This term refers to writings of argument and persuasion in ancient times. An essay of argument and persuasion was written to explore a theoretical issue in an in-depth way (lun) and make an argument about it to persuade people (shuo). According to Liu Xie (465?-520) of the Southern Dynasties, in writing an essay of argument and persuasion, one should not blindly copy theories developed by earlier scholars. Instead, one should have his independent views. One should draw his own persuasive conclusion on a theory or a subject by way of reasoning on the basis of numerous facts. He should find support in classics and other relevant sources, draw on previous scholarly reflection and explore an issue comprehensively and elaborately. The wording of such an essay, whose aim is to convince its readers, should be candid and sincere; such an essay should expound truths and uphold the cardinal principle of righteousness. It should increase its persuasive power and emotional appeal by using rhetorical devices and citing concrete examples. But such an essay should not be written to please the readers against one's own will, nor should it be designed to mislead them. One who writes an essay of argument and persuasion should, as Liu Xie pointed out, arrive at a truth through independent thinking, basing his judgment on his own views and conscience. He should be both incisive in wording and elaborate in argument. All these views have become essential criteria for judging the merit of essays and important rules governing their writing.

The truths articulated by sages are called classics (jing). The interpretations of classics which explain permanent truths are called writings of argument (lun). (Liu Xie: The Literary Mind and the Carving of Dragons)

Writings of argument aim to distinguish right from wrong, explore concrete issues to arrive at an abstract principle,solve a difficult problem in an in-depth way, and make an exhaustive study to attain an ultimate truth. (Liu Xie: The Literary Mind and the Carving of Dragons)

The key to making a convincing argument is to seize an opportune moment and ensure that one's argument is justified. If an argument thus made is accepted, it will enhance one's credibility. If not, it will not harm one's reputation. To reason things out is not to fool one's opponents. Therefore, in making an argument,one should be truthful and credible. (Liu Xie: The Literary Mind and the Carving of Dragons)