Section Two: From Popular Ethics to Moral Metaphysics

If we have hitherto drawn our notion of duty from the common use of our practical reason, it is by no means to be inferred that we have treated it as an empirical notion. On the contrary, if we attend to the experience of men's conduct, we meet frequent and, as we ourselves allow, just complaints that one cannot find a single certain example of the disposition to act from pure duty. Although many things are done in conformity with what duty prescribes, it is nevertheless always doubtful whether they are done strictly from duty, so as to have a moral worth. Hence there have at all times been philosophers who have altogether denied that this disposition actually exists at all in human actions, and have ascribed everything to a more or less refined self-love. Not that they have on that account questioned the soundness of the conception of morality; on the contrary, they spoke with sincere regret of the frailty and corruption of human nature, which, though noble enough to take its rule an idea so worthy of respect, is yet weak to follow it and employs reason which ought to give it the law only for the purpose of providing for the interest of the inclinations, whether singly or at the best in the greatest possible harmony with one another.

So far, we have drawn our idea of duty from the ordinary use of our practical reason. But this does not mean we have treated duty as an idea based on experience. On the contrary, consider what experience shows us about human conduct. We often hear complaints that no one can find a single certain example of a commitment to acting purely from duty. We ourselves admit that these complaints are justified. Many actions agree with what duty requires. Yet it always remains doubtful whether people perform these actions strictly from duty, giving the actions moral worth. For this reason, philosophers in every age have denied that a commitment to acting purely from duty ever appears in human actions. They have attributed everything to self-love, whether more or less refined. But these philosophers have not therefore questioned the soundness of the idea of morality. On the contrary, they spoke with sincere regret about the weakness and corruption of human nature. Human nature is noble enough to take such a worthy idea as its rule, yet too weak to follow it. Reason ought to give human nature its law. Instead, human nature uses reason only to serve its inclinations, either individually or, at best, in the greatest possible harmony.

In fact, it is absolutely impossible to make out by experience with complete certainty a single case in which the maxim of an action, however right in itself, rested simply on moral grounds and on the conception of duty. Sometimes it happens that with the sharpest self-examination we can find nothing beside the moral principle of duty which could have been powerful enough to move us to this or that action and to so great a sacrifice; yet we cannot from this infer with certainty that it was not really some secret impulse of self-love, under the false appearance of duty, that was the actual determining cause of the will. We like them to flatter ourselves by falsely taking credit for a more noble motive; whereas in fact we can never, even by the strictest examination, get completely behind the secret springs of action; since, when the question is of moral worth, it is not with the actions which we see that we are concerned, but with those inward principles of them which we do not see.

In fact, experience can never establish with complete certainty even one case of an action guided solely by duty. However right the principle behind an action may be, we cannot know that its basis was purely moral. Sometimes, even after the closest self-examination, we find no motive other than the moral principle of duty. We find nothing else powerful enough to have moved us to a particular action or such a great sacrifice. Yet we cannot conclude with certainty that no hidden impulse of self-love actually determined our will, disguised as duty. We like to flatter ourselves by falsely taking credit for a nobler motive. But even the most rigorous examination can never fully uncover the hidden motives behind our actions. For when we judge moral worth, we are not concerned with the actions we can see. We are concerned with the inner principles behind those actions, which we cannot see.

Moreover, we cannot better serve the wishes of those who ridicule all morality as a mere chimera of human imagination over stepping itself from vanity, than by conceding to them that notions of duty must be drawn only from experience (as from indolence, people are ready to think is also the case with all other notions); for or is to prepare for them a certain triumph. I am willing to admit out of love of humanity that even most of our actions are correct, but if we look closer at them we everywhere come upon the dear self which is always prominent, and it is this they have in view and not the strict command of duty which would often require self-denial. Without being an enemy of virtue, a cool observer, one that does not mistake the wish for good, however lively, for its reality, may sometimes doubt whether true virtue is actually found anywhere in the world, and this especially as years increase and the judgement is partly made wiser by experience and partly, also, more acute in observation. This being so, nothing can secure us from falling away altogether from our ideas of duty, or maintain in the soul a well-grounded respect for its law, but the clear conviction that although there should never have been actions which really sprang from such pure sources, yet whether this or that takes place is not at all the question; but that reason of itself, independent on all experience, ordains what ought to take place, that accordingly actions of which perhaps the world has hitherto never given an example, the feasibility even of which might be very much doubted by one who founds everything on experience, are nevertheless inflexibly commanded by reason; that, e.g., even though there might never yet have been a sincere friend, yet not a whit the less is pure sincerity in friendship required of every man, because, prior to all experience, this duty is involved as duty in the idea of a reason determining the will by a priori principles.

Moreover, we could do no greater favor to those who mock all morality as a fantasy born of human vanity. We need only concede that ideas of duty must come from experience alone. Out of laziness, people readily assume that all other ideas must come from experience too. But making this concession about duty would guarantee morality’s critics a victory. Out of love for humanity, I am willing to admit that even most of our actions are right. But if we examine these actions closely, we find our dear self everywhere pushing to the front. Our actions aim to serve that self, rather than obey duty’s strict command, which would often require self-denial. A calm observer need not be an enemy of virtue to doubt sometimes whether true virtue exists anywhere. Such an observer does not mistake a wish for goodness, however strong, for goodness itself. These doubts may arise especially with age, as experience makes judgment wiser and observation makes it sharper. Given these doubts, only one clear conviction can keep us from abandoning our ideas of duty altogether. Only this conviction can preserve within us a well-grounded respect for duty’s law. Even if no actions have ever sprung from such pure motives, what actually happens is not the issue. Rather, reason itself, independently of all experience, commands what ought to happen. Reason therefore firmly commands actions that the world may never yet have seen. Someone who bases everything on experience might even seriously doubt whether such actions are possible. For example, even if a sincere friend has never yet existed, everyone is still required to be completely sincere in friendship. For, before any experience, this duty is already contained in the idea of reason guiding the will through a priori principles.

When we add further that, unless we deny that the notion of morality has any truth or reference to any possible object, we must admit that its law must be valid, not merely for men but for all rational creatures generally, not merely under certain contingent conditions or with exceptions but with absolute necessity, then it is clear that no experience could enable us to infer even the possibility of such apodeictic laws. For with what right could we bring into unbounded respect as a universal precept for every rational nature that which perhaps holds only under the contingent conditions of humanity? Or how could laws of the determination of our will be regarded as laws of the determination of the will of rational beings generally, and for us only as such, if they were merely empirical and did not take their origin wholly a priori from pure but practical reason?

Unless we deny that morality has any truth or refers to any possible object, we must also accept the following. Moral law must hold not just for humans, but for all rational beings. It must hold with absolute necessity, not just under particular conditions or with exceptions. So no experience could allow us to infer even the possibility of laws that hold with such necessity. For what right would we have to demand unconditional respect for a rule as universal for every rational being? Perhaps that rule holds only under conditions particular to humanity. Or how could laws governing our will count as laws governing the will of rational beings generally? And how could those laws apply to us solely as rational beings? Could they do so if they came merely from experience, rather than entirely a priori from pure practical reason?

Nor could anything be more fatal to morality than that we should wish to derive it from examples. For every example of it that is set before me must be first itself tested by principles of morality, whether it is worthy to serve as an original example, i.e., as a pattern; but by no means can it authoritatively furnish the conception of morality. Even the Holy One of the Gospels must first be compared with our ideal of moral perfection before we can recognise Him as such; and so He says of Himself, "Why call ye Me (whom you see) good; none is good (the model of good) but God only (whom ye do not see)?" But whence have we the conception of God as the supreme good? Simply from the idea of moral perfection, which reason frames a priori and connects inseparably with the notion of a free will. Imitation finds no place at all in morality, and examples serve only for encouragement, i.e., they put beyond doubt the feasibility of what the law commands, they make visible that which the practical rule expresses more generally, but they can never authorize us to set aside the true original which lies in reason and to guide ourselves by examples.

Nothing could be more fatal to morality than trying to derive morality from examples. For every example presented to me must first be tested against moral principles. These principles determine whether the example deserves to serve as a model. But no example can authoritatively establish the concept of morality. Even the Holy One of the Gospels must first be compared with our ideal of moral perfection. Only then can we recognize him as the Holy One. And so he says of himself, "Why do you call me (whom you see) good? No one is good (the model of goodness) except God alone (whom you do not see)." But where do we get the concept of God as the supreme good? Simply from the idea of moral perfection, which reason forms a priori, independently of experience. Reason connects this idea inseparably with the notion of a free will. Imitation has no place at all in morality, and examples serve only to encourage us. Examples remove all doubt that we can do what the moral law commands. They make visible what the practical rule expresses more generally. But examples can never justify setting aside the true original model found in reason and letting examples guide us instead.

If then there is no genuine supreme principle of morality but what must rest simply on pure reason, independent of all experience, I think it is not necessary even to put the question whether it is good to exhibit these concepts in their generality (in abstracto) as they are established a priori along with the principles belonging to them, if our knowledge is to be distinguished from the vulgar and to be called philosophical.

If any genuine supreme principle of morality must rest on pure reason alone, independent of all experience, I think one question need not even be asked. Should we present these concepts in their general, abstract form, together with their principles, as established independently of experience? That is, should we do so if our knowledge is to differ from ordinary knowledge and deserve to be called philosophical?

In our times indeed this might perhaps be necessary; for if we collected votes whether pure rational knowledge separated from everything empirical, that is to say, metaphysic of morals, or whether popular practical philosophy is to be preferred, it is easy to guess which side would preponderate.

In our time, this might indeed be necessary. For if we voted on whether to prefer pure rational knowledge independent of all experience (the metaphysics of morals) or popular practical philosophy, the likely winner would be easy to guess.

This descending to popular notions is certainly very commendable, if the ascent to the principles of pure reason has first taken place and been satisfactorily accomplished. This implies that we first found ethics on metaphysics, and then, when it is firmly established, procure a hearing for it by giving it a popular character. But it is quite absurd to try to be popular in the first inquiry, on which the soundness of the principles depends. It is not only that this proceeding can never lay claim to the very rare merit of a true philosophical popularity, since there is no art in being intelligible if one renounces all thoroughness of insight; but also it produces a disgusting medley of compiled observations and half-reasoned principles. Shallow pates enjoy this because it can be used for every-day chat, but the sagacious find in it only confusion, and being unsatisfied and unable to help themselves, they turn away their eyes, while philosophers, who see quite well through this delusion, are little listened to when they call men off for a time from this pretended popularity, in order that they might be rightfully popular after they have attained a definite insight.

Making philosophy accessible is certainly admirable, if we have first worked our way up to pure reason’s principles and established them satisfactorily. This means first grounding ethics in metaphysics. Then, once ethics is firmly established, we can win an audience for it by presenting it accessibly. But trying to appeal to a general audience during the initial inquiry is quite absurd. The soundness of the principles depends on that inquiry. Such an approach can never claim the very rare merit of making philosophy genuinely accessible. There is no skill in being understandable if one gives up all depth of understanding. Worse, this approach produces a disgusting jumble of collected observations and half-reasoned principles. Shallow minds enjoy this jumble because they can use it in everyday conversation. But discerning people find only confusion in it. Dissatisfied and unable to find their own way out, they turn away. Meanwhile, philosophers see right through this illusion, but few listen when they urge people to abandon this false accessibility temporarily. Their purpose is to achieve genuine accessibility once they have gained a clear understanding.

We need only look at the attempts of moralists in that favourite fashion, and we shall find at one time the special constitution of human nature (including, however, the idea of a rational nature generally), at one time perfection, at another happiness, here moral sense, there fear of God. a little of this, and a little of that, in marvellous mixture, without its occurring to them to ask whether the principles of morality are to be sought in the knowledge of human nature at all (which we can have only from experience); or, if this is not so, if these principles are to be found altogether a priori, free from everything empirical, in pure rational concepts only and nowhere else, not even in the smallest degree; then rather to adopt the method of making this a separate inquiry, as pure practical philosophy, or (if one may use a name so decried) as metaphysic of morals,³ to bring it by itself to completeness, and to require the public, which wishes for popular treatment, to await the issue of this undertaking.

We need only look at the attempts of moralists who follow this favorite approach. Sometimes they appeal to the particular makeup of human nature (though they include the idea of rational nature in general). Sometimes they appeal to perfection, sometimes to happiness, sometimes to moral sense, and sometimes to fear of God. They mix a little of this and a little of that in a remarkable blend. Yet they never think to ask whether moral principles should be sought in knowledge of human nature at all. We can gain such knowledge only through experience. Or, if moral principles do not come from that source, are they found entirely a priori, independently of all experience? Are they found only in pure rational concepts, and nowhere else, not even to the slightest degree? If so, these moralists should instead make the search for moral principles a separate inquiry, as pure practical philosophy. Or they could call it a metaphysics of morals³ (if we may use a name so widely condemned). They should complete this inquiry on its own. And they should ask the public, which wants an accessible treatment, to wait for the outcome of this undertaking.

Such a metaphysic of morals, completely isolated, not mixed with any anthropology, theology, physics, or hyperphysics, and still less with occult qualities (which we might call hypophysical), is not only an indispensable substratum of all sound theoretical knowledge of duties, but is at the same time a desideratum of the highest importance to the actual fulfilment of their precepts. For the pure conception of duty, unmixed with any foreign addition of empirical attractions, and, in a word, the conception of the moral law, exercises on the human heart, by way of reason alone (which first becomes aware with this that it can of itself be practical), an influence so much more powerful than all other springs⁴ which may be derived from the field of experience, that, in the consciousness of its worth, it despises the latter, and can by degrees become their master; whereas a mixed ethics, compounded partly of motives drawn from feelings and inclinations, and partly also of conceptions of reason, must make the mind waver between motives which cannot be brought under any principle, which lead to good only by mere accident and very often also to evil.

