陳大齊先生為政治大學在臺復校首任校長，也是「孔孟學會」首任理事長，一生奉獻於文化與教育，貢獻卓著。學術從早先的心理學與理則學，轉為名理之學，最後歸本於儒學研究，其中包括西方的心理學、理則學、印度因明學、以及儒家孔子、孟子、荀子的思想研究，從不同文化根基著眼，而歸結於名理內涵的辨析，兼容古今，學貫中西，儒學成為最後生命的依歸。然而陳大齊先生在完成荀子、孔子學說的建構之後，以名理辨析方式完成《孟子待解錄》，孟子成為建構儒學事業最後的工作，卻留下儒學思想「待解」的提醒，本文以「性論」作為討論核心，釐清辨析內容與相歧之處，期以了解陳大齊先生思考的重點，也藉此再次思考孟子性論的價值。

Ta-Tsi Chen (1886-1983), the first president at the reestablished National Chengchi University in Taiwan as well as the first director of the Confucius- Mencius Society in Taipei, dedicates all his life in culture and education. Chen is knowledgeable of Eastern and Western cultures: he focuses on learning psychology and logics from the West in the beginning of his academic life, then Hetuvidya in India, and in the later part of his life, he turns to study Confucianism, which includes thoughts of Confucius, Mencius, and Xunzi. After he establishes theories on Xunzi and Confucius, Ta-Tsi Chen writes The Record of Questions Waiting to Be Solved about Mencius (Mengzi daijie lu), and thus Mencius becomes the last important part of Chen's study of Confucianism. This paper aims to examine theory on human nature and the part ＂waiting to be solved＂ in order to understand the main point of Ta-Tsi Chen's thought as well as rethink the value of Mencius' thoughts.