The popular and influential Śūramgama sūtra receives a fresh lookin James A. Benn's study. Although Japanese, Chinese, and European scholars have firmly established the scripture to be an eighth-century Chinese Buddhist apocryphon, its contents and their parallels in non-Buddhist Chinese sources invite further exploration. Benn notes some connections with other Chan-related apocrypha, such as the Vajrasāmddhi sūtra and the Yuanjue jing, but his main focus is on tracing ideas in the Śūramgama back to works of secular literature that were well known in Tang China. Some passages were clearly influenced by Chinese, rather than Indian, ideas about certain natural phenomena, animals, and demonic beings. The Śūramgama sūtra, Benn argues, was a sophisticated attempt to create an entirely new hybrid cosmology that would attract the interest of the monastic and lay intelligentsia in China.