「仁義禮智」這組概念，在春秋時似乎尚未出現，《論語》和《左傳》中都還沒有將仁、義、禮、智合成一組概念的記載。但到了戰國中期，儒家已經將這四個字合在一起並且賦予它們一定的內容和意義。這個情形可由《郭店楚簡》和《孟子》的記載得知。 《郭店楚簡》中的「仁義禮智」存在於「四行」和「五行」兩種方式當中，「四行」中的「仁義禮智」側重於社會規範的一面，而「五行」中的「仁義禮智聖」，則重在內在道德規範的一面。「五行」通過「聖」和「智」的作用，反省到道德規範與人性、天道間的關係，從而使這五種德行，不再只是社會規範，而是天道人性的自然呈露。 由於「五行」經過「形於內」的工夫後，會個別的與天道連結，形成各自獨立的五種德行；這五種德行雖然都十分美好，但當面臨人生種種複雜的境遇時，難免發生顧此失彼的現象。例如：古有叔嫂不相問之禮，但面臨嫂失足落於井時，為叔者當不當伸手相援？〈五行〉的作者顯然考慮過這方面的問題，所以提出「慎獨」的主張，讓五者合而為一。到了孟子時，他直接將仁義禮智納入人性的基本結構當中，一方面免除五行「形於內」時，向內追尋道德根源時的繁複步驟，另一方面避免五行各自為政所帶來的困擾。 〈五行〉的作者為了替道德尋找內在的依據，藉助的是「智」與「聖」兩種方法。孟子則將仁義禮智視為「四端」存在的基礎，而又將四端統稱為「心」，如此一來「心」的活動即是仁義禮智的外顯。另外他又認為「盡其心者，知其性也。知其性，則知天矣」，由此可知仁義禮智即是天理內在於人心的形式。因此他不再需要經由「聖」「智」的歷程，才能為仁義禮智找到形上的基礎。「聖」因此不再需要，在孟子一書中，「聖」從聽之以心的方法，和由之而得的德行，轉變成理想道德的實踐者－「聖人」。而「智」也不再具有見賢人知其為賢人的意思，轉而成為在判斷是非時，能以人性中最基礎的親親與敬長作為考量的那把尺，在分別對錯時，能以仁義作為標準，反問自己這樣做心安不安的智慧。 就孟子而言，他不需要〈五行篇〉中的「聖」與「智」，但他卻需要能夠強力反思的「思」與「求」。用以反省「心」的內涵，心的放失，與仁義禮智的擴充。 吾人觀察「仁義禮智」從郭店楚簡中代表社會規範的「四行」，到經由「形於內」的歷程，尋找到人性中的基礎與天道的依據後的「五行」；再到孟子時直接將它視為人性中的基本結構，這個轉變可說明思孟學派的儒家仁義禮智逐步內化的軌跡。

The set of concept of "Jen, Yi, Li, Chi" (Benevolence, righteousness, ritual and wisdom) still did not emerge as main thoughts in the times of the Spring and the Autumn. "The Analects" and "Biography of Zhuo Shi" did not have any record about Jen, Yi, Li, Chi as a whole. It was not until the mid period of the Warring State that the Confucians integrates them and provides a content of a certain meaning. This can be seem from the records of "Kuo Dian Chu Chien" and "Mencius". But did each have the same views on Jen, Yi, Li, Chi? The Jen, Yi, Li, Chi in "Kuo Dian Chu Chien" was comprehended in terms of the Four Elements and Five Elements. The Jen, Yi, Li, Chi expressed in the Four Elements emphasizes the establishment of social rules. But the Jen, Yi, Li, Chi, Sheng expressed the Five Elements indicates the establishment of inner moral rules. Through the function of Sheng and Chi, it reveals the resemblance of The Five Elements and Humans as part of the Heaven. It then elevates these Five Elements from social rules up to the level of natural emanation of humans as part of the Heaven. These Fie Elements combine with the way of Heaven respectively by means of the spiritual efforts from within. Thus Five Elements as virtues take shape. These Five Elements, though perfect, were impossible to be equally emphasized in face of the various troubles of life. For example, what should a man do when his sister-in-law gets drowned according to ancient ritual? Chang Rang indentified these five as one. But Mencius viewed Jen, Yi, Li, Chi as the foundation of human nature. It can thus achieve his philosophy of the Five Elements by omission of the process of inner moral efforts, and it can also eschew the disturbance caused by the fragmentation of that five. Mencius saw Jen, Yi, Li, Chi as the basis of the Si Duan (Four Cardinal virtues), and identified these four as "mind" which precisely displays the virtues of Jen, Yi, Li, Chi. The presentation of mind enables Mencius to contemplate the content of mind and waning and expression of it through "reflection" and "pursuit". There is no need to experience the process of Sheng and Chi. Through the social rules of the Five Elements Jen, Yi, Li, Chi find out the basis of human nature and the way of Heaven by means of the process of inner moral efforts. In the thoughts of Mencius, it was the basis structure of human nature. Transformation effectively helps us trace origin of Jen, Yi, Li, Chi back to early Confucianism.