Kant’s Moral Law

Will, Duty, and the Categorical Imperative

Kant’s moral theory in some ways connects with the rest of his philosophy but mainly stands apart from it. Kant took seriously Hume’s critique of epistemology, but he dismissed Hume’s contention that morality is based on feeling. For Kant, everything is about reason, and that includes morality. His basic assumption about all morality is that there is a rational, universal moral law. Kant put forward a moral system centered on the concept of moral duty. In some respects, Kant’s system can be understood as a post-Enlightenment version of the ancient command to obey the moral law.

Kant did recognize what Hume meant by saying that we have an internal moral sense. For Kant, our inherent moral law is within us. Morality is not a matter of following a rule book like the Ten Commandments or the do’s and don’ts of etiquette. There is a moral law that we sense, but through reason not through emotion. The moral law is a transcendent, universal, objective part of reality. If someone violates the moral law, that does not affect the law. The universality lies in the law itself and not in a sense that all humans always act on it. Kant thus believed that there is a pure practical rationality for a science of morality just like there is a…