Chu Hsi's "Treatise on Jen"
THE ISSUES most actively discussed by scholars in recent years concerning Chu Hsi's thought, in particular his weltanschauung, are his views on t'ai-chia (Supreme Ultimate), which explore the original substance of the cosmos, and on li-ch'ib (principle and material force), which explain the overall structure of the cosmos. These issues have generally been regarded as the most philosophical aspect of Chu Hsi's thinking. Yet there is, in the traditional thinking of the Chinese people, the notion of the unity of Heaven and man (t'ien-jen he-ic). In the long history of Chinese thought, this idea has manifested itself in various forms. This is a concept that asserts the continuity between nature and man as well as the identity between the principles of the natural world and that of the human world. Furthermore, it is a concept that maintains that if something spiritual does exist in the natural world, this spirituality is best manifested in the human mind. The Mencian statement that "when the original nature of man is understood, then Heaven will also be understood" 1 is premised upon this idea of t'ien-jen he-i. Concerning this statement, Chu Hsi offers the following explanation:
Nature (hsingd) is the allotment that is endowed to man. Heaven (t'iene) is the principle that is shared in common by the myriad things. Heaven is thus an enlarged version of man, while man is a miniaturized version of Heaven. The Four Moral Qualities of Humanity (jenf), Righteousness (ig), Propriety (lih), and Wisdom (chihi) inherent in human nature are identical with the Four Qualities of Origination (yüani), Flourish (hengk), Advantage (lil), and Firmness (chenm) intrinsic to Heaven. All things possessed by human beings come from Heaven. Thus if we understand our own nature, we will understand Heaven as well. 2
According to Chu Hsi, therefore, even though there may be a vast disparity between Heaven and man, their basic structures are essentially identical. This being the case, it follows that when man is understood, so will be Heaven. Indeed, there were thinkers who argued precisely from this standpoint. Ch'eng I-ch'uan (Ch'eng I,n 1033-1107) made the following observation: