• Two Variants of the First Formula
• Hypothetical and Categorical Imperatives
• The Derivation
• The Formula of the Law of Nature
• Applying the Formula of the Law of Nature
  • Suicide
  • False Promises
  • Rusting Talents
  • Refusing Aid
• The Table of Duties in the Metaphysics of Morals
• Problems with the First Formula
  • Failures of Sufficiency
  • Failures of Necessity
  • The Significance of these Failures
• The Moral Point of the First Formula

Two Variants of the First Formula

The first formula of the supreme principle of morality specifies the form of the moral law (G 4:436) and has two variants:

1. The Formula of Universal Law: “Act only in accordance with that maxim through which you can at the same time will that it become a universal law.” (G 4:421; 4:402)
2. The Formula of the Law of Nature: “Act as if the maxim of your action were to become by your will a universal law of nature.” (G 4:421; 4:436)

Hypothetical and Categorical Imperatives

Kant distinguishes two kinds of imperative:

1. Hypothetical imperatives
2. Categorical imperatives

Hypothetical imperatives presuppose the adoption of an end and prescribe an action as a means to achieving that end. The normative force of an hypothetical imperative is conditional on the adoption of the antecedent end: If a rational being has not adopted that end, then he is not required to perform the action prescribed as a means to that end.

In contrast, the normative force of a categorical imperative is not conditional upon the adoption of any antecedent end: A rational being is required to perform the relevant action whatever ends he may in fact have adopted.

Two points of clarrification. First, Kant is not making any grammatical distinctions. Imperatives can be expressed by sentences in the indicative mood:

• Aiding those in the need is a good thing to do.

Similarly, categorical imperatives, though unconditional, can be expressed by a conditional sentence:

• If you make a promise, keep it

while hypothetical imperatives, though conditional, need not. Thus:

*Look out!

can express the hypothetical imperative to pay attention to some immanent danger if you have adopted the end of avoiding bodily injury. Second, the claim that categorical imperatives are unconditional and so not dependent upon the adoption of some antecedent end is easily misunderstood. Kant is not claiming that a categorical imperative requires a person to act without an end. According to Kant, every action involves an end (Ms 6:384f). Rather, a categorical imperative is a requirement to adopt a particular end.

The Derivation

Kant thinks that a characterization of the supreme principle of morality follows from the concept of the categorical imperative. The existence of such a principle does not follow from the concept of a categorical imperative. Given the overall argumentative structure of the Groundwork, the question of the existence of categorical imperatives is postponed until the third section. Rather, what follows from the concept of a categorical imperative, is merely that if there were categorical imperatives, they would have a certain characterization, i.e., they would be represented by the two variations of the first formula. The characterization is formal in that it abstracts from the value that grounds the imperative and considers only the form of categorical requirements:

When I think of a hypothetical imperative in general I do not know beforehand what it will contain; I do not know this until I am given the condition. But when I think of a categorical imperative I know at once what it contains. For, since the imperative contains, beyond the law, only the necessity that the maxim be in conformity with this law, while the law 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; and this conformity alone is what the imperative properly represents as necessary.” (G 4:420–421)

A maxim is a rule or policy governing action that a person adopts, at least implicitly, whenever they act. A categorical imperative requires a person to adopt maxims in conformity with with the law. The law is based on objective grounds, i.e., grounds valid for every rational being (G 4:413). They are thus univerally valid rational requirements on action. Thus from the mere concept of a categorical imeprative Kant provisionally concludes that a categorical imperative requires that a person adopt maxims in conformity with the universality of law as such.

At this point, from the claim:

• Categorical imperatives require that a person adopts only maxims that conform to the universality of law as such.

Kant concludes:

There is, therefore, only a single categorical imperative and it is this: act only in accordance with that maxim through which you can at the same time will that it become a universal law. (G 4:421)

This is essentially the same derivation of the Formula of Universal Law that Kant gave in the first section (G 4:402) and is therefore subject to the same difficulty. While the moral law may be valid for all rational beings, we so far have been given no reason to suppose that the law necessarily involves what a person could or could not will. Put another way, from the the fact that maxims should conform to universal law it does not follow that the will of a rational being has any role in determining the content of the law. Just as the Formula of Universal Law not follow from the concept of a categorical imperative neither does the other variant of the first formula, the Formula of the Law of Nature, and for precisely the same reason.

Kant is plausibly anticipating the idea of autonomy here for if rational beings are the authors of the moral law, then what rational beings could coherently will would be relevant to determining the content of that law. This undercores the way in which the three formulations of the supreme principle of morality should be read in light of the others.

