 Canon A80 gives a categorization of three sources and four objects of knowledge. The sources of knowledge are hearsay, or testimony; “explanation,” or inference; and “in person,” or observation. Hearsay or testimony (wén 聞) is explained as “receiving it as passed along.” Elsewhere, “passing along” is glossed as “someone reports it” (A81), and “reporting” (gào 告, also “informing”) is itself explained as “making someone know” (B9). Explanation (shuō 說) is illustrated by the example “squares do not rotate.” Other passages explain it as “that by which one understands” (A72) and as a process of citing reasons or causes (NO11). “In person” or “personal” (qīn 親) is explained as “observing it there oneself.” This notion is probably the closest the Mohists come to articulating a conception of experience. However, since they do not, in fact, use any term interpretable as expressing an explicit concept of experience, we should stick closely to their terminology and characterize “personal knowledge” (qīn zhī 親知, B70) as knowledge by observation (guān 觀). 