Kant: The Critique of Practical Reason { Philosophy Index }

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Immanuel Kant

Critique of Practical Reason

CHAPTER II. Of the Concept of an Object of Pure Practical Reason.

By a concept of the practical reason I understand the idea of an object as an effect possible to be produced through freedom. To be an object of practical knowledge, as such, signifies, therefore, only the relation of the will to the action by which the object or its opposite would be realized; and to decide whether something is an object of pure practical reason or not is only to discern the possibility or impossibility of willing the action by which, if we had the required power (about which experience must decide), a certain object would be realized. If the object be taken as the determining principle of our desire, it must first be known whether it is physically possible by the free use of our powers, before we decide whether it is an object of practical reason or not. On the other hand, if the law can be considered a priori as the determining principle of the action, and the latter therefore as determined by pure practical reason, the judgement whether a thing is an object of pure practical reason or not does not depend at all on the comparison with our physical power; and the question is only whether we should will an action that is directed to the existence of an object, if the object were in our power; hence the previous question is only as the moral possibility of the action, for in this case it is not the object, but the law of the will, that is the determining principle of the action. The only objects of practical reason are therefore those of good and evil. For by the former is meant an object necessarily desired according to a principle of reason; by the latter one necessarily shunned, also according to a principle of reason.

If the notion of good is not to be derived from an antecedent practical law, but, on the contrary, is to serve as its foundation, it can only be the notion of something whose existence promises pleasure, and thus determines the causality of the subject to produce it, that is to say, determines the faculty of desire. Now, since it is impossible to discern a priori what idea will be accompanied with pleasure and what with pain, it will depend on experience alone to find out what is primarily good or evil. The property of the subject, with reference to which alone this experiment can be made, is the feeling of pleasure and pain, a receptivity belonging to the internal sense; thus that only would be primarily good with which the sensation of pleasure is immediately connected, and that simply evil which immediately excites pain. Since, however, this is opposed even to the usage of language, which distinguishes the pleasant from the good, the unpleasant from the evil, and requires that good and evil shall always be judged by reason, and, therefore, by concepts which can be communicated to everyone, and not by mere sensation, which is limited to individual [subjects] and their susceptibility; and, since nevertheless, pleasure or pain cannot be connected with any idea of an object a priori, the philosopher who thought himself obliged to make a feeling of pleasure the foundation of his practical judgements would call that good which is a means to the pleasant, and evil, what is a cause of unpleasantness and pain; for the judgement on the relation of means to ends certainly belongs to reason. But, although reason is alone capable of discerning the connexion of means with their ends (so that the will might even be defined as the faculty of ends, since these are always determining principles of the desires), yet the practical maxims which would follow from the aforesaid principle of the good being merely a means, would never contain as the object of the will anything good in itself, but only something good for something; the good would always be merely the useful, and that for which it is useful must always lie outside the will, in sensation. Now if this as a pleasant sensation were to be distinguished from the notion of good, then there would be nothing primarily good at all, but the good would have to be sought only in the means to something else, namely, some pleasantness.

It is an old formula of the schools: Nihil appetimus nisi sub ratione boni; Nihil aversamur nisi sub ratione mali, and it is used often correctly, but often also in a manner injurious to philosophy, because the expressions boni and mali are ambiguous, owing to the poverty of language, in consequence of which they admit a double sense, and, therefore, inevitably bring the practical laws into ambiguity; and philosophy, which in employing them becomes aware of the different meanings in the same word, but can find no special expressions for them, is driven to subtile distinctions about which there is subsequently no unanimity, because the distinction could not be directly marked by any suitable expression. *

[* Besides this, the expression sub ratione boni is also ambiguous. For it may mean: "We represent something to ourselves as good, when and because we desire (will) it"; or "We desire something because we represent it to ourselves as good," so that either the desire determines the notion of the object as a good, or the notion of good determines the desire (the will); so that in the first case sub ratione boni would mean, "We will something under the idea of the good"; in the second, "In consequence of this idea," which, as determining the volition, must precede it.]