Such a metaphysics of morals must stand entirely alone, unmixed with anthropology, theology, physics, or hyperphysics. Still less may it include occult qualities (which we might call hypophysical). It is not only an essential foundation for all sound theoretical knowledge of duties. It is also something of the highest importance for actually carrying out their commands. For the pure concept of duty contains no added appeal drawn from experience. In short, it is the concept of the moral law. Through reason alone, this concept has a far stronger influence on the human heart than all other motives⁴ drawn from experience. Through this influence, reason first recognizes that it can guide action on its own. Aware of its own worth, reason looks down on those other motives and can gradually become their master. By contrast, a mixed ethics draws its motives partly from feelings and inclinations, and partly from concepts of reason. Such an ethics must leave the mind wavering between motives that cannot be united under any principle. These motives lead to good only by chance, and very often also lead to evil.

From what has been said, it is clear that all moral conceptions have their seat and origin completely a priori in the reason, and that, moreover, in the commonest reason just as truly as in that which is in the highest degree speculative; that they cannot be obtained by abstraction from any empirical, and therefore merely contingent, knowledge; that it is just this purity of their origin that makes them worthy to serve as our supreme practical principle, and that just in proportion as we add anything empirical, we detract from their genuine influence and from the absolute value of actions; that it is not only of the greatest necessity, in a purely speculative point of view, but is also of the greatest practical importance, to derive these notions and laws from pure reason, to present them pure and unmixed, and even to determine the compass of this practical or pure rational knowledge, i.e., to determine the whole faculty of pure practical reason; and, in doing so, we must not make its principles dependent on the particular nature of human reason, though in speculative philosophy this may be permitted, or may even at times be necessary; but since moral laws ought to hold good for every rational creature, we must derive them from the general concept of a rational being. In this way, although for its application to man morality has need of anthropology, yet, in the first instance, we must treat it independently as pure philosophy, i.e., as metaphysic, complete in itself (a thing which in such distinct branches of science is easily done); knowing well that unless we are in possession of this, it would not only be vain to determine the moral element of duty in right actions for purposes of speculative criticism, but it would be impossible to base morals on their genuine principles, even for common practical purposes, especially of moral instruction, so as to produce pure moral dispositions, and to engraft them on men's minds to the promotion of the greatest possible good in the world.

What we have said makes clear that all moral concepts originate entirely a priori in reason, independently of experience. This holds just as much for ordinary reason as for the most advanced theoretical reasoning. Moral concepts cannot be drawn by abstraction from any knowledge based on experience, since such knowledge is merely contingent. Their pure origin is precisely what makes them worthy to serve as our highest practical principle. The more we add anything drawn from experience, the more we weaken their genuine influence and the absolute value of actions. Deriving these concepts and laws from pure reason is essential for theoretical inquiry and also of the greatest practical importance. We must present them pure and unmixed. We must also establish the full scope of this practical knowledge based on pure reason. In other words, we must determine the entire capacity of pure practical reason. In doing so, we must not make its principles depend on the particular nature of human reason. Such dependence may be permitted in theoretical philosophy, and may sometimes even be necessary. But moral laws ought to hold for every rational being. We must therefore derive moral laws from the general concept of a rational being. Although applying morality to human beings requires anthropology, we must first study morality independently as pure philosophy. That means treating morality as metaphysics, complete in itself. This is easily done in such clearly defined branches of knowledge. We must recognize what follows if we lack this metaphysics of morals. For theoretical evaluation, trying to identify the moral element of duty in right actions would be futile. Even for ordinary practical purposes, grounding morality in its genuine principles would be impossible. This is especially true of moral instruction aimed at developing pure moral attitudes and instilling them in people's minds. Such instruction seeks to promote the greatest possible good in the world.

But in order that in this study we may not merely advance by the natural steps from the common moral judgement (in this case very worthy of respect) to the philosophical, as has been already done, but also from a popular philosophy, which goes no further than it can reach by groping with the help of examples, to metaphysic (which does allow itself to be checked by anything empirical and, as it must measure the whole extent of this kind of rational knowledge, goes as far as ideal conceptions, where even examples fail us), we must follow and clearly describe the practical faculty of reason, from the general rules of its determination to the point where the notion of duty springs from it.

But in this study, we must do more than move naturally from ordinary moral judgment to philosophical judgment. We have already made that move, and ordinary moral judgment deserves great respect in this case. We must also move from popular philosophy to metaphysics. Popular philosophy can only feel its way forward with the help of examples. Metaphysics allows anything drawn from experience to serve as a check on it. And because metaphysics must survey the full scope of this kind of rational knowledge, it reaches as far as ideal concepts. At that point, even examples fail us. To make this transition, we must trace and clearly describe reason’s capacity to guide action. We must begin with the general rules that determine how this capacity works. Then we must follow it to the point where the concept of duty arises from it.

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, i.e., have a will. Since the deduction of actions from principles requires reason, the will is nothing but practical reason. If reason infallibly determines the will, then the actions of such a being which are recognised as objectively necessary are subjectively necessary also, i.e., the will is a faculty to choose that only which reason independent of inclination recognises as practically necessary, i.e., as good. But if reason of itself does not sufficiently determine the will, if the latter is subject also to subjective conditions (particular impulses) which do not always coincide with the objective conditions; in a word, if the will does not in itself completely accord with reason (which is actually the case with men), then the actions which objectively are recognised as necessary are subjectively contingent, and the determination of such a will according to objective laws is obligation, that is to say, the relation of the objective laws to a will that is not thoroughly good is conceived as the determination of the will of a rational being by principles of reason, but which the will from its nature does not of necessity follow.

Everything in nature works according to laws. Only rational beings can act according to their conception of laws, or in other words, according to principles. That capacity is the will. Since deriving actions from principles requires reason, the will is nothing other than practical reason. If reason unfailingly determines the will, then actions recognized as objectively necessary are also subjectively necessary for such a being. In other words, the will chooses only what reason, independently of inclination, recognizes as practically necessary, or good. But suppose reason alone does not sufficiently determine the will. Suppose the will is also subject to subjective conditions (particular impulses) that do not always agree with objective conditions. In short, suppose the will does not fully agree with reason, as is actually the case with human beings. Then actions recognized as objectively necessary are subjectively contingent: the being may or may not perform them. Determining such a will according to objective laws is obligation. In other words, objective laws relate to a will that is not wholly good in the following way. Principles of reason determine the will of a rational being, but the will does not necessarily follow those principles by its nature.

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.

The idea of an objective principle, insofar as it binds a will, is called a command (of reason). The formula expressing this command is called an imperative.

All imperatives are expressed by the word ought [or shall], and thereby indicate the relation of an objective law of reason to a will, which from its subjective constitution is not necessarily determined by it (an obligation). 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. That is practically good, however, which determines the will by means of the conceptions of reason, and consequently not from subjective causes, but objectively, that is on principles which are valid for every rational being as such. It is distinguished from the pleasant, as that which influences the will only by means of sensation from merely subjective causes, valid only for the sense of this or that one, and not as a principle of reason, which holds for every one.⁵

All imperatives use the word ought [or shall]. They express the relation between an objective law of reason and a will whose subjective nature does not ensure obedience. This relation is an obligation. Imperatives say that something would be good to do or to avoid doing. But they address a will that does not always act because it understands an action to be good. What is practically good, however, guides the will through concepts of reason, not through subjective causes. It therefore guides the will objectively, through principles valid for every rational being as such. The practically good differs from the pleasant. The pleasant influences the will only through sensation, from purely subjective causes. These causes hold only for the senses of a particular individual, not as a principle of reason valid for everyone.⁵

A perfectly good will would therefore be equally subject to objective laws (viz., laws of good), but could not be conceived as obliged thereby to act lawfully, because of itself from its subjective constitution it can only be determined by the conception of good. Therefore no imperatives hold for the Divine will, or in general for a holy will; ought is here out of place, because the volition is already of itself necessarily in unison with the law. Therefore imperatives are only formulae to express the relation of objective laws of all volition to the subjective imperfection of the will of this or that rational being, e.g., the human will.

A perfectly good will would therefore also be subject to objective laws, that is, laws of good. But such a will could not be understood as obliged by these laws to act according to them. Because of its own nature, a perfectly good will can be guided only by the idea of good. Therefore, no imperatives apply to the Divine will or, more generally, to a holy will. “Ought” has no place here, because such a will already necessarily agrees with the law on its own. Imperatives are therefore only formulas expressing how objective laws governing all willing relate to a rational being’s imperfect will. The human will, for example, is such an imperfect will.

Now all imperatives command either hypothetically or categorically. The former represent the practical necessity of a possible action as means to something else that is willed (or at least which one might possibly will). The categorical imperative would be that which represented an action as necessary of itself without reference to another end, i.e., as objectively necessary.

All imperatives command either hypothetically or categorically. Hypothetical imperatives present a possible action as practically necessary to achieve something else one wills (or might possibly will). A categorical imperative would present an action as necessary in itself, without reference to any other goal. In other words, the action would be objectively necessary.

Since every practical law represents a possible action as good and, on this account, for a subject who is practically determinable by reason, necessary, all imperatives are formulae determining an action which is necessary according to the principle of a will good in some respects. If now the action is good only as a means to something else, then the imperative is hypothetical; if it is conceived as good in itself and consequently as being necessarily the principle of a will which of itself conforms to reason, then it is categorical.

Every practical law presents a possible action as good. For anyone whose actions can be guided by reason, the law therefore presents the action as necessary. Thus, all imperatives are formulas specifying an action as necessary according to the principle of a will good in some respect. If the action is good only as a means to something else, the imperative is hypothetical. If the action is understood as good in itself, the imperative is categorical. In that case, the action is necessarily understood as the principle of a will that, by itself, conforms to reason.

Thus the imperative declares what action possible by me would be good and presents the practical rule in relation to a will which does not forthwith perform an action simply because it is good, whether because the subject does not always know that it is good, or because, even if it know this, yet its maxims might be opposed to the objective principles of practical reason.

Thus, the imperative states which action I could perform would be good. It presents the practical rule to a will that does not immediately act simply because an action is good. This may be because the person does not always know that the action is good. Or, even if the person knows this, their maxims may conflict with the objective principles of practical reason.

Accordingly the hypothetical imperative only says that the action is good for some purpose, possible or actual. In the first case it is a problematical, in the second an assertorial practical principle. The categorical imperative which declares an action to be objectively necessary in itself without reference to any purpose, i.e., without any other end, is valid as an apodeictic (practical) principle.

Accordingly, a hypothetical imperative says only that an action is good for some purpose, whether possible or actual. If the purpose is possible, the practical principle is problematical. If the purpose is actual, the practical principle is assertorial. A categorical imperative declares an action objectively necessary in itself, without reference to any purpose or other end. A categorical imperative therefore holds as an apodeictic practical principle, one that is necessarily valid.

Whatever is possible only by the power of some rational being may also be conceived as a possible purpose of some will; and therefore the principles of action as regards the means necessary to attain some possible purpose are in fact infinitely numerous. All sciences have a practical part, consisting of problems expressing that some end is possible for us and of imperatives directing how it may be attained. These may, therefore, be called in general imperatives of skill. Here there is no question whether the end is rational and good, but only what one must do in order to attain it. The precepts for the physician to make his patient thoroughly healthy, and for a poisoner to ensure certain death, are of equal value in this respect, that each serves to effect its purpose perfectly. Since in early youth it cannot be known what ends are likely to occur to us in the course of life, parents seek to have their children taught a great many things, and provide for their skill in the use of means for all sorts of arbitrary ends, of none of which can they determine whether it may not perhaps hereafter be an object to their pupil, but which it is at all events possible that he might aim at; and this anxiety is so great that they commonly neglect to form and correct their judgement on the value of the things which may be chosen as ends.

Anything possible only through a rational being’s power can also be seen as a possible goal of some will. So there are infinitely many principles of action concerning the means needed to achieve some possible goal. All sciences have a practical part. This part includes problems showing that some goal is possible for us, and commands explaining how to achieve that goal. These commands may therefore be called, in general, imperatives of skill. Here the question is not whether the goal is rational and good, but only how to achieve it. Consider the instructions for a physician to make a patient completely healthy, and for a poisoner to ensure certain death. In this respect, the instructions have equal value: each serves its purpose perfectly. Since no one can know in early childhood what goals may arise later in life, parents teach their children many things. Parents seek to develop their children’s skill in using the means to achieve all sorts of freely chosen goals. For none of these goals can parents rule out the possibility that their children might later pursue it. Their concern is so great that parents commonly neglect to develop and correct their children’s judgment about these goals’ worth.

There is one end, however, which may be assumed to be actually such to all rational beings (so far as imperatives apply to them, viz., as dependent beings), and, therefore, one purpose which they not merely may have, but which we may with certainty assume that they all actually have by a natural necessity, and this is happiness. The hypothetical imperative which expresses the practical necessity of an action as means to the advancement of happiness is assertorial. We are not to present it as necessary for an uncertain and merely possible purpose, but for a purpose which we may presuppose with certainty and a priori in every man, because it belongs to his being. Now skill in the choice of means to his own greatest well-being may be called prudence,⁶ in the narrowest sense. And thus the imperative which refers to the choice of means to one's own happiness, i.e., the precept of prudence, is still always hypothetical; the action is not commanded absolutely, but only as means to another purpose.

There is, however, one goal we can assume all rational beings actually have: happiness. This applies insofar as imperatives apply to rational beings, that is, as dependent beings. Happiness is therefore not merely a purpose they may have. We can be certain that all rational beings actually have this purpose by natural necessity. A hypothetical imperative states that an action is practically necessary as a means of promoting happiness. Such an imperative is assertorial. We must not present the action as necessary for an uncertain, merely possible purpose. Instead, the action is necessary for a purpose we can confidently assume a priori in every human being. This is because the purpose belongs to human nature. Skill in choosing the means to one's own greatest well-being may be called prudence,⁶ in the narrowest sense. Thus, the imperative concerning the choice of means to one's own happiness, the rule of prudence, is still always hypothetical. The action is not commanded unconditionally, but only as a means to another purpose.

