The sources of "knowledge," for Hsün-tzu, came from the realities in objective existence. He took the impressions of these objectively existent realities as his basis of knowledge.

The thirty-three sections of the Chuang Tzu annotated by Kuo Hsiang of the Chin dynasty were published during the period of the Northern Sung dynasty. Meanwhile, a preface allegedly by Kuo Hsiang was also printed in the book. The preface is as follows:Chuang Tzu was a man who had good knowledge of the origins of things in the universe and avoided no fantastic ideas. His remarks are hard to understand yet pertinent to phenomena. Any remark which is hard to understand (...) yet pertinent to phenomena may be true but useless; any remark which touches no actual things may be lofty but impracticable. This is surely different from a reluctant rise after inability. If the mind is free from preoccupations, it will respond to events at any time, and as a result, remarks will be cautious. Adapting himself to changes in the universe, Chuang Tzu was not merely turning out writings in the form of dialogues on things beyond human experience. (shrink)