Cheng
誠 (chéng)
Confucian sincerity, but understood in a strong sense that the French word weakens: not honesty toward others, but the perfect coincidence of a being with its own reality. The *Zhongyong* makes it the Way of Heaven itself; for Zhou Dunyi and Zhu Xi, it is the foundation of virtues and the driving force that leads things to their fulfillment. To be fully *cheng* is to realize one’s nature—and, in the same movement, to complete that of all things. (Confucianism has no proper entry in the nomenclature: this term is classified there as transversal.)
Sincerity is the beginning and end of things. Without sincerity there would be nothing. Therefore the superior man values sincerity.
« Sincerity is the beginning and end of all things. Without it, nothing would exist.» — Sincerity is the alpha and omega; without it, there would be nothing. The Zhongyong thus places cheng (誠) at the very core of being, not merely of morality. The term does not first denote candor toward others, but rather realizing authenticity: the seamless coincidence of a thing with its own nature.
The same chapter puts it another way: «Sincerity is the Way of Heaven; attaining sincerity is the way of man.» Heaven is cheng effortlessly—it does not dissemble what it is. Man, however, must become so, by fully developing his nature until it fulfills itself. To perfect one’s own being, the text says, is humanity; to perfect that of all things is wisdom—sincerity unites inner and outer.
Zhou Dunyi takes this further: «Wisdom is nothing other than sincerity», the foundation of the five constant virtues and the source of all activity. For this school, the Confucian Dao is not the Taoist void but precisely this cheng—a course of things described as truthful, where reality never eludes itself. This is why cheng paves the way for the fusion of knowledge and action: a fully sincere being knows no other way than it acts.
Cheng is not psychological sincerity, that feeling of speaking truthfully which may still accompany error: it demands reality, not intention. Nor is it one virtue among others—it is that without which no virtue holds.