In an original and compelling examination of traditional mathematics, this comprehensive study of the anonymous Manual of Mongolian Astrology and Divination (published by A. Mostaert in 1969) takes on the fundamental problem of the post-enlightenment categorization of knowledge, in particular the inherently problematic realms of religion and science, as well as their subsets, medicine, ritual, and magic. In the process of elucidating the rhetoric and logic shaping this manual the author reveals not only the intertwined intellectual history of Eurasia from Greece to China but also dismantles many of the discourses that have shaped its modern interpretations.