Finally, there is an imperative which commands a certain conduct immediately, without having as its condition any other purpose to be attained by it. This imperative is categorical. It concerns not the matter of the action, or its intended result, but its form and the principle of which it is itself a result; and what is essentially good in it consists in the mental disposition, let the consequence be what it may. This imperative may be called that of morality.

Finally, there is an imperative that directly commands a certain kind of conduct, without depending on any further purpose. This imperative is categorical. It concerns not what the action involves or its intended result, but the action’s form and guiding principle. What makes the action essentially good is the mindset behind it, whatever the consequences may be. This imperative may be called the imperative of morality.

There is a marked distinction also between the volitions on these three sorts of principles in the dissimilarity of the obligation of the will. In order to mark this difference more clearly, I think they would be most suitably named in their order if we said they are either rules of skill, or counsels of prudence, or commands (laws) of morality. For it is law only that involves the conception of an unconditional and objective necessity, which is consequently universally valid; and commands are laws which must be obeyed, that is, must be followed, even in opposition to inclination. Counsels, indeed, involve necessity, but one which can only hold under a contingent subjective condition, viz., they depend on whether this or that man reckons this or that as part of his happiness; the categorical imperative, on the contrary, is not limited by any condition, and as being absolutely, although practically, necessary, may be quite properly called a command. We might also call the first kind of imperatives technical (belonging to art), the second pragmatic⁷ (to welfare), the third moral (belonging to free conduct generally, that is, to morals).

Acts of will based on these three kinds of principles also differ markedly in how they bind the will. To make this difference clearer, I think the following names would be most suitable, in order: rules of skill, counsels of prudence, and commands (laws) of morality. For only law involves unconditional, objective necessity and is therefore universally valid. Commands are laws that must be obeyed, even against our inclinations. Counsels also involve necessity, but only under a subjective condition that may or may not hold. They depend on whether a particular person considers something part of their happiness. By contrast, the categorical imperative is not limited by any condition. Because it is absolutely necessary in practical terms, it may properly be called a command. We might also call the first kind of imperatives technical (concerned with art or skill). The second kind would be pragmatic⁷ (concerned with well-being). The third would be moral (concerned with free conduct in general, that is, with morals).

Now arises the question, how are all these imperatives possible? This question does not seek to know how we can conceive the accomplishment of the action which the imperative ordains, but merely how we can conceive the obligation of the will which the imperative expresses. No special explanation is needed to show how an imperative of skill is possible. Whoever wills the end, wills also (so far as reason decides his conduct) the means in his power which are indispensably necessary thereto. This proposition is, as regards the volition, analytical; for, in willing an object as my effect, there is already thought the causality of myself as an acting cause, that is to say, the use of the means; and the imperative educes from the conception of volition of an end the conception of actions necessary to this end. Synthetical propositions must no doubt be employed in defining the means to a proposed end; but they do not concern the principle, the act of the will, but the object and its realization. E.g., that in order to bisect a line on an unerring principle I must draw from its extremities two intersecting arcs; this no doubt is taught by mathematics only in synthetical propositions; but if I know that it is only by this process that the intended operation can be performed, then to say that, if I fully will the operation, I also will the action required for it, is an analytical proposition; for it is one and the same thing to conceive something as an effect which I can produce in a certain way, and to conceive myself as acting in this way.

The question now arises: how are all these imperatives possible? We are not asking how we can conceive of carrying out the action an imperative commands. We are asking only how we can conceive of the obligation it places on the will. No special explanation is needed to show how an imperative of skill is possible. Whoever wills an end also wills the means within their power that are absolutely necessary to achieve it. This holds insofar as reason guides their conduct. As a statement about willing, this proposition is analytical. For when I will something as an effect I will produce, I already conceive of myself as its acting cause. That means I already conceive of using the means. So the imperative draws the idea of the necessary actions from the idea of willing the end. We must, of course, use synthetic propositions to identify the means to a proposed end. But those propositions concern the object and its realization, not the principle governing the act of willing. For example, to bisect a line by a reliable method, I must draw two intersecting arcs from its endpoints. Mathematics teaches this procedure only through synthetic propositions. But suppose I know that the intended operation can be performed only through this procedure. Then the following proposition is analytical: if I fully will the operation, I also will the action required for it. For conceiving of something as an effect I can produce in a certain way is the same as conceiving of myself acting in that way.

If it were only equally easy to give a definite conception of happiness, the imperatives of prudence would correspond exactly with those of skill, and would likewise be analytical. For in this case as in that, it could be said: "Whoever wills the end, wills also (according to the dictate of reason necessarily) the indispensable means thereto which are in his power." But, unfortunately, the notion of happiness is so indefinite that although every man wishes to attain it, yet he never can say definitely and consistently what it is that he really wishes and wills. The reason of this is that all the elements which belong to the notion of happiness are altogether empirical, i.e., they must be borrowed from experience, and nevertheless the idea of happiness requires an absolute whole, a maximum of welfare in my present and all future circumstances. Now it is impossible that the most clear-sighted and at the same time most powerful being (supposed finite) should frame to himself a definite conception of what he really wills in this. Does he will riches, how much anxiety, envy, and snares might he not thereby draw upon his shoulders? Does he will knowledge and discernment, perhaps it might prove to be only an eye so much the sharper to show him so much the more fearfully the evils that are now concealed from him, and that cannot be avoided, or to impose more wants on his desires, which already give him concern enough. Would he have long life? who guarantees to him that it would not be a long misery? would he at least have health? how often has uneasiness of the body restrained from excesses into which perfect health would have allowed one to fall? and so on. In short, he is unable, on any principle, to determine with certainty what would make him truly happy; because to do so he would need to be omniscient. We cannot therefore act on any definite principles to secure happiness, but only on empirical counsels, e.g. of regimen, frugality, courtesy, reserve, etc., which experience teaches do, on the average, most promote well-being. Hence it follows that the imperatives of prudence do not, strictly speaking, command at all, that is, they cannot present actions objectively as practically necessary; that they are rather to be regarded as counsels (consilia) than precepts precepts of reason, that the problem to determine certainly and universally what action would promote the happiness of a rational being is completely insoluble, and consequently no imperative respecting it is possible which should, in the strict sense, command to do what makes happy; because happiness is not an ideal of reason but of imagination, resting solely on empirical grounds, and it is vain to expect that these should define an action by which one could attain the totality of a series of consequences which is really endless. This imperative of prudence would however be an analytical proposition if we assume that the means to happiness could be certainly assigned; for it is distinguished from the imperative of skill only by this, that in the latter the end is merely possible, in the former it is given; as however both only ordain the means to that which we suppose to be willed as an end, it follows that the imperative which ordains the willing of the means to him who wills the end is in both cases analytical. Thus there is no difficulty in regard to the possibility of an imperative of this kind either.

If only happiness were just as easy to define, the imperatives of prudence would exactly match the imperatives of skill. They would also be analytical. For in both cases, we could say: "Whoever wills the end also necessarily wills, as reason requires, the indispensable means within their power." Unfortunately, however, the idea of happiness is so vague that everyone wants happiness without knowing precisely what they want. No one can say clearly and consistently what they really wish for and will. The reason is that all the elements of happiness are empirical, meaning they must come from experience. Yet the idea of happiness requires a complete whole, the greatest possible well-being in my present and all future circumstances. Even the most clear-sighted and powerful being, if finite, cannot form a definite idea of what they really want here. Do they want wealth? How much anxiety, envy, and how many traps might wealth bring upon them? Do they want knowledge and insight? Perhaps these would only sharpen their vision, revealing more terrifyingly the unavoidable evils now hidden from them. Or perhaps knowledge would add more wants to the desires that already cause them enough concern. Do they want a long life? Who can guarantee that a long life would not mean prolonged misery? Do they at least want health? How often has physical discomfort held someone back from excesses that perfect health would have allowed them to fall into? And so on. In short, no principle can tell a person with certainty what would make them truly happy. To know that, they would need to know everything. We therefore cannot follow any definite principles to secure happiness. We can follow only advice drawn from experience, such as advice about health routines, thrift, courtesy, restraint, and so on. Experience teaches that these practices generally do the most to promote well-being. It follows that the imperatives of prudence do not, strictly speaking, command anything at all. They cannot present actions as objectively necessary in practice. They should therefore be regarded as advice (consilia), rather than commands of reason. The problem of determining, with certainty and for everyone, what action would promote a rational being’s happiness is completely insoluble. Consequently, no imperative concerning happiness can, strictly speaking, command us to do what makes us happy. For happiness is not an ideal of reason but of imagination, based entirely on experience. We cannot expect experience to define an action that would achieve the complete set of consequences in a truly endless series. Still, the imperative of prudence would be an analytical proposition if we assumed that the means to happiness could be identified with certainty. For prudence differs from skill only in the status of its end. With skill, the end is merely possible. With prudence, the end is given. Both, however, prescribe only the means to something we assume is willed as an end. In both cases, therefore, the imperative requiring whoever wills the end to will the means is analytical. So there is no difficulty in explaining how an imperative of this kind is possible either.

On the other hand, the question how the imperative of morality is possible, is undoubtedly one, the only one, demanding a solution, as this is not at all hypothetical, and the objective necessity which it presents cannot rest on any hypothesis, as is the case with the hypothetical imperatives. Only here we must never leave out of consideration that we cannot make out by any example, in other words empirically, whether there is such an imperative at all, but it is rather to be feared that all those which seem to be categorical may yet be at bottom hypothetical. For instance, when the precept is: "Thou shalt not promise deceitfully"; and it is assumed that the necessity of this is not a mere counsel to avoid some other evil, so that it should mean: "Thou shalt not make a lying promise, lest if it become known thou shouldst destroy thy credit," but that an action of this kind must be regarded as evil in itself, so that the imperative of the prohibition is categorical; then we cannot show with certainty in any example that the will was determined merely by the law, without any other spring of action, although it may appear to be so. For it is always possible that fear of disgrace, perhaps also obscure dread of other dangers, may have a secret influence on the will. Who can prove by experience the non-existence of a cause when all that experience tells us is that we do not perceive it? But in such a case the so-called moral imperative, which as such appears to be categorical and unconditional, would in reality be only a pragmatic precept, drawing our attention to our own interests and merely teaching us to take these into consideration.

On the other hand, how the moral imperative is possible is undoubtedly the one question that requires a solution. For the moral imperative is not hypothetical at all. The objective necessity it expresses cannot rest on any hypothesis, as the necessity of hypothetical imperatives does. But we must always remember that no example, or experience, can establish whether such an imperative exists at all. Rather, we must fear that all apparently categorical imperatives may ultimately be hypothetical. For example, consider the rule: "You must not make a deceitful promise." Suppose we assume that this rule is necessary, not merely advice for avoiding some other evil. In that case, the rule would not mean: "You must not make a lying promise, lest you lose your credibility if the lie becomes known." Instead, making such a promise must be regarded as wrong in itself, making the prohibition categorical. Yet no example can show with certainty that the law alone determined the will, without any other motive. This remains true even when the law appears to be the only motive. For fear of disgrace, and perhaps also a vague fear of other dangers, may always secretly influence the will. Who can prove through experience that a cause does not exist, when experience only tells us we do not perceive it? But in such a case, the so-called moral imperative would really be only a practical rule. Although it appears categorical and unconditional, it would draw our attention to our own interests and merely teach us to consider them.

We shall therefore have to investigate a priori the possibility of a categorical imperative, as we have not in this case the advantage of its reality being given in experience, so that [the elucidation of] its possibility should be requisite only for its explanation, not for its establishment. In the meantime it may be discerned beforehand that the categorical imperative alone has the purport of a practical law; all the rest may indeed be called principles of the will but not laws, since whatever is only necessary for the attainment of some arbitrary purpose may be considered as in itself contingent, and we can at any time be free from the precept if we give up the purpose; on the contrary, the unconditional command leaves the will no liberty to choose the opposite; consequently it alone carries with it that necessity which we require in a law.

We must therefore investigate a priori whether a categorical imperative is possible. In this case, we lack the advantage of having its reality given in experience. If we had that advantage, we would need to clarify its possibility only to explain it, not to establish it. Meanwhile, we can already see that only the categorical imperative has the force of a practical law. All other imperatives may indeed be called principles of the will, but not laws. Whatever is necessary only to achieve some freely chosen purpose may be considered contingent in itself. And we can free ourselves from the command at any time if we give up the purpose. By contrast, an unconditional command leaves the will no freedom to choose the opposite. Consequently, only an unconditional command carries the necessity we require in a law.

Secondly, in the case of this categorical imperative or law of morality, the difficulty (of discerning its possibility) is a very profound one. It is an a priori synthetical practical proposition;⁸ and as there is so much difficulty in discerning the possibility of speculative propositions of this kind, it may readily be supposed that the difficulty will be no less with the practical.

Secondly, understanding how this categorical imperative, or moral law, is possible presents a very deep difficulty. It is an a priori synthetic practical proposition.⁸ Understanding how speculative propositions of this kind are possible is already very difficult. So we may readily suppose that understanding how practical propositions of this kind are possible will be no less difficult.

In this problem we will first inquire whether the mere conception of a categorical imperative may not perhaps supply us also with the formula of it, containing the proposition which alone can be a categorical imperative; for even if we know the tenor of such an absolute command, yet how it is possible will require further special and laborious study, which we postpone to the last section.

We will first ask whether the concept of a categorical imperative alone may perhaps also give us its formula. This formula would state the only principle that can be a categorical imperative. For even if we know what such an absolute command says, explaining how it is possible requires further study. That study will be demanding and will need separate attention. We will leave it until the final section.

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 maxims⁹ 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.

When I think of a hypothetical imperative, I generally cannot know what it requires until I am given the condition. But when I think of a categorical imperative, I know at once what it requires. For the imperative contains only the law and the requirement that maxims⁹ must conform to that law. And since no conditions limit the law, only one general requirement remains: the maxim of the action must conform to a universal law. This conformity alone is what the imperative presents 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.

