 The four objects of knowledge (A80) are names (míng 名, words), stuff (shí 實, including objects, events, and situations), “matching” (hé 合), and acting (wéi 為). The first two are explained by their role in language. Names are “that by which we call” (what we use to talk). Stuff (shí) is “what we call” (what we talk about). The next two concern the correctness of assertion and action. “Matching” is when name and thing fit together properly. “Acting” is intentional conduct. 