自孟子提出「人性為善」的思想後，「人性」一直是儒家倫理學與人的哲學的中心概念。但何為性？性何為心？性何為理？性何為體？性何為命？都是儒學中最重要而必須回答的問題。儒學自其發展起點孔子到當代新儒家可說都是環繞著「性」的問題展開與深化。子貢雖言孔子之言性與天道不可得而聞，但孔子卻不是不言性與天道。人而無性，何以言仁，但孔子以性為德，實有更深刻的含義在，即為：性是人的自覺的向德之心志，也是力行成德的實踐過程。性兼具德之生、德之行、德之成三項意義，而非超越而定著的本質存在。孟子與《中庸》繼此發揮、逐能揭櫫性之為善的真諦。因為只有性能成於德，性乃為善，依此乃能有「天命為性」「繼之者善、成之者性」的體認。 本文抉發此一根德性及發展性的人性概念，並就其能完成其自身的創造性特予闡述，此即由原性以達圓性思想分析。舉出六項原性之典範以建立十二項之圓性內涵。原初之性如何圓成，圓成之性又如何彰顯原初之性之純以乃其源流之綿綿不絕但不失為儒學探索的大方向。依此大方向，我們也才能了解宋明理學中性為心、為生、為化等諸項命題的整體性意義與互補性意義，基於此我們才能賦予心性之學以「生命永遠創新之道」的涵義，也因而體會人性之內在超越相依互成的價值境界。

　　　　　The purpose of this article is to analyze the implication and presuppostion of the two philosophical theses "xing ji li" (nature is truth) and "xin Ji li" (heart/mind is truth) in Song-Ming Neo-Confucianism in a larger context of the Confucian-Neo-Confucian understanding of "xing/性 ". I plan to contrast "xing" as "naturality" with "li/理" as rationality which is atemporal and ahistorical as generally understood. In fact, "naturality" is even better understood as "xingli/性理" whereas "rationality" is to be better understood as "lixing/理性". The point of "xing Ji li" is to assert the explanation of naturality in terms of rationality. But here I render the two propositions in a common non-technical terms like "nature" and "truth" in order to be further explained and explicated. This context is determined in terms of correlative or polaristic paradigms involving "xing" which have evolved from the time of Mencius and the Commentaries 'of the Yi Jing (Yi Zhuan) which　provide the ontological and epistemological meanings of the xing.In the article I have divided the discussions under the following sections: 1.Points of divergence between Cheng-Zhu and Lu-Wang2. Comprehensive framework for a theory of original nature3. A proposed theory of perfection of the human nature4. Contemporary significances, of philosophy of heart/mind and human nature The question of xing has received much attention in the revival of Neo-Confucian philosophy (called Contemporary Neo-Confucianism) in both present-day Taiwan, Hong Kong, China and among scholars of Chinese philosophy in the United States. It has much also to do with a critical consciousness of both the difference and affinity between the Chinese philosophy of man and morality and contemporary Western philosophy of human existence and moral virtues. The study of this is very meaningful for development of a global onto-ethics and onto-ethics of futurity of humankind.