顧炎武(16I3-1682)於順治14年(1657)離開江南北上之後，先後在山東、北京、 山西、陝西等地結交了很多新朋友。其中不少是堅苦守節、矢志忠於前朝的遺民。此事一直 為治亭林生平者所樂道。但亭林晚年在北方的知交中，其實也包括了一些名節已虧、行誼廣 遭物議的「貳臣」在內。其事則尚鮮為史家所注意。利用亭林的詩文和《年譜》，以及同時 人的詩文別集， 比對互證，可以確定亭林與朱彝尊 (1629-1709) 曾在康熙初年的十餘年間 ，和當時著名的「貳臣」孫承澤 (1592-1676) 建立過深摯的友誼。 三人在孫氏京師的寓所 及其近郊的別業，經常舉行詩酒之會，研藝論文，涼亭觀晝，超然於政治之外，彼此相視莫 逆。可見亭林晚年擇友，固未嘗以其人之政治操守為去取的標準也。

　　　　　It is well known that Ku Yen-wu 顧炎武 (1613- 1682 ), a Ming I-min 遺民 living in the early Ch'ing, made many new friends in North China during the last twenty-five years of his life. Also uncontested is the fact that many of Ku's new friends shared his devotion to scholarship, as well as his anti-Ch'ing political stance. In fact, on the basis of these friendships, a number of scholars have concluded that Ku continued to carry on his struggle against the new regime after moving northward in 16@7. What few scholars realize, however, is that among Ku's many new friends were also a number of individuals who had displayed highly questionable political ethics during the dynastic transition. Among these were Ts'ao Jung 曹溶 (1613-1685)and Ch'eng Hsein-chen 程先貞 (1607-1673), whose friendships with Ku I have already analyzed else-where. The present article, a continuation of this earlier study, reconstructs the intriguing friendships among Ku; Sun Ch'eng-tse 孫承澤 (1593-1675), a Ming high-ranking offical who surrendered first to the rebel leader Li Tzu ch'eng(1605?-1645)and then to the Ch'ing in 1644;andChu I-tsun 朱尊 (1629-1709), who participated in military strugles against the Ch'ing while young but was in his later years co-opted by the new regime. The discovery of the close friendships between Ku and the two collaborators Sun and Chu confirms my earlier finding that proper political behavior was by no means a requisite in Ku's choice of friends. Further-more, it provides additional evidence to support my contention that those common interests in scholarship, poetry, and other cultural activities figured so prominently in Ku's choice of friends that he was willing even to befriend individuals whose political behavior directly violated his own ethical standards. Finally, it seems reasonable to conclude that duringthe last years of his life, Ku, contrary to the views of some recent schol-ars, placed a much higher premium on cultural affinity than on political agreement. He seemed no: longer to expect that all of his friends sharehis political stance.