Immanuel Kant (1724–1804) introduced the term "categorical imperative" to characterize the fundamental principle of morality as it presents itself to beings. The principle is categorical, or unconditional, because it is valid for all humans, indeed, for all rational beings, independently of any particular desires or aims they may have. It presents itself as an imperative precisely because human beings have desires and aims that can be incompatible with the unconditional demands of the principle of morality and thus those demands often present themselves as obligations and constraints. Hence the propositional content of the fundamental principle of morality is identical for all rational beings, but its coloration as an imperative is distinctively human. For Kant, since there is a single fundamental principle of morality, there is, properly speaking, only a single categorical imperative, although more specific moral duties and obligations derivable from it are themselves unconditionally valid for any agent in the situation in which they arise. Kant contrasts the categorical imperative with "hypothetical imperatives," which express only the necessity of adopting certain means to achieve certain ends that are themselves merely conditional. Hypothetical imperatives can also present themselves to us as constraints, because we are not always sufficiently rational even to accept willingly the means to ends that we have willingly adopted, but in the case of hypothetical imperatives, we are not under any moral constraint to adopt the ends concerned.
Kant anticipated his mature distinction between categorical and hypothetical imperatives in his Inquiry concerning the Distinctness of the Principles of Natural Theology and Morality of 1764. There he wrote, "Every ought expresses a necessity of the action and is capable of two meanings. … Either I ought to do something (as a means ) if I want something else (as an end ), or I ought immediately to do something else (as an end ) and make it actual." He argued that the former do not really express obligations at all; rather, they express only "recommendations to adopt a suitable procedure, if one wish[es] to attain a given end." Genuine obligations, by contrast, are "subordinated to an end which is necessary in itself." Kant's examples of ends that might be necessary in themselves were advancing the greatest total perfection and acting in accord with the will of God (Kant 1764; in Kant 1900, 2: 298; in Kant 1992, p. 272). The first of these is the ultimate end of morality according to Christian Wolff (1679–1754) and Alexander Baumgarten (1714–1762), and the latter the ultimate end of morality according to their Pietist opponent Christian August Crusius (1715–1775). In his Anweisung, vernünftig zu leben (Guide to living rationally; 1744/1964), Crusius himself anticipated the distinction that Kant made in the Inquiry by contrasting duties of prudence, which are grounded "only in certain ends already desired by us," with true obligations, which are grounded in "moral necessity" lying "in a law and in our owing fulfillment of it," and ultimately, in the case of "the obligation of virtue, or true obligation in a narrower sense," in divine law (§161). A widespread account of Kant's development of his mature conception of the categorical imperative is that he moved from the idea of an unconditional obligation grounded in a necessary end to the idea of an unconditional obligation that does not depend on any end whatever. Below, that will turn out to be misleading.
Kant first published his mature account of the categorical imperative in his Groundwork for the Metaphysics of Morals (1785). There Kant distinguished the categorical imperative from two kinds of hypothetical imperatives, namely, hypothetical imperatives of skill, which simply prescribe practically necessary means to realize entirely optional ends, and the hypothetical imperative of prudence, which prescribes means to an end that all human beings have as a matter of fact, namely happiness. Kant described the imperatives of skill as "problematic" (debatable, since the ends are optional) and the imperative of prudence as "assertoric" (impelled by the goal of happiness). Because the end of happiness is universal but not obligatory and because it is also indeterminate what will actually make anyone happy, the imperative of prudence can give rise only to "counsels of prudence." Finally, Kant stated, "There is one imperative that, without being based upon and having as its condition any other purpose to be attained by certain conduct, commands this conduct immediately. … It has to do not with the matter of the action and what is to result from it, but with the form and principle from which the action itself follows" (Kant 1785; in Kant 1900, 4:415–416; in Kant 1996, pp. 68–69). This is the categorical imperative, which is apodictic (certain).
