Kant’s Categorical Imperative
Immanuel Kant (1724-1804) was well aware of the Euthyphro Dilemma. His solution to the problem was to choose the second horn of the dilemma and accept that there exists a standard of rightness (goodness, justice) that is independent of God’s commands. He argued that the required standard was “reason”. Kant’s metaphysics included the notion that because God is presumed to be supremely rational, the world that God created must be logically consistent and obey rules (laws) that we can learn. To Kant, the concept of “practical reason” meant to apply the rules that the world follows, to the circumstances we find ourselves in, in order to find what logic demonstrates is the only reasonable action. In Kant’s terminology, “Theoretical reasoning” uses logic to move from beliefs to beliefs. “Practical reasoning” uses logic to move from circumstances to motives for action. Thus Kant assumes that God is a rational and reasoning being, and the omnipotence of God is limited by the rules of logic, and the nature of reasoning. And he also assumes that we are created “in God’s image” and so are also rational and reasoning beings.
I won’t try to provide any detailed synopsis of Kant’s metaphysical and moral philosophy here, as it is an incredibly complex construction. And there are libraries full of texts to provide more than sufficient detail for those interested. I will limit myself here to a very brief outline of some of the key points of his Moral philosophy.
Kant argued that conformity to the Categorical Imperative can be shown to be essential to rational agency. This argument he based on his doctrine that a rational will must be autonomous — in the sense of being the author of the rules that bind it.(1)
Kant’s three significant formulations of his Categorical Imperative are:
(i) (Universal Law Formulation) Act only according to that maxim by which you can also will that it would become a universal law.
(ii) (Humanity Formulation) 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.
(iii) (Autonomy Formulation) Every rational being must so act as if he were, through his maxim, always a legislating member in a universal kingdom of ends.
Kant’s moral philosophy is the arch-type of the Social conception of Morality. It focuses on universalizable maxims that are applicable to all rational beings, because of their very rationality. According to Kant, the moral worth of an action comes from the fact that it is motivated by the moral duty to adhere to the Categorical Imperative, not from any consequences that might ensue.
The universal law formulation comes from thinking about the rule-ish nature of practical reasoning. If morality is going to mean anything at all, Kant argues, then it has to apply to everyone. The notion of a morality that applies only to a small group (or a single individual) violates the whole meaning of “morality”. But if morality applies to everyone, then its rules must be universal laws. A number of commentators on Kant have summarized his argument into a decision procedure for moral reasoning —
“First, formulate a maxim that enshrines your reason for acting as you propose. Second, recast that maxim as a universal law of nature governing all rational agents, and so as holding that all must, by natural law, act as you yourself propose to act in these circumstances. Third, consider whether your maxim is even conceivable in a world governed by this law of nature. If it is, then, fourth, ask yourself whether you would, or could, rationally will to act on your maxim in such a world. If you could, then your action is morally permissible.”(1)
The humanity formulation comes from thinking about practical reason’s ability to set ends. And the autonomy formula comes from thinking about the difference between autonomous (from within oneself) and heteronomous (from outside oneself) sources of action. Basically, it is a matter of logical consistency. Since we are rational reasoning beings, if we think that a reason is sufficient reason (a motivation) for our action, then we must think that it is a sufficient reason for others to act in the same circumstances. One of his famous examples is the honest shopkeeper. If the shopkeeper is honest because she considers she has a moral dut to be honest, then being honest from that motivation is morally worthy. But if the shopkeeper is honest because she considers that honesty is a good policy to gain and retain customers, then her honesty has no moral worth.
There are three serious problems with Kant’s Categorical Imperative as a system of morality. The first problem stems from Kant’s assumption that we humans are rational reasoning beings. I think that Kant had an overly optimistic view of people. People, in general, are not rational and reasoning beings. We are, instead, as Hume pointed out, rationalizing and emotional beings. Perhaps we today have an advantage of being able to observe far more people than could Kant in his time. A single afternoon spent watching day-time television soap-operas will convince even the hardened supporter of “rational man” that in general we are anything but. The vast majority of people, the vast majority of time, will go with what feels good, not what reason dictates. The “moral rules” that most people follow, most of the time, are habits of thought instilled in us in our youth by parents, teachers, role models, the media, and so forth. They are not reasoned responses to circumstances.
