Jiu Tian" theory is an essential part of YANG Xiong's philosophy .It plays a central and guiding role in the formation of
his philosophical and literary thought. "
article should be abstruse" is one of Yang Xiong's most important literary thoughts. Ever since the Song Dynasty, when Su Shi severely criticized his theory ,most critics throughout history have taken a negative attitude toward it. No scholars had done a thorough analysis based on the general characteristics of his philosophies. There have been even fewer people,if not at all , who have examined his theories on "Jiu Tian" and "article should be abstruse" in combination. The author thinks that YANG Xiong's "Jiu Tian" idea actually serves as the foundation for his "article should be abstruse " theory, and that at the same time the theory is consistent with prevailing aesthetic standards of that time.It is therefore,a reasonable philosophy in theory and the critics ' total negation of it since its inception has been unscientific and unwarranted.