Categorical Imperative

To begin with, Kant draws an analogy between the laws of ethics and the laws of science. Just as the

laws of science can be known by pure reason, the laws of ethics, or morality, can be known by

practical reason. Morality, though, is a normative system, as opposed to the natural laws of science. A

normative system prescribes what ought to happen, as opposed to a natural system that determines

what actually does happen. Since morality only cares for what ought to happen and not with what

actually happens, moral laws, then, must be found a priori. Everything a posteriori or discovered with

the senses only shows with did happen, not what ought to have happened. Moral laws must not be

derived from examples, since moral laws would hold even if there were no examples. Therefore, the

foundation of morality for Kant must lie with reason alone. Rationality is the key to morality. Based

on this premise, it follows that all rational beings must have the same moral laws, and all moral laws

would have absolute necessity that would apply universally to all rational beings.

An action to have moral worth, besides being a universal law, also must come from duty and duty

alone. Duty is the cause of an action when it is done purely out of respect for the law. Kant

distinguishes between two kinds of duties: perfect and imperfect duties. A perfect duty is one where

people are not treated as a means to an end, while imperfect duties involve treating people as ends. To

not tell lies is an example of a perfect duty, since when one tells a lie, one is using the other person as

a means to one's end. To be beneficent and charitable to others is an imperfect duty. Even though not

helping others does not treat others as a means to one's end, it does not treat others as an end in

themselves. When perfect and imperfect duties conflict, Kant believes that perfect duties override

imperfect duties. In other words, it is more important to not treat someone as a means than it is to treat

someone as an end. For example, one must tell the truth even if in so doing, one hurts someone's

feelings and is a catalyst to their suicide.

To follow duties, rational beings have wills. A will that accords with duty is the only unconditional

good, since only with a good will can any other good be achieved. From a good will come all other

goods. Since good comes from the will alone, the consequences of an action are irrelevant in

determining moral actions. A moral act is good in itself, so the end result of an action cannot be used

to justify the morality of an action. For example, lying cannot be justified as being moral or immoral

by observing the consequences from the action. These consequences are only the subjective ends that

arise from the particular situation. The basis of moral and practical must be from objective principles

that are universally valid for any rational being. Consequently, we cannot use subjective ends, that is

our inclinations or feelings in the determination of moral law, since these are contingent on specific

facts, while any moral law must apply to all rational beings.

Since morality lies with rationality, and a good will is necessary for duty to be followed, then the

purpose of reason is to produce a good will. Kant defines an imperative as a command that reason

gives to the will. There are two kinds of imperatives: hypothetical imperatives and categorical

imperatives. Hypothetical imperatives are based on some specific end or purpose: "If I want to get a

good grade, then I must write a good essay" or "if I want to sleep, then I must lie down." These