1 Buddhist Cosmology in Late Nara and Early Heian Japan Ronald S. Green 1 Presented at the 2024 ASIANetwork Conference April 14, 2024, Atlanta, Georgia This paper examines the rich and complex cosmological views held during the late Nara and early Heian periods in Japan, focusing on the contributions of two eminent Buddhist scholars, Gomyō (758-843) and Kūkai (774–835). Through an in-depth analysis of their writings, we explore the multifaceted Buddhist understanding of the universe and multiverse, encompassing its evolutionary cycles, structural organization, and the intricate geography of its worlds. As shown in other studies, knowledge of medicine, civil engineering, architecture, and other areas were often spread from other countries to Japan by Buddhist travelers and Indian Buddhist texts. 2 Gomyō's writing containing the description of the geography of the earth and beyond is Chapters Providing a Brief Study of the Mahāyāna Yogācāra (Daijō hossō kenjenshō, Taishō 2309) and Kūkai's is the Mysterious Maṇḍala of the Ten Abodes of Mind (Himitsu mandara jūjūshinron, Taishō 2425). Both of these writing are believed to have been composed in response to an imperial order around the year 830. They are considered to by a part of the Tenchō era Writings of Six Schools (Tenchō rokuhon shūsho). Gomyō's sources Gomyō's cosmological descriptions reference Abhidharma and Yogācāra literature, providing a detailed account of the structure of the universe and the cyclic nature of its existence. The specific sources he mentions are: • Abhidharma-nyāyânusāra śāstra: A work that provides an analytical and detailed description of Buddhist cosmology, psychology, and philosophy, discussing the various realms of existence and the process of rebirth according to karma. • Yogācārabhūmi-śāstra: A foundational text of the Yogācāra school of Mahayana Buddhism, which includes detailed discussions on the stages of the bodhisattva path, meditation practices, and the nature of consciousness. • Abhidharmakośa-bhāṣya: A comprehensive encyclopedic work by Vasubandhu that summarizes and analyzes the teachings of the Abhidharma, presenting a systematic account of Buddhist psychology, cosmology, and doctrine. Kūkai's sources: Kūkai mentions the following sources for his descriptions of cosmology, relying heavily on Yogācāra texts. Unlike Gomyō and without taking sides, Kūkai points to where these texts sometimes disagree in their description of cosmology. 1 Coastal Carolina University, rgreen@coastal.edu 2 See for example Confluences of Medicine in Medieval Japan: Buddhist Healing, Chinese Knowledge, Islamic Formulas, and Wounds of War by Andrew Edmond Goble.