楚簡儒家佚籍的性情說，在文獻依據上係指《郭店楚墓竹書》中之〈性自命出〉篇，以及《上海博物館藏戰國楚竹書（一）》之〈性情論〉篇。這兩篇的文字內容幾乎相同，竹簡原無篇名，二書的編輯者分別補上不同的篇名。茲為論述的方便起見，我們暫且使用「楚簡性情說」來指稱。此說，就目前學者們所做過的多方面研究而官，其抄寫的時問應早於紀元前三百年前。由其文字資料編輯之形式，所論述之問題及要旨，可推測出是儒家較早期的思想史料。學界大致推認〈性自命出〉為孔子七十子後學所作，但是看法有所分波。有的學者將之定位於孔、孟之間，屬孔門後學向內求索的一派，有的學者定位為孔、荀之問。兩篇的主題雖各有側重，就思想的內在理路觀之卻相互關聯，旨在論述心性問題。心性之學是儒家思想的核心課題，至宋明理學受佛、道的影響，心性思想得到深廣的發展。朱熹與陸王的不同，其關鍵處即在心性論之不同，陸王主張心即理，朱熹則堅持性即理。本文旨在對比朱熹與楚簡儒家佚籍性情說之同異，以突出朱熹人性論得以長足的發展處及理論的精細周備性。在內容的安排上分為兩者之間「性」與「命」，「情」的概念涵義及其與性之關係，「心」的概念涵義及其與性情之關係，以及對兩方人性論之評價。

The anonymous book of the Chu Bamboo Slips was a manuscript produced before 300 B.C. In view of the editing formats and the questions and topics presented here, we can infer that this is an early philosophical text of Confucianism. Most scholars agree on the fact that the anonymous book was written by Confucius and the seventy disciples of his. The “doctrine of mind and human nature” is central to Confucianism, and this doctrine was more widely and profoundly developed in Neo-Confucianism due to the influence of Buddhism and Taoism. The distinction between Zhu Xi and the Lu-Wang school is their difference in the doctrine of mind and human nature. The Lu-Wang school claimed that Mind is Li (reason), while Zhu Xi maintained that Nature is Li (reason). This paper is meant to compare the similarity and difference between Zhu Xi's doctrine and the “doctrine of nature” recorded in the anonymous book of the Chu Bamboo Slips so as to stress the strengths, sophistication and wholeness of Zhu Xi's doctrine of human nature.