A gentleman has benevolence in his heart and etiquette in his heart: a benevolent person loves others, and a polite person respects others. Those who love others will always love them, and those who respect others will always respect them.

——Mencius: " Mencius. "Li Lou Xia"

Courtesy should be reciprocated. Going but not coming back is not polite; coming but not going back is also not polite.

——"Book of Rites. Qu Li Part 1"