In Kant's philosophical system, there exists a contradiction between the externality and the unconditional normativity of the duty of right-This contradiction is seen in Kant's view that“the duty of right is indirect ethical duty”The ethical duty is derived from the application of the categorical imperative to the special nature of human beingsDue to the special nature of human beings, the ethical duty can be distinguished from the duty of rightKant further divides the ethical duty into the duty of right which can be externally forced and the duty of virtue which cannot be externally forced because of the characteristics of human's practical activitiesSince the basic principle of right can be derived from the categorical imperative, the duty of right belongs to ethicsFrom the viewpoint that the duty of right can be forced externally, the duty of right is indirect ethical dutyWe should not understand the duty of right as only a means of morality, but as ethical duty that can be externally forcedTherefore, if viewed from the relationship between the duty of right and the ethical duty, it is unconditional; if from the perspective that it can be forced externally, it has externality.