There is therefore only one categorical imperative: Act only on a principle you can, at the same time, will to become a universal law.

Now if all imperatives of duty can be deduced from this one imperative as from their principle, then, although it should remain undecided what is called duty is not merely a vain notion, yet at least we shall be able to show what we understand by it and what this notion means.

Suppose all imperatives of duty can be derived from this one imperative as their guiding principle. Whether what we call duty is merely an empty idea may still remain unresolved. Even so, we can at least show what we understand by duty and what the concept means.

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), that is the existence of things so far as it is determined by general laws, 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.

In the broadest sense, nature is defined by the universality of the law governing how effects occur. This definition concerns nature’s form: the existence of things insofar as that existence is determined by general laws. So the command of duty may be expressed as follows: Act as if the guiding principle of your action were to become, through your will, a universal law of nature.

We will now enumerate a few duties, adopting the usual division of them into duties to ourselves and ourselves and to others, and into perfect and imperfect duties.¹⁰

We will now list a few duties, using the usual divisions: duties to ourselves and duties to others. We will also divide duties into perfect and imperfect duties.¹⁰

1. A man reduced to despair by a series of misfortunes feels wearied of life, but is still so far in possession of his reason that he can ask himself whether it would not be contrary to his duty to himself to take his own life. Now he inquires whether the maxim of his action could become a universal law of nature. His maxim is: "From self-love I adopt it as a principle to shorten my life when its longer duration is likely to bring more evil than satisfaction." It is asked then simply whether this principle founded on self-love can become a universal law of nature. Now we see at once that a system of nature of which it should be a law to destroy life by means of the very feeling whose special nature it is to impel to the improvement of life would contradict itself and, therefore, could not exist as a system of nature; hence that maxim cannot possibly exist as a universal law of nature and, consequently, would be wholly inconsistent with the supreme principle of all duty.

1. A man driven to despair by a series of misfortunes is tired of life. But he can still reason well enough to ask whether taking his own life would violate his duty to himself. He now asks whether his maxim, the principle behind his action, could become a universal law of nature. His maxim is: "Out of self-love, I make it my principle to shorten my life when living longer would likely bring more suffering than satisfaction." The question is simply whether this principle, based on self-love, can become a universal law of nature. We immediately see that such a system of nature would contradict itself. In this system, the very feeling whose particular purpose is to promote life’s improvement would, by law, destroy life. Such a system therefore could not exist as a system of nature. So this maxim cannot possibly be a universal law of nature. Consequently, the maxim would be wholly inconsistent with the highest principle of all duty.

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 stoutly to repay it in a definite time. He desires to make this promise, but he has still so much conscience as to ask himself: "Is it not unlawful and inconsistent with duty to get out of a difficulty in this way?" Suppose however that he resolves to do so: then the maxim of his action would be expressed thus: "When I think myself in want of money, I will borrow money and promise to repay it, although I know that I never can do so." Now this principle of self-love or of one's own advantage may perhaps be consistent with my whole future welfare; but the question now is, "Is it right?" I change then the suggestion of self-love into a universal law, and state the question thus: "How would it be if my maxim were a universal law?" Then I see at once that it could never hold as a universal law of nature, but would necessarily contradict itself. For supposing it to be a universal law that everyone when he thinks himself in a difficulty should be able to promise whatever he pleases, with the purpose of not keeping his promise, the promise itself would become impossible, as well as the end that one might have in view in it, since no one would consider that anything was promised to him, but would ridicule all such statements as vain pretences.

2. Another person is forced by necessity to borrow money. He knows he will not be able to repay the loan. But he also knows no one will lend him anything unless he firmly promises to repay it by a specific date. He wants to make this promise, but still has enough conscience to ask himself: "Isn't escaping my difficulty this way wrong and contrary to duty?" Suppose, however, that he decides to make the promise. Then the maxim, or guiding principle, of his action would be: "When I believe I need money, I will borrow money and promise to repay it, although I know I never can." Now this principle of self-love, or personal advantage, may perhaps be consistent with my well-being throughout the future. But the question now is: "Is it right?" I therefore turn the proposal of self-love into a universal law and ask: "What if my maxim were a universal law?" I immediately see that this maxim could never hold as a universal law of nature. Instead, it would necessarily contradict itself. For suppose there were a universal law allowing everyone who believes himself in difficulty to promise whatever he likes, intending not to keep his promise. Then making a promise would become impossible, as would achieving whatever purpose the promise was meant to serve. For no one would believe that anything had been promised to him. Instead, everyone would ridicule all such statements as empty pretenses.

3. A third finds in himself a talent which with the help of some culture might make him a useful man in many respects. But he finds himself in comfortable circumstances and prefers to indulge in pleasure rather than to take pains in enlarging and improving his happy natural capacities. He asks, however, whether his maxim of neglect of his natural gifts, besides agreeing with his inclination to indulgence, agrees also with what is called duty. He sees then that a system of nature could indeed subsist with such a universal law although men (like the South Sea islanders) should let their talents rest and resolve to devote their lives merely to idleness, amusement, and propagation of their species- in a word, to enjoyment; but he cannot possibly will that this should be a universal law of nature, or be implanted in us as such by a natural instinct. 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.

3. A third person recognizes a talent in himself that, with some training, could make him useful in many ways. But he lives comfortably and prefers enjoying himself to making the effort to develop and improve his natural abilities. Still, he asks whether his principle of neglecting his natural gifts agrees with duty, as well as with his desire for pleasure. He sees that a system of nature could indeed exist under such a universal law. People (like the South Sea islanders) could leave their talents unused and choose to devote their lives only to idleness, amusement, and reproduction. In short, they could live only for enjoyment. But he cannot possibly will that this principle should become a universal law of nature. Nor can he will that this principle should be implanted in us as a natural instinct. For, as a rational being, he necessarily wills that his abilities should develop. Those abilities serve him and have been given to 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 and that he could help them, thinks: "What concern is it of mine? Let everyone be as happy as Heaven pleases, or as he can make himself; I will take nothing from him nor even envy him, only I do not wish to contribute anything to his welfare or to his assistance in distress!" Now no doubt if such a mode of thinking were a universal law, the human race might very well subsist and doubtless even better than in a state in which everyone talks of sympathy and good-will, or even takes care occasionally to put it into practice, but, on the other side, also cheats when he can, betrays the rights of men, or otherwise violates them. But although it is possible that a universal law of nature might exist in accordance with that maxim, it is impossible to will that such a principle should have the universal validity of a law of nature. For a will which resolved this would contradict itself, inasmuch as many cases might occur in which one would have need of the love and sympathy of others, and in which, by such a law of nature, sprung from his own will, he would deprive himself of all hope of the aid he desires.

4. A fourth person is prosperous but sees others struggling with great hardship and knows he could help them. He thinks: "Why should I care? Let everyone be as happy as Heaven pleases, or as happy as he can make himself. I will take nothing from anyone, nor will I envy anyone. I simply do not wish to contribute anything to anyone’s well-being or help anyone in distress!" Now, if this way of thinking were a universal law, humanity could certainly survive. Humanity would doubtless fare even better than when everyone talks of sympathy and goodwill, or even occasionally acts on them. Yet those same people also cheat whenever they can, betray people’s rights, or otherwise violate them. But although a universal law of nature based on this principle is possible, we cannot will such a law. For a will that chose this law would contradict itself. Many situations might arise in which a person would need the love and sympathy of others. Yet this law of nature, arising from his own will, would deprive him of all hope of the help he desires.

These are a few of the many actual duties, or at least what we regard as such, which obviously fall into two classes on the one principle that we have laid down. We must be able to will that a maxim of our action should be a universal law. This is the canon of the moral appreciation of the action generally. Some actions are of such a character that their maxim cannot without contradiction be even conceived as a universal law of nature, far from it being possible that we should will that it should be so. In others this intrinsic impossibility is not found, but still it is impossible to will that their maxim should be raised to the universality of a law of nature, since such a will would contradict itself It is easily seen that the former violate strict or rigorous (inflexible) duty; the latter only laxer (meritorious) duty. Thus it has been completely shown how all duties depend as regards the nature of the obligation (not the object of the action) on the same principle.

These are a few of the many actual duties, or at least what we regard as duties. They clearly fall into two classes under the single principle we have established. We must be able to will that our rule for acting, or maxim, become a universal law. This is the general standard for judging an action morally. Some actions have maxims that cannot even be conceived as universal laws of nature without contradiction. Much less could we will that those maxims become universal laws. Other maxims involve no such inherent impossibility. But we still cannot will that these maxims become universal laws of nature, because such a will would contradict itself. Clearly, actions in the first class violate strict or rigorous (inflexible) duties. Actions in the second class violate only less strict (meritorious) duties. This fully shows how all duties depend on the same principle in terms of the nature of their obligation. The point concerns the nature of the obligation, not the object of the action.

If now we attend to ourselves on occasion of any transgression of duty, we shall find that we in fact do not will that our maxim should be a universal law, for that is impossible for us; on the contrary, we will that the opposite should remain a universal law, only we assume the liberty of making an exception in our own favour or (just for this time only) in favour of our inclination. Consequently if we considered all cases from one and the same point of view, namely, that of reason, we should find a contradiction in our own will, namely, that a certain principle should be objectively necessary as a universal law, and yet subjectively should not be universal, but admit of exceptions. As however we at one moment regard our action from the point of view of a will wholly conformed to reason, and then again look at the same action from the point of view of a will affected by inclination, there is not really any contradiction, but an antagonism of inclination to the precept of reason, whereby the universality of the principle is changed into a mere generality, so that the practical principle of reason shall meet the maxim half way. Now, although this cannot be justified in our own impartial judgement, yet it proves that we do really recognise the validity of the categorical imperative and (with all respect for it) only allow ourselves a few exceptions, which we think unimportant and forced from us.

If we examine ourselves when we violate a duty, we find that we do not actually want our maxim to become a universal law. We cannot want that. Instead, we want the opposite to remain a universal law. We merely claim the freedom to make an exception for ourselves or (just this once) for our inclination. So if we considered all cases from the same standpoint, namely reason, we would find a contradiction in our will. We would want a principle to be objectively necessary as a universal law. Yet subjectively, we would want the same principle to allow exceptions rather than apply universally. However, we view our action first from the standpoint of a will fully guided by reason. Then we view the same action from the standpoint of a will influenced by inclination. So there is no actual contradiction, but rather a conflict between inclination and reason’s command. Through this conflict, a principle that applies universally becomes one that applies merely in general. Reason’s practical principle is thus made to meet our maxim halfway. Now, although our own impartial judgment cannot justify these exceptions, they still show that we really recognize the categorical imperative’s validity. With all respect for the categorical imperative, we merely allow ourselves a few exceptions. We regard these exceptions as unimportant and as forced upon us.

We have thus 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 also, which is of great importance, exhibited clearly and definitely for every practical application the content of the categorical imperative, which must contain the principle of all duty if there is such a thing at all. We have not yet, however, advanced so far as to prove a priori that there actually is such an imperative, that there is a practical law which commands absolutely of itself and without any other impulse, and that the following of this law is duty.

We have established at least one point. If duty is to have any meaning and real authority over our actions, it can only take one form. Duty must be expressed through categorical imperatives, never hypothetical ones. We have also clearly and precisely stated the content of the categorical imperative for every practical application. This clarity is especially important. The categorical imperative must contain the principle of all duty, if duty exists at all. But we have not yet proved through reason alone that such an imperative actually exists. We have not proved that there is a practical law that commands unconditionally, by itself, without any other motivating force. Nor have we proved that following this law is a 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. For duty is to be a practical, unconditional necessity of action; it must therefore hold for all rational beings (to whom an imperative can apply at all), and for this reason only be also a law for all human wills. On the contrary, whatever is deduced from the particular natural characteristics of humanity, from certain feelings and propensions, nay, even, if possible, from any particular tendency proper to human reason, and which need not necessarily hold for the will of every rational being; this may indeed supply us with a maxim, but not with a law; with a subjective principle on which we may have a propension and inclination to act, but not with an objective principle on which we should be enjoined to act, even though all our propensions, inclinations, and natural dispositions were opposed to it. In fact, the sublimity and intrinsic dignity of the command in duty are so much the more evident, the less the subjective impulses favour it and the more they oppose it, without being able in the slightest degree to weaken the obligation of the law or to diminish its validity.

To achieve this, we must remember something crucial. We must not try to establish this principle’s reality from the particular features of human nature. For duty must make an action practically necessary, without conditions. Duty must therefore apply to all rational beings to whom an imperative can apply at all. Only for that reason must duty also be a law for every human will. By contrast, consider any principle derived from humanity’s particular natural characteristics, or from certain feelings and inclinations. Such a principle might even, if possible, come from a particular tendency belonging to human reason itself. But suppose that tendency does not necessarily apply to the will of every rational being. A principle derived from such sources may indeed give us a maxim, but not a law. It may give us a subjective principle that we feel inclined to follow. But it cannot give us an objective principle that commands us to act. Such an objective principle must command us even if all our impulses, inclinations, and natural dispositions oppose it. Indeed, the less our subjective impulses support duty’s command, and the more they oppose it, the clearer its greatness and inherent dignity become. Yet those opposing impulses cannot weaken the law’s binding force or diminish its validity in the slightest.

Here then we see philosophy brought to a critical position, since it has to be firmly fixed, notwithstanding that it has nothing to support it in heaven or earth. Here it 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 or who knows what tutelary nature. Although these may be better than nothing, yet they can never afford principles dictated by reason, which must have their source wholly a priori and thence their commanding authority, expecting everything from the supremacy of the law and the due respect for it, nothing from inclination, or else condemning the man to self-contempt and inward abhorrence.