[BOOK_1|CHAPTER_2 ^paragraph 5]

The German language has the good fortune to possess expressions which do not allow this difference to be overlooked. It possesses two very distinct concepts and especially distinct expressions for that which the Latins express by a single word, bonum. For bonum it has das Gute [good], and das Wohl [well, weal], for malum das Bose [evil], and das Ubel [ill, bad], or das Well [woe]. So that we express two quite distinct judgements when we consider in an action the good and evil of it, or our weal and woe (ill). Hence it already follows that the above quoted psychological proposition is at least very doubtful if it is translated: "We desire nothing except with a view to our weal or woe"; on the other hand, if we render it thus: "Under the direction of reason we desire nothing except so far as we esteem it good or evil," it is indubitably certain and at the same time quite clearly expressed.

Well or ill always implies only a reference to our condition, as pleasant or unpleasant, as one of pleasure or pain, and if we desire or avoid an object on this account, it is only so far as it is referred to our sensibility and to the feeling of pleasure or pain that it produces. But good or evil always implies a reference to the will, as determined by the law of reason, to make something its object; for it is never determined directly by the object and the idea of it, but is a faculty of taking a rule of reason for or motive of an action (by which an object may be realized). Good and evil therefore are properly referred to actions, not to the sensations of the person, and if anything is to be good or evil absolutely (i.e., in every respect and without any further condition), or is to be so esteemed, it can only be the manner of acting, the maxim of the will, and consequently the acting person himself as a good or evil man that can be so called, and not a thing.

However, then, men may laugh at the Stoic, who in the severest paroxysms of gout cried out: "Pain, however thou tormentest me, I will never admit that thou art an evil (kakov, malum)": he was right. A bad thing it certainly was, and his cry betrayed that; but that any evil attached to him thereby, this he bad no reason whatever to admit, for pain did not in the least diminish the worth of his person, but only that of his condition. If he had been conscious of a single lie, it would have lowered his pride, but pain served only to raise it, when he was conscious that he had not deserved it by any unrighteous action by which he had rendered himself worthy of punishment.

What we call good must be an object of desire in the judgement of every rational man, and evil an object of aversion in the eyes of everyone; therefore, in addition to sense, this judgement requires reason. So it is with truthfulness, as opposed to lying; so with justice, as opposed to violence, &c. But we may call a thing a bad [or ill) thing, which yet everyone must at the same time acknowledge to be good, sometimes directly, sometimes indirectly. The man who submits to a surgical operation feels it no doubt as a bad thing, but by their reason he and everyone acknowledge it to be good. If a man who delights in annoying and vexing peaceable people at last receives a right good beating, this is no doubt a bad thing; but everyone approves it and regards it as a good thing, even though nothing else resulted from it; nay, even the man who receives it must in his reason acknowledge that he has met justice, because he sees the proportion between good conduct and good fortune, which reason inevitably places before him, here put into practice.

[BOOK_1|CHAPTER_2 ^paragraph 10]

No doubt our weal and woe are of very great importance in the estimation of our practical reason, and as far as our nature as sensible beings is concerned, our happiness is the only thing of consequence, provided it is estimated as reason especially requires, not by the transitory sensation, but by the influence that this has on our whole existence, and on our satisfaction therewith; but it is not absolutely the only thing of consequence. Man is a being who, as belonging to the world of sense, has wants, and so far his reason has an office which it cannot refuse, namely, to attend to the interest of his sensible nature, and to form practical maxims, even with a view to the happiness of this life, and if possible even to that of a future. But he is not so completely an animal as to be indifferent to what reason says on its own account, and to use it merely as an instrument for the satisfaction of his wants as a sensible being. For the possession of reason would not raise his worth above that of the brutes, if it is to serve him only for the same purpose that instinct serves in them; it would in that case be only a particular method which nature had employed to equip man for the same ends for which it has qualified brutes, without qualifying him for any higher purpose. No doubt once this arrangement of nature has been made for him he requires reason in order to take into consideration his weal and woe, but besides this he possesses it for a higher purpose also, namely, not only to take into consideration what is good or evil in itself, about which only pure reason, uninfluenced by any sensible interest, can judge, but also to distinguish this estimate thoroughly from the former and to make it the supreme condition thereof.