In facing moral challenges, all but the devout Kantian simply does not reason the way that Kant suggests that we ought. The evidence of everyday life demonstrates that David Hume was right and Kant is wrong. Hume asserted three theses:
(i) Reason alone cannot be a motive to the will, but rather is the “slave of the passions”;
(ii) Moral distinctions are not derived from reason;
(iii) Moral distinctions are derived from the moral sentiments – feelings of approval (esteem, praise) and disapproval (blame) felt by spectators (including oneself) who contemplate a character trait or action.(2)
The second problem stems from the formalism of Kant’s logic. It is extremely onerous to consistently apply the reasoning that Kant recommends. Although Kant outlines a number of tests that prospective maxims must meet to be acceptable candidates for universalizable moral maxims under his Categorical Imperative, he does not provide any “cookie cutter” operating procedures that an average person can apply. Many critics of Kant’s moral system claim that it is very hard to come up with candidate maxims acceptable to all of Kant’s strictures, unless one is highly schooled in his writings. Critics of Kant frequently point out that coming up with proper Kantian maxims results in both false positives (ruling morally permissible things that intuitively we would reject as immoral) and false negatives (ruling morally prohibited things that intuitively we would accept as morally permissible).
One of Kant’s famous examples is that of the lying promise. He explores the ramifications of a candidate maxim of – “Always promise someone you will repay money even if you have no intention of doing so.” Kant argues that this maxim cannot be a universal law, because if everyone lies about promising to repay borrowed money, the business of lending money could not exist. And if everyone lies when it feels as if it suits their interests, communication with language could not exist. If the maxim cannot be a universal law, then no one can consistently will that the maxim be a universal law. Therefore the maxim is not morally acceptable. Hence, Kant concludes that telling a lie is absolutely wrong, in all circumstances. This conclusion runs afoul of our intuition that it is morally acceptable to lie to the axe murder looking for his next victim. And for most people, “little white lies” are more morally acceptable in polite company than the bald unvarnished truth. So Kant’s maxim on lying appears to generate a false negative on some occasions.
Another famous example of Kant’s is his maxim on charity. He explores the ramifications of the candidate maxim — “When I am flourishing and others are in distress, I shall give nothing to charity.” Kant argues that this cannot be a universal law because everyone necessarily wills that he or she be helped in desperate circumstances. If everyone necessarily wills this, then no one can consistently will that the maxim be a universal law. Therefore, the maxim is not morally right. So Kant assumes that the reverse is therefore morally right – “When I am flourishing and others are in distress, I must give something to charity.” Although this maxim strikes the intuition as unacceptably broad. Helping others in distress is intuitively acceptable when it is an instance of “I’ll scratch your back if you scratch mine”. But helping others in distress with no constraints on the amount of help being required, and no expectation of a return favour is just not something that most people will do. (Some will, of course, but most will not.) So Kant’s maxim on charity appears to generate a false positive.
In addition, with a little creativity, those with the requisite knowledge of his exacting tests, can come up with maxims that are distinctly un-Kantian sounding. Consider, for example, the maxim — “Act always to maximize the estimated probability of your genes inclusive fitness over the long run”. Inclusive fitness, it should be noted, is a term used in population genetics and evolutionary biology for the frequency of genetic transmission through direct and in-direct reproduction (reproduction by genetically related individuals), and includes both reciprocal altruism and kin altruism. This un-Kantian sounding maxim actually does pass all of the tests that Kant specified for a moral rule. But it is far too consequentialist to be acceptable to any deontologist. And it emphasizes the Personal conception of morality in contrast to Kant’s clear emphasis on the Social conception of morality.
Many critics of Kant argue that coming up with acceptable maxims that will pass the tests that Kant prescribes, and will look like acceptable moral rules, actually requires a pre-existing moral conscience. In other words, Kant’s moral logic may be used to provide suitable authority “from the dictates of reason” to maxims that we already accept as moral. But it can’t provide moral maxims sui generis. Given a blank slate, with no moral pre-conceptions, Kant’s moral logic can provide that authority “from the dictates of reason” to what in some people’s minds are some pretty odd sounding maxims.
Finally, the whole notion of a “Categorical” imperative has been challenged. A “hypothetical imperative” has the form “If A then B”. If the goal is A and doing B will get you to A, then do B. Kant’s idea of a Categorical Imperative says just “B”. Under any and all assumptions or conditions, do B. Philippa Foot has argued(3) that the very notion of an unqualified imperative is problematic. What Kant is doing is hiding an assumed hypothetical within his categorical imperative. Kant is in effect arguing “If one wishes to be rational (according to my notion of rationality), then B”. Foot argues that acknowledging this hidden hypothetical focuses the discussion on Kant’s notion of “rationality”, which she then argues is flawed. Besides which, of course, as I argued above, individual Homo sapiens, with their suite of cognitive biases, are very far from being rational creatures, even at the best of times.
For these reason, most moral philosophers seek the basis of our moral conscience elsewhere.
Footnotes
(1) Johnson, Robert; “Kant’s Moral Philosophy” in The Stanford Encyclopedia of Philosophy, Edward N. Zalta (ed.), URL=
(2) Cohon, Rachel; “Hume’s Moral Philosophy”, The Stanford Encyclopedia of Philosophy, Edward N. Zalta (ed.), URL=
(3) Foot, Philippa; “Morality as a System of Hypothetical Imperatives”, in The Philosophical Review, Vol 81, No 3 (July, 1972) pp 305-316
