曆數與推厄──漢唐間的「陽九百六」說及其災異論述

Calendar Systems and Calculating Natural Disasters: The Thought of“Yang Jiu Bai Liu”陽九百六and Related Discourses during the Han and Tang Dynasties

「陽九百六」 首見於谷永「三難」，後經王莽引述已經擺 了《易九厄》的曆算邏輯，其災厄週期因現實處境的變化而被無限期延長。中古時期「陽九百六」 ，既有對《易九厄》水旱災害本義的傳續，也有結合政治情境作出的引申，此外兼可指代個體的死亡，皆與曆法之災厄週期無關。最終，陽九百六成為一個帶有宿命論色彩的災異政治文化符號。溯其淵源，作為緯書曆法思想中災厄推算模式的代表，《易九厄》、《易緯》推厄法與京氏《易》學緊密相關，是陰陽災異思想與曆法知識結合、比附的產物，反映出《太初曆》頒行後曆法知識與災異學 互動交流的現實情況。

The thought of “yang jiu bai liu” 陽九百六, which concerns long-term cycles of natural disasters and first appeared in the works of Gu Yong 谷永 (?-ca. 8 BCE), namely those on “san nan” 三難 (lit. the three disasters), was later quoted by Wang Mang 王莽 (45 BCE-23 CE) and broke away from the calendar logic of Yi jiu e 易九厄, the disaster cycle of which became indefinitely extended due to changes in the real contemporary situation. In the Middle Ages, “yang jiu bai liu” not only inherits the original meanings of flood and drought disasters from Yi jiu e, but also expands their connotations by incorporating the political situation of the times; moreover, it can refer to the death of individuals, which is admittedly unrelated to the disaster cycle of the calendar system. Ultimately, “yang jiu bai liu” became a political and cultural symbol of fatalism. Tracing its origin, the method of calculating natural disasters and their cycles in Yi jiu e and Yi wei 易緯, representative of the calculation models in the calendar thought of weft texts 緯書, is closely related to the study of the Book of Changes of Jing Fang 京房 (ca. 78-37 BCE), which is the product of the combination and comparison of thought on yin, yang, and natural disasters or other strange phenomena and calendar knowledge as well as reflecting the reality of the interactions between calendar knowledge and related theories on disasters after the issuing of the Taichu Calendar 太初曆.