Duduan 獨斷 "Definitions [in government and administration]" is a short handbook on the political institutions and rules of government ("constitution") of ancient China until the Later Han period 後漢 (25-220). It is traditionally attributed to the scholar Cai Yong 蔡邕 (132-192) from the very end of the Han period. The compilers of the series Siku quanshu 四庫全書, however, were aware that the received version cannot have been written by Cai Yong but must be of a somewhat later date. The oeuvre of Cai Yong is very rich and includes rhapsodies, poems, odes, tomb inscriptions, memorials to the throne, letters, and treatises like the Shihui 釋誨, Xuyue 敘樂, Nüxun 女訓, Nüjie 女誡, Zhuanshi 篆勢, or the Quanxue 勸學.
The information provided in the Duduan corresponds to descriptions in the contemporary ritual classic Liji 禮記, and not to that in the Zhouli 周禮, which allegedly reflects administrative rules of the government of the Western Zhou period 西周 (11th cent.-770 BCE). Exceptions are some minor differences like the size of official caps. It can also be seen that sources quoting from the Duduan, like the Tang-period 唐 (618-907) encyclopaedia Chuxueji 初學記, present sentences not included in the received version. The latter nevertheless seems to be a complete overview of the most important ceremonial aspects of the central government. The Song-period 宋 (960-1279) scholar Wang Yinglin 王應麟 (1223-1296) reconstructed the Duduan from the literary fragments he could obtain. His Xinding duduan 新定獨斷, a revised version of the Duduan, is lost, and the version compiled for the Siku quanshu 四庫全書 is thus only fragmentary.
The Duduan begins with definition of a lot of terms centering around the emperor, personal pronouns used by himself and by others, imperial carriages, the palace, seals, and documents issued by the emperor and submitted to him. It goes on to define the different terms for the imperial consorts, the princely establishments, the hereditary states, ancestors and gods, and the various sacrificial spots. It describes the ritual activities of the emperors through the year, like offerings or hunts. The last part of the Duduan deals with names of ceremonial caps and posthumous honorific titles for emperors and dignified persons.
|制書：帝者制度之命也，其文曰制詔，三公赦令贖令之屬是也。刺史太守相劾奏申下土遷書文亦如之。其徵為九卿，若遷京師近宮，則言官具言姓名，其免若得罪無姓。凡制書有印使符下，遠近皆璽封。尚書令印重封。唯赦令贖令，召三公詣朝堂受制書。司徒印封，露布下州郡。||Documents issued by the sovereign are standardized as decrees (zhi) and ordinances (zhao). [Decrees] are, for instance, orders to the Three Dukes, orders of amnesty, or orders of transmuting punishments into financial payment. The term is also used when regional inspectors or commandery governors check and submit to the court documents from subordinates. For the identification of the Nine Chamberlains, if they approach the imperial capital and palace, their titles and full names are indicated in the document, but not the name, if they are involved in a trial. All decrees bear the imperial seal as a token for transmission. If the Imperial Secretariat double-seals its decrees. Only for amnesties and orders of transmuting punishments, the Three Dukes are ordered to instruct the court to accept such documents. The Minister of Education seals decrees to pronounce military orders to the provinces and commanderies.|
|詔書者：詔誥也，有三品，其文曰告某官。官如故事，是為詔書。羣臣有所奏請，尚書令奏之，下有制曰天子答之曰可。若下某官云云。亦曰詔書，羣臣有所奏請，無尚書令奏制之字，則荅曰已奏。如書本官下所當至，亦曰詔。戒書戒勅，刺史太守及三邊營官被勅文曰有詔勅某官，是為戒勅也。世皆名此為策書，失之遠矣。||Ordinances are "explanative instructions", with three degrees. The text goes "announcement to the official NN". xxx. If any minister desires to submit a petition, the Imperial Secretariat shall allow him to do so, and the petition shall be answered positively by a decree of the Son of Heaven. Documents with the formula "Sent down to officer NN" are also called ordinances. If any minister desires to submit a petition but no notification for a decree is made by the Imperial Secretariat, [the sovereign's] answer includes the words "already submitted [at an earlier point of time]". xxx|
The Duduan is included in the series Baichuan xuehai 百川學海, Gujin yishi 古今逸史, Gezhi congshi 格致叢書, Han-Wei congshu 漢魏叢書, Congshu jicheng 叢書集成, Sibu congkan 四部叢刊. These editions are based on several prints, one from the Baojing Studio 抱經堂, one facsimile of a Song print by the Ming-period scholar Liu Xun 劉遜, and one from Jin Weiyuan 金維垣.