Categorical Imperative of Immanuel Kant and Its Criticism

Benedict Wisco, RN, MAN (contributor)

Introduction

Immanuel Kant (1724–1804) believed that we have a clear moral responsibility to be truthful. For Kant, our human reason makes moral demands on our lives. If we think rationally about how we should behave, then we will immediately see that some kinds of actions are unreasonable. Dishonesty in all of its forms, he argues, is fundamentally unreasonable. Many philosophers before Kant also said that morality is linked to the rational part of human nature. But Kant goes a step further and formulates a supreme rational principle that tells us precisely whether a specific action is right or wrong. He calls this principle the categorical imperative: Act only on that maxim by which you can at the same time will that it should become a universal law. According to the categorical imperative, it is wrong for me to be deceitful since I couldn’t reasonably want everyone to act in that way. He explains this with the example of breaking one’s promise: “if no man were to keep his promise. . . . then promises would in the long run become useless.” So, it is unreasonable for me to wish this fate on humanity. If the categorical imperative succeeds as a true test of moral conduct, then it is the most important contribution to moral philosophy ever. All moral controversies would be quickly resolved, and no one could claim ignorance about their moral obligations.

Biography 

Immanuel Kant (1724–1804) is the central figure in modern philosophy. He synthesized early modern rationalism and empiricism, set the terms for much of nineteenth and twentieth century philosophy, and continues to exercise a significant influence today in metaphysics, epistemology, ethics, political philosophy, aesthetics, and other fields. The fundamental idea of Kant's “critical philosophy” especially in his three Critiques: the Critique of Pure Reason (1781, 1787), the Critique of Practical Reason (1788), and the Critique of the Power of Judgment (1790) — is human autonomy. He argues that the human understanding is the source of the general laws of nature that structure all our experience; and that human reason gives itself the moral law, which is our basis for belief in God, freedom, and immortality. Therefore, scientific knowledge, morality, and religious belief are mutually consistent and secure because they all rest on the same foundation of human autonomy, which is also the final end of nature according to the teleological worldview of reflecting judgment that Kant introduces to unify the theoretical and practical parts of his philosophical system.

The Concept of Categorical Imperative

Constrained only by the principle of universalizability, the practical reason of any rational being understands the categorical imperative to be: "Act only according to that maxim whereby you can at the same time will that it should become a universal law." That is, each individual agent regards itself as determining, by its decision to act in a certain way that everyone (including itself) will always act according to the same general rule in the future. This expression of the moral law, Kant maintained, provides a concrete, practical method for evaluating particular human actions of several distinct varieties.

The Formula of the Law of Nature

So much for the psychology behind the categorical imperative but the most important part of Kant’s theory is the categorical imperative itself:

“Act only on that maxim by which you can at the same time will that it should become a universal law.”

The categorical imperative offers us a step-by-step procedure for determining the moral status of particular actions. First, I take a specific action, such as stealing my neighbor’s lawnmower. Second, I see what the guiding principle or “maxim” is behind the action, such as “I will steal my neighbor’s lawnmower to gain material wealth.” Third, I reflect on what that maxim would be like if it were a universal rule that everyone followed, such as “Everyone may steal his or her neighbor’s lawnmower to gain material wealth.” Fourth, if the universal rule is reasonable, then I accept the action as moral; if unreasonable, I reject the action as immoral. It is almost like asking “What would happen if everyone did this?” However, we don’t want to consider what happens regarding our selfish inclinations, such as whether a universal rule would make me happy or not. Instead, we only want to look at what happens in our reasoning process as we think about a universal rule. Kant has a specific notion of reason in mind, with specific indicators about when a rule is rational or irrational. Kant gives four formulations of the categorical imperative that reflect different facets of human rationality.

            The first and most famous formulation is sometimes called the Formula of the Law of Nature: “Act as if the maxim of your action were to become through your will a universal law of nature.” The wording of this is very close to that of the original statement of the categorical imperative. However, as Kant explains, the distinguishing feature here is that we consider whether our maxim could function as a law of nature—and specifically, whether it is free from contradiction. Suppose I tell you that gravity will make the rock in my right hand fall to the ground and will at the same time make the rock in my left hand hover in mid-air. You will think that this is impossible since laws of nature cannot be inconsistent like this. Similarly, this formula of the categorical imperative instructs us to search for a contradiction within a universalized maxim.

