The metaphysical concept of “the causality of freedom （the causality from itself）” is a pre-Kantian metaphysical concept， and the “

causa sui

（cause of itself）” is a concept of Descartes and especially of Spinoza （and also of Leibniz）. It is a significant contribution of Kant to introduce the metaphysical concept of “the causality of freedom” and the early modern philosophical concept of “

causa sui

” into the autonomy of the will. In order to resolve the contradiction in the autonomy， Ka

nt introduced the framework of teleology， which was the key inspiration for Hegel to complete the science of metaphysics， so much so that it could be argued that without Kant there would be no Hegel， and thereby there would be no completion of metaphysics as we see today in classical German philosophy. Therefore， the importance of Kant’s metaphysical revolution is immeasurable.