康德实践哲学中的“应该”问题及其类型学分析

康德的实践哲学是一种“应该”哲学,即与人“必须做又不必然做”有关的哲学,而这样的哲学又是基于他对“人”本身的理解。康德不仅把存在者划分为不同类型,而且把作为存在者之一的人的性质也划分为不同层级;由此,对他来说,人就其自身而言就是由感性与理性构成的、充满内部张力的矛盾统一体。人的这种本质,既使“应该”对人来说得以可能,也使“应该”对人来说成为“必须”。从类型学上看,康德的实践哲学蕴涵着各种不同的“应该”类型。这些“应该”类型的关系在于:首先,它们之间存在等级之分。越趋于感性的“应该”等级越低,越趋于理性的则等级越高。其次,它们之间存在奠基关系。等级低的“应该”只有以等级高的“应该”为奠基,才更趋近于、乃至合乎道德要求。第三,它们之间在有效性上存在程度之分。“应该”类型的等级越高,其有效性也越普遍。由于康德把衡量行为道德性的最终标准落实到行为动机的“应该”上,这就给道德评价带来了难题。从消极方面看,它使得社会对人的道德行为的评价变得不确定、甚或不可能,因为行为动机的不可见性使评价者只能对行为者的行为动机进行猜测或揣摩;从积极方面看,它却恰恰反映出道德现象的实情:由于人们通常确实会用行为动机判定行为的道德性质,但由于评价者只能猜测这种不可见的动机为何,所以,行为的道德性质就可能随评价者的不同而发生变化,并因此具有不确定性或模棱两可性。
Abstract：Kant’s practical philosophy is a philosophy of “ought”. Namely, it is related to “what one must do but don’t necessarily do”, and such a philosophy is based on his understanding of “Man” itself. Kant not only divides beings into different types, but also thinks that man has different properties. Based on this, for him, man is composed of sense and reason, and a contradictory unity full of internal tensions. It is this essence of man that makes “ought” not only possible but also necessary for man. From this point of view of typology, Kant’s practical philosophy contains different types of “ought”. The relationship among these types of “ought” lies in: firstly, the hierarchy among them. The more emotional, the lower the rank; the more rational, the greater the rank. Secondly, the groundbreaking relationship among them. The “ought” in lower rank must be based on the one in greater rank in order to be closer to, and even meet the moral requirements. Thirdly, the degree of validity among them. The higher rank the “ought” is in, the more universal its validity is. Kant thinks that the motive of an action is the ultimate guarantee for its morality, but this brings problems to moral evaluation. On its negative side, this makes social moral judgment of person uncertain, or even impossible, because the motive of his action is invisible to others, and others can only read or guess it; on its positive side, it reflects the truth of moral phenomena: people often judge one’s moral action according to his motive, and as they can only guess what this invisible motive might be, the moral nature of an action might be changing with different estimators, and thus has uncertainty or ambiguity.