西漢「堯後火德」說的成立

The Establishment of the Western Han 'Yao hou de' Doctrine

本文以辨析文獻的方法，試圖恢復西漢「堯後火德」說的成立經過。進而發現：此說不僅是「漢為火德」、「漢家堯後」的複合命題，並且「漢家堯後」亦可分作「傳國之運」、「劉姓世系」兩部分。就「漢為火德」而言，乃劉向改造鄒衍學說而成；以「傳國之運」來說，最早由昭帝時的眭弘提出。其後劉歆融合「堯後」、「火德」兩說，建構出《世經》的古史系統。另外，劉向以漢室親族、職任宗正的身分，回溯「劉姓世系」至戰國初期。到了新莽、光武之際，儒生才於《左傳》中增添「其處者為劉氏」一語，確認堯帝和劉姓的血緣譜系。至於儒者立論的證據，完全都可以在司馬遷所著《太史公書》中找到相應資料，可知《史記》正是西漢儒生建構「堯後火德」的主要參考。

This paper uses textual analysis to try to recover the process by which the Yao hou huo de堯後火德doctrine was established. The research concludes that this doctrine is not merely a combination of the Iwo claims that the Western Han dynasty were the ”descendents of Emperor Yao” and ”holders of the virtue of fire.” The claim that the Han imperial family were Yao's descendants can be divided into two aspects: first, the fated passing down of state power to the Han, first mentioned by Sui Hong 眭弘; and second, the dating back by Liu Xiang 劉向 of the pedigree of the Liu 劉 family surname to the early Warring States period, and later confirmation by scholars that the bloodline could indeed be traced back to the Emperor Yao. The claim declaring the Han as ”holders of the virtue of fire” can also be traced to Liu Xiang, who remolded Zou Yan's 鄒衍 earlier doctrine. This refers to a schema in which each successive dynasty was associated with one of the five elements. Finally, it was Liu Xin 劉歆 who later combioed the two claims together in the Yao hou huo de doctrine. The main references for the construction of this doctrine by Confucian scholars can all be found in the Shi ji 史記.