Critique of Practical Reason

In Immanuel Kant’s view, moral law is universal and unconditional. This is what Kant also means by a “categorical imperative” (19): Moral law applies to everyone and does not depend on changing circumstances. Kant differentiates categorical imperatives from maxims, which are rules people live by that are subject to changing circumstances and needs, making them “subjective” (17). As an example, someone who owns a business may refuse to lie to their clients, but they will lie to spare the feelings of a friend. On the other hand, a categorical imperative would be “Do not steal,” since through reason we can view this dictum as a practical law that can be applied universally and without conditions.

While moral law is universal and objective, this does not mean that ethical action is also objective. Since ethical decisions take place in the context of a complex material world, each decision has to be reasoned out to ensure that it complies with universal moral law. Since humans are fallible, Kant argues that perfect adherence to moral law is a practical impossibility. A person who always knows the morally correct course of action and takes it without hesitation has achieved