Yi (義) means justice and rightness. Yi is the fundamental virtues because it makes Li is reasonable. Yi also means suitability. The decision what is right and properly ,it depends on the decision rationally. Therefore, it can be said that Yi is a virtue that show decision rationally that what should act in a specific situation. In generally, to followed the Li it is right and proper, but in specific situations beyond that Li set or in case of emergency. Yi will decide how it should do.