在荀子，「天」代表「自然」或「自然現象」；而〈性惡篇〉云：「性者，天之就也。」依之，「自然」與「人性」，在荀子看似為「生與所生／成」的關係。此外，如吾人所知，在主張「性惡」的同時，他特別強調「善偽」──人之成善乃出自後天人為的努力。成善之所以可能，客觀上乃因有聖王制定禮法以為人「化性以成善」之準則，主觀上則因人生而有能「以禮義來化『性惡』之『性』」的「心」。「心」，就荀子來，乃是人所以能成就道德行為之主觀根據。荀子從未明白說「心是性」；相反的，〈性惡篇〉說：「性不知禮義」，而〈解蔽篇〉表示：「知禮義」乃「心」之故。依之，「心不是性」。但「心」與其「知」的能力是人「生而有」（〈解蔽篇〉）。而荀子了解人性的原則是「生之所以然者謂之性」（〈正名篇〉）；此外，〈天論篇〉稱「心」為「天君」。（依「性，天之就也」，）這些都表示，對荀子來說，「心應當是性」。作為「道德實踐的根據」，嚴格說／一般說來，「心」應當是個「具道德意義與價值的存在」。但，無論「天」與「性」的關係為何，兩者於荀子都是一「自然義」的存在。在此情形下，荀子的「心」是否具有或能具有道德的意義、或只是一「自然義」的存在呢？除了由「心是性」方面之「心」為「天官」的身分來討論外，本文也將由「心不是性」方面之「心」的雙重性（「天君」與任之心）來作探討。經過扣緊文本的了解與分析，我們將發現，無論是從「心是性」或「心不是性」來看，荀子所了解的「心」都很難說它是個帶有道德色彩、具道德意義的概念。這表示荀子的道德實踐理論在此存在著、也必須面對「非道德意義的存在如何產生出／成就道德意義的存在（行為）？」之倫理學中最棘手的問題。

In XunZi, “T’ien” calls for “nature,” and the relationship between nature and human nature (Hsing) is “human nature is what T’ien produces.” Accordingly, Hsing in XunZi is natural and neutral in value. As we know, He claims “Hsing-er Sang-wei”, and views morally good action as resulting from mind’s (Hsin’s) directing and correcting Hsing with Li-Yi, which is made by the sage, not innate in our mind or nature. It is in terms of Hsin’s knowing Li-Yi and its directing and correcting Hsing according to Li-Yi that human has moral performance. Since so, Hsin is the foundation of morals in some sense. Hsin is given by nature. In this sense, it is Hsing (human nature). And Hsin can do these two works, for XunZi, because its essential function is to know things and it is at the same time the T’ien-Chung. But, according to XunZi, Hsin has to practice Hsi-Yi- Ching, otherwise it cannot really know Li-Yi and actually do what it can and should do as the T’ien-Chung. No matter as the knowing subject or as the T’ien-Chung, it is very hard to say that Hsin in XunZi is a moral being or carries out any moral sense itself (this is determined by its being Hsing). Thus, XunZi has to face the following problem in his moral theory: How is it possible for a non moral being to be the foundation of morals and carry out itself with moral value? In this paper, though deeply and carefully analyzing XunZi’s views about how human succeeds in doing morally, I conclude: The motivation and purpose of Hsin’s exercising Hsi-Yi- Ching, knowing Li-Yi, and directing and correcting Hsing with Li-Yi are all due to a moral purpose — acting morally and thereby becoming a sage, a man perfect in morals. Being so, we cannot say that XunZi’s Hsin (especially from the point of view that it’s functioning its essential functions, no matter as a knowing mind or as T’ien-Chung) does not carry out any moral sense at all though it is nor a moral being in itself.