            To illustrate, Kant gives four examples that he thinks represent our main types of moral duties. The clearest of the four examples is this: Suppose I borrow money from you promising to return it later, but I know full well that I will not return it. The intended maxim or guiding principle behind my action is this: “Whenever I believe myself short of money, I will borrow money and promise to pay it back, though I know that this will never be done.” Kant then explains that a contradiction arises once I view this maxim as a universal rule. Specifically, if such deceit were followed universally, then the whole institution of promising would be undermined and I couldn’t make my promise to begin with. So, on the one hand, I state “I promise such and such” yet, on the other, once universalized the practice of promise keeping itself would be nonexistent.

            In another example, Kant explains why it is wrong for me to kill myself when misfortunes push me to the point of despair. The maxim of this action is “From self-love I make it my principle to shorten my life if its continuance threatens more evil than it promises pleasure.” But a law of nature of this sort would be contradictory. The self-love principle inclines me to preserve my life, but according to this maxim, it also inclines me to end my life. In a third example, Kant explains why I must develop my talents rather than let them waste away. The maxim of the contrary action might be something like “I will let my talents decay and devote my life to idleness.” Kant concedes that this maxim by itself isn’t contradictory since in theory everyone could become an idle slug. However, the contradiction emerges when I willfully assert this maxim while at the same time acknowledging my inherent rational obligation to develop my talents. In a final example, Kant explains why it is wrong to be uncharitable. The maxim of this action might be “I will not help someone in need.” Similar to the last example, a contradiction arises when I willfully assert this maxim while at the same time acknowledging my inherent rational obligation to receive charity when I am in need.

            From these four examples, two different types of contradictions emerge. The first example in particular involves an internal contradiction within the proposed universal rule; the last two involve a contradiction between the proposed universal rule and another inherently rational obligation. The important point, though, is that a particular maxim fails as a universal law of nature if a contradiction arises at some point once a maxim is universalized.

The Formula of the End in itself

The second formulation of the categorical imperative is called the Formula of the End in itself: “Act in such a way that you always treat humanity, whether in your own person or in the person of any other, never simply as a means, but always at the same time as an end.” In other words, we should not use people as means to an ends, as objects, but instead recognize the inherent dignity and value that we all have. It helps to understand Kant’s point if we distinguish between things that have merely instrumental value and things that have inherent value. Some things in life are valuable only as instruments to obtain something else. My car keys, for example, are very valuable to me, and when I lose them, my life grinds to a halt. But my car keys are valuable only as tools that perform a task—namely, the task of starting my car. Even the value of my car itself is mainly instrumental insofar as it allows me to get from one place to another. By contrast, other things in life are inherently valuable, and we appreciate them for what they are, and not for what they enable us to do. Companionship and the enjoyment of music are good examples. We don’t think of these as being instruments for any further benefit, but instead appreciate them for what they are in and of themselves.

            Kant believes that human beings have inherent value and should never be treated as instruments:

In so acting man reduces himself to a thing, to an instrument of animal amusement. We are, however, as human beings, not things but persons, and by turning ourselves into things we dishonor human nature in our own persons.

The reason humans have inherent value, according to Kant, is because, unlike animals, we have the ability to rise above our brute instincts and to freely make crucial decisions in shaping our lives and the world around us. This ability to freely make such decisions is a feature of our human reason, and it confers on us an inherent dignity that is valuable in and of itself. We have a moral responsibility, then, to treat people in ways that reflect their inherent value, and not to reduce people to mere objects of instrumental value. So, when I treat someone as an end, I respect her inherent value; and when I treat someone as a means, I see her as having only instrumental value.

            Kant explains that there is both a negative and positive component to this formula. The negative component is that we should avoid treating people as a mere means. But this tells us only to abstain from using people as instruments, which is a bare minimum obligation. The positive component is that we should undertake to treat people as an end in themselves. This tells us to actively assist or support others in retaining their dignity. It isn’t enough simply to avoid abusing people; we must go a step further and help them, especially when misfortune strikes them.

            Kant again illustrates this formula with the same four examples that we considered earlier. If I make a deceitful promise to you with the intention of acquiring financial gain, then I’m treating you as a thing or instrument and not recognizing your inherent value. If I commit suicide, then I am using myself as a means to attain a tolerable state of affairs until the point that I’m actually dead. If I let my talents decline, then I am not acknowledging my inherent worth as a rational person who shapes the world through my decisions; I’m not treating myself as an end. And if I fail to help people in need, then I am not helping them maintain their dignity; I’m failing to treat them as an end. The first two examples illustrate the negative obligation to avoid treating people as a means, and the last two illustrate the positive obligation to undertake treating people as an end.

