This article provides a translation with commentary of the key parts of the Book of Han (Hanshu) concerning the reforms of the state cults during the reign of Chengdi (32-7 BC). The translated texts represent a substantial source on the form of, and ideology underlying state-sponsored religious rites in early imperial China. The translated debates demonstrate the controversy between partisans of the traditional view on the meaning and form of the rites, and the reformers (though the latter likewise present their case as a return to ancient models attested in the Classics). The traditional view of the religious rites holds that the rites should be conducted at the place where the gods themselves appear (the humans respond to the gods' actions). The reformists, on the other hand, set a universal rational framework (based on yinyang classification), which prescribes the proper way of revelation and sacrifice for both the humans and the gods. Furthermore, the debates are an interesting testimony to the identity of Confucianism in the given period. The rationalization of religious rites promoted by the reformists is usually associated with Confucianism. However, in these debates we find famous Confucians in both camps.