The Formula of the Law of Nature

The Formula of Universal Law is abstract and so difficult to apply, but Kant thinks that it is easier and more intuitive to apply the Formula of the Law of Nature in determining the permissibility of a maxim. The Formula of Universal Law differs from the Formula of the Law of Nature in that the former involves willing a law whereas the latter involves willing a law of nature. A law is necessary in the sense that there are reasons that rational beings must conform to it. A law of nature, on the other hand, is necessary in a distinct sense. Specifically, it is causally impossible for rational beings to act contrary to a law of nature. Kant’s idea is that we can gain an intutive understanding of which maxims we can will as a universal law by imagining a generalized form of the maxim as a law of nature conjoined to the actual laws of nature as we understand them and by asking whether we could coherently will that the resulting system of nature obtain.

The first step in applying the Formula of the Law of Nature is to specify the maxim to be tested:

• I am to perform action A in circumstances C in order to bring about end E.

The second step is to generalize the maxim so that it applies to everyone:

• Everyone is to perform action A in circumstances C in order to bring about end E.

The third step is to transform the generalized maxim into a law of nature:

• It is a law of nature that everyone performs action A in circumstances C in order to bring about end E.

The fourth step is to conjoin the hypothetical law of nature to the existing laws of nature and to work out the consequences of this in determining the new system of nature:

• Conjoin the hypothetical law of nature to the laws of nature as we understand them and work out what the system of nature would be once the effects of conjoining the novel law stabilize.

The target maxim is permissible just in case one can coherently will the resulting system of nature.

Kant distinguishes two tests for whether a person can coherently will the hypothetical system of nature:

1. Contradiction in Conception: The hypothetical system of nature cannot be conceived without self-contradiction.
2. Contradiction in Volition: The hypothetical system of nature cannot be willed without contradictory volition.

Applying the Formula of the Law of Nature

We can get a clearer understanding about these tests and the procedure involved in applying the Formula of the Law of Nature by working through Kant’s four examples.

Suicide

In the first example, Kant argues that the following maxim fails to be permissible:

…from self-love I make it my principle to shorten my life when its longer duration threatens more troubles than it promises agreeableness. (G 4:422)

Generalizing this maxim so that it applies to everyone, we get:

• From self-love everyone makes it their principle to shorten their life when its longer duration threatens more troubles than it promises agreeableness.

Transforming this generalized maxim into a hypothetical law of nature we get:

• It is a law of nature that from self-love everyone makes it their principle to shorten their life when its longer duration threatens more troubles than it promises agreeableness.

The next step is to determine whether we can, without self-contradiction, conjoin this hypothetical law of nature to the existing laws of nature as we understand them. Kant argues that we cannot and hence the maxim is impermissible:

…a nature whose law it would be to destroy life itself by means of the same feeling whose destination is to impel toward the furtherance of life would contradict itself and would therefore not subsist as nature; thus that maxim could not possibly be a law of nature and, accordingly, altogether opposes the supreme principle of all duty. (G 4:422)

Kant’s idea is that we cannot, without self-contradiction, conjoin the hypothetical law of nature to the existing laws of nature as we understand them given our teleological understanding of nature. Specifically, the following principle, according to Kant, is part of our understanding of nature:

• The Principle of Natural Teleology: If F is a feeling whose natural function is to produce effect E, then it would be self-contradictory to suppose that there could be a system of nature that includes a law that under circumstances C F produces the contrary of E.

Since self-love has the natural function of furthering life, it is self-contradictory to suppose that there could be a system of nature that includes a law that under circumstances of more troubles than agreeableness self-love endeavors to shorten life. Since we cannot coherently suppose that there could be such a system of nature, we cannot coherently will that there should be such a system of nature, and hence the maxim of shortening life from self love when its longer duration threatens more troubles than agreeableness is impermissible.

Interestingly, Kant’s argument here is controversial less for its deployment of the Formula of the Law of Nature and the contradiction in conception test than for its application of the principle of natural teleology. Specifically, after Darwin, it is controversial whether nature is in fact teleological in the way that Kant understands it to be. Even if it were, it would still be controversial whether self-love has the natural function that Kant assigns to it.

False Promises

In the second example, Kant argues that the following maxim is impermissible:

…when I believe myself to be in need of money I shall borrow money and promise to repay it, even though I know that this will never happen. (G 4:422)

Generalizing this maxim so that it applies to everyone, we get:

• When everyone believes themselves to be in need of money they will borrow money and promise to repay it, even though they know that this will never happen.

Transforming this generalized maxim into a hypothetical law of nature we get:

• It is a law of nature that when everyone believes themselves to be in need of money they will borrow money and promise to repay it, even though they know that this will never happen.