Here, then, we see philosophy at a critical point. Philosophy must stand firm, even though nothing in heaven or on earth supports it. Here philosophy must show its purity as the absolute maker of its own laws. It must not merely announce laws whispered by an inborn sense or by who knows what guiding nature. Although these sources may be better than nothing, they can never provide principles dictated by reason. Such principles must come entirely a priori, independently of experience, and draw their commanding authority from that source. They must expect everything from the supremacy of the law and proper respect for it, and nothing from inclination. Otherwise, they must condemn the person to self-contempt and inward disgust.

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, for the proper and inestimable worth of an absolutely good will consists just in this, that the principle of action is free from all influence of contingent grounds, which alone experience can furnish. We cannot too much or too often repeat our warning against this lax and even mean habit of thought which seeks for its principle amongst empirical motives and laws; for human reason in its weariness is glad to rest on this pillow, and in a dream of sweet illusions (in which, instead of Juno, it embraces a cloud) it substitutes for morality a bastard patched up from limbs of various derivation, which looks like anything one chooses to see in it, only not like virtue to one who has once beheld her in her true form.¹¹

Thus, no element drawn from experience can help establish the principle of morality. Such elements are even deeply harmful to moral purity. For the true and priceless worth of an absolutely good will lies precisely in its principle of action. That principle is free from all influence of contingent grounds, the only grounds experience can provide. We cannot warn too strongly or too often against this lax and even base way of thinking. It seeks its principle among motives and laws drawn from experience. For when human reason grows weary, it gladly rests on this pillow and dreams sweet illusions. (Instead of Juno, it embraces a cloud.) In these dreams, reason replaces morality with an illegitimate creation patched together from parts of different origins. This creation looks like whatever anyone chooses to see in it. But to anyone who has once seen virtue in her true form, it looks nothing like virtue.¹¹

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?" If it is so, then it must be connected (altogether a priori) with the very conception of the will of a rational being generally. But in order to discover this connexion we must, however reluctantly, take a step into metaphysic, although into a domain of it which is distinct from speculative philosophy, namely, the metaphysic of morals. In a practical philosophy, where it is not the reasons of what happens that we have to ascertain, but the laws of what ought to happen, even although it never does, i.e., objective practical laws, there it is not necessary to inquire into the reasons why anything pleases or displeases, how the pleasure of mere sensation differs from taste, and whether the latter is distinct from a general satisfaction of reason; on what the feeling of pleasure or pain rests, and how from it desires and inclinations arise, and from these again maxims by the co-operation of reason: for all this belongs to an empirical psychology, which would constitute the second part of physics, if we regard physics as the philosophy of nature, so far as it is based on empirical laws. But here we are concerned with objective practical laws and, consequently, with the relation of the will to itself so far as it is determined by reason alone, in which case whatever has reference to anything empirical is necessarily excluded; since if reason of itself alone determines the conduct (and it is the possibility of this that we are now investigating), it must necessarily do so a priori.

The question, then, is this: "Must all rational beings always judge their actions by principles they themselves can will to become universal laws?" If so, this law must follow entirely a priori from the very concept of a rational being’s will. In other words, the connection must be independent of experience. But to discover this connection, we must enter metaphysics, however reluctantly. We must enter a branch distinct from speculative philosophy, namely, the metaphysics of morals. Practical philosophy does not ask why things happen. Instead, it seeks the laws of what ought to happen, even if it never does. These are objective practical laws. Here we need not ask why anything pleases or displeases us. Nor need we ask how pleasure from sensation alone differs from taste. We need not ask whether taste differs from a general satisfaction of reason. Nor must we investigate what underlies feelings of pleasure or pain, or how desires and inclinations arise from those feelings. We also need not ask how reason works with desires and inclinations to produce maxims, or principles of action. All these questions belong to empirical psychology, which would form the second part of physics. This holds if we understand physics as the philosophy of nature insofar as it rests on empirical laws. But here we are concerned with objective practical laws. We therefore examine the will’s relation to itself insofar as reason alone determines the will. In this case, anything involving experience must necessarily be excluded. For if reason alone determines conduct, reason must necessarily do so a priori, independently of experience. Whether reason can determine conduct in this way is precisely what we are now investigating.

The will is conceived as a faculty of determining oneself to action in accordance with the conception of certain laws. And such a faculty can be found only in rational beings. Now that which serves the will as the objective ground of its self-determination is the end, and, if this is assigned by reason alone, it must hold for all rational beings. On the other hand, that which merely contains the ground of possibility of the action of which the effect is the end, this is called the means. The subjective ground of the desire is the spring, the objective ground of the volition is the motive; hence the distinction between subjective ends which rest on springs, and objective ends which depend on motives valid for every rational being. Practical principles are formal when they abstract from all subjective ends; they are material when they assume these, and therefore particular springs of action. The ends which a rational being proposes to himself at pleasure as effects of his actions (material ends) are all only relative, for it is only their relation to the particular desires of the subject that gives them their worth, which therefore cannot furnish principles universal and necessary for all rational beings and for every volition, that is to say practical laws. Hence all these relative ends can give rise only to hypothetical imperatives.

The will is understood as the ability to choose how to act according to the idea of certain laws. Only rational beings can have this ability. An end is the objective basis on which the will determines itself to act. If reason alone sets this end, the end must hold for all rational beings. A means, by contrast, is simply what makes possible an action whose effect is the end. The subjective basis of desire is the incentive. The objective basis of willing is the motive. Hence the distinction between subjective ends, based on incentives, and objective ends, based on motives valid for every rational being. Practical principles are formal when they leave all subjective ends out of account. They are material when they assume subjective ends and therefore particular incentives to act. All ends that rational beings freely choose as effects of their actions (material ends) are only relative. For these ends have worth only through their relation to the individual's particular desires. Their worth therefore cannot provide principles that are universal and necessary for all rational beings and every act of willing. Such principles would be practical laws. Thus all these relative ends can give rise only to hypothetical imperatives.

Supposing, however, that there were something whose existence has in itself an absolute worth, something which, being an end in itself, could be a source of definite laws; then in this and this alone would lie the source of a possible categorical imperative, i.e., a practical law.

Suppose, however, that something existed whose existence had absolute worth in itself. Suppose that, as an end in itself, it could be a source of definite laws. Then this alone would be the source of a possible categorical imperative, that is, a practical law.

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. All objects of the inclinations have only a conditional worth, for if the inclinations and the wants founded on them did not exist, then their object would be without value. But the inclinations, themselves being sources of want, are so far from having an absolute worth for which they should be desired that on the contrary it must be the universal wish of every rational being to be wholly free from them. Thus the worth of any object which is to be acquired by our action is always conditional. Beings whose existence depends not on our will but on nature's, have nevertheless, if they are irrational beings, only a relative value as means, and are therefore called things; rational beings, on the contrary, are called persons, because their very nature points them out as ends in themselves, that is as something which must not be used merely as means, and so far therefore restricts freedom of action (and is an object of respect). These, therefore, are not merely subjective ends whose existence has a worth for us as an effect of our action, but objective ends, that is, things whose existence is an end in itself; an end moreover for which no other can be substituted, which they should subserve merely as means, for otherwise nothing whatever would possess absolute worth; but if all worth were conditioned and therefore contingent, then there would be no supreme practical principle of reason whatever.

Now I say: human beings, and all rational beings, exist as ends in themselves. They are not merely means for any will to use however it chooses. In all their actions, whether concerning themselves or other rational beings, they must always also be regarded as ends. Everything we desire has only conditional value. For if our desires and the needs based on them did not exist, their objects would have no value. But desires themselves, as sources of need, are far from having absolute value that would make them worth wanting. On the contrary, every rational being must wish to be entirely free from desires. Thus, the value of any object we acquire through our actions is always conditional. Some beings owe their existence to nature rather than to our will. Nevertheless, if these beings lack reason, they have only relative value as means and are therefore called things. Rational beings, by contrast, are called persons because their very nature marks them as ends in themselves. That is, persons must not be used merely as means. Their nature therefore limits freedom of action in this respect and makes them objects of respect. Persons, therefore, are not merely subjective ends whose existence, brought about by our actions, has value for us. Instead, persons are objective ends, beings whose existence is an end in itself. No other end can replace persons as ends in themselves, reducing them to mere means serving that other end. Otherwise, nothing at all would have absolute value. But if all value were conditional and therefore contingent, there would be no supreme practical principle of reason at all.

If then there is a supreme practical principle or, in respect of the human will, a categorical imperative, it must be one which, being drawn from the conception of that which is necessarily an end for everyone because it is an end in itself, constitutes an objective principle of will, and can therefore serve as a universal practical law. The foundation of this principle is: rational nature exists as an end in itself. Man necessarily conceives his own existence as being so; so far then this is a subjective principle of human actions. But every other rational being regards its existence similarly, just on the same rational principle that holds for me:¹² so that it is at the same time an objective principle, from which as a supreme practical law all laws of the will must be capable of being deduced. 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.

Suppose, then, that there is a supreme practical principle or, for the human will, a categorical imperative. Such a principle must rest on the idea of something necessarily an end for everyone because it is an end in itself. The principle must therefore be an objective principle of the will and serve as a universal practical law. Its foundation is this: rational nature exists as an end in itself. Every human being necessarily understands their own existence in this way. To that extent, this understanding is a subjective principle of human action. But every other rational being understands its existence in the same way, on the same rational principle that applies to me:¹² so this principle is also objective. All laws of the will must be derivable from this principle as a supreme practical law. The practical imperative is therefore this: Always act so that you treat humanity, whether in yourself or anyone else, as an end, never merely as a means. We will now ask whether this imperative can be put into practice.

To abide by the previous examples:

To stick with the earlier examples:

Firstly, under the head of necessary duty to oneself: 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, that is to say, something which can be used merely as means, 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, to damage or kill him. (It belongs to ethics proper to define this principle more precisely, so as to avoid all misunderstanding, e. g., as to the amputation of the limbs in order to preserve myself, as to exposing my life to danger with a view to preserve it, etc. This question is therefore omitted here.)

First, consider a necessary duty to oneself: Anyone considering suicide should ask whether their action respects humanity as an end in itself. If someone destroys themselves to escape painful circumstances, they use a person merely as a means. Their purpose is to maintain a tolerable condition until life ends. But a person is not a thing, something that can be used merely as a means. Rather, a person must always be treated as an end in themselves in all their actions. Therefore, I cannot treat the person I am as something I may mutilate, harm, or kill. (Ethics itself must define this principle more precisely to prevent any misunderstanding. For example, clarification is needed about amputating limbs to preserve my life or risking my life to preserve it. These questions are therefore left aside here.)

Secondly, as regards necessary duties, or those 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 mean, without the latter containing at the same time the end in himself. For he whom I propose by such a promise to use for my own purposes cannot possibly assent to my mode of acting towards him and, therefore, cannot himself contain the end of this action. This violation of the principle of humanity in other men is more obvious if we take in examples of attacks on the freedom and property of others. For then it is clear that he who transgresses the rights of men intends to use the person of others merely as a means, without considering that as rational beings they ought always to be esteemed also as ends, that is, as beings who must be capable of containing in themselves the end of the very same action.¹³

Second, consider necessary duties, or strict obligations, to others. Anyone thinking of making a false promise will immediately see that they would be using someone merely as a means. They would not also be treating that person as an end in themselves. For the person I intend to use for my own purposes through such a promise cannot possibly accept my conduct. Therefore, that person cannot share in the purpose of my action. This violation of the principle of humanity in others becomes more obvious when we consider attacks on their freedom and property. Such cases make it clear that anyone violating others’ rights intends to use those people merely as means. The offender fails to consider that rational beings must always also be valued as ends in themselves. In other words, those people must be able to share in the purpose of the very same action.¹³

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. Now there are in humanity capacities of greater perfection, which belong to the end that nature has in view in regard to humanity in ourselves as the subject: to neglect these might perhaps be consistent with the maintenance of humanity as an end in itself, but not with the advancement of this end.

Thirdly, consider our contingent (meritorious) duties to ourselves. Our actions must do more than avoid violating the humanity in ourselves as an end in itself. They must also support that end. Our humanity includes capacities for greater perfection. Developing these capacities is part of nature’s purpose for the humanity within us. Neglecting these capacities might perhaps be consistent with preserving our humanity as an end in itself. But such neglect would not advance that end.

Fourthly, as regards meritorious duties towards others: The natural end which all men have is their own happiness. Now humanity might indeed subsist, although no one should contribute anything to the happiness of others, provided he did not intentionally withdraw anything from it; but after all this would only harmonize negatively not positively with humanity as an end in itself, if every one does not also endeavour, as far as in him lies, to forward the ends of others. For 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.

Fourth, regarding duties toward others that deserve moral credit: Everyone naturally aims at their own happiness. Humanity could indeed survive even if no one contributed to anyone else’s happiness, provided no one intentionally reduced it. But this would agree only negatively, not positively, with treating humanity as an end in itself. Positive agreement requires everyone to do what they can to advance the aims of others. For if I am to fully apply this idea, I ought, as far as possible, to share those aims. They are the aims of people who are ends in themselves.

This principle, that humanity and generally every rational nature is an end in itself (which is the supreme limiting condition of every man's freedom of action), is not borrowed from experience, firstly, because it is universal, applying as it does to all rational beings whatever, and experience is not capable of determining anything about them; secondly, because it does not present humanity as an end to men (subjectively), that is as an object which men do of themselves actually adopt as an end; but as an objective end, which must as a law constitute the supreme limiting condition of all our subjective ends, let them be what we will; it must therefore spring from pure reason. In fact the objective principle of all practical legislation lies (according to the first principle) in the rule and its form of universality which makes it capable of being a law (say, e. g., a law of nature); but the subjective principle is in the end; now by the second principle the subject of all ends is each rational being, inasmuch as it is an end in itself. Hence follows the third practical principle of the will, which is the ultimate condition of its harmony with universal practical reason, viz.: the idea of the will of every rational being as a universally legislative will.

