郑玄易学中的天道与政教

Heavenly Principle and the Political Civilizing Process in Zheng Xuan's Theory of Yi

魏晋南北朝时期,易学最主要的是郑玄、王弼两家。李鼎祚评骘两家说:“郑则多参天象,王乃全释人事。”此语颇嫌武断,问题的关键在于如何理解郑玄所谓的“天象”及“天道”。有别于王弼抽象化的天道论述,郑玄将天道与天象紧密关联,建立了具体而形上的天道论述。相比于以体用模式以及按照时间生成顺序来理解形上-形下结构,基于空间的意象来理解其实更符合其本义。形而上之天道,便是人被造之来源;形而下之器具,便是人展现自身创造性、参天地化育之结果。在这样一种空间意识的理解中,“形上-形下”之分不是抽象与具体之别,而是本源与生成之分。天道因此在郑玄那里成为其“政教”的本原,而以二十八宿、干支等体系来解释或理解具体的天道,是郑玄“爻辰说”这一象数体例的形上学来源和政治学目的。以此对照王弼的言象意理路,有助于揭示六朝时期郑王两家此消彼长的思想实质。

Zheng Xuan and Wang Bi were the most important commentators on the Yijing in the Six Dynasties period.Li Dingzuo has said that Zheng Xuan preferred the principles of Heaven while Wang Bi focused on human affairs.However,this judgment is questionable:we need to study what did Zheng Xuan meant by“the principles of Heaven”.When he spoke of what is“beyond form or beneath form”,he was trying to show a spatial meaning besides an ontological or temporal meaning.That is,Zheng Xuan developed a spatial metaphor.Heaven which was above was the originator of human beings,while the implements which were below were the production of human beings.Therefore“above-form”and“below-form”are not about the difference between the abstract and idiographic,but the relationship between the source and the current.Zhengxuan's Yaochen-learning,which explained the hexagram diagrams using lunar mansions,can thus be understood more clearly.We can also distinguish Zheng and Wang Bi's learning more clearly.