=The Problem of the Critique of Practical Reason: The Ethics of Kant.= “Two things fill the mind with ever new and increasing admiration and awe, the oftener and the longer we reflect upon them: the starry heavens above and the moral law within.” In this classic sentence Kant showed that he had no desire to humiliate the theoretical reason, which is the understanding. He was merely assigning it to its place among the powers of man, in order that it might do its proper work more efficiently. The world of morality and the starry heaven impressed Kant equally. Kant would not have the understanding chasing will-o’-the-wisps. After his criticism of the understanding he turned to the will, or as he calls it the practical reason, and criticized its functions and scope. This ethical teaching of Kant appears in his _Metaphysic of Morality_ and in the _Critique of Practical Reason_. His early Pietistic education, his reading of Rousseau, his study of the English moralists, influenced his theory of morals; while his investigations into the history of civilization, his theoretical philosophy, and his independent analysis of the ethical feeling marked the route which his ethical development took. The world of morality to Kant has primacy. In his theory it is the real world, for compared to it the world of scientific phenomena, the world of the theoretical reason, is relative. The central idea in Kant’s theory of morals is that rational spontaneity is exactly the same as freedom. This contrasts his theory with Hedonism. The value of man’s life depends on what he does spontaneously, not on what happens to him. This idea of freedom is the central thought in all Kant’s discussions of society. In his theory of government the republic is to be preferred to the monarchy, because of the opportunity to its citizens of spontaneous freedom; in religion the true church is composed of free beings worshiping God freely; in education self-activity is the sole principle of growth. Ethics is a system of the pure rational laws of freedom, just as science is a system of the pure rational laws of nature. If ethics has real validity its laws must be, as in science, _a priori_ or derived from the reason itself, and synthetic or applicable to experience everywhere. If the moral law be valid it must be indifferent as to its content, and yet valid for all content irrespectively. The source of the principle of morals is thus the same as that of science: it is _a priori_. The principle of morals is universal in its application to experience, just as the _a priori_ synthesis of knowledge is. However, just at that point the difference is to be seen between the foundation of science and that of morals――between the reason as pure and the reason as practical. Reason in the form of knowledge is restricted to experience; but reason in the form of the will, while applicable to experience, is not restricted to experience. If the understanding is without the