This study examines the cosmology of the monk Amoghavajra (Bukong 不空; 705–774), as outlined in his astrological manual, the Xiuyao jing 宿曜經 (Sūtra of Lunar Stations and Planets), as well as its historical background and context, in relation to classical Buddhist models of Mt. Meru and the Four Continents in the Āgamas and Abhidharma. These models all use a flat-earth model, in contrast to the spherical-earth model utilized within classical Indian astronomy. This study shows that although the spherical model was known in Chinese from at least the early eighth century via the Jiuzhi li 九執曆 (*Navagraha-karaṇa), a translation of an Indian astronomical treatise, Amoghavajra consciously adopted the flat-earth model in his cosmology, yet at the same time he was willing to introduce new astronomical elements, such as the planets and the zodiac signs. It is argued that Amoghavajra’s cosmology constitutes an intriguing example in Buddhist history of a religious worldview taking precedence over a scientific one, yet at the same time it is demonstrated that Chinese Buddhist literature was not averse to incorporating some scientific astronomical elements before, during and after Amoghavajra’s time.