In estimating what is good or evil in itself, as distinguished from what can be so called only relatively, the following points are to be considered. Either a rational principle is already conceived, as of itself the determining principle of the will, without regard to possible objects of desire (and therefore by the more legislative form of the maxim), and in that case that principle is a practical a priori law, and pure reason is supposed to be practical of itself. The law in that case determines the will directly; the action conformed to it is good in itself; a will whose maxim always conforms to this law is good absolutely in every respect and is the supreme condition of all good. Or the maxim of the will is consequent on a determining principle of desire which presupposes an object of pleasure or pain, something therefore that pleases or displeases, and the maxim of reason that we should pursue the former and avoid the latter determines our actions as good relatively to our inclination, that is, good indirectly, i.e., relatively to a different end to which they are means), and in that case these maxims can never be called laws, but may be called rational practical precepts. The end itself, the pleasure that we seek, is in the latter case not a good but a welfare; not a concept of reason, but an empirical concept of an object of sensation; but the use of the means thereto, that is, the action, is nevertheless called good (because rational deliberation is required for it), not however, good absolutely, but only relatively to our sensuous nature, with regard to its feelings of pleasure and displeasure; but the will whose maxim is affected thereby is not a pure will; this is directed only to that in which pure reason by itself can be practical.

This is the proper place to explain the paradox of method in a critique of practical reason, namely, that the concept of good and evil must not be determined before the moral law (of which it seems as if it must be the foundation), but only after it and by means of it. In fact, even if we did not know that the principle of morality is a pure a priori law determining the will, yet, that we may not assume principles quite gratuitously, we must, at least at first, leave it undecided, whether the will has merely empirical principles of determination, or whether it has not also pure a priori principles; for it is contrary to all rules of philosophical method to assume as decided that which is the very point in question. Supposing that we wished to begin with the concept of good, in order to deduce from it the laws of the will, then this concept of an object (as a good) would at the same time assign to us this object as the sole determining principle of the will. Now, since this concept had not any practical a priori law for its standard, the criterion of good or evil could not be placed in anything but the agreement of the object with our feeling of pleasure or pain; and the use of reason could only consist in determining in the first place this pleasure or pain in connexion with all the sensations of my existence, and in the second place the means of securing to myself the object of the pleasure. Now, as experience alone can decide what conforms to the feeling of pleasure, and by hypothesis the practical law is to be based on this as a condition, it follows that the possibility of a priori practical laws would be at once excluded, because it was imagined to be necessary first of all to find an object the concept of which, as a good, should constitute the universal though empirical principle of determination of the will. But what it was necessary to inquire first of all was whether there is not an a priori determining principle of the will (and this could never be found anywhere but in a pure practical law, in so far as this law prescribes to maxims merely their form without regard to an object). Since, however, we laid the foundation of all practical law in an object determined by our conceptions of good and evil, whereas without a previous law that object could not be conceived by empirical concepts, we have deprived ourselves beforehand of the possibility of even conceiving a pure practical law. On the other hand, if we had first investigated the latter analytically, we should have found that it is not the concept of good as an object that determines the moral law and makes it possible, but that, on the contrary, it is the moral law that first determines the concept of good and makes it possible, so far as it deserves the name of good absolutely.

This remark, which only concerns the method of ultimate ethical inquiries, is of importance. It explains at once the occasion of all the mistakes of philosophers with respect to the supreme principle of morals. For they sought for an object of the will which they could make the matter and principle of a law (which consequently could not determine the will directly, but by means of that object referred to the feeling of pleasure or pain; whereas they ought first to have searched for a law that would determine the will a priori and directly, and afterwards determine the object in accordance with the will). Now, whether they placed this object of pleasure, which was to supply the supreme conception of goodness, in happiness, in perfection, in moral [feeling], or in the will of God, their principle in every case implied heteronomy, and they must inevitably come upon empirical conditions of a moral law, since their object, which was to be the immediate principle of the will, could not be called good or bad except in its immediate relation to feeling, which is always empirical. It is only a formal law—that is, one which prescribes to reason nothing more than the form of its universal legislation as the supreme condition of its maxims—that can be a priori a determining principle of practical reason. The ancients avowed this error without concealment by directing all their moral inquiries to the determination of the notion of the summum bonum, which they intended afterwards to make the determining principle of the will in the moral law; whereas it is only far later, when the moral law has been first established for itself, and shown to be the direct determining principle of the will, that this object can be presented to the will, whose form is now determined a priori; and this we shall undertake in the Dialectic of the pure practical reason. The moderns, with whom the question of the summum bonum has gone out of fashion, or at least seems to have become a secondary matter, hide the same error under vague (expressions as in many other cases). It shows itself, nevertheless, in their systems, as it always produces heteronomy of practical reason; and from this can never be derived a moral law giving universal commands.