In the Groundwork, Kant gave his first official formulation of the categorical imperative and the one to which he most frequently refers in subsequent works. This is that one "must act only in accordance with that maxim through which you can at the same time will that it become a universal law" (Kant 1785; in Kant 1990, 4:421; in Kant 1996, p. 73). He reached this formulation by different routes in the first and second sections of the book. In the first section, he began with the claim that only a good will is of unconditional value, and then argued that a good will is demonstrated in acting from the motive of duty, where "duty is the necessity of an action from respect for law" (Kant 1785; in Kant 1900, 4:400; in Kant 1996, p. 55), rather than in acting from any inclination toward a particular end or object. The good will having thereby been deprived of any inclination to realize it with action, nothing is left as its principle "but the conformity of actions as such with universal law" (Kant 1785; in Kant 1900, 4:402; in Kant 1996, p. 56).
In the second section, Kant argued that the formula of universal law follows from the very concept of the categorical imperative, since once it is stipulated that such an imperative "contains no condition to which it would be limited, nothing is left with which the maxim of action is to conform but the universality of a law as such" (Kant 1785; in Kant 1900, 4:420–421; in Kant 1996, p. 73). In his Critique of Practical Reason of 1788 (1996), Kant derives a similar formulation of the categorical imperative from the initial premises that any practical law must be necessary, but that any objective for action is empirical and contingent—a circumstance that leaves only the form of a law to furnish content for the categorical imperative (theorem III, Kant 1788, in Kant 1900, 5:27; in Kant 1996, p. 160).
In the Groundwork, Kant offers four further formulations of the categorical imperative. The first of these is "Act as if your maxim were to become by your will a universal law of nature " (Kant 1785; in Kant 1900, 4:421; in Kant 1996, p. 73), where a maxim is a proposal to perform a certain type of action for a certain end. H. J. Paton (1947) held that this introduces a teleological conception of nature into Kant's argument, and this is true in Kant's first illustration of how the imperative yields a prohibition of suicide. But since all that Kant explicitly meant by a law of nature is a law that is uniformly followed, this formulation, like the initial one, requires only that you consider whether you could act on your proposed maxim if in fact everyone else were also to act on it. In the second formulation, Kant said that "a possible categorical imperative" needs a ground in "something the existence of which in itself has an absolute worth, something which as an end in itself could be a ground of determinate laws," and stated that this ground is "the human being and in general every rational being" (Kant 1785; in Kant 1900, 4:428; in Kant 1997, p. 78). This leads Kant to reformulate the imperative as follows: "So act that you use humanity, whether in your own person or in the person of any other, always as an end and never merely as a means " (Kant 1785; in Kant 1900, 4:429; in Kant 1996, p. 80). By "humanity" Kant meant just the capacity to set and pursue ends (Kant 1785; in Kant 1900, 4:437; in Kant 1996, p. 86; Kant 1797; in Kant 1900, 6:387, 392; in Kant 1996, pp. 518, 522), so this requirement means that the human capacity to set and pursue ends should itself always be an end and never merely a means. Kant interpreted this requirement in turn to mean that the categorical imperative requires that you act only for ends that others can accept or even adopt for themselves. Third, Kant reformulated the imperative as "the principle of a human will as a will giving universal laws through all its maxims " (Kant 1785; in Kant 1900, 4:432; in Kant 1996, p. 82), which requires that any maxim be part of a universally acceptable system of maxims. Finally, he formulated the imperative as the requirement that "all maxims from one's own lawgiving are to harmonize into a possible kingdom of ends" (Kant 1785; in Kant 1900, 4:436; in Kant 1996, p. 86), which is "a whole both of rational beings as ends in themselves and of the ends of his own that each may set himself" (Kant 1785; in Kant 1900, 4:433; in Kant 1996, p. 83).
This formulation makes explicit that to treat everyone as an end involves not only acting only on universally acceptable maxims but also allowing and promoting the individual ends of each insofar as doing so is consistent with treating all as ends in themselves. This sequence of formulations thus shows that the normative force of the categorical imperative is grounded on recognition of a necessary end, thus that the distance between Kant's mature formulation and his initial formulation of twenty years earlier is not as great as it initially seems, and that far from proscribing actions in behalf of particular, contingent ends, the categorical imperative prescribes such actions to the extent that such ends are freely chosen and are consistent with universal law. This is the foundation for Kant's doctrine of duties.
