Words can fully express the fundamental understanding of the universe. The relationship between language and thought was a prominent topic of debate in the Wei and Jin dynasties. Ouyang Jian (?-300) did not accept the view of Xun Can (209?-238) and Wang Bi (226-249), who alleged that “words cannot fully express thought.” Instead, he put forward the notion that “words can fully express thought.” In his opinion, thought represents perceptions of objects and reason, while names and words are reflections of them and are determined by things and reason. As a thought is acquired and expressed, it is analyzed and realized by names and words. Thoughts and their correspondent words are accord with each other and inseparable. Thus thought can be fully and exhaustively expressed.

Names change when the objects they refer to change. Language changes on the basis of reason. That is like the echo responding to a sound or a shadow following a shape. They are not to be considered as separate things. If they are not separate things, then there is nothing that cannot be fully expressed. Therefore, I believe language can fully express thought. (Ouyang Jian: On Fully Expressing Ideas, as cited in An Anthology of Pre-Tang Dynasty Literature)