An Exposition of Immanuel Kant’s Groundwork of the Metaphysics of Morals

Imperatives

According to Kant, the human will is required (commanded) by reason to act in accordance with various objective laws. The human will is also exposed to subjective conditions (various desires and inclinations) and, as a result, sometimes does not follow these objective laws. Because the objective laws command the will, they are called imperatives. There are two types of imperatives:

  • Hypothetical imperatives command an action as required in order to achieve some other end that one wills.
  • Categorical imperatives command an action as required in itself without any relation to other ends.

Kant asks, “How do hypothetical imperatives necessitate the will?” His answer is that they do so only given your willing of the end for which such and such an action is the necessary means. For example, if I will to ace the test, then, given that it is necessary for me to study in order to achieve this end, I must also will to study.

What about categorical imperatives? How do these necessitate the will? Are there any categorical imperatives? And what are they like? 

The Categorical Imperative

Kant thinks that each of our moral duties is commanded by reason regardless of our individual desires and inclinations. In this sense, each of our moral duties is a categorical imperative. Some examples of moral duties are:

  • Do not murder
  • Do not steal
  • Be honest
  • Help those in need

But not only does Kant think that we are commanded by reason not to murder, not to steal, to be honest and to help those in need, he also thinks that we can derive each of these duties from a very general sort of categorical imperative (henceforth the Categorical Imperative). 

The Categorical Imperative has two very important properties:

  • (a) it determines (rules for) what you should do regardless of your own desires and inclinations (particular categorical imperatives); and
  • (b) its authority is not contingent on your own desires or goals; rather, it commands the will without exception (i.e., categorically).

Kant presents this in three ways:

  1. The first expresses the categorical imperative in terms of its form as a universal law;
  2. the second in terms of its end (humanity); and
  3. the third in terms of autonomy (the role of law-maker that every rational being plays).

It is not entirely clear how these three formulations express the same idea. But, for now, let’s focus on (1). 

Kant formulates this in a number of ways:

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

Shortly afterward, he offers a second formulation:

Act as if the maxim of your action were to become through your will a UNIVERSAL LAW of NATURE.

Kant sees these as two ways of expressing the same thought: the notion of a “law of nature” and a “universal law” go hand-in-hand. We do not consider something to be a law of nature unless it is true for all things, in all places, and at all times. I think his clearest formulation occurs later:

Act always on that maxim whose universality as a law you can at the same time will.

Maxims

Kant’s formulations refer to maxims. Maxims have three parts: a situation, an action, and a reason.

A maxim =df. a conditional statement of the form “if [SITUATION], then [ACTION] because/in order to [REASON]”

  • If I am hungry, then I will go to the grocery store in order to buy food.
  • If I’m confused on the homework, then I will email my peer mentor to ask for help.
  • If the presidential election is today, then I will not vote because one vote doesn’t make a difference.

The Categorical Imperative tells us which maxims constitute moral rules: those which can be willed as universal laws. What does this mean? There are two questions that must be tackled.

  1. What is a “universal” law? A universal law is a law that applies to everything in the domain without exception. In the ethical sphere, the target is human action and so a universal law is one that applies to human actions without exception. The law requires that everyone follow it.
  2. What “can” be willed? A natural answer is that something can be willed only if doing so does not involve any sort of logical inconsistency. In this sense, I can’t will that I am both here and not here, since that is logically impossible; but logical consistency is fairly permissive: for example, I can will that I have wings and fly away.

Putting this together: a maxim constitutes a moral duty if willing that everyone follow it does not involve any logical inconsistency.

The categorical imperative functions as a criterion for maxims. It specifies the conditions a maxim must satisfy in order to express a moral duty. These conditions may now be formulated as the following “moral duty test” (MDT):

MDT. A maxim m expresses a duty if and only if willing that everyone act in accordance with m does not involve any logical inconsistency.

MDT captures the widely-held belief that if you act according to a maxim that you would not want others to follow, then you are not acting morally. This reflects the sort of reasoning we go through when we challenge ourselves with questions like:

  • How would you like it if someone did that to you?
  • How would you feel if everyone acted that way?

As Kant puts it:

If we now attend to ourselves whenever we transgress a duty, we find that we in fact do not will that our maxim should become a universal law—since that is impossible for us—but rather that its opposite should remain a law universally: we only take the liberty of making an exception to it for ourselves (or even just for this once) to the advantage of our inclination.