The next step is to determine whether we can, without self-contradiction, conjoin this hypothetical law of nature to the existing laws of nature as we understand them. Kant argues that we cannot and hence the maxim is impermissible:

For, the universality of a law that everyone, when he believes himself to be in need, could promise whatever he pleases with the intention of not keeping it would make the promise and the end one might have in it itself impossible, since no one would believe what was promised but would laugh at all such expressions as vain pretenses. (G 4:422)

Kant’s idea is that we cannot, without self-contradiction, conjoin the hypothetical law of nature to the existing laws of nature as we understand them given the nature of promising. Specifically, the following principle governs the practice of promising:

• Promises are only possible if the promiser is justified in thinking that the promise will be believed.

However, conjoining the hypothetical law with the existing laws of nature would bring it about that no promise is believed. Under such circumstances, no promise would be possible. Since we cannot coherently suppose that there could be such a system of nature, we cannot coherently will that there should be such a system of nature, and hence the maxim of borrowing money when in need of it and promising to repay it with no intention of doing so is impermissible.

Rusting Talents

While the previous examples deployed the contradiction in conception test, Kant’s third and fourth examples deploy the contradiction in volition test. In the third example, Kant argues that the following maxim is impermissible:

• I will neglect the development of my natural talents and instead devote myself to idleness and pleasure.

Generalizing this maxim so that it applies to everyone, we get:

• Everyone will neglect the development of their natural talents and instead devotes themselves to idleness and pleasure.

Transforming this generalized maxim into a hypothetical law of nature we get:

• It is a law of nature that everyone neglects the development of their natural talents and instead devotes themselves to idleness and pleasure.

However, Kant does not deny that we can, without self-contradiction, conjoin this hypothetical law of nature to the existing laws of nature as we understand them:

…nature could indeed always subsist with such a universal law, although (as with the South Sea Islanders) the human being should let his talents rust and be concerned with devoting his life merely to idleness, amusement, procreation–in a word, to enjoyment… (G 4:423)

While we can coherently conceive of the resulting system of nature, we cannot coherently will that such a system of nature obtain:

For as a rational being he necessarily wills that all the capacities in him be developed, since they serve him and are given to him for all sorts of possible purposes. (G 4:423)

This is an important and distinctively Kantian idea: that there are ends that every rational being must will. Kant, however, is less explicit about the specific rational principle from which he derives this result. (There are, however, plausible candidates available to Kant—rusting talents might be inconsistent with the counsels of prudence, for example.)

Refusing Aid

In the fourth example, Kant argues that the following maxim is impermissible:

…let each be as happy as heaven wills or as he can make himself; I shall take nothing from him nor even envy him; only I do not care to contribute to his welfare or to his assistance in need! (G 4:423)

Generalizing this maxim so that it applies to everyone, we get:

• No one will harm anyone, but everyone will refuse to contribute to another’s welfare or to provide assistance when in need.

Transforming this generalized maxim into a hypothetical law of nature we get:

• It is a law of nature that no one harms anyone, but everyone refuses to contribute to another’s welfare or to provide assistance when in need.

However, Kant does not deny that we can, without self-contradiction, conjoin this hypothetical law of nature to the existing laws of nature as we understand them:

Now, if such a way of thinking were to become a universal law the human race could admittedly very sell subsist, no doubt even better than when everyone prates about sympathy and beneveolence and even exerts himself to practice them occasionally, but on the other hand also cheats where he can, sells the rights of human beings or otherwise infringes upon them. (G 4:423)

While we can coherently conceive of the resulting system of nature, we cannot coherently will that such a system of nature obtain:

For, a will that decided this would conflict with itself, since many cases could occur in which one would need the love and sympathy of others in which, by such a law of nature arisen from his own will, he would rob himself of all hope of the assistance he wishes for himself. (G 4:423)

How are we to understand the contradiction in volition?

In Utilitarianism, Mill suggests that the contradiction in volition test should be understood as follows:

To give any meaning to Kant’s principle, the sense put upon it must be that we ought to shape our conduct by a rule which all rational beings might adopt with benefit to their collective interest.

Unfortunately, the sense Mill puts upon Kant’s principle could not be sense that Kant intends. Recall that Kant thinks that the system of nature in which no one harms anyone but everyone refuses aid is better than the existing system of nature, but the corresponding maxim is impermissible nonetheless. So the contradiction in volition could not be grounded in an appeal to utility as Mill evidently believed.

