Practical Reason In Kant's Interest In The Problem

As a result of the crisis in the fields of value system of modern society, moral reconstruct has become an urgent task. So, we must reexamine the tradition of modern moral philosophy. And the practical philosophy of Kant is the important component part of modern moral philosophy of West. The research of Kant's practical philosophy will contribute to comprehending and reflecting this tradition, and the problem of interest is the starting point of this research.Kant's practical reason could be regarded as the critique and summation of the Enlightenment. On the one hand, this practical reason criticized the utilitarianism of reason of the Enlightenment, attempted to rehabilitate the dignity of reason, and tried to seek new foundation for the moral improvement of mankind; on the other hand, it carried on the universality, subjectivity and exclusivity of reason of the Enlightenment. Moral interest is that by which resaon becomes practical, i.e., a ground determining will. Kant hold that this moral interest or practical interest is rational interest. Practical interest, however, has three levels of meanings, that is to say, rational, passional, and desired. In addition, practical interest plays the role of motive power and transcendence in two links of practical reason, namely the incentives of practical reason and the realization of practical reason.Practical reason demand not only legitimacy but also morality, so moral interest must play role of motive power in the link of incentives of practical reason. Despite Kant hold that this interest is rational reason, and the motive power of practical reason is moral law, but can not rule out this possibility, that is, practical interest as motive power, has passional meaning.Proceed from the prescript of practical reason, it demand that this reason should realize itself. It means the realization of whole objects of will, i.e., the realization of Highest good. On the one hand, since the promotion of this realization, practical interest transcend rational level, show it's passional level.; on the other hand, this realization need three postulates, namely, freedom, the immortality of the Soul, and the Existence of God, which could guarantee the realization of Highest good. So, practical interest can transcend the dimension of ego, and show it's dimension of other. Though Kant try to transform the interest of ego into the interest of other, but the tension between these two interests will always exist.By ways of approaching the question of interest in practical reason, the inherent contradictions of practical reason will be revealed, and the roots of these contradictions lie in the question of nature and freedom. Certainly, these contradictions are also attributed to the universality, subjectivity, and exclusivity of this practical reason. And through this approach, we can gain a clear idea about the position of Kant's practical reason in the tradition of West practical philosophy, and about the relations between this practical reason and modernity. Meanwhile, this approach provides an important lead, by which we can research this tradition of philosophy by a broad vision.