            Kant’s first two formulations of the categorical imperative are the most famous of the four and he devotes the most attention to these. The remaining two formulations draw from the central points of both the first and second formulations. The third is the formula of autonomy: “So act that your will can regard itself at the same time as making universal law through its maxims.” The focus of this formula is the authority that rests within our human will to productively shape the world around us when following reason. As we act, we should consider whether our intended maxims are worthy of our status as shapers of the world.

            The fourth formulation is the formula of the kingdom of ends: “So act as if you were through your maxims a law-making member of a kingdom of ends.” The point here is that the moral fate of all people hangs together. We saw that Kant thinks of human beings as ends in themselves, and so, collectively, we are a “kingdom of ends” or, more simply, a moral community. As I act, I should consider whether my actions contribute to or detract from the moral community. Specifically, I should consider whether the intended maxim of my action could productively function as a universal rule in the moral community.

            To summarize, here are the main points of Kant’s theory:

• Motives behind true moral choices are not those of selfish inclination but instead those of a rational duty conforming to the categorical imperative.

• Hypothetical imperatives have the form “If you want some thing, then you must do some act”; the categorical imperative mandates, “You must do some act.”

• The general formula of the categorical imperative has us consider whether the intended maxim of our action would be reasonable as a universal law.

• Specific formulations of the categorical imperative focus on a particular feature of human rationality, such as the absence of contradiction, free choice, and inherent dignity.

Criticism of Kant’s Theory 

Kant was an original thinker not only in the field of ethics but in virtually every area of philosophy. His reputation skyrocketed during the last two decades of his life, and during the nineteenth century his writings were more influential in Europe than those of any other philosopher. Many philosophers adopted his theories and perpetuated a specialized Kantian vocabulary. Others, however, were less happy with Kant’s elaborate philosophical system and picked away at parts of it, including the categorical imperative.

A.    Schopenhauer’s Criticism: The Categorical Imperative Reduces to Egoism

Kant’s writings were a source of inspiration for German philosopher Arthur Schopenhauer (1788–1860). Although Schopenhauer followed Kant in many particulars, he criticizes different aspects of Kant’s philosophy that don’t quite mesh with his own. This includes Kant’s categorical imperative. For Schopenhauer, Kant’s categorical imperative simply reduces to the egoistic principle that “I shouldn’t do to others what I don’t want done to myself.”

            To explain, Schopenhauer believes that human conduct is guided sometimes by sympathy for other people and other times by selfish or egoistic concerns for oneself. Truly moral conduct, he argues, must be sympathetic, but Kant denied the role of sympathy as the motive behind truly moral action. Sympathy is a fellow feeling or sense of commiseration that we have with other people. Like other feeling such as happiness and self-love sympathy focuses on specific people and specific situations. All such feelings, Kant says, are too unstable and unreliable to be an effective foundation for morality. According to Schopenhauer, if I shun my feelings of sympathy as Kant recommends then egoism will drive how I consider the universal implications of my actions in the categorical imperative. Without sympathy, the real step-by-step procedure of the categorical imperative is this: (1) I consider how willing I am to allow the egoism of others to encroach on my territory, and then (2) I recognize that this is as far as I can allow my own egoism to encroach on other people’s territory. Schopenhauer makes this point here:

This aim [concerning the well-being of all], however, still always remains [egoistic] well-being. I then find that all can be equally well off only if each makes the egoism of others the limit of his own. It naturally follows from this that I ought not to injure anyone, so that, since the principle is assumed to be universal, I also may not be injured. This, however, is the only ground on account of which I, not yet possessing a moral principle but only looking for one, can desire this to be a universal law. But obviously in this way the desire for well-being, in other words egoism, remains the source of this ethical principle. [The World as Will and Representation, Vol. 1, appendix]

For Schopenhauer, morality begins with my egoistic desire for my own well-being, which I then universalize into a principle that aims at the well-being of everyone.

            Schopenhauer believes that this is good enough for the purpose of establishing political laws that regulate how we behave as citizens, since political laws mainly limit how much we can encroach on other people’s territory. However, Schopenhauer argues, this is not sufficient for establishing moral obligations that go beyond the bare minimum obligations that we find in legal codes. For example, morality may require that we more aggressively help others in need, and egoism is inadequate for that task. For this we need sympathy.