Now, since the notions of good and evil, as consequences of the a priori determination of the will, imply also a pure practical principle, and therefore a causality of pure reason; hence they do not originally refer to objects (so as to be, for instance, special modes of the synthetic unity of the manifold of given intuitions in one consciousness) like the pure concepts of the understanding or categories of reason in its theoretic employment; on the contrary, they presuppose that objects are given; but they are all modes (modi) of a single category, namely, that of causality, the determining principle of which consists in the rational conception of a law, which as a law of freedom reason gives to itself, thereby a priori proving itself practical. However, as the actions on the one side come under a law which is not a physical law, but a law of freedom, and consequently belong to the conduct of beings in and consequently the consequently belong to the beings in the world of intelligence, yet on the other side as events in the world of sense they belong to phenomena; hence the determinations of a practical reason are only possible in reference to the latter and, therefore, in accordance with the categories of the understanding; not indeed with a view to any theoretic employment of it, i.e., so as to bring the manifold of (sensible) intuition under one consciousness a priori; but only to subject the manifold of desires to the unity of consciousness of a practical reason, giving it commands in the moral law, i.e., to a pure will a priori.

[BOOK_1|CHAPTER_2 ^paragraph 15]

These categories of freedom—for so we choose to call them in contrast to those theoretic categories which are categories of physical nature—have an obvious advantage over the latter, inasmuch as the latter are only forms of thought which designate objects in an indefinite manner by means of universal concept of every possible intuition; the former, on the contrary, refer to the determination of a free elective will (to which indeed no exactly corresponding intuition can be assigned, but which has as its foundation a pure practical a priori law, which is not the case with any concepts belonging to the theoretic use of our cognitive faculties); hence, instead of the form of intuition (space and time), which does not lie in reason itself, but has to be drawn from another source, namely, the sensibility, these being elementary practical concepts have as their foundation the form of a pure will, which is given in reason and, therefore, in the thinking faculty itself. From this it happens that as all precepts of pure practical reason have to do only with the determination of the will, not with the physical conditions (of practical ability) of the execution of one's purpose, the practical a priori principles in relation to the supreme principle of freedom are at once cognitions, and have not to wait for intuitions in order to acquire significance, and that for this remarkable reason, because they themselves produce the reality of that to which they refer (the intention of the will), which is not the case with theoretical concepts. Only we must be careful to observe that these categories only apply to the practical reason; and thus they proceed in order from those which are as yet subject to sensible conditions and morally indeterminate to those which are free from sensible conditions and determined merely by the moral law.

Table of the Categories of Freedom relatively to the Notions of Good and Evil.


[BOOK_1|CHAPTER_2 ^paragraph 20]

Subjective, according to maxims (practical opinions of the individual)

Objective, according to principles (Precepts)

A priori both objective and subjective principles of freedom (laws)

[BOOK_1|CHAPTER_2 ^paragraph 25]


Practical rules of action (praeceptivae)

Practical rules of omission (prohibitivae)

Practical rules of exceptions (exceptivae)

[BOOK_1|CHAPTER_2 ^paragraph 30]


To personality To the condition of the person.

Reciprocal, of one person to the others of the others.

[BOOK_1|CHAPTER_2 ^paragraph 35]


The Permitted and the Forbidden

Duty and the contrary to duty.

Perfect and imperfect duty.

