigned early sixth century), namely the Okinaga, the Wani, and the Owari families. In this historical compilation project, these families created various imperial lineages which asserted their nobility and their direct connection to Emperor Keitai. This is not to say, however, that these were the only families with influence. The families participating in the historical compilation project were related by blood to the Bidatsu imperial line, consisting of Emperor Jomei. As such, they sought to actualize the legitimacy of the Jomei succession. To this end, they also fabricated multiple examples of imperial princes, sons of these empresses, succeeding to the throne. On this basis, then, it becomes clear that the historical compilation project of the Jomei court took place under imperial leadership, based on and driven by the inclinations of Emperor Jomei.