Zhang Zai

Zhang Zai's metaphysics is largely based on the Classic of Changes. According to Zhang, all things of the world are composed of a primordial substance called qi (also spelled Chi). For Zhang, qi includes matter and the forces that govern interactions between matter, yin and yang. In its dispersed, rarefied state, qi is invisible and insubstantial, but when it condenses it becomes a solid or liquid and takes on new properties. All material things are composed of condensed qi: rocks, trees, even people. There is nothing that is not qi. Thus, in a real sense, everything has the same essence, an idea which has important ethical implications. The most significant contribution of Zhang Zai to Chinese philosophy is his concern of qi as the basis of his ontocosmology. The qi or vital force is, according to Zhang Zai, the fundamental substance by which all processes of the universe can be explained. First of all, according to Zhang Zai, the qi or vital force is something forever in the process of changing. Second, the perpetual change of the vital force follows a definite pattern of activity according to the two principles, the yin and yang. The changes undergone by qi result from the perpetual activity of the yin and yang principles. Zhang Zai's conclusion is that there is nothing in the universe that cannot be explained in terms of the interaction of the twofold activity of qi. Third, the change of anything from condensation to dispersion, or from visibility to invisibility does not imply the idea of quantitative extinction of the thing in question. Fourth, Zhang Zai stresses the fact that although the creation and transformation of manifold things can be reduced to one uniform pattern (the interaction of the yin and yang) nothing in the entire universe is the repetition of something else. As an example presented by Zhang Zai, there are no two persons whose minds are exactly alike. Fifth, the perpetual motion of the physical world is not originally caused by any outside force. He states that the cosmos depends on nothing to be its first mover, for the qi as such is a vital and self-moving force that alone makes all change and motion possible (Huang (1968)).

Neo-Confucians primarily valued Zhang Zai's doctrine of the sage "forming one body with the universe." This doctrine represents both the Confucian contiguity with its classical Confucian heritage and an enlargement of the Neo-Confucian system. At the center of Zhang Zai's teaching is the idea of ren, humaneness or human-heartedness, in many ways the salient teaching of the classical Confucian tradition. This basic quality, which was for Confucius and Mencius the bond between human society and the ways of Heaven (tian) and hence fundamental to the underlying moral structure of the universe, was expanded by Zhang Zai to encompass the universe itself, since for the sage to form "one body with the universe" suggests the complementarity and fundamental identity of microcosm and macrocosm. The doctrine illustrates as well Zhang Zai's belief in the fundamental goodness and purpose of the universe and in the potential of the individual to realize the ideal of the sage. In the teaching of "forming one body with the universe," Zhang Zai also claimed to distinguish Confucianism clearly from Buddhism and Daoism. For him the universe and its processes have a real existence. In turn, human life is looked upon as intrinsically valuable and ultimately the very foundation for the realization of sagehood. For Zhang Zai, such a view is clearly distinguishable from Daoism and Buddhism, both of which require a radical departure from the universe as it is given in order to fulfill the soteriological quest. In Zhang Zai's terms, Daoism and Buddhism both emphasize escape from the world, while Confucianism finds fulfillment and ultimate identity precisely within the changes found in this world, a world of qi rather than of emptiness. The sage accepts the ultimate reality of qi and its inherent goodness, he acknowledges the infusion of ren throughout the very structure of the universe itself, and thus he can fulfill the ideal of the sage, "forming one body with the universe."