Humanity, and every rational nature in general, is an end in itself. This principle sets the highest limit on every person's freedom of action. The principle does not come from experience, for two reasons. First, it is universal and applies to all rational beings without exception. Experience cannot establish anything about all such beings. Second, the principle does not present humanity as a subjective end, something people actually choose as a goal. Instead, the principle presents humanity as an objective end. As a law, this objective end must set the highest limit on all our subjective ends, whatever they may be. The principle must therefore come from pure reason. According to the first principle, the objective basis of all practical lawmaking lies in the rule and its universal form. This universal form makes the rule capable of serving as a law, for example, a law of nature. But the subjective basis lies in the end. According to the second principle, each rational being is the subject of all ends, because each is an end in itself. From this follows the third practical principle of the will. This third principle is the ultimate condition for the will's harmony with universal practical reason: the idea of every rational being's will as a will that makes universal laws.

On this principle 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).

This principle rejects all maxims inconsistent with the will itself making universal law. Thus, the will is not simply subject to the law. Rather, the will must be seen as making the law itself and as subject to the law only on that basis. (The will can regard itself as the author of the law.)

In the previous imperatives, namely, that based on the conception of the conformity of actions to general laws, as in a physical system of nature, and that based on the universal prerogative of rational beings as ends in themselves- these imperatives, just because they were conceived as categorical, excluded from any share in their authority all admixture of any interest as a spring of action; they were, however, only assumed to be categorical, because such an assumption was necessary to explain the conception of duty. But we could not prove independently that there are practical propositions which command categorically, nor can it be proved in this section; one thing, however, could be done, namely, to indicate in the imperative itself, by some determinate expression, that in the case of volition from duty all interest is renounced, which is the specific criterion of categorical as distinguished from hypothetical imperatives. This is done in the present (third) formula of the principle, namely, in the idea of the will of every rational being as a universally legislating will.

The previous imperatives rested on two ideas. The first was that actions must conform to universal laws, as in a physical system of nature. The second was that all rational beings have a special status as ends in themselves. Because these imperatives were understood as categorical, their authority excluded all interest as a motive for action. However, we only assumed they were categorical because we needed that assumption to explain the concept of duty. We could not independently prove that any practical principles command categorically. Nor can we prove that in this section. But we could do one thing. We could use precise wording in the imperative itself to show that willing from duty means renouncing all interest. This renunciation is the defining feature that distinguishes categorical imperatives from hypothetical ones. The present, third formulation of the principle expresses this distinction: every rational being’s will is a will that makes universal laws.

For although a will which is subject to laws may be attached to this law by means of an interest, yet a will which is itself a supreme lawgiver so far as it is such cannot possibly depend on any interest, since a will so dependent would itself still need another law restricting the interest of its self-love by the condition that it should be valid as universal law.

For a will subject to laws may follow a law because of an interest. But a will that is itself a supreme lawgiver cannot possibly depend on any interest in that role. A will dependent on an interest would still need another law to restrict the interest of its self-love. This further law would require that interest to be valid as a universal law.

Thus the principle that every human will is a will which in all its maxims gives universal laws,¹⁴ provided it be otherwise justified, would be very well adapted to be the categorical imperative, in this respect, namely, that just because of the idea of universal legislation it is not based on interest, and therefore it alone among all possible imperatives can be unconditional. Or still better, converting the proposition, if there is a categorical imperative (i.e., a law for the will of every rational being), it can only command that everything be done from maxims of one's will regarded as a will which could at the same time will that it should itself give universal laws, for in that case only the practical principle and the imperative which it obeys are unconditional, since they cannot be based on any interest.

Thus, consider the principle that every human will gives universal laws through all its maxims.¹⁴ If otherwise justified, this principle would be well suited to serve as the categorical imperative for this reason: the very idea of giving universal laws means that the principle is not based on any interest. Therefore, this principle alone, among all possible imperatives, can be unconditional. Or better still, we can reverse the statement. If there is a categorical imperative (a law for the will of every rational being), it can command only this: every action must follow maxims of a will that could also will to give universal laws itself. Only then are both the practical principle and the imperative that the will obeys unconditional. For neither the principle nor the imperative can be based on any interest.

Looking back now on all previous attempts to discover the principle of morality, we need not wonder why they all failed. It was seen that man was bound to laws by duty, but it was not observed that the laws to which he is subject are only those of his own giving, though at the same time they are universal, and that he is only bound to act in conformity with his own will; a will, however, which is designed by nature to give universal laws. For when one has conceived man only as subject to a law (no matter what), then this law required some interest, either by way of attraction or constraint, since it did not originate as a law from his own will, but this will was according to a law obliged by something else to act in a certain manner. Now by this necessary consequence all the labour spent in finding a supreme principle of duty was irrevocably lost. For men never elicited duty, but only a necessity of acting from a certain interest. Whether this interest was private or otherwise, in any case the imperative must be conditional and could not by any means be capable of being a moral command. I will therefore call this the principle of autonomy of the will, in contrast with every other which I accordingly reckon as heteronomy.

Looking back at all previous attempts to discover the principle of morality, we need not wonder why they all failed. People recognized that human beings were bound by duty to obey laws. But they overlooked that human beings are subject only to laws they give themselves, though these laws are also universal. They also overlooked that human beings are bound to act only in accordance with their own will. Yet this will is designed by nature to give universal laws. For if we see human beings merely as subject to a law, whatever that law may be, some interest is needed. That interest must either attract or compel them to obey. This is because the law does not come from their own will. Instead, something else obliges their will, under a law, to act in a certain way. As a necessary result, all the effort spent finding a supreme principle of duty was lost beyond recovery. For people never arrived at duty, but only at the necessity of acting out of some interest. Whether this interest was private or otherwise, the imperative must in any case be conditional. It therefore could not possibly be a moral command. I will therefore call the principle described here the principle of autonomy of the will. I contrast it with every other principle, which I accordingly classify as heteronomy.

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, so as to judge itself and its actions from this point of view- this conception leads to another which depends on it and is very fruitful, namely that of a kingdom of ends.

The idea is that every rational being’s will must see itself as making universal laws through all its maxims. From this standpoint, the will judges itself and its actions. This idea leads to a further, highly fruitful idea that depends on the first: a kingdom of ends.

By a kingdom I understand the union of different rational beings in a system by common laws. Now since it is by laws that ends are determined as regards their universal validity, hence, if we abstract from the personal differences of rational beings and likewise from all the content of their private ends, we shall be able to conceive all ends combined in a systematic whole (including both rational beings as ends in themselves, and also the special ends which each may propose to himself), that is to say, we can conceive a kingdom of ends, which on the preceding principles is possible.

By a kingdom, I mean a system of different rational beings united by common laws. Laws determine which ends are universally valid. So, if we set aside rational beings’ personal differences and all the content of their private ends, a possibility emerges. We can conceive of all ends united in a systematic whole. This whole includes both rational beings as ends in themselves and the particular ends each may set for themselves. In other words, we can conceive of a kingdom of ends, possible according to the principles already stated.

For all rational beings come under the law that each of them must treat itself and all others never merely as means, but in every case at the same time as ends in themselves. Hence results a systematic union of rational being by common objective laws, i.e., a kingdom which may be called a kingdom of ends, since what these laws have in view is just the relation of these beings to one another as ends and means. It is certainly only an ideal.

For all rational beings are subject to a law governing how each must treat itself and all others. Each must never treat itself or others merely as means, but always also as ends in themselves. This law thus unites rational beings into an organized whole under shared objective laws. Such a union is a kingdom, which may be called a kingdom of ends. For these laws concern precisely how rational beings relate to one another as ends and means. This kingdom is certainly only an ideal.

A rational being belongs as a member to the kingdom of ends when, although giving universal laws in it, he is also himself subject to these laws. He belongs to it as sovereign when, while giving laws, he is not subject to the will of any other.

A rational being is a member of the kingdom of ends when, although it gives universal laws, it is also subject to those laws. A rational being is sovereign in that kingdom when it gives laws but is not subject to anyone else's will.

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. He cannot, however, maintain the latter position merely by the maxims of his will, but only in case he is a completely independent being without wants and with unrestricted power adequate to his will.

A rational being must always see himself as making laws, either as a member or as a sovereign, in a kingdom of ends. Freedom of the will makes such a kingdom possible. But the principles guiding his will alone cannot give him the position of sovereign. He can hold that position only if he is completely independent, has no needs, and has unlimited power to carry out his 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, i.e., 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.

Morality, then, consists in relating all action to the lawmaking that alone can make a kingdom of ends possible. This lawmaking must be possible in every rational being and must come from that being’s will. So the will’s principle is never to act on a maxim that could not, without contradiction, also be a universal law. Accordingly, the will must always act so that it can also regard itself as making universal laws through its maxims. If rational beings’ maxims do not naturally agree with this objective principle, acting on the principle becomes necessary. This necessity is called practical necessitation, or duty. Duty does not apply to the sovereign in the kingdom of ends. But duty does apply to every member of that kingdom, and to all in the same degree.

The practical necessity of acting on this principle, i.e., duty, does not rest at all on feelings, impulses, or inclinations, but solely on the relation of rational beings to one another, a relation in which the will of a rational being must always be regarded as legislative, since otherwise it could not be conceived as an end in itself. Reason then refers every maxim of the will, regarding it as legislating universally, to every other will and also to every action towards oneself; and this not on account of any other practical motive or any future advantage, but from the idea of the dignity of a rational being, obeying no law but that which he himself also gives.

The practical necessity of acting on this principle, or duty, does not depend at all on feelings, impulses, or inclinations. Duty rests solely on the relationship between rational beings. In this relationship, a rational being’s will must always be seen as making laws. Otherwise, that rational being could not be understood as an end in itself. Reason therefore treats every maxim, or guiding principle, of the will as making universal law. Reason relates each maxim to every other will and also to every action directed toward oneself. Reason does so not because of any other practical motive or future advantage, but because of rational beings’ dignity. This dignity lies in obeying no law except one they themselves also give.

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.

In the kingdom of ends, everything has either value or dignity. Anything with value can be replaced by something else of equal value. But anything beyond all value has no equivalent and therefore has dignity.

Whatever has reference to the general inclinations and wants of mankind has a market value; whatever, without presupposing a want, corresponds to a certain taste, that is to a satisfaction in the mere purposeless play of our faculties, has a fancy value; but that which constitutes the condition under which alone anything can be an end in itself, this has not merely a relative worth, i.e., value, but an intrinsic worth, that is, dignity.

Whatever relates to humanity’s general desires and needs has a market value. Whatever appeals to a certain taste without depending on a need has a fancy value. Such taste takes pleasure simply in the purposeless play of our abilities. But whatever provides the necessary condition for anything to be an end in itself has more than relative worth. Its worth is intrinsic, not merely a value relative to something else. This intrinsic worth is dignity.

Now morality is the condition under which alone a rational being can be an end in himself, since by this alone is it possible that he should be a legislating member in the kingdom of ends. Thus morality, and humanity as capable of it, is that which alone has dignity. Skill and diligence in labour have a market value; wit, lively imagination, and humour, have fancy value; on the other hand, fidelity to promises, benevolence from principle (not from instinct), have an intrinsic worth. Neither nature nor art contains anything which in default of these it could put in their place, for their worth consists not in the effects which spring from them, not in the use and advantage which they secure, but in the disposition of mind, that is, the maxims of the will which are ready to manifest themselves in such actions, even though they should not have the desired effect. These actions also need no recommendation from any subjective taste or sentiment, that they may be looked on with immediate favour and satisfaction: they need no immediate propension or feeling for them; they exhibit the will that performs them as an object of an immediate respect, and nothing but reason is required to impose them on the will; not to flatter it into them, which, in the case of duties, would be a contradiction. This estimation therefore shows that the worth of such a disposition is dignity, and places it infinitely above all value, with which it cannot for a moment be brought into comparison or competition without as it were violating its sanctity.

Morality is the only condition under which a rational being can be an end in themselves. Only through morality can a rational being be a lawmaking member of the kingdom of ends. Thus morality, and humanity insofar as it is capable of morality, alone has dignity. Skill and diligence at work have a market value. Wit, lively imagination, and humour have a value based on personal taste. By contrast, faithfulness to promises and kindness based on principle (not instinct) have intrinsic worth. Neither nature nor art can offer anything to replace these qualities when they are absent. For their worth lies neither in their effects nor in the usefulness and advantages they provide. Instead, their worth lies in the attitude of mind, that is, the guiding principles of the will. These principles stand ready to express themselves in such actions, even if the actions fail to achieve their intended effect. These actions need no endorsement from personal taste or feeling to be viewed with immediate approval and satisfaction. They require no immediate inclination or feeling in their favour. They reveal the will behind them as worthy of immediate respect. Reason alone is needed to require these actions of the will, rather than coax the will into them. In matters of duty, such coaxing would be a contradiction. This judgment therefore shows that the worth of such an attitude of mind is dignity. It places that dignity infinitely above all price. Dignity cannot, even for a moment, be compared with or set against anything priced without, as it were, violating its sacredness.

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, a privilege to which he was already destined by his own nature as being an end in himself and, on that account, legislating in the kingdom of ends; free as regards all laws of physical nature, and obeying those only which he himself gives, and by which his maxims can belong to a system of universal law, to which at the same time he submits himself. For nothing has any worth except what the law assigns it. Now the legislation itself which assigns the worth of everything 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.

What, then, justifies the lofty claims of virtue, or a morally good disposition? Nothing less than the privilege virtue gives rational beings of helping to make universal laws. This privilege qualifies them to belong to a possible kingdom of ends. Their own nature already destined them for this privilege, since they are ends in themselves. As ends in themselves, they make laws in the kingdom of ends. They are free from all laws of physical nature and obey only the laws they give themselves. Through these self-given laws, their maxims can form part of a system of universal law. At the same time, they submit themselves to that system. For nothing has any worth except the worth the law assigns to it. The lawmaking that assigns worth to everything must, for that very reason, itself possess dignity. Dignity is unconditional worth beyond all comparison. Only the word respect properly expresses the esteem that rational beings must have for this lawmaking. Autonomy, then, is the basis of the dignity of human nature 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. There is, however, a difference in them, but it is rather subjectively than objectively practical, intended namely to bring an idea of the reason nearer to intuition (by means of a certain analogy) and thereby nearer to feeling. All maxims, in fact, have:

The three ways of presenting the principle of morality discussed above are, at bottom, just different formulations of the same law. Each formulation by itself includes the other two. There is, however, a difference between these formulations. But the practical difference concerns our subjective experience rather than anything objective. The purpose is to bring an idea of reason closer to intuition through a certain analogy, and thus closer to feeling. All maxims, in fact, have:

1. A form, consisting in universality; and in this view the formula of the moral imperative is expressed thus, that the maxims must be so chosen as if they were to serve as universal laws of nature.

