自孟子以仁義禮智建構著名的性善說開始，歷代儒者談論心性問題、工夫問題乃至天道問題，幾無不以這四個觀念作為主脈。唐君毅先生作為當代大儒，在其多部鉅著中對仁義禮智多所著墨，自屬當然之事。細察唐先生所論，不僅於孟子言仁義禮智之文字中應涵而未顯之義理，有極明晰的補充說明外，其對仁義禮智之義涵及四者之關係，更有許多創新的見解。尤有進者，唐先生對某些議題的探討，甚至反映出他有意把仁義禮智提昇為一種思考間架或說話方式。要之，唐先生論仁義禮智，既是解讀孟子意，亦屬賦與新義理，也在建立方法論。以下嘗就這三條線索，整理唐先生探討仁義禮智之文字，從中略論唐先生在儒學上的貢獻。

Since being given a significance by Mencius pertaining to the establishment of the theory that human nature is good, ren, yi, li, and zhi, which are commonly translated as benevolence, dutifulness, ritual, and wisdom, respectively, have traditionally been taken as main concepts by Confucians, including Tang Junyi undoubtedly, whose interests are themes including human nature, self-cultivation, as well as the essence of Dao. Focusing on Tang’s writings connecting to the four concepts mentioned above, it will be argued that Tang not only provided a reasonable interpretation of Mencius’s view on the goodness of human nature, but constituted a new theory where new meanings of, and new relations among, ren, yi, li, and zhi are created. Besides, it will too be claimed that, from a methodological point of view, the slogan of “ren-yi-li-zhi,” as originally a mere research material, has creatively been refined as a conceptual framework.