            How might we defend Kant from Schopenhauer’s charge of egoism? For the sake of argument, let’s suppose that Schopenhauer is correct that either something like sympathy or something like egoism must be the driving force behind our consideration of the universal implications of our actions. Even though Kant rejects a specific notion of sympathy that is, sympathy as a feeling toward particular people he still believes that there is a humanitarian emphasis within human reason. Although reason cannot directly instruct me to sympathize with this or that person, it does instruct me to sympathize with the whole race of humans. This more generalized notion of sympathy emerges in the Formula of the End in Itself, which tells us to respect the inherent value of all people. We’ve seen that this formula includes the positive mandate to treat people as ends in themselves by helping them when in need. This goes beyond the purely negative mandate to avoid treating people as a means or using them as an instrument. This reflects Schopenhauer’s precise point that there is more to morality than simply not encroaching on other people’s territory. The solution, then, to Schopenhauer’s egoistic spin on the categorical imperative is to accept a more generalized notion of sympathy toward humanity.

B.     Hegel’s Criticism: The Categorical Imperative has no Practical Application

A second early criticism of the categorical imperative is that by German philosopher Georg Wilhelm Friedrich Hegel (1770–1831). Like Schopenhauer, Hegel too focuses on the Formula of the Law of Nature: Act as if the maxim of your action were to become through your will a universal law of nature. According to Hegel, this formula “is reduced to empty formalism, and moral science is converted into mere rhetoric about duty for duty’s sake.” That is, it does not offer a clear guideline for assessing moral conduct, and it does not provide us with any specific moral duties that we can follow. The crux of the problem, for Hegel, is that the categorical imperative is a moral litmus test based on the absence or presence of a contradiction. While this may sound good in the abstract, it is difficult to detect contradictions within concrete actions that we know are contradictory. Hegel gives two examples here: 

The rule that there should be no private property contains of itself no contradiction, nor does the proposition that this or that particular nation or family should not exist, or that no one should live at all. Only if it is really fixed and assumed that private property and human life should exist and be respected, is it a contradiction to commit theft or murder. [The Philosophy of Right, Sect. 135]

The first example is the claim that “there should be no private property,” which is a position that we would all want to reject. Even communists or religious monks who take vows of poverty recognize that we have at least some private property, such as our toothbrushes and the clothes that we wear. But, Hegel argues, wherein lies the contradiction when making this claim? The second example is that a particular nation, family, or even the entire human race should not exist at all. At its worst, this claim would mean that genocide and even omnicide the killing of all humans would be morally permissible. Where, though, is the inherent contradiction in this claim? According to Hegel, in the absence of any clear contradiction, there is no way of ruling this out, and “all manner of wrong and immoral acts may be by such a method justified.”

            What can we say in defense of Kant? First, it is important to recognize that, with any moral principle, there will be a gap between how it appears as an abstract statement, and how we apply it in concrete situations. Take a basic abstract moral principle like “don’t harm others”. The challenge here is determining what counts as harm, and how serious that harm must be before it becomes morally wrong. Suppose that my hands are dirty, and I shake hands with you. You don’t want the grime that’s just been transferred onto your hands and have to wash them off, taking up one minute of your life and costing you one cent in hand soap. Does the harm here rise to the level of immorality? Probably not, but somehow we must decide whether the abstract principle “don’t harm others” applies in this particular case. Applying Kant’s Categorical Imperative in concrete situations may also be challenging, but this is a challenge that is built into the application of any general moral principle.

            Second, Kant provides enough examples to demonstrate how we apply the categorical imperative in concrete situations, particularly using the litmus test of detecting a contradiction. The example of deceitful promises is a perfect illustration of how an immoral maxim may produce an internal contradiction when universalized. If we universally allow deceitful promises, this means that we may (1) keep our word and (2) not keep our word at the same time. This is as explicit a contradiction as one can get. Other immoral maxims don’t lead to explicit internal contradictions like this, and, instead, Kant tries to show how they lead to external contradictions. We’ve seen that external contradictions occur between (1) the proposed universal rule and (2) another inherent rational obligation. For example, it is wrong to waste my talents since it is contrary to my inherent rational obligation to develop my talents. It is wrong to deny charity to others since it is contrary to my inherent rational wish to receive charity when I am in need.

            For most other immoral actions that Kant does not specifically illustrate, it is easiest to see these as involving external contradictions as well. Stealing is wrong, perhaps, because it is contrary to our rational obligation to live in peace with our neighbors. Murder is wrong, perhaps, because it is contrary to our rational obligation to respect the lives of others. This applies equally to Hegel’s example of genocide and omnicide, since these are contrary to our rational obligation to respect human life. With Hegel’s other example, that of prohibiting private property, this is contrary to our rational duty to take care of our minds and bodies. Such care of ourselves requires that we have at least some private property, just as, for example, a bird claims some type of ownership of its nest.

