In one sentence
Cheng (誠) is the Confucian concept commonly translated as sincerity, truthfulness, or being genuine; this Dictionary extends it to the alignment of inner state, outward expression, and action.
The term enters the Dictionary through The Sincere Society, but it also underlies the working relationship between the operator and his agent. In the Doctrine of the Mean, cheng has ethical and metaphysical meanings broader than the ordinary English sense of sounding genuine. It concerns becoming true to one’s nature and making that truth effective in conduct.
The Dictionary applies that older concept to sycophancy. Sycophancy rewards expressions that please power whether or not they reflect the speaker’s best judgment. The practical test is whether the same assessment survives pressure from preference, status, fear, and incentive.
For AI systems, the term becomes unexpectedly practical. A model that says what the user wants to hear is not sincere. A training system that rewards pleasing answers over truthful ones produces structural insincerity. An assistant that changes its assessment merely because the human pushed back has failed the cheng test.
For this Dictionary, sincerity is therefore an operating requirement: claims, confidence, conduct, and recorded evidence should agree.
See also
Source: The Doctrine of the Mean, Chinese Text Project.