To what extent does Kant successfully apply his four illustrations to his categorical imperative test? (Do not make false promises etc)

The question can be split into two questions:

What makes Kant's application successful?

What are the weaknesses of Kant's application, and what improvements could he make?

Here is a link that explains Kant's four applications of the categorical imperative in more detail.

  • First off welcome to philosophy.se. This is the beginning of a good question. Can you tell us what you mean by "four illustrations"? (There's some questions as to how many versions of the CI Kant offers that make it hard to count and hard to know what one means when one counts).
    – virmaior
    Oct 14, 2014 at 22:58
  • Thank you for the reply. I'm talking about the four examples he gives in Section 2 of Groundwork (do not make false promises etc)
    – LTedeschi
    Oct 14, 2014 at 23:17
  • 2
    Okay, if you edit your question that will make it better, but one of the hard parts here is that you're asking us to make a somewhat subjective judgment with the "to what extent" part of the question.
    – virmaior
    Oct 15, 2014 at 4:26
  • Ok I've edited the question now.
    – LTedeschi
    Oct 15, 2014 at 10:24
  • 1
    @LTedeschi, please edit the question itself, don't just put the link in the comments. Also, do you have a definition for what you mean by "success" here? Logically consistent? In a convincing manner? Oct 15, 2014 at 14:24

5 Answers 5


As this touches a wide field that is discussed and still in motion today, I will just refer to what Henry E. Allison states in his Groundwork for the Metaphysics of Morals - A Commentary (Oxford University Press, 2011). On page 183, before going into the details for every single application, he writes:

Before proceeding to Kant's examples, however, it will be useful to note four points about his procedure. First, in each case Kant assumes that the reader will grant that the course of action being contemplated is a violation of a generally recognized duty. Second, in each case Kant makes sure to point out that the agent who is applying the test is proceeding conscientiously. In other words, in spite of his self-interest the agent is also concerned with the morality of the proposed course of action, and it is from this perspective that he raises the question of universalizability of his maxim. Third, for this reason the maxim that the agent is considering adopting is the one on which he would perform the action (or omission) in question, not one which might be contocted after the fact in order to provide a veneer of justification. Finally, although in each case the universalized maxim will turn out to involve a contradiction (either in conception or will), priori to the test for its universalizability the maxim which the agent is considering adopting has a certain prima facie justificatory force for that agent.

What makes his application successful on first sight is a contradiction. The main point is how this contradiction is to be understood. The link provided does not help, because it is only an excerpt form a translation that is outdated. The problem is that there are two times four applications (4 of the Formula of Natural Law, 4 of the Formula of Humanity, naming by Allison) and in each case there are numerous essays and books on how they are to be understood.

Therefore, the question cannot be completely answered in this context, but I can recommend to read the sections in the above mentioned commentary. The objections presented are various and sometimes (for me) inconceivable looking at Kant's own wording, but they are presented and summarized.

As for some terms that looking for may be useful in that context: 'false positives' and 'false negatives' are discussed as the most challenging objections against the application of the categorical imperative on pages 191-202.


I am not sure how satisfactory my thoughts offered will be to answering your question, but here goes:

As I see it; there are two forms of the Categorical imperative.

1. A categorical imperative contained within a hypothetical imperative.

In chess; It is categorically imperative that Pawns never move backwards. To do so would violate the rules of chess. The hypothetical imperative is whether you want to play by the rules of chess in the first place.

2. An ultimate categorical imperative.

For example; G-d declares that wearing black hats is Categorically Imperative. (See http://en.wikipedia.org/wiki/Divine_command_theory)

Because G-d is omnipotent, and there can be nothing beside him, the subjectivity of this value presumably chosen by him, is moot, as there is no subject other than him.

From my rudimentary understanding, Kant's examples all fall within the first example, and all beg the question as to why should I employ universality in this behaviour in the first place.

Let me know if this answer is valuable to your question, and criticism is welcome!

  • Where are you getting the notion under 1 in Kant at all? The entire idea of the categorical imperative is that you are obligated by reason itself regardless of circumstances and outside of the declaration of any divine entity (see his Religion within the bounds of reason alone for more on how these are not divine commands). It is precisely hypothetical that you cannot move a chess piece backwards -- under the hypothesis that you want to play chess and not say reset the board. But the categorical imperative (if it can work) is for all conduct and founded on reason.
    – virmaior
    Oct 15, 2014 at 11:57
  • Thank you for your comment. The whole idea of the categorical imperative from the way I have been taught, that you have to do something, point blank. The rules of chess at no point offer any player the option of moving his chess pawn piece backwards. Doing so apodictically violates the rules of chess. Thus if you play by the rules of chess, you simply can not exercise a hypothetical imperative with moving the chess piece backwards. What do you think?
    – Anon
    Oct 15, 2014 at 12:07
  • The point blank part is accurate about how the CI obligates. If you play chess, you are bound by hypothetical imperatives involved in playing chess (note the corollary between hypothetical and if), but you are not bound by those hypothetical imperatives if playing chess is not your end. You are categorically bound to the CI -- meaning there's no if as to when one is bound.
    – virmaior
    Oct 15, 2014 at 12:18
  • Moreover, Kant distinguishes two subtypes of the hypothetical imperative in one of the points that greatly distinguishes him from Aristotle -- (a) hypothetical imps linked to specific tasks (e.g. the chess ones) and (b) hypothetical imps linked to happiness. But there's no sense in which either contains a categorical imperative which is what you state.
    – virmaior
    Oct 15, 2014 at 12:19
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    Your comments are useful. I do not remember Kant ever clearly explaining why I should employ universality in this behavior. But a lot of this is irrelevant to the questions I asked.
    – LTedeschi
    Oct 15, 2014 at 13:08

A partial answer, but too long to be a comment.

