魏禧（1624-1680）是清初重要明遺民群體――「易堂九子」中的核心人物。從魏禧及其弟子梁份（1641-1729）所探討的經世之學可知，清代經世之學發生了重大的演變：從清初致用於「後世」（「復明之世」）的恢復和重塑故國之學，演變為清中後期致用於「現世」（「清朝之世」）的治國理政之學。該演變其實早在17世紀後期即已發生，而非遲至現今學界所謂的18世紀才出現；該演變的決定性因素，也非清朝統治者「治道合一」觀的政治文化實踐等，而是三藩之亂（1673-1681）。三藩之亂對魏禧、梁份等明遺民的影響極為深遠，不僅使他們對清朝統治者的態度出現重大變化，而且使其探討的經世之學意涵也開始發生轉變。清代經世之學的演變，標誌著清朝統治合法性在明遺民心目中的確立，也標誌著清初的結束和清中葉的開始，明遺民開始從志在恢復和重塑故國的清初進入輔佐清朝統治的清中葉。通過這些討論，本文將有望展現清代學術與政治之間複雜的互動關係，深化我們對清初至清中葉一系列轉變及其歷史過程的認識，並由此揭示傳統的明遺民史與新興的「新清史」研究相結合的必要性。

Wei Xi (1624-1680) was the core figure of a Ming Dynasty loyalist group called “Yitang Jiuzi” (Nine scholars of Yi-hall), active in the early Qing Dynasty. By examining the scholarism of statecraft conducted by the Ming Dynasty loyalists Wei Xi and his disciple Liang Fen (1641-1729), in particular, we find that the scholarism of statecraft in the Qing Dynasty transformed from the scholarism to be used at a later time (when the Ming Dynasty was restored), that is, for restoring and reforming the Ming regime in the early Qing Dynasty to the scholarism to be used in the present age (during the Qing Dynasty) for better governing the empire in the middle to late Qing Dynasty. The critical period to effect this transformation was not to be some time in the eighteenth century but the Late seventeenth century, and the determining factor was not considered to be the political culture practices as based on the political tradition and Confucian orthodoxy, but rather the Revolt of Three Feudatories (1673-1681). The Revolt of Three Feudatories was highly significant to the Ming Dynasty loyalists, such as Wei Xi and his disciple Liang Fen. It changed their attitude towards the rulers of the Qing Dynasty, Which resulted in the transformation of their approach to the scholarism of statecraft. This transition marked that the legitimacy of Qing Dynasty rule had been established in the hearts of the Ming Dynasty loyalist, and meant the end of the early Qing and the beginning of the middle Qing Dynasty, the Ming Dynasty loyalists began to give up their ideal of restoring and reforming the old Ming regime and assist the rule of Qing Dynasty. Through this reexamination, this chapter is aimed to highlight the highly complex, interactive relationship between academia and politics in the Qing Dynasty, cast light on a series of changes and their historical process during the first half of the Qing, and reveal the need to combine the traditional history of the Ming Dynasty loyalists with the emerging “New Qing History.”