Kant: The Categorical Imperative

From James Rachels, "The Right Thing to Do: Basic Readings in Moral Philosophy", 2^nd ed. (New York: McGraw Hill, 1999)

From Immanuel Kant, "Foundations of the Metaphysics of Morals" (1785) in The Critique of Practical Reason and Other Writings in Moral Philosophy, trans. Lewis White Beck (Chicago: University of Chicago Press, 1949), pp. 73-74, 80-83, 86-87.

All imperatives command either hypothetically or categorically. The former present the practical necessity of a possible action as a means to achieving something else which one desires (or which one may possibly desire). The categorical imperative would be one which presented an action as of itself objectively necessary, without regard to any other end.

Since every practical law presents a possible action as good and thus as necessary for a subject practically determinable by reason, all imperatives are formulas of the determination of action which is necessary by the principle of a will which is in any way good. If the action is good only as a means to something else, the imperative is hypothetical; but if it is thought of as good in itself, and hence as necessary in a will which of itself conforms to reason as the principle of this will, the imperative is categorical.

The imperative thus says what action possible to me would be good, and it presents the practical rule in relation to a will which does not forthwith perform an action simply because it is good, in part because the subject does not always know that the action is good and in part (when he does know it) because his maxims can still be opposed to the objective principles of practical reason.

The hypothetical imperative, therefore, says only that the action is good to some purpose, possible or actual. In the former case it is a problematical, in the latter an assertorical, practical principle. The categorical imperative, which declares the action to be of itself objectively necessary without making any reference to a purpose, i.e., without having any other end, holds as an apodictical (practical) principle....

If I think of a hypothetical imperative as such, I do not know what it will contain until the condition is stated [under which it is an imperative]. But if I think of a categorical imperative, I know immediately what it contains. For since the imperative contains besides the law only the necessity of the maxim of acting in accordance with this law. while the law contains no condition to which it is restricted, there is nothing remaining in it except the universality of law as such to which the maxim of the action should conform; and in effect this conformity alone is represented as necessary by the imperative.

There is, therefore, only one categorical imperative. It is: Act only according to that maxim by which you can at the same time will that it should become a universal law.
Now if all imperatives of duty can be derived from this one imperative as a principle, we can at least show what we understand by the concept of duty and what it means, even though it remain undecided whether that which is called duty is an empty concept or not.

The universality of law according to which effects are produced constitutes what is properly called nature in the most general sense (as to form), i.e., the existence of things so far as it is determined by universal laws. [By analogy], then, the universal imperative of duty can be expressed as follows: Act as though the maxim of your action were by your will to become a universal law of nature.

We shall now enumerate some duties, adopting the usual division of them into duties to ourselves and to others and into perfect and imperfect duties.

1. A man who is reduced to despair by a series of evils feels a weariness with life but is still in possession of his reason sufficiently to ask whether it would not be contrary to his duty to himself to take his own life. Now he asks whether the maxim of his action could become a universal law of nature. His maxim, however, is: For love of myself, I make it my principle to shorten my life when by a longer duration it threatens more evil than satisfaction. But it is questionable whether this principle of self-love could become a universal law of nature. One immediately sees a contradiction in a system of nature, whose law would be to destroy life by the feeling whose special office is to impel the improvement of life. In this case it would not exist as nature; hence that maxim cannot obtain as a law of nature, and thus it wholly contradicts the supreme principle of all duty.

2. Another man finds himself forced by need to borrow money. He well knows that he will not be able to repay it, but he also sees that nothing will be loaned him if he does not firmly promise to repay it at a certain time. He desires to make such a promise, but he has enough conscience to ask himself whether it is not improper and opposed to duty to relieve his distress in such a way. Now, assuming he does decide to do so, the maxim of his action would be as follows: When I believe myself to be in need of money, I will borrow money and promise to repay it, although I know I shall never do so. Now this principle of selflove or of his own benefit may very well be compatible with his whole future welfare, but the question is whether it is right. He changes the pretension of self-love into a universal law and then puts the question: How would it be if my maxim became a universal law? He immediately sees that it could never hold as a universal law of nature and be consistent with itself; rather it must necessarily contradict itself. For the universality of a law which says that anyone who believes himself to be in need could promise what he pleased with the intention of not fulfilling it would make the promise itself and the end to be accomplished by it impossible; no one would believe what was promised to him but would only laugh at any such assertion as vain pretense.

