<論説>大宝二年戸籍と寄口 : 造籍原理とその転換

Abstract

本稿は、大宝二年御野国戸籍と同西海道戸籍を比較分析し、もって両戸籍がもつ造籍原理の歴史的背景を明らかにするものである。御野国戸籍にみえる寄口は、各里の一戸あたり課丁数を均一化する目的で、人為的に分割され、各戸に分配された戸口である。これに対し、西海道戸籍の寄口は、課丁数を調整するという性格は弱く、一定数以上のまとまりをもつ親族集団が分割されることなく附籍されている。また、御野国戸籍で確認できる各里の規模には偏差が大きく、里が何らかの実態をもつ単位であることを示唆している。両戸籍にみえる造籍原理の差異は書式の違いに即応しており、時期差によるものと考えられる。御野国戸籍では決して不課戸を出さないという造籍方針が採られており、戸を人力・物資双方の供給源として強力な統制下においているが、これは七世紀戦時体制の反映である。八世紀に入り、平時体制に移行したことによって、西海道戸籍の造籍原理へ転換する。

The goal of this paper is to clarify the principles and transformation of the system of ancient household registers (koseki 戸籍) in Japan through a comparative analysis of the household registers of Mino province and the Saikaido region that are dated Taiho 2 (702) and elucidate the term kiko (寄口), which indicated a particular member of a household designated koko (戸口) within these registers, The understanding that the ko (戸; a sort of household) seen in the ancient household register system did not refer to an actual family but was an artificial unit created in response to administrative needs is the scholarly consensus today. If one were thereby to employ household registers as primary sources in an attempt to grasp the historical reality of ancient society, one must clarify the principle on which the household registers were compiled. kiko, the special object of analysis in this paper, is an appellation for the residents (koko) whose relationship to the main householder is not clearly identified in the household record, and they are concentrated in the both household records dated Taiho 2. In regard to the kiko, there has been debate over whether they were related to the main householder and their origins, and these debates have not been resolved. Yet, the current arguments over kiko have exaggerated the search for the general characteristic of the kiko to the extent that its changes over time have hardly been considered. This article is particularly concerned with this point. Both the household register of Mino province and that of Saikaido region are labeled as household records of Taiho 2, but the manner in which they are recorded vary greatly, and in fact it is thought that the Saikaido household register was likely produced sometime after Taiho 4. The manner of compiling household registers for Mino province was adopted from the seventh century and later, but the one for Saikaido region was reflected the newly introduced methods which was introduced in the eighth century. These household registers differ much from each other in the way of distributing kiko. In the case of the Mino household register, kiko were distributed so that the number of katei (課丁), men who shouldered the tax and labor tax burden, in each household would be equal. There would never be households without a tax burden. On the other hand, in the Saikaido household register, the distribution of kiko was not necessarily equal. It is thought that in the Mino household register the leveling of the number of katei was achieved at times by the arbitrary method of splitting family units, and it was the kiko that provided the margin to make this adjustment. In contrast, in the Salkaido household registers, it appears that they were compiled in a less capricious manner, maintaining the family unit. In recent scholarship questions concerning the leveling of the number of katei in a household have been raised, and it has been hypothesized that it was surely maintained at a minimum level. Furthermore, the hypothesis that the leveling was probably not implemented on each household but on each ri (里), a sort of settlement, is convincing. However, at least in the case of the Mino household register, the leveling was ultimately implemented on the household level, and the number of katei in each ri varied. There is a high possibility that this fact indicates that the ri, which has been thought not to have been an actual settlement but an artificial group compiled for the collection of taxes, did exist in some real sense. It is thought that the circumstances of the two periods are reflected in the creation of each method of compilation. In the seventh century under the diplomatic tension that peaked with the defeat at the Battle of Hakuson'ko, the collection of human and material resources was forcefully implemented. However, tensions eased after the reign of Tenmu, and the eighth century proceeded peacefully as is symbolized by the dispatch of envoys to Tang in the first year of the Taiho era. The historical background of the two periods, the warlike seventh century and peaceful eighth century, are reflected in the Mino household register and the Saikaido household register, respectively. The style similar to that used in writing the Mino household register was employed over a long period in the province of Mutsu, but this was likely a reflection of Mutsu's character as a frontline base in the conflicts of the period.