The usage of the word Asura differs depending on whether people in the past took Asura as good or evil beings. In my Ph. D. thesis, I threw light on the historical usage of the word Asura in the Vedas, Nikāyas, and early Mahāyāna sūtras, literature created before the dawn of the Common Era. I also investigated the difference between Asura in myths and human Asura, as the usage of the word Asura was applied to each group. Additionally, I found that Asura were written about not only as human beings in some situations but also as spirits in others. In a former study, I examined sūtras but did not examine Vinayas or later sources. Therefore now I use the Mahāvastu and the Datang Xiyu ji大唐西域記,a travelogue of Xuanzang玄奘,and the Datang daci’ensi sanzang fashi zhuan大唐大慈恩寺三藏法師伝,a biography of Xuanzang, and I examine the influence of the historical human Asura on the rise in mythical Asura of scriptures from various viewpoints.
