In this summary, I will emphasize those of his doctrines which were most influential on such nineteenth-century philosophers as Scopenhauer and Hegel. Philosophy Philosophy, according to Kant, is the outcome of the use of human reason, which undertakes investigations a priori , or independently of experience.
Reason also has both a theoretical and a practical employment.
Reason is theoretical when it is concerned with the way things really are, and it is practical when it considers how things ought to be. Thus the two main branches of philosophy are metaphysics , the investigation a priori of the nature of reality, and ethics , which seeks a priori for rules governing the way in which beings with free will ought to decide what to do. An important difference between the traditional practice of metaphysics and ethics illustrates Kant's fundamental orientation toward philosophy. He believed that traditional metaphysics attempts to describe objects that are completely beyond the scope of the senses. It divides objects into a sensible world and an intelligible world and claims that human reason has insight into the nature of purely intelligible objects.