C.    Mill’s Criticism: The Categorical Imperative Reduces to Utilitarianism

British philosopher John Stuart Mill (1806–1873) developed a view of morality that was about as contrary to Kant’s theory as one could imagine. Kant believed that our moral duties spring immediately from human reason, without any consideration of the tangible effects of our actions on our personal happiness. For Kant, the categorical imperative is a method of directly accessing the commands of our reason, independent of other considerations. By contrast, Mill believed that our moral obligations spring only from considerations of how our actions affect human happiness. Mill proposes his own principle of morality, which he calls the “utilitarian principle”: “Actions are right in proportion as they tend to promote happiness; wrong as they tend to produce the reverse of happiness.” According to this principle, we look at the consequences of our actions and assess whether they bring about more happiness than unhappiness.

            Mill was aware of Kant’s categorical imperative and the enormous influence that Kant’s theory had on philosophers of the time. However, Mill argues that the categorical imperative does not succeed as a purely rational source of obligation. Instead, he says, it is actually a disguised version of the utilitarian principle which is the very last thing that Kant thought his principle was:

[Kant lays] down a universal first principle as the origin and ground of moral obligation; it is this: “So act, that the rule on which thou actest would admit of being adopted as a law by all rational beings.” But when he begins to deduce from this precept any of the actual duties of morality, he fails, almost grotesquely, to show that there would be any contradiction, any logical (not to say physical) impossibility, in the adoption by all rational beings of the most outrageously immoral rules of conduct. All he shows is that the consequences of their universal adoption would be such as no one would choose to incur. [Utilitariansim, 1]

Although Mill cites the general formula of the categorical imperative in the above quote, he directs his attack against the Formula of the Law of Nature, which tells us that an action is wrong if a contradiction arises when universalizing the intended maxim. According to Mill, the categorical imperative fails to reveal any such contradiction, and the only thing it does reveal is that the consequences of universalizing a maxim involve more unhappiness than happiness.

            Part of Mill’s criticism sounds much like Hegel’s: the categorical imperative fails as a moral litmus test since contradictions do not arise when universalizing immoral actions. We’ve already seen how Kant can overcome Hegel’s objection. But there is a second part to Mill’s criticism that is potentially fatal to Kant’s theory: universalization isn’t about rational conflicts; it’s about envisioning good or bad consequences. Suppose I tell you that I’m going to cheat on my taxes, and in response you say “what if everyone did that?” My natural inclination to your question is to envision the disastrous effects this would have on the country, and then hopefully conclude that I should have nothing to do with that. Kant, though, is telling me that I’m looking at the issue of universalization improperly. I should ignore the harmful consequences of universalized tax evasion, and, instead, hunt for a contradiction, either internal or external. But this is a tough task to accomplish. It requires a college course in ethics to understand what it means for universalized maxims to be “contradictory”, and Kant’s examples of exposing contradictions are not obvious. Thus, Kant’s conception of universalization is unnatural, difficult to grasp, and probably impossible to follow in real life situations. Although Kant thinks that universalization merely involves looking for the presence of a contradiction, according to Mill we are actually envisioning the unpleasant effects of a universalized rule.

            How might Kant respond to Mill’s criticism? The short answer is that Kant is in fact trying to rescue the moral principle of universalization from the distorted ways that consequentialists like Mill have been using it. Kant would probably agree that universalized tax evasion would have bad effects on society. That is just a natural side effect of widespread deceit. What Kant is saying, though, is that harmful effects do not make actions immoral. There is something inherently wrong with the actions themselves because they conflict with our rational intuitions about moral duty. We must reject the whole tendency to link morality with consequences. If universalization is only about envisioning consequences, then universalization must be rejected as a moral guideline. But Kant is trying to salvage our common tendency to connect universalization and morality when we ask the question “what if everyone did that?” Yes, Kant’s view of universalization is a bit odd, but it’s better than rejecting the entire conception of universalization because of its faulty connection with consequences. Universalization still can be an important moral litmus test, in spite of its tainted history.