Evaluating the Categorical Imperative

Kant’s strategy for evaluating his principle is to show that an act is in conformity with duty if it accords with a maxim that passes the moral duty test: he does this by showing that any act not in conformity with duty fails the moral duty test (MDT). To be thorough, he applies a standard division of moral duties into four kinds:

  • perfect duties to one’s self;
  • perfect duties to others;
  • imperfect duties to one’s self; and
  • imperfect duties to others.

(A “perfect” duty is one that admits of no exceptions. The prohibition against murder is a perfect duty. Other duties, such as the duty to help others, are imperfect. We are not required to be always helping others.)

Suicide

The duty to preserve our own life is a perfect duty that each of us bears to our self. Is this supported by the categorical imperative? To show that it is, Kant seeks to show that maxims which advocate suicide fail MDT.

Suppose your future holds a lot of suffering and very little happiness. Is it morally permissible to kill yourself out of a concern for your well-being? Kant describes the maxim you would be acting on as follows:

From self-love I make it my principle to shorten my life if its continuance threatens more evil than it promises pleasure.

Let m0 stand for this maxim. And let A be an act of suicide that accords with m0. To determine whether A is in accordance with duty, we need to determine whether m0 “can become a universal law of nature,” i.e., whether it satisfies MDT, i.e., whether willing that everyone act in accordance with m0 would involve a logical inconsistency. Kant argues that it would:

It is then seen at once that a system of nature by whose law the very same feeling whose function is to stimulate the furtherance of life should actually destroy life would contradict itself and consequently could not subsist as a system of nature. Hence this maxim cannot possibly hold as a universal law of nature and is therefore entirely opposed to the supreme principle of all duty.

Kant is claiming that there is some sort of inconsistency in m0. Presumably, this consists in the fact that self-love would serve two contrary functions. Since (he takes this to) be logically contradictory, he concludes that m0 cannot express a duty.

Lying

The duty to tell the truth is a perfect duty that each of us bears to others. Is this supported by the categorical imperative? To show this, Kant seeks to show that maxims which advocate lying fail MDT.

Suppose you want to borrow some money, but know that if you do, you will be unable to repay the loan. You ask whether it would be morally permissible to falsely promise a loan officer that you will repay the money you borrowed. Kant describes the maxim you would be acting on as follows:

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.

Let m1 stand for this maxim. And let A be an act of borrowing money according to m1. To determine whether A is in accordance with duty, we need to determine whether m1 satisfies MDT, i.e., whether m1 “can become a universal law of nature,” i.e., whether willing that everyone act in accordance with m1 would involve a logical inconsistency. Kant answers:

I then see straight away that this maxim can never rank as a universal law and be self-consistent, but must necessarily contradict itself. For the universality of a law that everyone believing himself to be in need may make any promise he pleases with the intention not to keep it would make promising, and the very purpose of promising, itself impossible, since no one would believe he was being promised anything, but would laugh at utterances of this kind as empty shams.

Kant’s reasoning here is that a necessary consequence of everyone’s following m1 would be that no one would trust the promises made by anyone in need of a loan. As a result, the act of promising to repay a loan would cease to have any positive influence on the prospective lender. If everyone acted that way, then it wouldn’t make sense for anyone to act that way. Thus, to will that everyone act in accordance with m1 would be to will something that undermined the end of m1, which is also willed. This is a logical inconsistency in the will. Therefore, m1 is contrary to duty.

Self-indulgence

The duty to develop one’s talents is an imperfect duty that each of us bears to himself. Is this supported by the categorical imperative? To show this, Kant seeks to show that maxims which advocate self-indulgence fail the moral duty test.

The contradiction in this case involves an assumption about what a rational being necessarily wills. As Kant puts it, the contradiction involved does not concern an “inner impossibility” located within the maxim itself, but rather involves a contradiction between the maxim and the will of the agent.

Indifference

The duty to assist others is an imperfect duty that each of us bears to others. Is this supported by the categorical imperative? To show this, Kant seeks to show that maxims which advocate indifference fail the moral duty test.

Once again, the contradiction in this case involves an assumption about what a person may will in the future: assistance from others.

Questions for further thought:

  1. Do agree that the examples – throughout the reading – of (supposedly) perfect duties pass Kant’s test for being a moral duty?
  2. Can you formulate another maxim that passes Kant’s test for being a duty (other than those given as examples in this reading)?
  3. Is Kant’s a criterion for what counts as a moral duty superior or inferior to the Utilitarian’s criterion? In what respects?