Transition Across the Incalculable Abyss between the Domain of Nature and the Domain of Morality; the Meaning of such Transition and its Realization in Kant’s Aesthetics

In the first Critique, Kant delineated the principles of metaphysics of nature and in the second Critique, those of metaphysics of morality. Since these two kinds of principles were essentially distinguished, there appeared an absolute gap between nature and morality, which Kant called abyss or gulf and emphasized that it is "incalculable". That is, if one considers only the first and the second Critique, one should accept the dualism in the essence of subject. Kant, however, takes over in the third Critique the task of investigating the possibility of transition between the two sections of the dualism.
In this paper, we try first to clarify what it means that a transition occurs between nature and morality and then to show how it occurs. Before that, however, we should transform the metaphorical expression of "gulf" into a logical one in order to get the problem right. Once this is done, the meaning of transition becomes clear. In order to delineate how the transition is realized, we should appeal to concepts of the beautiful and the sublime. The transition in the sphere of the beautiful occurs in three instances: intellectual interest in beautiful, the genius, and being the symbol of morality. But in the sphere of the sublime which is "formless", one should go beyond the purposiveness of the form of nature. It will be clear that the sublime represents the possibility of transition in two respects:  by  introducing  the  idea  of   humanity  and  morality  and  by   aesthetic  representation of reason "as both theoretical and practical" which is nothing but unity of the first and the second part of Kantian philosophy.