While Mill did not intend his interpretation of the contradiction in volition test as a criticism of Kant, Schopenhauer’s interpretation of the test is so intended. According to Schopenhauer, Kant’s application of the contradiction in volition test in the fourth example makes what would be, by Kant’s lights, an illicit appeal to self-interest. After all, Kant does make a claim about what a person must will on the grounds of self-interest, i.e., that a person might require the aid of others and hence cannot rationally will that a system of nature obtain in which they are deprived of that aid. While Kant’s argument does employ a premise about rational self-interest, Kant’s conclusion is not grounded in an illicit appeal to self-interest. Kant is making a hypothetical claim about what would be in a person’s self-interest if the maxim were a law of nature. No claim is being made about what is in fact in their interest given the existing laws of nature. So the duty to give aid is not grounded in what is in fact in a person’s self-interest in the way that Schopenhauer suggests.

The Table of Duties in The Metaphysics of Morals

Kant’s four examples are supposed to be exemplars of a fourfold division of duties. Specifically, Kant posits a pair of overlapping distinctions:

1. Duties are distinguished with respect to their objects: There are duties to oneself and duties to other human beings.
2. Duties are distinguished with respect to whether they admit of exception in favor of inclination: There are imperfect duties that do not and perfect duties that do.

This division of duties anticipates the more complex table of duties that Kant presents in The Metaphysics of Morals.

The division of duties into perfect and imperfect is suppposed to correspond to the two universalizability tests:

• The Correspondence Thesis: Maxims that violate perfect duties violate the contradiction in conception test; maxims that violate imperfect duties violate the contradiction in volition test.

Perfect duties admit of no exception in favor of inclination whereas imperfect duties do. How are we to understand this? In The Metaphysics of Morals, Kant explains further. Perfect duties are requirements on actions and any violation of a perfect duty is an instance of wrongdoing and hence blameworthy. Imperfect duties are requirements on the adoption of ends though there is latitude in the fulfillment of these ends since a person has a variety of ends and these must be rationally ordered. (This is the sense in which they admit of exception in favor of inclination.) Specific actions taken toward the fulfillment of required ends is meritorious, whereas the failure to act toward the fulfillment of the required end merely lacks merit and is not an instance of wrongdoing and hence not blameworthy.

How plausible is the correspondence thesis? One difficulty is the existence of maxims that can be conceived without contradiction as a universal law of nature but where acting on that maxim violates a perfect duty. Consider the following maxim:

• I will kill another human being when it is a safe and effective way of furthering my self-interest.

Generalizing this maxim we get:

• Everyone will kill another human being when it is a safe and effective way of furthering their self-interest.

Transforming this generalized maxim into a law of nature we get:

• It is a law of nature that everyone will kill another human being when it is a safe and effective way of furthering their self-interest.

While we may be unable to will the resulting system of nature (the system of nature that results from conjoining the hypothetical law of nature with the existing laws of nature), it is at least arguable that it can be conceived without contradiction. But to act on this maxim would be to violate a duty of justice and duties of justice are perfect duties if any are.

Problems with the First Formula

There are two potential problems for the application of the Formula of the Law of Nature: First, applying the formula may classify morally impermissible maxims as permissible; second, applying the formula may classify morally permissible maxims as impermissible. If the proper application of the Formula of the Law of Nature classifies morally impermissible maxims as permissible, then passing the univeralizability test is not sufficient for a maxim to be permissible. If the proper application of the Formula of the Law of Nature classifies morally permissible maxims as impermissible, then passing the universalizability test is not necessary for a maxim to be permissible.

Failures of Sufficiency

Many commentators (Hegel, Mill, and Sidgwick among them) have criticized the Formula of the Law of Nature on the grounds that it improperly classifies immoral maxims as morally permissible. If such maxims exist, then passing the universalizabilty test is not sufficient for a maxim to be morally permissible.

To see how there could be such maxims, first consider how maxims differ in degree of generality or specificity. Some maxims such as:

…when I believe myself to be in need of money I shall borrow money and promise to repay it, even though I know that this will never happen. (G 4:422)

are more general than other maxims:

• When I believe myself to be in need of money I shall borrow money from Jones on the second Tuesday of the Month and promise to repay it, even though I know that this will never happen.

The latter maxim is more specific than the former more general maxim in the sense that it restricts the conditions under which the false promise would be made.

