by Immanuel Kant
Transition from Popular Moral Philosophy to the Metaphysic of Morals
Everything in nature works according to laws. Rational beings alone have the faculty of acting according to the conception of laws, that is according to principles, ie., have a will. Since the deduction of actions from principles requires reason, the will is nothing but practical reason.
The conception of an objective principle, in so far as it is obligatory for a will, is called a command (of reason), and the formula of the command is called an imperative.
All imperatives are expressed by the word ought (or shall). They say that something would be good to do or to forbear, but they say it to a will which does not always do a thing because it is conceived to be good to do it.
Now all imperatives command either hypothetically or categorically. If the action is good only as a means to something else, then the imperative is hypothetical; if it is conceived as good in itself, then it is categorical.
Now arises the question, how are these imperatives possible? We shall therefore have to investigate a priori the possibility of a categorical imperative.
When I conceive a hypothetical imperative, in general I do not know beforehand what it will contain until I am given the condition. But when I conceive a categorical imperative, I know at once what it contains. For as the imperative contains besides the law only the necessity that the maxims [a subjective principle of action] shall conform to this law, while the law contains no conditions restricting it, there remains nothing but the general statement that the maxim of the action should conform to a universal law, and it is this conformity alone that the imperative properly represents as necessary.
There is therefore but one categorical imperative, namely, this: Act only on that maxim whereby thou canst at the same time will that it should become a universal law. Since the universality of the law according to which effects are produced constitutes what is properly called nature in the most general sense (as to form), the imperative of duty may be expressed thus: Act as if the maxim of thy action were to become by thy will a universal law of nature.
We will now enumerate a few duties, adopting the usual division of them into duties to ourselves and to others, and into perfect and imperfect duties.
1. A man reduced to despair by a series of misfortunes feels wearied of life, and asks himself whether it would not be contrary to his duty to take his own life. We see at once that a system of nature in which it should be a law to destroy life would contradict itself and, therefore, could not exist; hence that maxim cannot possibly exist as a universal law of nature.
2. Another finds himself forced by necessity to borrow money. He knows that he will not be able to repay it, but sees also that nothing will be lent to him unless he promises so. But supposing it to be a universal law that everyone when he thinks himself in a difficulty should be able to promise whatever he pleases, the promise itself would become impossible, since no one would consider that anything was promised to him, but would ridicule all such statements as vain pretences.
3. A third finds in himself a talent which, with the help of some culture, might make him useful. But he prefers to indulge in pleasure rather than to take pains in improving his happy natural capacities. He sees that a system of nature could indeed subsist with such a universal law where men (like the South Sea islanders) devote their lives to idleness, amusement, and propagation of their species; but he cannot possibly will that this should be a universal law of nature. For, as a rational being, he necessarily wills that his faculties be developed, since they serve him and have been given him, for all sorts of possible purposes.
4. A fourth, who is in prosperity, while he sees that others have to contend with great wretchedness, thinks: “What concern is it of mine? But it is impossible to will that such a principle should have the universal validity of a law of nature, for many cases might occur in which one would have need of the love and sympathy of others.
We have established at least this much, that if duty is a conception which is to have any import and real legislative authority for our actions, it can only be expressed in categorical and not at all in hypothetical imperatives. We have not yet, however, advanced so far as to prove a priori that there actually is such an imperative, and that following this law is duty.
With the view of attaining to this, it is of extreme importance to remember that we must not allow ourselves to think of deducing the reality of this principle from the particular attributes of human nature. Human reason may indeed supply us with a maxim, but not with a law.
Here then we see philosophy put in a precarious position, which is to be firmly fixed, even though it has nothing to support it in heaven or earth. Philosophy must show its purity as absolute director of its own laws, not the herald of those which are whispered to it by an implanted sense.
Thus every empirical element is not only quite incapable of being an aid to the principle of morality, but is even highly prejudicial to the purity of morals.
The question then is this: “Is it a necessary law for all rational beings that they should always judge of their actions by maxims of which they can themselves will that they should serve as universal laws?” But in order to discover this connexion we must, however reluctantly, take a step into a domain of metaphysic, namely, the metaphysic of morals. Here we are concerned with the relation of the will to itself so far as it is determined by reason alone.
The will is conceived as a faculty of determining oneself to action in accordance with the conception of certain laws.
Now I say: man and generally any rational being exists as an end in himself, not merely as a means to be arbitrarily used by this or that will, but in all his actions, whether they concern himself or other rational beings, must be always regarded at the same time as an end.
Man necessarily conceives his own existence as being so. But every other rational being regards its existence similarly. Accordingly the practical imperative will be as follows: So act as to treat humanity, whether in thine own person or in that of any other, in every case as an end withal, never as means only. We will now inquire whether this can be practically carried out.