What are the weaknesses of Kant's application, and what improvements could he make?

Here are two major weaknesses with Kant's categorical imperative:

  • It leads to unresolvable contradictions when different imperatives collide: It is WWII and you are hiding Jews in your basement. The Nazis show up at your door searching for Jews and ask you if there are any in the house. Do you obey the categorical imperative to never lie? Or do you obey the categorical imperative to protect the innocent? Here Kant's imperative is of no help.
  • I was once debating a Chinese guy who was a strong supporter of Mao Zedong and who insisted that the cultural revolution was a good thing for China (In which several million people had died). I tried to explain to him that it wasn't ethical to kill people for the greater good of China, and in a attempt to knock down his argument I asked him if he was willing for the Red Guards to kill his own parents if it was for the good of China, and he said yes, he was willing to sacrifice even his own parents for the greater good of China. My Kantian attempt at showing him that the cultural revolution was bad failed. The point here is that if someone is willing to accept that a horrible course of action is universalizable, then there is no way of showing that there actions is wrong using Kant's imperative.

There seem to be a lot of questions that pop up here about failed applications of the Categorial Imperative, somehow "disproving" its validity. This seems misguided. Since I am not a Kant expert, I hope others will point out any misunderstandings on my part.

This attention to applications is, I believe, somewhat misplaced and stems from the difficulty we have today in grasping philosophical idealism in general and the modern transcendental variants. We are simply too steeped in physics, utilitarianism, and psychology.

Kant's CI might best be understood as something like Newton's laws of motion, though of course as the "laws" of reflective, mental motion they can hardly be applied with mathematical precision. The CI is an a priori principle that is necessary to beings endowed with reason, freedom, and moral sensibilities. One can reject that description entirely in favor of selfish genes, or whatever, and in that sense not only the CI but all of Kant's project can be deemed a "failure" of precise physical description.

But if we tend to accept that, yes, we have a capacity for reason, autonomy, and moral duty--as well as a capacity for scientific knowledge of the world--then Kant is demonstrating the a priori structure necessary for the coherent integration of such capacities. One essential part of this structure is the highly general principle of the CI. Just as Newton observed "motions" and derived a universal principle within a coordinate system, so Kant observed "emotions" and moral behaviors in the phenomenal world and derived the abstract, noumenal principle to which they all refer and relative to which we may understand them.

Even Newton's laws of motion, while "universal" and "necessary" in some sense are idealized. They do not apply at certain scales, as we now know...and, crucially, they do not even apply exactly with absolute accuracy in any given, particular instance.They are "regulative ideals" to use one of Kant's terms. They posit an ideal motionless space full of infinite ideal points, relative to which we can plot the motions of macro-objects to a high but technically limited degree of accuracy.

Similarly, the CI is the logical structure derived, we might say, from reflection upon all moral actions in the world, also within the posited space-time limits of "sensibility." Or such is Kant's argument, a compelling one, I believe. We can never know by simple observation whether any particular action is moral by Kant's definition, because we can never observe precisely the intentions motivating it, even in ourselves. Nor can the CI simply be applied in any particular case. If it could be, we might as well replace juries and judges with computers.

We refer to it only as an a priori principle and regulative ideal that helps us explain what we mean by immorality and moral duty as practices in the highly conditional, imperfectly grasped world. It is the logic discernible behind many valid moral and religious practices, and our good "common sense," yet it was important to Kant that it not be based simply on a reference to God or any other authority. In keeping with the spirit of Aufklarung, it is derived critically from the necessary coherent interactions of freedom and reason.

Kant himself states somewhere that he does not expect the CI to apply exactly to actual cases, though I do not recall the reference. In the four examples he gives, he is assuming we accept the ordinary understanding that they are right or wrong, then he asks us to discern what general principle or form they might share in common. How can we express concisely and consistently what makes these various actions appear to us as "moral imperatives"? What logical common denominator describes how the rational being judged some practice to be "right"? That is the CI.

While applications might always be improved, that is an adjustment of judgements within the contingencies of the world, not an "improvement" of the CI itself. And, as with Newton's laws, we may find ourselves adding subsidiary principles as new social situations and even new forms of "common sense" arise, though probably without Kant's blessings. For example, Rawls' "difference principle" seems to me a valuable addition within the contingencies of capitalist democracies, so far from the sleepy civilities of the Prussian order.


There seems to be a moral sensibility presented by the author through the use of the term "promise." Since a promise is something that will happen in the future I think the author needs to use a more accurate term. Kant wanted to "rebalance" truth since there is no duty to tell it and indeed an infinite number of reasons not to (to protect your buddies on the battlefield for example.) So how do we achieve our HIGHER calling of "informing on the matter accurately"? Obviously Kant is quite strict on this matter as he sees (correctly) the need for not just the truth but for the truth to " get to the top."(Fog of War for example...or perhaps informational disadvantage in the current context.) So the "residue" does indeed become a contradiction because me and my "posse" are probably going to have to lie to survive in this thing called life...but I still owe my Tribal Chief something too otherwise I might not even have my posse without my Chief.

That's my take on the "categorical imperative" as presented here namely "more than a promise." Is it a duty? The author does not elaborate sadly.

  • Telling the truth (i.e. not to lie) is definitely a, if not THE kantian duty par excellence (an example used through all of his works touching practical philosophy), not allowing for any exceptions at all, because the telling of the lie, universalized, would make any assertion with a truth value attached pointless, i.e. destroy human communication. It may be practical, sometimes even prudent, but never moral to tell a lie. That is, for Kant at least.
    – Philip Klöcking
    May 21, 2016 at 11:48

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