Abstract
One of the most notable historical features of Japanese writing was the coexistence of two or more writing styles. Therefore, in the historical research of Japanese writing systems, one of the most important problems is to solve why two or more writing styles coexisted and how the uses of two or more writing styles were distinguished. Current historical research into Japanese writing systems has suggested only the indexes of formality and informality for these questions. But this is clearly insufficient to give a satisfactory explanation for that historical phenomenon. So, this thesis emphasizes the viewpoints of generality and distinctiveness for historical research into Japanese writing systems. In this research field, generality and distinctiveness have two levels as follows.(1) Generality and distinctiveness of the literate society within the whole society. (2) Generality and distinctiveness of a specific writing system in the literate society. Each element of these is related to the cause of transition and the transition speed of the writing systems. To be more concrete, in the non-general literate society, new writing systems were easily invented, and each writing system was frequently distinctive; in the general literate society, each writing system was also to become general, and new writing systems were not easily invented. The turning points between these aspects of things were connected with the collapse of the ancient social systems that called Ritsuryo-sei.
