魏禧(1624-1680)少好《左氏》，處江山易代之際，隱居江西翠微峰，放廢山中二十年間，以《左傳》授徒，對《左氏》中古人之經世大用，隱而未發之旨，頗有體會，因成《左傳經世》一書。該書自敘云：「《左傳》史之大宗。……古今御天下之變備於《左傳》。……嘗觀後世賢者，當國家之任，執大事，決大疑，定大變，學術勳業爛然天壤。然尋其端緒，求其要領，則《左傳》已先具之。」可知魏禧將《左傳》定位於決疑、定變之經世典籍。〈自敘〉對《左傳》的定位，也決定了《左傳經世鈔》的鈔選方針，本文擬擇魏禧所舉「古今定變大略」之《左傳》事例－「石碏誅吁、厚」、「子產焚載書」，「子皮授子產政」諸事件，探究魏禧所關注的春秋時代重要的人或事，並論證魏禧以史學經世之思考。又，魏禧以《左傳》作為教學重要教材，以上諸事件，都有魏禧與弟子間的論難詰辯，可以體察到魏禧之教學目的，在訓練學生日後從政時，當面對政治上重大變局與抉擇時，如何多元思考並尋覓解決之道。以下先略述魏禧其人其書，次論明清之際的經世風潮與魏禧的權變觀，再舉石碏及子產為例，論析石碏大義滅親所涉及君臣之道及親情倫理之衝突時，魏禧之處置態度；就子產追盜與焚載書兩事，探究魏禧如何設計論題，就處變定亂的經權之道課業諸生。章學誠(1738-1801)曾云：「史學所以經世，固非空言著述也。且如六經，同出於孔子，先儒以為其功莫大於《春秋》，正以切合當時人事耳。……學者不知斯義，不足言史學也。」《左傳》兼經史兩種性質，但古本無經史之分，窮經即是窮史，六藝（或云六經）皆「古帝王經世之大法」，明王陽明有「五經皆史」說，清章學誠有「六經皆史」說，以為「六經皆先王之政典也」，因此，稽古可以明道，經術可以經世。本論文以此觀點探論明末遺臣魏禧取鏡《左傳》本事，正所謂「窮經將以致用也」。

Wei Xi (1624-1680) was born in an era of dynasty transition. As an avid reader of Zuo Zhuan since his youth, he later taught Zuo Zhuan when leading a secluded life in Mountain Cuiwei, Jiangxi Province. During the two decades of his teaching, he explored the implications for government administration embedded in Zuo Zhuan and his collected findings were published in Zuo Zhuan Jing Shi Chao. Zuo Zhuan Jing Shi Chao is a book complied from a series of discussions conducted by Wei Xi to inspire his pupils to see things with panoramic perspectives. The events in Zuo Zhuan such as Shi Que's putting Zhou Xu and Shi Hou to death, Zi Chan's burning the treaty, and Zi Pi appointing Zi Chan as the premier serve as perfect exemplifications for Wei Xi to illustrate to his pupils his thinking about the theory of policy-making and change-tackling. This essay first tells about Wei Xi's personal background and his book, then introduces the intellectual and political ambiance of Wei Xi's contemporary. The aim of this essay is to scrutinize Wei Xi's thinking about policy-making and change-tackling in Zuo Zhuan Jing Shi Chao through the examples used in his teaching. Zuo Zhuan Jing Shi Chao has proved to the world that Wei Xi is not only an erudite historian but also an inspirational mentor who excels in his academic field and distinguishes himself in understanding the infrastructure of politics.