Second, just as maxims can differ in their degree of specificity so can the hypothetical laws of nature that correspond to them. Moreover, the greater the specificity of the law the less widespread its effects would be. The effects of conjoining a more specific hypothetical law to the existing laws of nature would be less widespread than the effects of conjoining a more general law. Thus while the effect of making false promises when in need of money a law of nature would be that no promise would be believed, the effects of making false promises to Jones on the second Tuesday of every month a law of nature would be less widespread. Perhaps people named Jones would fail to believe promises made on the second Tuesday of the month especially if made by people known to be in debt, but promises would otherwise be believed. Since promises would be believed in general (except by some in exceptional circumstances) this would be consistent with the possibility of promising. And if promising is possible in the resulting system of nature then, for all Kant has said, it is conceivable without self-contradiction. Thus, an immoral maxim, to make false promises to Jones on the second Tuesday of the month, passes the universalizabilty test. So passing the universalizability test is not sufficient for a maxim to be morally permissible.

Failures of Necessity

The Formula of the Law of Nature can be criticized on the grounds that it improperly classifies morally permissible maxims as impermissible. To see how there could be such maxims, consider innocuous actions whose existence depends on their being exceptional. There is nothing immoral about adopting the following financial policy: I will sell my stocks when the Dow hits 10,000.

But the policy would lack the financial benefits that it actually has in a world where it is a law of nature that everyone sells their stock when the Dow hits 10,000. If everyone is selling, who is there to buy? And if no one is buying, the selling of stock is not possible under those circumstances. But that means that the resulting system of nature cannot be conceived without self-contradiction. Thus a morally permissible maxim, to sell stock when the Dow hits 10,000, fails the universalizability test. So passing the universalizabilty test is not necessary for a maxim to be morally permissible.

The Significance of these Failures

Applying the Formula of the Law of Nature fails to provide a test the satisfaction of which is both necessary and sufficient for a maxim to be permissible. Or at least, at this stage of the Groundwork, our understanding of the first formula is subject to these failures. Recall, the three formulas are supposed to represent different aspects of the same law. This places a constraint on our interpretation of them: Each should be interpreted in light of the other. Perhaps when the Formula of the Law of Nature is interpreted in light of the other formulas, the failures of necessity and sufficiency will be avoided. Indeed, Kant discusses the four examples again in light of the Formula of Humanity. His case for the impermissibility of these maxims is deepened and illuminates and supports his earlier arguments. So one possibility is that the failures of necessity and sufficiency are due to an incomplete understanding of the Formula of the Law of Nature.

Even so, perhaps the Formula of the Law of Nature was never intended to be a mechanical algorithm for determining the permissibility of maxims. When Kant claimed that the first formula is a “compass” sufficient for common rational moral cognition to act in conformity with duty, perhaps he did not promise a test the satisfaction of which is necessary and sufficient for the permissibility of a given maxim. Even if they were possible, no such test would be mechanical. The application of the Formula of the Law of Nature not only requires background empirical information but judgement as to its relevance as well.

If the first formula is not an algorithm for determining the permissibility of maxims, in what sense is it a moral compass?

The Moral Point of the First Formula

What’s the moral point of the first formula? Kant provides an explicit answer:

If we now attend to ourselves in any transgression of duty, we find that we do not really will that our maxim should become a universal law, since that is impossible for us, but that the opposite of our maxim should instead remain a universal law, only we take the liberty of making an exception to it for ourselves (or just for this once) to the advantage of our inclination. Consequently, if we weighed all cases from one and the same point of view, namely that of reason, we would find a contradiction in our own will, namely that a certain principle be objectively necessary as a universal law and yet subjectively not hold universally but allow exceptions. (G 4:424)

Normally, when we act contrary to duty, we will “that the opposite of our maxim should instead remain a universal law, only we take the liberty of making an exception to it for ourselves (or just for this once) to the advantage of our inclination.” When tempted to make false promises when in need of money, we do not will that everyone should make false promises when in need of money. Rather if we succumb to temptation, we will that in general people truly promise only that we, just this once, falsely promise to repay a creditor. In acting contrary to duty, a person gives unjustifiable preference to his own inclinations over the inclinations of other finite rational beings.

It is the counterweight of inclination that tempts otherwise innocent human beings to act contrary to duty. Specifically, human beings possess:

…a propensity to rationalize aginst those strict laws of duty and to cast doubt upon their validity, or at least upon their purity and strictness, and where possible, to make them better suited to our wishes and inclinations, that is, to corrupt them at their basis and to destroy all their dignity—something that even common rational cognition cannot, in the end, call good. (G 4:405)

Perhaps the first formula is a moral compass for those lost to temptation in the following sense: It is a reminder not to make oneself a special exception to a moral law that everyone else must follow. Perhaps the moral point of the first formula is as a vivid reminder not to give unjustifed preference to ones own inclinations over the inclinations of other finite rational beings, and hence as a corrective to our human propensity to make exceptions for ourselves.