1. A form, consisting in universality. From this perspective, the moral imperative states: Maxims must be chosen as if they were to serve as universal laws of nature.

2. A matter, namely, an end, and here the formula says that the rational being, as it is an end by its own nature and therefore an end in itself, must in every maxim serve as the condition limiting all merely relative and arbitrary ends.

2. A content, namely, an end. Here the formula states that a rational being is by nature an end and therefore an end in itself. As such, in every maxim, a rational being must limit all merely relative and arbitrarily chosen ends.

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.¹⁵ There is a progress here in the order of the categories of unity of the form of the will (its universality), plurality of the matter (the objects, i.e., the ends), and totality of the system of these. In forming our moral judgement of actions, it is better to proceed always on the strict method and start from the general formula of the categorical imperative: Act according to a maxim which can at the same time make itself a universal law. If, however, we wish to gain an entrance for the moral law, it is very useful to bring one and the same action under the three specified conceptions, and thereby as far as possible to bring it nearer to intuition.

3. A complete account of all maxims through that formula: all maxims ought, through their own lawmaking, to agree with a possible kingdom of ends, as with a kingdom of nature.¹⁵ The progression here follows the order of the categories. First comes unity in the form of the will (its universality). Next comes plurality in its content (the objects, that is, the ends). Finally comes the totality of the system formed by these. When judging actions morally, it is better always to follow the strict method. Begin with the general formula of the categorical imperative: Act on a maxim that can also make itself a universal law. If, however, we want to make the moral law accessible, considering the same action under the three specified conceptions is very useful. Doing so brings the action as close as possible to intuitive understanding.

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"; this is the sole condition under which a will can never contradict itself; and such an imperative is categorical. Since the validity of the will as a universal law for possible actions is analogous to the universal connexion of the existence of things by general laws, which is the formal notion of nature in general, the categorical imperative can also be expressed thus: Act on maxims which can at the same time have for their object themselves as universal laws of nature. Such then is the formula of an absolutely good will.

We can now end where we began, with the idea of an unconditionally good will. A will is absolutely good if it cannot be evil. In other words, its maxim, if made a universal law, could never contradict itself. The supreme law of such a will is therefore: "Always act on a maxim you can also will to become a universal law". Only under this condition can a will never contradict itself. Such a command is a categorical imperative. The will’s validity as a universal law for possible actions has a parallel in nature. The existence of things is universally connected through general laws. This connection is the formal concept of nature in general. Because of this parallel, the categorical imperative can also be expressed as follows: Act on maxims that can also have themselves as universal laws of nature as their object. This, then, is the formula for an absolutely good will.

Rational nature is distinguished from the rest of nature by this, that it sets before itself an end. This end would be the matter of every good will. But since in the idea of a will that is absolutely good without being limited by any condition (of attaining this or that end) we must abstract wholly from every end to be effected (since this would make every will only relatively good), it follows that in this case the end must be conceived, not as an end to be effected, but as an independently existing end. Consequently it is conceived only negatively, i.e., as that which we must never act against and which, therefore, must never be regarded merely as means, but must in every volition be esteemed as an end likewise. Now this end can be nothing but the subject of all possible ends, since this is also the subject of a possible absolutely good will; for such a will cannot without contradiction be postponed to any other object. The principle: "So act in regard to every rational being (thyself and others), that he may always have place in thy maxim as an end in himself," is accordingly essentially identical with this other: "Act upon a maxim which, at the same time, involves its own universal validity for every rational being." For that in using means for every end I should limit my maxim by the condition of its holding good as a law for every subject, this comes to the same thing as that the fundamental principle of all maxims of action must be that the subject of all ends, i.e., the rational being himself, be never employed merely as means, but as the supreme condition restricting the use of all means, that is in every case as an end likewise.

Rational nature differs from the rest of nature because it sets itself an end. This end would give every good will its content. But consider a will that is absolutely good, without depending on any condition of achieving this or that end. To conceive of such a will, we must leave out every end to be achieved. Otherwise, every will would be good only in relation to that end. So here we must understand the end not as something to be achieved, but as something that exists independently. Consequently, we conceive of this end only negatively, as something we must never act against. We must therefore never regard this end merely as a means. In every act of willing, we must also value it as an end. Now this end can only be the being who sets all possible ends. For this being is also capable of having an absolutely good will. Such a will cannot, without contradiction, be made subordinate to any other object. Accordingly, the following two principles are essentially identical: "Act toward every rational being (yourself and others) so that your maxim always includes that being as an end in themselves." And: "Act on a maxim that at the same time carries its own universal validity for every rational being." For whenever I use means to pursue any end, I should restrict my maxim to meet one condition. The maxim must hold as a law for every rational being. This amounts to the following fundamental principle of all maxims of action. The being who sets all ends, that is, the rational being, must never be used merely as a means. Instead, respect for that being must be the highest condition limiting the use of all means. In every case, the rational being must therefore also be treated as an end.

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, since it is just this fitness of his maxims for universal legislation that distinguishes him as an end in himself; also it follows that this implies his dignity (prerogative) above all mere physical beings, that he must always take his maxims from the point of view which regards himself and, likewise, every other rational being as law-giving beings (on which account they are called persons). In this way a world of rational beings (mundus intelligibilis) is possible as a kingdom of ends, and this by virtue of the legislation proper to all persons as members. 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. The formal principle of these maxims is: "So act as if thy maxim were to serve likewise as the universal law (of all rational beings)." A kingdom of ends is thus only possible on the analogy of a kingdom of nature, the former however only by maxims, that is self-imposed rules, the latter only by the laws of efficient causes acting under necessitation from without. Nevertheless, although the system of nature is looked upon as a machine, yet so far as it has reference to rational beings as its ends, it is given on this account the name of a kingdom of nature. Now such a kingdom of ends would be actually realized by means of maxims conforming to the canon which the categorical imperative prescribes to all rational beings, if they were universally followed. But although a rational being, even if he punctually follows this maxim himself, cannot reckon upon all others being therefore true to the same, nor expect that the kingdom of nature and its orderly arrangements shall be in harmony with him as a fitting member, so as to form a kingdom of ends to which he himself contributes, that is to say, that it shall favour his expectation of happiness, still that law: "Act according to the maxims of a member of a merely possible kingdom of ends legislating in it universally," remains in its full force, inasmuch as it commands categorically. And it is just in this that the paradox lies; that the mere dignity of man as a rational creature, without any other end or advantage to be attained thereby, in other words, respect for a mere idea, should yet serve as an inflexible precept of the will, and that it is precisely in this independence of the maxim on all such springs of action that its sublimity consists; and it is this that makes every rational subject worthy to be a legislative member in the kingdom of ends: for otherwise he would have to be conceived only as subject to the physical law of his wants. And although we should suppose the kingdom of nature and the kingdom of ends to be united under one sovereign, so that the latter kingdom thereby ceased to be a mere idea and acquired true reality, then it would no doubt gain the accession of a strong spring, but by no means any increase of its intrinsic worth. For this sole absolute lawgiver must, notwithstanding this, be always conceived as estimating the worth of rational beings only by their disinterested behaviour, as prescribed to themselves from that idea [the dignity of man] alone. The essence of things is not altered by their external relations, and that which, abstracting from these, alone constitutes the absolute worth of man, is also that by which he must be judged, whoever the judge may be, and even by the Supreme Being. 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. The dependence of a will not absolutely good on the principle of autonomy (moral necessitation) is obligation. This, then, cannot be applied to a holy being. The objective necessity of actions from obligation is called duty.

The following conclusion is beyond dispute. Whatever laws a rational being must obey, that being must also be able to see themselves as making those laws universally. This is because every rational being is an end in themselves. Their principles of action, or maxims, must be fit to serve as universal laws. This fitness is precisely what distinguishes them as an end in themselves. It also gives them dignity (a privileged standing) above all merely physical beings. They must therefore always choose their maxims from a standpoint that treats themselves and every other rational being as lawmakers. For this reason, rational beings are called persons. In this way, a world of rational beings (mundus intelligibilis) is possible as a kingdom of ends. Such a kingdom is possible because all persons, as its members, have the power to make its laws. Every rational being must therefore act as if their maxims always made them a lawmaking member of the universal kingdom of ends. The formal principle governing these maxims is: "Act as if your maxim were also to serve as the universal law (of all rational beings)." A kingdom of ends is thus possible only by analogy with a kingdom of nature. But a kingdom of ends is possible only through maxims, meaning rules its members impose on themselves. A kingdom of nature is possible only through laws of efficient causes, whose operation is compelled from outside. Nevertheless, although nature's system is viewed as a machine, it is also called a kingdom of nature. It receives this name insofar as it treats rational beings as its ends. A kingdom of ends would actually come into being if everyone followed maxims meeting the categorical imperative's standard for all rational beings. But even a rational being who follows this maxim exactly cannot count on everyone else doing the same. Nor can they expect nature's kingdom and its orderly arrangements to work in harmony with them as a fitting member. They cannot expect nature to help form the kingdom of ends they themselves help create, and thus support their hopes of happiness. Still, the following law remains fully binding: "Act according to the maxims of a member of a merely possible kingdom of ends, making universal laws within it." The law remains binding because it commands categorically. Here lies the paradox. Human dignity as a rational creature should itself provide an unyielding rule for the will, without any further goal or advantage. In other words, respect for a mere idea should provide such a rule. The maxim's sublimity consists precisely in its independence from all such motives. This independence makes every rational being worthy to be a lawmaking member of the kingdom of ends. Otherwise, that being would have to be understood as subject only to the physical law of their needs. Suppose, however, that the kingdom of nature and the kingdom of ends were united under one sovereign. The kingdom of ends would then cease to be a mere idea and become a reality. It would undoubtedly gain a powerful motivating force, but its intrinsic worth would not increase at all. For this sole, absolute lawgiver must still be understood as judging rational beings only by their conduct free from self-interest. Such conduct is what they prescribe to themselves solely from that idea [the dignity of man]. The nature of things does not change because of their external relationships. Setting those relationships aside, what alone gives human beings absolute worth must also be the basis for judging them. This holds whoever the judge may be, even the Supreme Being. Morality, then, is the relationship of actions to the will's autonomy, its capacity to make universal laws through its maxims. An action consistent with the will's autonomy is permitted. An action inconsistent with that autonomy is forbidden. A will whose maxims necessarily agree with the laws of autonomy is a holy will, absolutely good. Obligation is the dependence of a will that is not absolutely good on the principle of autonomy (moral constraint). Obligation therefore cannot apply to a holy being. The objective necessity of acting from obligation is called duty.

From what has just been said, it is easy to see how it happens that, although the conception of duty implies subjection to the law, we yet ascribe a certain dignity and sublimity to the person who fulfils all his duties. There is not, indeed, any sublimity in him, so far as he is subject to the moral law; but inasmuch as in regard to that very law he is likewise a legislator, and on that account alone subject to it, he has sublimity. We have also shown above that neither fear nor inclination, but simply respect for the law, is the spring which can give actions a moral worth. Our own will, so far as we suppose it to act only under the condition that its maxims are potentially universal laws, this ideal will which is possible to us is the proper object of respect; and the dignity of humanity consists just in this capacity of being universally legislative, though with the condition that it is itself subject to this same legislation.

What we have just said makes the following point easy to understand. Although the concept of duty implies being subject to the law, we still attribute dignity and greatness to someone who fulfills all their duties. Their greatness does not lie in being subject to the moral law. Rather, their greatness lies in also making that very law and being subject to it for that reason alone. We have also shown above that neither fear nor inclination can give actions moral worth. Only respect for the law can serve as the motive that gives actions moral worth. Our own will is the true object of respect, insofar as we imagine it acting only under one condition. The principles guiding its actions must be capable of serving as universal laws. Such an ideal will is possible for us. Human dignity consists precisely in this capacity to make universal laws, though we must ourselves be subject to those same laws.

Autonomy of the will is that property of it by which it is a law to itself (independently of any property of the objects of volition). The principle of autonomy then is: "Always so to choose that the same volition shall comprehend the maxims of our choice as a universal law." We cannot prove that this practical rule is an imperative, i.e., that the will of every rational being is necessarily bound to it as a condition, by a mere analysis of the conceptions which occur in it, since it is a synthetical proposition; we must advance beyond the cognition of the objects to a critical examination of the subject, that is, of the pure practical reason, for this synthetic proposition which commands apodeictically must be capable of being cognized wholly a priori. This matter, however, does not belong to the present section. But that the principle of autonomy in question is the sole principle of morals can be readily shown by mere analysis of the conceptions of morality. For by this analysis we find that its principle must be a categorical imperative and that what this commands is neither more nor less than this very autonomy.

Autonomy of the will is the will’s ability to give itself a law, independently of any properties of its objects. The principle of autonomy is therefore: "Always choose so that, in the same act of willing, you will the principles guiding your choice as universal law." We cannot prove through analysis of these concepts alone that this practical rule is an imperative. That is, such analysis cannot prove that every rational being’s will is necessarily bound by this rule. This is because the claim is a synthetic proposition, one that goes beyond what its concepts alone contain. We must move beyond knowledge of objects to critically examine the subject, that is, pure practical reason. For this synthetic proposition commands with absolute necessity and must be knowable entirely a priori, independently of experience. However, that examination does not belong in this section. But analysis of the concepts of morality alone can readily show that autonomy is the sole principle of morality. For this analysis shows that the principle of morality must be a categorical imperative. And what this imperative commands is nothing more or less than autonomy itself.