G. W. F. Hegel famously charged that Kant's categorical imperative is an "empty formalism," that is, that it either presupposes some already accepted particular end or else licenses any action that anyone is willing to universalize. This is clearly false, since the imperative requires consistency between any maxim on which you are proposing to act and the universalization of that maxim. Moreover, as the analysis above shows, universalization includes the requirement that your maxim be universally acceptable. This means that it is not enough that you be willing for your maxim to be universalized; everyone must be willing. More recent authors, including Marcus G. Singer (1971), Onora O'Neill (1975, 1989), and Allen Wood (1999), have considered cases in which clearly permissible maxims seem to fail the test of universalizability while clearly impermissible maxims seem to pass it. This shows that considerable care is needed in properly formulating maxims to be tested by the categorical imperative. John Rawls (2000) has interpreted the categorical imperative as yielding a "CI-procedure," which can be directly applied to individual maxims or proposals of action, while Barbara Herman (1993) has argued that it rather yields "rules of moral salience," that is, general factors of moral relevance that need to be considered in undertaking any particular action. The latter seems closer to Kant's own use of "categorical imperative" in the Metaphysics of Morals (1797) to yield general categories of duty, although Kant himself sometimes interpreted the requirement of being universalizable to apply to very specific types of action, as in his notorious argument of 1798 that lying is always wrong, no matter what the circumstances.
In addition to these questions about the interpretation and application of the categorical imperative, it has been criticized from a number of other points of view. Philippa Foot (1972/1978) has argued that categorical form is not sufficient to show that a requirement is moral, since rules of etiquette are also stated in categorical form. She concluded that both etiquette and morality, in spite of their categorical form, are really systems of hypo-thetical imperatives, to be adopted only if one wants to be regarded as polite or moral respectively. Bernard Williams (1985) accepted the categorical imperative as formulating the demands of morality, but raised questions about whether these demands are "overriding," that is, whether one's own personal projects and goals must always be sacrificed to the demands of morality in cases of conflict between them. R. M. Hare (1971) likewise accepted that moral principles have the form of categorical imperatives, or universal prescriptions, while raising the question of whether such prescriptions must always be accepted. These latter objections suggest that Kant was correct to use the concept of the categorical imperative to characterize the demands of morality, but that there is room to debate both whether he correctly identified the ground of any possible categorical imperative and whether morality itself is overriding.
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Paul Guyer (2005)
The Kantian categorical imperative follows from a conception of rational morality that is valid and binding for all rational minds. Just as kant, in his Critique of Pure Reason, considered rational science as knowledge valid and binding for all rational minds, so in his Critique of Practical Reason, he considered morality as comparable to science in the sense of being true necessarily and universally without qualification. The categorical imperative is categorical not because of a divine command, nor because of a conformity with nature, nor because of any consensus, however large; rather it has the category of an a priori. Once rational knowledge and rational morality are agreed to, according to Kant's reasoning, their universality and validity give evidence of their a priori character.
Explanation. The principle of Kantian rational morality is that an act is moral if and only if the principle in the act is capable of universalization without an internal contradiction. Even more fundamental for Kant, however, is the deontological primary principle that "there is nothing in the world or even out of it that can be called good without qualification except a good will." The principle on which the good will wills its acts must not contain any implication of circumstances or pragmatic consequences, because these would introduce contingencies that Kant wished to avoid. The right act is determined, for him, by a principle that is the same for every individual regardless of circumstances. To admit contingent circumstances would destroy the purely rational and categorical nature of the imperative.
First Formulation. Such reasoning led Kant to the first formulation of his categorical imperative: "Act only on that maxim which you can at the same time will to become a universal law." This categorical imperative is present in every moral act that is obligatory in itself without reference to any other end. In this way the categorical imperative is distinguished from the hypothetical, which represents the practical necessity of a possible act as a means to something else that is willed or might be willed. An act that is good only as a means to something else is commanded by a hypothetical "ought" or imperative, but an act that is conceived to be good in itself without any ordination to a further end is commanded by a categorical "ought" or imperative. The hypothetical imperative asserts only that an act is good for some purpose, actual or possible. The categorical imperative declares an act to be binding and exacting in itself, without reference to any purpose or end beyond itself.