3. A third finds in himself a talent which could, by means of some cultivation, make him in many respects a useful man. But he finds himself in comfortable circumstances and prefers indulgence in pleasure to troubling himself with broadening and improving his fortunate natural gifts. Now, however, let him ask whether his maxim of neglecting his gifts, besides agreeing with his propensity to idle amusement, agrees also with what is called duty. He sees that a system of nature could indeed exist in accordance with such a law, even though man (like the inhabitants of the South Sea Islands) should let his talents rust and resolve to devote his life merely to idleness, indulgence, and propagation-in a word, to pleasure. But he cannot possibly will that this should become a universal law of nature or that it should be implanted in us by a natural instinct. For, as a rational being, he necessarily wills that all his faculties should be developed, inasmuch as they are given to him for all sorts of possible purposes.

4. A fourth man, for whom things are going well, sees that others (whom he could help) have to struggle with great hardships, and he asks, "What concern of mine is it? Let each one be as happy as heaven wills, or as he can make himself, I will not take anything from him or even envy him; but to his welfare or to his assistance in time of need I have no desire to contribute." If such a way of thinking were a universal law of nature, certainly the human race could exist, and without doubt even better than in a state where everyone talks of sympathy and good will or even exerts himself occasionally to practice them while, on the other hand, he cheats when he can and betrays or otherwise violates the rights of man. Now although it is possible that a universal law of nature according to that maxim could exist, it is nevertheless impossible to will that such a principle should hold everywhere as a law of nature. For a will which resolved this would conflict with itself, since instances can often arise in which he would need the love and sympathy of others, and in which he would have robbed himself, by such a law of nature springing from his own will, of all hope of the aid he desires.

The foregoing are a few of the many actual duties, or at least of duties we hold to be actual, whose derivation from the one stated principle is clear. We must be able to will that a maxim of our action become a universal law; this is the canon of the moral estimation of our action generally. Some actions are of such a nature that their maxim cannot even be thought as a universal law of nature without contradiction, far from it being possible that one could will that it should be such. In others this internal impossibility is not found though it is still impossible to will that their maxim should be raised to the universality of a law of nature, because such a will would contradict itself. We easily see that the former maxim conflicts with the stricter or narrower (imprescriptable) duty, the latter with broader (meritorious) duty. Thus all duties, so far as the kind of obligation (not the object of their action) is concerned, have been completely exhibited by these examples in their dependence on the one principle....

Now, I say, man and, in general, every rational being exists as an end in himself and not merely as a means to be arbitrarily used by this or that will. In all his actions, whether they are directed to himself or to other rational beings, he must always be regarded at the same time as an end. All objects of inclinations have only a conditional worth, for if the inclinations and the needs founded on them did not exist, their object would be without worth. The inclinations themselves as the sources of needs, however, are so lacking in absolute worth that the universal wish of every rational being must be indeed to free himself completely from them. Therefore, the worth of any objects to be obtained by our actions is at all times conditional. Beings whose existence does not depend on our will but on nature, if they are not rational beings, have only a relative worth as means and are therefore called "things"; on the other hand, rational beings are designated "persons," because their nature indicates that they are ends in themselves, i.e., things which may not be used merely as means. Such a being is thus an object of respect and, so far, restricts all [arbitrary] choice. Such beings are not merely subjective ends whose existence as a result of our action has a worth for us but are objective ends, i.e., beings whose existence in itself is an end. Such an end is one for which no other end can be substituted, to which these beings should serve merely as means. For, without them, nothing of absolute worth could be found, and if all worth is conditional and thus contingent, no supreme practical principle for reason could be found anywhere.

Thus if there is to be a supreme practical principle and a categorical imperative for the human will, it must be one that forms an objective principle of the will from the conception of that which is necessarily an end for everyone because it is an end in itself. Hence this objective principle can serve as a universal practical law. The ground of this principle is: rational nature exists as an end in itself. Man necessarily thinks of his own existence in this way; thus far it is a subjective principle of human actions. Also every other rational being thinks of his existence by means of the same rational ground which holds also for myself, thus it is at the same time an objective principle from which, as a supreme practical ground, it must be possible to derive all laws of the will. The practical imperative, therefore, is the following: Act so that you treat humanity, whether in your own person or in that of another, always as an end and never as a means only.