Critics argue that Kant made the rule by reason and the freedom of will the core of ethics, but natural feelings in human nature were ignored as irrelevant, so that many problems and paradoxes are present in everyday life.Partial emotions including friendship and love especially have no ground.This paper points out that Kant fully elaborates this kind of personal relations in his later ethics.As the duty of love, they are virtues that humans should have.On the basis of the moral feelings, Kant puts forward a more perfect theorydeontological sentimentalism that claims reason and emotions cooperate based on the moral rule.Kant’s methed avoids criticism from the emotionalists effectively.Furthermore,it develops the intension and extension of moral duty.Kant objects that a person makes use of reasonable rules disregarding concrete conditions in the name of justice.He advocates that the founding of moral rule should aim to keep the more positive and favorable sentimental relationships between humans.

German philosophy; ethics; Kant; moral emotion; moral rule; reason; friendship