[BOOK_1|CHAPTER_2 ^paragraph 40]

It will at once be observed that in this table freedom is considered as a sort of causality not subject to empirical principles of determination, in regard to actions possible by it, which are phenomena in the world of sense, and that consequently it is referred to the categories which concern its physical possibility, whilst yet each category is taken so universally that the determining principle of that causality can be placed outside the world of sense in freedom as a property of a being in the world of intelligence; and finally the categories of modality introduce the transition from practical principles generally to those of morality, but only problematically. These can be established dogmatically only by the moral law.

I add nothing further here in explanation of the present table, since it is intelligible enough of itself. A division of this kind based on principles is very useful in any science, both for the sake of thoroughness and intelligibility. Thus, for instance, we know from the preceding table and its first number what we must begin from in practical inquiries; namely, from the maxims which every one founds on his own inclinations; the precepts which hold for a species of rational beings so far as they agree in certain inclinations; and finally the law which holds for all without regard to their inclinations, etc. In this way we survey the whole plan of what has to be done, every question of practical philosophy that has to be answered, and also the order that is to be followed.

Of the Typic of the Pure Practical Judgement.

[BOOK_1|CHAPTER_2 ^paragraph 45]

It is the notions of good and evil that first determine an object of the will. They themselves, however, are subject to a practical rule of reason which, if it is pure reason, determines the will a priori relatively to its object. Now, whether an action which is possible to us in the world of sense, comes under the rule or not, is a question to be decided by the practical judgement, by which what is said in the rule universally (in abstracto) is applied to an action in concreto. But since a practical rule of pure reason in the first place as practical concerns the existence of an object, and in the second place as a practical rule of pure reason implies necessity as regards the existence of the action and, therefore, is a practical law, not a physical law depending on empirical principles of determination, but a law of freedom by which the will is to be determined independently on anything empirical (merely by the conception of a law and its form), whereas all instances that can occur of possible actions can only be empirical, that is, belong to the experience of physical nature; hence, it seems absurd to expect to find in the world of sense a case which, while as such it depends only on the law of nature, yet admits of the application to it of a law of freedom, and to which we can apply the supersensible idea of the morally good which is to be exhibited in it in concreto. Thus, the judgement of the pure practical reason is subject to the same difficulties as that of the pure theoretical reason. The latter, however, had means at hand of escaping from these difficulties, because, in regard to the theoretical employment, intuitions were required to which pure concepts of the understanding could be applied, and such intuitions (though only of objects of the senses) can be given a priori and, therefore, as far as regards the union of the manifold in them, conforming to the pure a priori concepts of the understanding as schemata. On the other hand, the morally good is something whose object is supersensible; for which, therefore, nothing corresponding can be found in any sensible intuition. Judgement depending on laws of pure practical reason seems, therefore, to be subject to special difficulties arising from this, that a law of freedom is to be applied to actions, which are events taking place in the world of sense, and which, so far, belong to physical nature.

But here again is opened a favourable prospect for the pure practical judgement. When I subsume under a pure practical law an action possible to me in the world of sense, I am not concerned with the possibility of the action as an event in the world of sense. This is a matter that belongs to the decision of reason in its theoretic use according to the law of causality, which is a pure concept of the understanding, for which reason has a schema in the sensible intuition. Physical causality, or the condition under which it takes place, belongs to the physical concepts, the schema of which is sketched by transcendental imagination. Here, however, we have to do, not with the schema of a case that occurs according to laws, but with the schema of a law itself (if the word is allowable here), since the fact that the will (not the action relatively to its effect) is determined by the law alone without any other principle, connects the notion of causality with quite different conditions from those which constitute physical connection.

The physical law being a law to which the objects of sensible intuition, as such, are subject, must have a schema corresponding to it—that is, a general procedure of the imagination (by which it exhibits a priori to the senses the pure concept of the understanding which the law determines). But the law of freedom (that is, of a causality not subject to sensible conditions), and consequently the concept of the unconditionally good, cannot have any intuition, nor consequently any schema supplied to it for the purpose of its application in concreto. Consequently the moral law has no faculty but the understanding to aid its application to physical objects (not the imagination); and the understanding for the purposes of the judgement can provide for an idea of the reason, not a schema of the sensibility, but a law, though only as to its form as law; such a law, however, as can be exhibited in concreto in objects of the senses, and therefore a law of nature. We can therefore call this law the type of the moral law.

