陳寅恪嘗言，「寅恪平生為不古不今之學，思想囿於咸豐同治之世，議論近乎湘鄉南皮之間。」歷來解者甚多，且各有精義，本文除全面檢索各家說法外，藉新出及過往所忽略的史料，更求新意者，即作為史家的陳寅恪非但專注於中古以降的史學，兼欲為歷代興亡的經世之學，非僅不古不今，且要通古知今，在不中不西之間，講求洋務兼顧中西之學，以肆應近代以來中國歷史遭遇的大變局。

Chen Yin-ko once said: “I have been preoccupied all my life with studies of subjects that are neither ancient nor modern, my thinking doesn’t go beyond the Hsienfeng and Tungchih periods of the Ching Dynasty, and my views are close to those of Teng Kuo-fan and Chang Chi-tung.” Many people have tried to explain the meaning of these remarks, and some of their interpretations are indeed valuable. In addition to present a comprehensive review of these interpretations, this study also tries to ex-examine Chen’s remarks in the light of previously ignored historical
materials. As a historian, Chen paid close attention to China’s pre-modern, medieval history. However, he was also interested in the kind of “practical, applicable studies” that seek to account for the rise and fall of dynasties. Thus, these studies are neither ancient nor modern in the history of philosophy, but it call for an understanding of the
present based on a thorough grasp of the past. In addition, these studies are neither in a realm of Chinese nor those of Western one. Furthermore, his scholarship also was neither exclusively Chinese nor exclusively Western. In the context of an unprecedented crisis in Chinese history, Chen’s scholarship, while focused on China’s response to the Western challenge in its dealing with foreigners, encompassed both Chinese and Western traditions.