To abide by the previous examples:
Firstly, he who contemplates suicide should ask himself whether his action can be consistent with the idea of humanity as an end in itself. If he destroys himself in order to escape from painful circumstances, he uses a person merely as a mean to maintain a tolerable condition up to the end of life. But a man is not a thing, but must in all his actions be always considered as an end in himself. I cannot, therefore, dispose in any way of a man in my own person so as to mutilate him, damage or kill him. (It belongs to ethics proper to define this principle more precisely, so as to avoid all misunderstanding, eg., as to the amputation of limbs in order to preserve myself, as exposing my life to danger with a view to preserve it, etc.)
Secondly, as regards duties of strict obligation towards others: He who is thinking of making a lying promise to others will see at once that he would be using another man merely as a means, without the latter containing at the same time the end in himself.
Thirdly, as regards contingent (meritorious) duties to oneself: It is not enough that the action does not violate humanity in our own person as an end in itself, it must also harmonize with it.
Fourthly, as regards meritorious duties towards others: The ends of any subject which is an end in himself ought as far as possible to be my ends also, if that conception is to have its full effect with me.
Thus all maxims are rejected which are inconsistent with the will being itself universal legislator. Thus the will is not subject simply to the law, but so subject that it must be regarded as itself giving the law and, on this ground only, subject to the law (of which it can regard itself as the author).
Thus the principle that every human will is a will which in all its maxims gives universal laws, would be very well adapted to be the categorical imperative because the idea of universal legislation is not based on any particular interest, and therefore it alone can be unconditional.
Looking back now on all previous attempts to discover the principle of morality, we need not wonder why they all failed. It was not seen that the laws to which man is subject are only those of his own giving, though at the same time they are universal.
The conception of the will of every rational being as one which must consider itself as giving in all the maxims of its will universal laws leads to a very fruitful conception, namely that of a kingdom of ends.
By a kingdom I understand the union of different rational beings in a system by common laws. A rational being must always regard himself as giving laws either as member or as sovereign in a kingdom of ends which is rendered possible by the freedom of will.
Morality consists then in the reference of all action to the legislation which alone can render a kingdom of ends possible. This legislation must be capable of existing in every rational being and of emanating from his will, so that the principle of this will is never to act on any maxim which could not without contradiction be also a universal law and, accordingly, always so to act that the will could at the same time regard itself as giving in its maxims universal laws. If now the maxims of rational beings are not by their own nature coincident with this objective principle, then the necessity of acting on it is called practical necessitation, ie., duty. Duty does not apply to the sovereign in the kingdom of ends, but it does to every member of it and to all in the same degree.
In the kingdom of ends everything has either value or dignity. Whatever has a value can be replaced by something else which is equivalent; whatever, on the other hand, is above all value, and therefore admits of no equivalent, has a dignity.
Whatever has reference to the general inclinations and wants of mankind has a market price; whatever, without presupposing a want, corresponds to a certain taste, has a fancy price; but that which constitutes the condition under which alone anything can be an end in itself, this has not merely a relative worth, ie., value, but an intrinsic worth, that is, dignity.
Skill and diligence in labour have a market price; wit, lively imagination, and humour, have a fancy price; on the other hand, fidelity to promises, benevolence from principle (not from instinct), have an intrinsic worth.
What then is it which justifies virtue or the morally good disposition, in making such lofty claims? It is nothing less than the privilege it secures to the rational being of participating in the giving of universal laws, by which it qualifies him to be a member of a possible kingdom of ends. For it is the legislation itself which assigns the worth of everything, and must for that very reason possess dignity, that is an unconditional incomparable worth; and the word respect alone supplies a becoming expression for the esteem which a rational being must have for it. Autonomy then is the basis of the dignity of human and of every rational nature.
The three modes of presenting the principle of morality that have been adduced are at bottom only so many formulae of the very same law, and each of itself involves the other two. All maxims, in fact, have:
1. A form, consisting in universality.
2. A matter, namely, an end.
3. A complete characterization of all maxims by means of that formula, namely, that all maxims ought by their own legislation to harmonize with a possible kingdom of ends as with a kingdom of nature.
We can now end where we started at the beginning, namely, with the conception of a will unconditionally good. That will is absolutely good which cannot be evil – in other words, whose maxim, if made a universal law, could never contradict itself. This principle, then, is its supreme law: “Act always on such a maxim as thou canst at the same time will to be a universal law”.
It follows incontestably that, to whatever laws any rational being may be subject, he being an end in himself must be able to regard himself as also legislating universally in respect of these same laws. Therefore every rational being must so act as if he were by his maxims in every case a legislating member in the universal kingdom of ends. Morality, then, is the relation of actions to the relation of actions will, that is, to the autonomy of potential universal legislation by its maxims. An action that is consistent with the autonomy of the will is permitted; one that does not agree therewith is forbidden. A will whose maxims necessarily coincide with the laws of autonomy is a holy will, good absolutely.
We have shown that neither fear nor inclination, but simply respect for the law, is the spring which can give actions a moral worth.
Via Kant’s Groundwork in the Metaphysics of Morals