If nothing can be called good without qualification except a good will, the good will is good in itself and not because of what it accomplishes or the uses to which it is put. Even if a good will achieves nothing, for Kant it is comparable to a jewel that would shine by its own light as something with intrinsic value. This good will operates solely from the motive of duty, not because God commands the act, but because it is good in itself. This deontological strain in Kant leads him to consider the good will as the will to do what ought to be done on the presupposition that man is free. Freedom and duty are reciprocal terms for Kant, although he admits that morality requires man only to be able to think freedom without self-contradiction, not to understand it. Freedom is postulated by the moral law, but human intelligence will never fully uncover how freedom is possible.
Other Formulations. Kant stated the categorical imperative in two other forms in addition to the one enunciated above. The second form was "Treat every rational being including yourself always as an end, and never as a mere means." The third form asserted that "a principle of moral conduct is morally binding on me if and only if I can regard it as a law which I impose on myself." The latter form stresses the autonomous morality of Kant, which denies that the moral law is something imposed upon man ab extra.
Critique. All three formulations of the Kantian categorical imperative have been criticized on the grounds of their ethical formalism, which would in application lead to conclusions opposed to established moral judgments. Refusing to repay borrowed money, for example, does not seem to involve a contradiction that is purely logical or formal, but it is dependent upon social and economic conditions in which people would not lend money if there were no assurance of repayment. A good will seems to require definition in terms of content as well as form. Again, a formal principle or categorical imperative to obey laws that are universal and necessary leaves out of the moral sphere the performance of unique acts in particular existential circumstances. It implies a consistency and uniformity in good acts that is not borne out in practice, where moral life is rich in diversity.
Kantian formulations of the categorical imperative are to be criticized as much on grounds that they cannot be validly applied as on grounds of their formalism. In addition there is a rigidity, an inflexibility, and a harshness in the application of these principles. They restrict morally good acts to those done out of respect for the moral law; and yet it is good to help others from motives of compassion and love when duty and obligation are not clearly present. These motives have independent moral value according to most moralists, but Kant seems to consider all inclinations other than that to duty as morally irrelevant. He also confuses the goodness of an act with the merit one receives in performing it.
For the philosopher with theistic presuppositions there is a further criticism of the autonomous, rather than the heteronomous, nature of Kantian morality. The human reason does not create morality; it merely articulates morality in practical prudential judgments of conscience, which may be termed the "prismatic analysis" through which the law of God is transmitted. Obligation is not self-imposed; it is heteronomously imposed through the mediation of law in the individual conscience of man. Circumstances and motives are required for the existential consideration of the moral act, and the moral act is good if motivated by charity as well as by duty.
Kant's dissatisfaction with a theistic ethics arose both from his own moral philosophy and his epistemology. For him a theistic ethics would imply a theological voluntarism, because the divine perfection in such an ethics would be God's will considered as independent of His goodness and wisdom. However one may criticize theological voluntarism, even Kant would not conclude that in such an ethic every moral law would depend exclusively on God's will alone. Kant's fundamental objection to a theistic ethics arose from his epistemological position that God is accessible neither to intuition nor to demonstrative knowledge. Thus any critique of the Kantian categorical imperative is reductively a critique of Kant's philosophical position on the possibility of man's speculative knowledge of God and of the nature of the moral "ought."
See Also: deontologism; ethics, history of.
Bibliography: i. kant, The Moral Law; or, Kant's Groundwork of the Metaphysic of Morals, tr. and ed. h. j. paton (New York 1948). w. t. jones, Morality and Freedom in the Philosophy of Immanuel Kant (London 1940). j. d. collins, A History of Modern European Philosophy (Milwaukee 1954).
[t. a. wassmer]