D.    Anscombe’s Criticism: There Is No Procedure for Constructing Maxims

In a famous essay entitled “Modern Moral Philosophy” (1958), contemporary British philosopher Elizabeth Anscombe criticizes virtually the entire lineup of traditional moral philosophers. With regard to Kant, she argues that Kant’s “rule about universalizable maxims is useless without stipulations as to what shall count as a relevant description of an action with a view to constructing a maxim about it.” That is, for any action I pick, I could devise a wide variety of maxims that might represent my action. But how do I know which one is the correct maxim? To illustrate Anscombe’s criticism, we will use a rather grotesque example that Kant himself discusses. Suppose I yank out one of my healthy teeth and sell it to a dentist, who will then insert it into someone else’s mouth. We would expect any adequate moral theory to condemn this action. So, if Kant is correct, universalizing this action should generate a contradiction. But what is the maxim of my action here? It might be that “I should pull out my tooth and sell it to a dentist,” or that “I should extract a healthy part of my body and sell it,” or that “I should pull out my right upper molar and sell it to a dentist by the name of John Smith.” Each of these maxims has entirely different implications, and if I cannot figure out exactly which maxim represents my action, then I cannot test the action by universalizing it. So, Kant’s categorical imperative fails to give us the guidance that we need.

            In defense of Kant, Anscombe’s criticism misses the point about what a “maxim” is, and Kant really does provide an appropriate way to construct maxims. The key to constructing a maxim is to determine the intention behind an action. Kant illustrates the connection between maxims and intentions here:

Every immoral man has his maxims May a man, for instance, mutilate his body for profit? May he sell a tooth? May he surrender himself at a price to the highest bidder? . . . What is the intent in these cases? It is to gain material advantage. [Lectures, “The Supreme Principle of Morality]

Kant is correct that, if we want to understand the moral worth of someone’s action, we must look beyond the specific action and examine the underlying intention. For example, if I hit a pedestrian while driving my car, from a moral standpoint it makes a big difference whether I was hoping to hit or to avoid the pedestrian. Just as it is important to discover one’s underlying intention in moral assessments, it is also important in criminal law, especially in determining the severity of punishment. Today, we don’t speak about the maxim of our actions but prefer to speak simply about our intention. However, philosophers in Kant’s time were comfortable viewing intentions as maxims. Wolff, for example, writes that “man must have certain maxims or general rules according to which he directs his action, even if he himself does not clearly recognize this.”

            In constructing my maxim, then, I look to my intention. In the case of the extracted tooth, my intention is, in Kant’s words, “to gain material advantage.” The more precisely stated maxim is that “I should disfigure myself by extracting my tooth to gain material advantage.” In the spirit of Anscombe’s criticism, we must acknowledge that it is sometimes difficult to uncover the exact intention behind our actions, but that’s a problem that plagues morality in general, and not just Kant’s theory. In criminal court cases, prosecutors and defense attorneys may battle for days over a defendant’s true underlying intention. It may not be any easier for us as individuals when we struggle to discover why we do things. In fact, Kant believes that it is nearly impossible to discover our precise intentions:

We can never, even by the strictest examination, get completely behind the secret incentives 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. [Foundations, 2]

Although I may not know what my exact intentions are for a given action, I can make a best guess or even consider a few possible intentions just to cover all the bases. With the categorical imperative, then, I may have to devise a few maxims and see what the outcome of each would be when universalized. This adds extra steps to the categorical imperative, but they are steps that realistically reflect our limited knowledge of our intentions.

Conclusion

Immanuel Kant (1724–1804) argued that moral requirements are based on a standard of rationality he dubbed the “Categorical Imperative” . Immorality thus involves a violation of the categorical imperative and is thereby irrational. Other philosophers, such as Locke and Hobbes, had also argued that moral requirements are based on standards of rationality. However, these standards were either desire based instrumental principles of rationality or based on  rational intuitions. Kant agreed with many of his predecessors that an analysis of practical reason will reveal only the requirement that rational agents must conform to instrumental principles. Yet he argued that conformity to the Categorical imperative (a non-instrumental principle) and hence to moral requirements themselves, can nevertheless be shown to be essential to rational agency. This argument was based on his striking doctrine that a rational will must be regarded as autonomous, or free in the sense of being the author of the law that binds it. The fundamental principle of morality is none other than the law of an autonomous will. Thus, at the heart of Kant's moral philosophy is a conception of reason whose reach in practical affairs goes well beyond that of a Humean ‘slave’ to the passions. Moreover, it is the presence of this self-governing reason in each person that Kant thought offered decisive grounds for viewing each as possessed of equal worth and deserving of equal respect.