 To sum up, the Dialectics presents a theory of language on which reference is explained by speakers’ associating “names” with kinds of similar objects, events, or situations (shí 實). Communication is explained by language users’ familiarity with the kinds of similar things referred to by “names.” The relation between language and the world is not explained by appeal to meanings, ideas, or concepts in the mind, nor abstract essences of things, but by practices for distinguishing different kinds of similar objects. This naturalistic theory seems highly plausible, as far as it goes. But it raises several crucial questions: How should things be divided into kinds? What makes things belong to one kind or another? What justifies recognizing certain kinds rather than others? As we will see, a weakness in later Mohist thought is that they leave these questions partly unanswered. Their texts make it clear that they recognize the issues. Yet they lack an explicit, principled explanation of what similarities and differences should count in distinguishing kinds of things and why. 