In a society of acquaintances, friends and neighbours deal with one another largely through favour, face and yuanfen. When someone has helped me I must repay him, which is the reciprocity of favour; and yuanfen says that a meeting between two people has a cause.
The ritual thought of the Warring States held that "courtesy values coming and going, and going without coming is discourteous", and the line was later taken into the chapter on the rules of propriety in the Book of Rites, setting the ethic of reciprocal favour.
In about 402 Kumarajiva and others translated Buddhist texts in quantity, the Buddhist idea of causes and conditions spread widely, and the word yuanfen gradually entered Chinese thinking about human relations.
Reciprocity is the class in the chapter on Values on how people deal with one another in a society of acquaintances. Favour, face and yuanfen, the sense of a bond fated between people, are the habits of mind by which friends and neighbours repay one another, and beyond ties of blood they form bonds of mutual care.
