文探討康德倫理學的三種選擇行動的主體性：1.道德抉擇的，2.法權的，以及3.經驗的主體性。道德抉擇是意謂在義務規範下自由選擇是否服從或違反規範，不被先前條件所規定；法權概念下的選擇是意謂：在被容許的範圍內可自由選擇，雖有害傷他人權利而被責備的問題，但這責備不是道德上的；經驗的自由選擇是如一般性購物的選擇，無涉於法權與道德責任的問題，不預設先天的規範。每一種選擇行動都相應一種主體性，用以解釋此行動如何成為可能。在〈根本惡論〉中，道德抉擇的主體是自由意念，其主體性是先天而同一的。法權概念下的主體是以相互規定為其基本性格，不是從令式規範性來理解，在容許範圍內自由選擇行動，但規定範圍之先天條件卻是在主體間的相互強制性。主體的經驗性格其實無關於道德抉擇，因為所謂經驗是意謂依待性，而抉擇是自主性的，經驗主體之依待性與主動的抉擇並非一事，因而它不是道德抉擇中的主體－先天而同一的主體性。康德雖有大量討論經驗人類學主體，它扮演違反法則的主體之角色，但在批判時期，在主體之經驗性格下，藉此人類學概念，並不能證成它的抉擇自由，此工作要到〈根本惡論〉才能完成，康在三年之後的《道德形上學》更明白的說：經驗主體的選擇是無關於道德之無差異的自由。

In this paper I would like to research the subjectivities in regards to three actions of choice in Kant's ethics: 1. the subjectivity of moral decision; 2. of right and 3. of experience. The first means that subject chooses freely whether it obeys the norm of duty or not. The choice in regards to right means that subject can freely choose within an admitted limit, there is here only problem with blame because of breach of the other's right, but no problem with duty. The free choice in experience is somethings in no relation to right and moral, and has no presupposed norm, somethings like shopping. Each action of choice correspons to a subjectivity in order to explain how the action becomes possible. In 〈basical evil〉the subject in regards to moral decision is free Willkuer, his subjectivity is a priori and identical. The basical character of subject of right is reciprocal determinations between subjects which can't be understood as an imperative of norm. It is an action of free choice within admitted limit, and the a priori condition to the determination of the limit is nothings but the reciprocal Verbindlicht between subjects. In fact empirical character of subject has no relation to moral decision, because the called experience means dependence, but decision is spontan, the dependence of empirical subject and the spontaneous decision is not the same, so it is not the subject in moral decision-a subjectivity which is a priori and identical. Kant dicusses subject of empirical anthropology largely and such subject plays the role against duty. In period of critique Kant can't justify the free decision of a subject by means of subjectivity of empirical anthropology. Until 'basical evil' the justification can be finished and three years later in 'metaphyics of moral' Kant says clearly that the choice of empirical subject has no relation to moral: “libertas indifferentiae”.