The rule of the judgement according to laws of pure practical reason is this: ask yourself whether, if the action you propose were to take place by a law of the system of nature of which you were yourself a part, you could regard it as possible by your own will. Everyone does, in fact, decide by this rule whether actions are morally good or evil. Thus, people say: "If everyone permitted himself to deceive, when he thought it to his advantage; or thought himself justified in shortening his life as soon as he was thoroughly weary of it; or looked with perfect indifference on the necessity of others; and if you belonged to such an order of things, would you do so with the assent of your own will?" Now everyone knows well that if he secretly allows himself to deceive, it does not follow that everyone else does so; or if, unobserved, he is destitute of compassion, others would not necessarily be so to him; hence, this comparison of the maxim of his actions with a universal law of nature is not the determining principle of his will. Such a law is, nevertheless, a type of the estimation of the maxim on moral principles. If the maxim of the action is not such as to stand the test of the form of a universal law of nature, then it is morally impossible. This is the judgement even of common sense; for its ordinary judgements, even those of experience, are always based on the law of nature. It has it therefore always at hand, only that in cases where causality from freedom is to be criticised, it makes that law of nature only the type of a law of freedom, because, without something which it could use as an example in a case of experience, it could not give the law of a pure practical reason its proper use in practice.

It is therefore allowable to use the system of the world of sense as the type of a supersensible system of things, provided I do not transfer to the latter the intuitions, and what depends on them, but merely apply to it the form of law in general (the notion of which occurs even in the commonest use of reason, but cannot be definitely known a priori for any other purpose than the pure practical use of reason); for laws, as such, are so far identical, no matter from what they derive their determining principles.

[BOOK_1|CHAPTER_2 ^paragraph 50]

Further, since of all the supersensible absolutely nothing [is known] except freedom (through the moral law), and this only so far as it is inseparably implied in that law, and moreover all supersensible objects to which reason might lead us, following the guidance of that law, have still no reality for us, except for the purpose of that law, and for the use of mere practical reason; and as reason is authorized and even compelled to use physical nature (in its pure form as an object of the understanding) as the type of the judgement; hence, the present remark will serve to guard against reckoning amongst concepts themselves that which belongs only to the typic of concepts. This, namely, as a typic of the judgement, guards against the empiricism of practical reason, which founds the practical notions of good and evil merely on experienced consequences (so-called happiness). No doubt happiness and the infinite advantages which would result from a will determined by self-love, if this will at the same time erected itself into a universal law of nature, may certainly serve as a perfectly suitable type of the morally good, but it is not identical with it. The same typic guards also against the mysticism of practical reason, which turns what served only as a symbol into a schema, that is, proposes to provide for the moral concepts actual intuitions, which, however, are not sensible (intuitions of an invisible Kingdom of God), and thus plunges into the transcendent. What is befitting the use of the moral concepts is only the rationalism of the judgement, which takes from the sensible system of nature only what pure reason can also conceive of itself, that is, conformity to law, and transfers into the supersensible nothing but what can conversely be actually exhibited by actions in the world of sense according to the formal rule of a law of nature. However, the caution against empiricism of practical reason is much more important; for mysticism is quite reconcilable with the purity and sublimity of the moral law, and, besides, it is not very natural or agreeable to common habits of thought to strain one's imagination to supersensible intuitions; and hence the danger on this side is not so general. Empiricism, on the contrary, cuts up at the roots the morality of intentions (in which, and not in actions only, consists the high worth that men can and ought to give to themselves), and substitutes for duty something quite different, namely, an empirical interest, with which the inclinations generally are secretly leagued; and empiricism, moreover, being on this account allied with all the inclinations which (no matter what fashion they put on) degrade humanity when they are raised to the dignity of a supreme practical principle; and as these, nevertheless, are so favourable to everyone's feelings, it is for that reason much more dangerous than mysticism, which can never constitute a lasting condition of any great number of persons.

The Critique of Practical Reason by Immanuel Kant. Translated by by Thomas Kingsmill Abbott.