This refers to the rectification of what things are called so that name and reality correspond. A name is what is used to refer to a thing, which determines the attributes of the thing and its relations with other things. “Reality” refers to a thing or an entity that its name refers to. The name of a thing should conform to what the thing actually is. However, very often name and reality do not match in real life. To deal with this situation, the name of a thing should not go beyond the nature of the thing； likewise, the reality referred to by the name must not go beyond the scope that the name implies. The “rectification of names” is an important way to maintain the social order constructed by the names. Various schools of thoughts have agreed on the necessity of rectifying names, but they differ in their views of the concrete meanings of the names to be rectified.

If names are not rectified, one’s argument will not be proper. If speech is not proper, nothing can be accomplished. If nothing is accomplished, rites and music will not flourish. If rites and music do not flourish, punishments will not be meted out properly. If punishments are not meted out properly, people will have no guidance as how to behave. (The Analects)

Rectification is to bring forth what actuality is. To bring forth what actuality is is what it means to rectify the name.

(Gongsunlongzi)