Kant's universalizability principle
We have already seen that Kant held that it was a distinguishing mark of moral propositions that they were categorical imperatives. This is an observation about the form of moral judgments, since it doesn't tell us anything about the content of morality, about which particular categorical imperatives we should accept.
Kant's universalizability principle was intended to allow us to test any moral judgment by the use of our reason and decide whether we should assent to it. It was a way of using reason to give the content of morality.According to Kant, the universalizability principle that allows us to give content to morality is this categorical imperative:
UNIVERSALIZABILITY: You ought to act only on maxims that you can at the same time will should become universal laws of nature.
In fact, Kant argued in the Groundwork of the Metaphysic of Morals that this was the only categorical imperative, from which all of the principles of morality derived. It is important, therefore, to understand what Kant means by this principle. To see what it means, we can consider how Kant applies it in a particular case.
He considers a man who is in desperate need of money and is deciding whether he should take a loan. This person knows that he will not be able to pay the loan back. He knows, Kant says, that acting in this way is “perhaps quite compatible with my own entire future welfare.” But he then applies the test of universalizability.
This leads him to see that he cannot act morally this way. For in so acting, he is following this maxim:
Whenever I believe myself short of money, I will borrow money and promise to pay it back, though I know this will never be done.
And if this maxim became a universal law of nature and everybody followed it, then no one would ever believe in promises “but would laugh at utterances of this kind as empty shams.”
The crucial idea of the universalizability test, then, is this.
When deciding what to do, you consider what your general reason is for acting in this particular way. That is what is meant by discovering the maxim of your action. Then you see what would happen if this maxim became a law of nature. Now, we saw in the previous chapter that a law of nature is a generalization that must be true. Thus, if your maxim became a law of nature, everybody would have to act on it. If our reasons allow us to accept this possibility, then we may act according to the maxim. Otherwise, we may not.There is one central idea here, which is crucial to the way Kant thought about morality. It is that the principles of morality should be impersonal: they should apply to everybody. Of course, since a maxim will generally be of the form
When conditions C obtain, you ought to do A,
it may never apply to me because I never get to be in those conditions. But moral rules, according to Kant, apply to us all equally. In any possible world where you are in the conditions that make the maxim operative, you ought to obey it.
This idea is one that fits very well with the ideas we all have about morality. You may disagree with me about whether a principle is morally correct, but if you agree with me on the principle, you have to accept that it governs both of us.
Kant's moral philosophy is extremely complex and connects very closely with his views on the nature of the mind and the role of reason in our lives. The universalizability principle, which is perhaps his most famous contribution to moral philosophy, has built into it a very important role for reason in our moral thought. For, according to Kant, applying the universalizability principle involves the exercise only of our capacity to reason.
Though the universalizability principle certainly does capture a feature of our moral thought, the claim that it derives solely from reason is not easy to accept.
For the principle refers to what you can will. And it is not obvious that there has to be anything wrong with the reason of someone who accepts that moral principles have to be universalizable but disagrees with our normal moral ideas, because they are willing to accept consequences we are not. The case of promising, in this way, is rather misleading. For the institution of promising is, in the context of human social life, one that everyone can benefit from, whatever they happen to want. Perhaps only someone who couldn't reason properly would be unable to recognize this.But consider a rather different principle, from which some of us can expect to benefit more than others:
It is wrong to kill innocent people against their will simply because it pleases you.
Consider someone who is a certain kind of psychopath. He is strong and well-armed and enjoys killing people. Call him “Attila the Hun.” Attila the Hun might be willing that it should become a universal law that you may kill innocent people for fun, because he is quite sure that no one is likely to be able to kill him. He could say that he is quite happy to accept the possibility that other people would try to kill him for fun if the maxim became a law of nature. “But,” he would add, “just let them try.”
The only way Kant can get round the fact that Attila the Hun does not see that his proposed maxim is morally unacceptable is to say that he is being unreasonable: to say that no reasonable person could will that this maxim should become a universal law. To get any moral substance out of the universalizability principle, in other words, you not only have to make assumptions about human life— that promising is something we can all benefit from, for example— but you also have to suppose that there are constraints, beyond consistency, placed by reason on what you can will to become a law of nature.
Kant's derivation of content for moral principles, then, requires both
a) that we make substantial assumptions about human life, and
b) that we rule out as unreasonable some things that a person could will to become a law of nature.
The first requirement, (a), is not too troublesome.
It makes morality depend on contingent facts about how the world happens to be. But Kant does not need to be worried by this. For it is surely reasonable that human morality should be tailored to the needs of human life. It is because he does not explicitly recognize this fact that he can regard the moral principles he derives both as a priori— knowable by reason alone—and yet synthetic—not true simply as a matter of meaning. For, in fact, like other synthetic truths, the moral principles depend on empirical assumptions and are thus not really a priori at all. Indeed, because of (b), the moral principles Kant derives depend also on an assumption about what a reasonable person can will: for this reason also, the content of the moral rules depends on more than facts about meanings. But even if Kant's theory did not face these problems, it would also face another serious difficulty.In order to apply the universalizability principle, you have first to identify the maxim of your action. But someone who is both uncaring about others and sufficiently ingenious can always describe the maxim of his or her action in such a way that he or she would be willing to universalize it. Consider a Nazi, such as Hitler, who thinks it is all right to kill members of what he regards as inferior races. Hitler, who regards himself as an “Aryan,” could agree that he was not willing to universalize the principle
You may kill innocent people if it suits you
but simply add that he was willing to universalize the principle
You may kill innocent people if it suits you, provided they are not Aryans.
Even if we think it is unreasonable for Hitler to universalize the first principle, because it would put his own life unnecessarily at risk, it is hard to see that it is unreasonable—as opposed to just plain wrong—to universalize the second one.
He might even agree that if he had been a Gypsy, a Jew, or an African, it would be quite permissible to kill him if it suited you.Despite first appearances, then, Kant's rather abstract universalizability principle is not going to be enough to get us a content for morality. It will certainly rule out, as a matter of pure reason, any maxims whose universalization will lead to inconsistency. Thus Kant will be able to explain why you cannot both accept the maxim that killing innocent people is wrong and allow that it is all right to engage in indiscriminate bombing in warfare. If we are to give a philosophical foundation to our moral beliefs, consistency will be a very important beginning. But we need more than that if we are to have principles with substantial moral content. Just to apply Kant's principle, we need to know some general facts about human life; and even people who agree with us about these facts might be able to get round the universalizability principle by gerrymandering the maxims on which they acted.
5.7