Kuo Hsiang was a high government official and an enthusiast for Taoism. Unlike Wang Pi who commented on the Lao Tzu, however, he commented on the Chuang Tzu. Evidences show that he incorporated much of Hsiang Hsiu's (fl. 250) commentary into his own-thus indicating plagiarism, of which he was not at all incapable. Some scholars speak of Hsiang-Kuo instead of Kuo Hsiang alone. However, their ideas are not different, and all texts still name Kuo Hsiang as the commentator.
Just as Wang Pi went beyond Lao Tzu, so Kuo Hsiang went beyond Chuang Tzu. The major concept is no longer Tao, as in Chuang Tzu, but Nature Jzu-jan). Things exist and transform themselves spontaneously and there is no other reality or agent to cause them. Heaven is not something behind this process of Nature but is merely its general name. Things exist and transform according to principle, but each and every thing has its own principle. Everything is therefore self-sufficient and there is no need of an over-all original reality to combine or govern them, as in the case of Wang Pi. In other words, while Wang Pi emphasizes non-being, Kuo emphasizes being, and while Wang Pi emphasizes the one, Kuo emphasizes the many. To Wang Pi, principle transcends things, but to Kuo, it is immanent in them.
However, Kuo Hsiang and Wang Pi are similar in that both consider that the sage rises above all distinctions and contradictions. He remains in the midst of human affairs although he accomplishes things by taking no unnatural action. But he is not someone who "folds his arms and sits in silence in the midst of some mountain forest." To such a sage, all transformations are the same and in dealing with things he has "no deliberate mind of his own" (wu-hsin) but responds to them spontaneously without any discrimination. Confucius, and not Lao Tzu or, Chuang Tzu, was such a sage.
In their philosophy of life, Kuo Hsiang differed greatly from Wang Pi in one respect. Kuo was a fatalist while Wang was not. Since according to Kuo everything has its own nature and ultimate principle, everything is determined and correct. Therefore he taught contentment in whatever situation one may find himself. Neither free will nor choice has meaning in his system.
Source : Wing-Tsit Chan, in Chinese Philosophy