If the will seeks the law which is to determine it anywhere else than in the fitness of its maxims to be universal laws of its own dictation, consequently if it goes out of itself and seeks this law in the character of any of its objects, there always results heteronomy. The will in that case does not give itself the law, but it is given by the object through its relation to the will. This relation, whether it rests on inclination or on conceptions of reason, only admits of hypothetical imperatives: "I ought to do something because I wish for something else." On the contrary, the moral, and therefore categorical, imperative says: "I ought to do so and so, even though I should not wish for anything else." E.g., the former says: "I ought not to lie, if I would retain my reputation"; the latter says: "I ought not to lie, although it should not bring me the least discredit." The latter therefore must so far abstract from all objects that they shall have no influence on the will, in order that practical reason (will) may not be restricted to administering an interest not belonging to it, but may simply show its own commanding authority as the supreme legislation. Thus, e.g., I ought to endeavour to promote the happiness of others, not as if its realization involved any concern of mine (whether by immediate inclination or by any satisfaction indirectly gained through reason), but simply because a maxim which excludes it cannot be comprehended as a universal law in one and the same volition.

The will must seek its guiding law in whether its maxims can serve as universal laws that it gives itself. If the will seeks this law anywhere else, it always becomes subject to heteronomy, or rule from outside itself. This happens when the will looks beyond itself for the law in the nature of any of its objects. In that case, the will does not give itself the law. Instead, the object gives the will its law through the object's relationship to the will. Whether this relationship rests on inclination or on rational concepts, it allows only hypothetical imperatives: "I ought to do something because I want something else." By contrast, the moral imperative, which is therefore categorical, says: "I ought to act in this way, even if I want nothing else." For example, the first says: "I ought not to lie if I want to keep my reputation." The second says: "I ought not to lie, even if lying would not damage my reputation at all." The categorical imperative must therefore set aside all objects so that none influences the will. Otherwise, practical reason (the will) would be limited to serving an interest that is not its own. Instead, practical reason must simply exercise its own authority to command as the supreme source of law. Thus, for example, I ought to try to promote the happiness of others. I ought to do so not because achieving their happiness would serve any interest of mine. Such an interest might arise from a direct inclination or from some satisfaction gained indirectly through reason. Rather, I ought to promote their happiness simply because I cannot consistently will a maxim that excludes it as a universal law.

Here as elsewhere human reason in its pure use, so long as it was not critically examined, has first tried all possible wrong ways before it succeeded in finding the one true way.

Here, as elsewhere, human reason in its pure use tried every possible wrong path before finding the one true path. This happened as long as reason had not been critically examined.

All principles which can be taken from this point of view are either empirical or rational. The former, drawn from the principle of happiness, are built on physical or moral feelings; the latter, drawn from the principle of perfection, are built either on the rational conception of perfection as a possible effect, or on that of an independent perfection (the will of God) as the determining cause of our will.

All principles available from this point of view are either empirical or rational. Empirical principles come from the principle of happiness and rest on physical or moral feelings. Rational principles come from the principle of perfection and rest on one of two rational concepts. The first is perfection as a possible effect. The second is an independent perfection (the will of God) as the cause that determines our will.

Empirical principles are wholly incapable of serving as a foundation for moral laws. For the universality with which these should hold for all rational beings without distinction, the unconditional practical necessity which is thereby imposed on them, is lost when their foundation is taken from the particular constitution of human nature, or the accidental circumstances in which it is placed. The principle of private happiness, however, is the most objectionable, not merely because it is false, and experience contradicts the supposition that prosperity is always proportioned to good conduct, nor yet merely because it contributes nothing to the establishment of morality- since it is quite a different thing to make a prosperous man and a good man, or to make one prudent and sharp-sighted for his own interests and to make him virtuous- but because the springs it provides for morality are such as rather undermine it and destroy its sublimity, since they put the motives to virtue and to vice in the same class and only teach us to make a better calculation, the specific difference between virtue and vice being entirely extinguished. On the other hand, as to moral feeling, this supposed special sense,¹⁶ the appeal to it is indeed superficial when those who cannot think believe that feeling will help them out, even in what concerns general laws: and besides, feelings, which naturally differ infinitely in degree, cannot furnish a uniform standard of good and evil, nor has anyone a right to form judgements for others by his own feelings: nevertheless this moral feeling is nearer to morality and its dignity in this respect, that it pays virtue the honour of ascribing to her immediately the satisfaction and esteem we have for her and does not, as it were, tell her to her face that we are not attached to her by her beauty but by profit.

Principles based on experience are entirely incapable of providing a foundation for moral laws. Moral laws must apply universally to all rational beings without distinction. They must impose an unconditional necessity to act. Both requirements are lost when moral laws rest on the particular makeup of human nature or its accidental circumstances. The principle of personal happiness, however, is the most objectionable. This is not merely because the principle is false. Experience contradicts the assumption that prosperity always corresponds to good conduct. Nor is it merely because the principle contributes nothing to establishing morality. Making someone prosperous is quite different from making someone good. Making someone prudent and alert to their own interests is quite different from making them virtuous. Rather, the principle is most objectionable because the motives it offers for morality actually undermine morality and destroy its grandeur. These motives place the reasons for virtue and vice in the same category. They teach us only to calculate better, entirely erasing the essential difference between virtue and vice. On the other hand, consider moral feeling, the supposed special sense.¹⁶ Appealing to moral feeling is indeed superficial when people unable to think believe feeling will help them, even with universal laws. Besides, feelings naturally vary infinitely in degree, so they cannot provide a uniform standard of good and evil. Nor does anyone have the right to judge for others on the basis of their own feelings. Nevertheless, moral feeling comes closer to morality and its dignity in one respect. Moral feeling honors virtue by attributing our satisfaction in virtue and our esteem for her directly to virtue herself. Moral feeling does not, so to speak, tell virtue to her face that we value her for profit, not her beauty.

Amongst the rational principles of morality, the ontological conception of perfection, notwithstanding its defects, is better than the theological conception which derives morality from a Divine absolutely perfect will. The former is, no doubt, empty and indefinite and consequently useless for finding in the boundless field of possible reality the greatest amount suitable for us; moreover, in attempting to distinguish specifically the reality of which we are now speaking from every other, it inevitably tends to turn in a circle and cannot avoid tacitly presupposing the morality which it is to explain; it is nevertheless preferable to the theological view, first, because we have no intuition of the divine perfection and can only deduce it from our own conceptions, the most important of which is that of morality, and our explanation would thus be involved in a gross circle; and, in the next place, if we avoid this, the only notion of the Divine will remaining to us is a conception made up of the attributes of desire of glory and dominion, combined with the awful conceptions of might and vengeance, and any system of morals erected on this foundation would be directly opposed to morality.

Among rational principles of morality, the ontological concept of perfection is better than the theological concept, despite its defects. The theological concept derives morality from an absolutely perfect divine will. The ontological concept is admittedly empty and vague. It therefore cannot help us find, among limitless possible realities, the greatest degree of reality suitable for us. Moreover, trying to distinguish this particular kind of reality from every other inevitably leads to circular reasoning. The ontological account cannot avoid silently assuming the morality it is supposed to explain. Nevertheless, the ontological account is preferable to the theological view for two reasons. First, we have no direct knowledge of divine perfection and can infer it only from our own concepts. The most important of these concepts is morality, so our explanation would involve a glaring circular argument. Second, if we avoid this circularity, our only remaining concept of the divine will combines desires for glory and dominion with terrifying ideas of power and vengeance. Any moral system built on this foundation would directly oppose morality.

However, if I had to choose between the notion of the moral sense and that of perfection in general (two systems which at least do not weaken morality, although they are totally incapable of serving as its foundation), then I should decide for the latter, because it at least withdraws the decision of the question from the sensibility and brings it to the court of pure reason; and although even here it decides nothing, it at all events preserves the indefinite idea (of a will good in itself free from corruption, until it shall be more precisely defined.

However, suppose I had to choose between the idea of a moral sense and the idea of perfection in general. Neither system weakens morality, although neither can provide its foundation. I would choose perfection because it at least takes the question away from the senses and places it before pure reason. Although pure reason settles nothing here either, it at least keeps the still-undefined idea of a will good in itself uncorrupted. The idea remains intact until it can be defined more precisely.

For the rest I think I may be excused here from a detailed refutation of all these doctrines; that would only be superfluous labour, since it is so easy, and is probably so well seen even by those whose office requires them to decide for one of these theories (because their hearers would not tolerate suspension of judgement). But what interests us more here is to know that the prime foundation of morality laid down by all these principles is nothing but heteronomy of the will, and for this reason they must necessarily miss their aim.

As for the rest, I think I may be excused from refuting all these doctrines in detail here. Such work would be unnecessary, since refuting them is so easy. Even those whose duties require them to choose one of these theories probably see this ease of refutation clearly. (Their listeners would not tolerate a suspension of judgment.) But our greater concern here is to recognize the basic foundation of morality that all these principles establish. That foundation is nothing but heteronomy of the will. For this reason, all these principles must necessarily fail to achieve their aim.

In every case where an object of the will has to be supposed, in order that the rule may be prescribed which is to determine the will, there the rule is simply heteronomy; the imperative is conditional, namely, if or because one wishes for this object, one should act so and so: hence it can never command morally, that is, categorically. Whether the object determines the will by means of inclination, as in the principle of private happiness, or by means of reason directed to objects of our possible volition generally, as in the principle of perfection, in either case the will never determines itself immediately by the conception of the action, but only by the influence which the foreseen effect of the action has on the will; I ought to do something, on this account, because I wish for something else; and here there must be yet another law assumed in me as its subject, by which I necessarily will this other thing, and this law again requires an imperative to restrict this maxim. For the influence which the conception of an object within the reach of our faculties can exercise on the will of the subject, in consequence of its natural properties, depends on the nature of the subject, either the sensibility (inclination and taste), or the understanding and reason, the employment of which is by the peculiar constitution of their nature attended with satisfaction. It follows that the law would be, properly speaking, given by nature, and, as such, it must be known and proved by experience and would consequently be contingent and therefore incapable of being an apodeictic practical rule, such as the moral rule must be. Not only so, but it is inevitably only heteronomy; the will does not give itself the law, but is given by a foreign impulse by means of a particular natural constitution of the subject adapted to receive it. An absolutely good will, then, the principle of which must be a categorical imperative, will be indeterminate as regards all objects and will contain merely the form of volition generally, and that as autonomy, that is to say, the capability of the maxims of every good will to make themselves a universal law, is itself the only law which the will of every rational being imposes on itself, without needing to assume any spring or interest as a foundation.

Whenever a rule for determining the will requires us to first assume an object of desire, the rule is heteronomy. The imperative is conditional: if or because someone wants this object, they should act in a certain way. Such an imperative can therefore never command morally, that is, categorically. The object may determine the will through inclination, as in the principle of personal happiness. Or the object may determine the will through reason directed toward anything we could possibly will, as in the principle of perfection. In either case, the will does not determine itself directly through the idea of the action. Instead, the action’s expected effect influences the will: I ought to do something because I want something else. But this assumes another law within me, as the subject, under which I necessarily will that other thing. And this further law requires an imperative to constrain this maxim. An object within the reach of our abilities can influence our will through our idea of that object. But this influence, arising from the object’s natural properties, depends on our own nature. It depends either on sensibility (inclination and taste) or on understanding and reason. Because of their particular natural constitution, exercising understanding and reason brings satisfaction. So the law would, strictly speaking, come from nature. As such, the law would have to be known and proved through experience. It would therefore be contingent, incapable of being a necessarily valid practical rule, as a moral rule must be. Moreover, such a law inevitably amounts only to heteronomy. The will does not give itself the law. Instead, an outside impulse gives the will its law through the subject’s particular natural constitution, suited to receiving that impulse. An absolutely good will, then, must have a categorical imperative as its principle. No object will determine such a will. Such a will will contain only the form of willing in general, understood as autonomy. This means that the maxims of every good will must be capable of becoming universal law. This capacity is itself the only law that the will of every rational being imposes on itself. It requires no motivating impulse or interest as its foundation.

How such a synthetical practical a priori proposition is possible, and why it is necessary, is a problem whose solution does not lie within the bounds of the metaphysic of morals; and we have not here affirmed its truth, much less professed to have a proof of it in our power. We simply showed by the development of the universally received notion of morality that an autonomy of the will is inevitably connected with it, or rather is its foundation. Whoever then holds morality to be anything real, and not a chimerical idea without any truth, must likewise admit the principle of it that is here assigned. This section then, like the first, was merely analytical. Now to prove that morality is no creation of the brain, which it cannot be if the categorical imperative and with it the autonomy of the will is true, and as an a priori principle absolutely necessary, this supposes the possibility of a synthetic use of pure practical reason, which however we cannot venture on without first giving a critical examination of this faculty of reason. In the concluding section we shall give the principal outlines of this critical examination as far as is sufficient for our purpose.

How is such a synthetic practical a priori proposition possible, and why is it necessary? Solving this problem lies beyond the scope of the metaphysics of morals. We have not claimed here that this proposition is true, much less that we can prove it. We have simply developed the universally accepted concept of morality. In doing so, we showed that autonomy of the will is inseparable from morality, or rather, is its foundation. Anyone who regards morality as real, rather than an imaginary idea without any truth, must therefore also accept this principle. This section, then, like the first, was purely analytical. We must now prove that morality is not merely a product of the imagination. Morality cannot be merely imaginary if the categorical imperative, and with it autonomy of the will, is true and absolutely necessary as an a priori principle. But proving this requires that pure practical reason be capable of a synthetic use. We cannot, however, attempt such a use without first critically examining this faculty of reason. In the final section, we will outline this critical examination as far as our purpose requires.