后期康德以“同时是义务的目的”概念为线索,展开德性学说的建构。他将人之“自我完善”的德性目的“同时”视为义务,并对这个概念作了详细的阐明。然而问题在于,“自我完善”作为德性目的,康德将其纳入义务论框架中是否违背了原有自律伦理学的核心立场?此外,他将这个目的“同时”视为人对自己义务的理据何在?显然,在康德的德性论中,“目的”与“义务”概念的对接面临诸多困难,我们必须追问“自我完善”作为德性义务如何可能的理论根据。一方面,“自我完善”概念直接的理论源头来自康德对莱布尼茨—沃尔夫学派“完善性”概念的批判性重释;另一方面,这个德性目的“同时”作为义务更为深层的理论根据必须从康德对人性理念的基本设计和对人类道德现状的先验考察入手才能得到自洽的解释。 In the later period, Kant started the construction of the doctrine of virtue by clueing the concept of “at the same time obligatory purpose”. He regarded the moral purpose of “self-improvement ” “at the same time ” as an obligation and elaborates the concept in detail. However, the problem lies in whether “self-improvement” as a virtue object and Kant’s inclusion in the framework of the doctrine of obligations have violated the original position of self-discipline ethics. In addition, he regards this purpose as “simultaneous” as his own Obviously, in Kant’s theory of virtue, there are many difficulties in the connection between the “purpose” and the concept of “obligation”. We must ask how “self-improvement” as a possible obligation of virtue obligation according to. On the one hand, the direct theoretical origin of the concept of “self-improvement” comes from Kant’s critical reinterpretation of the concept of the Leibniz-Wolfe school of perfection; on the other hand, "As a deeper theoretical basis of obligation, we must get a consistent explanation from Kant’s basic design of human nature and a priori investigation of the present state of human morality.