9.3 The Categorical Imperative

So how is Kant going to try to defend the claim that we have strict, unconditional duties to each other? Earlier we considered the basic distinction between conditional and unconditional claims. Conditional claims are claims about what is right or true that may or may not hold. It all depends on circumstances. Unconditional claims must hold no matter what else is the case. It is, for example, unconditionally true that, say \(2 + 2 = 4\). That is, it does not matter what else is true, as long as we understand what it means to say that \(2 + 2 = 4\) we will see that it is true. But how do we show this? We can prove it in one of two ways. First of all we could establish that it is true by reasoning validly from true premises about basic arithmetic and the definitions of numbers to show that it must be the case – that is we can build a sound argument with \(2 + 2 = 4\) as the conclusion. On the other hand we could use a method known as “indirect proof,” and show that \(2 + 2 = 4\) must be true because denying its truth leads us to a contradiction. This is less obscure than it sounds. If I can show that it makes no sense – that it entails a contradiction – to say that \(2 +2 \neq 4\) then it must be true that \(2 + 2 = 4\).

Kant realized that the same line of thinking applies to unconditional claims in ethics. If we have any unconditional duties, this can be shown by showing that denying these duties makes no sense at all, that it leads to a contradiction to do so. His basic argument in defense of unconditional duties is thus:

If an action is to be morally acceptable its goal must make sense.
But some actions have goals that contradict themselves.

So such actions are unconditionally wrong and we have strict duties not to do them.

This argument is an extremely general argument. In fact we might consider it to be a kind of template for moral arguments in general, an argument schema that is to be turned into a moral argument be substituting particular actions for the general claims. Here is an example that shows why we have an unconditional duty not to steal:

If stealing is to be moral its goal must make sense.
When I steal something, I do so in order to take possession of it.
But stealing undermines private property, since if everyone stole, there would be no such thing as private property.
Thus stealing has a contradictory goal – it both assumes and undermines the possession of private property.

So stealing is unconditionally wrong and we have a strict duty not to steal.

The same general argument can be used to show that other things are immoral as well. Another example is lying. Why is it that lying is wrong? Is it because of the harm that lies cause as utilitarians might claim? Is it wrong to lie just because people lie are at risk of getting caught. Neither of these reasons come close, in Kant’s view, to accounting for the moral status of lying. In his view, the following argument shows just why lying is wrong:

If lying is to be moral its goal must make sense.
When I lie, I do so in the hope that others will believe my lie.
But lying undermines communication, since if everyone lied, there could be no reliable communication.
Thus lying has a contradictory goal – it both assumes and undermines reliable communication.

So lying is unconditionally wrong and we have a strict duty not to lie.

Likewise with murder. Murder is wrong, not because it causes pain (as utilitarians might argue), or because God commands us not to murder (as Divine Command Theory argues), but because the idea that murder could be acceptable contains an inner contradiction. The argument that it does runs like so:

If murder is to be moral its goal must make sense.When I murder someone, I do so in the hope that my life will be better without that person around.
But murder undermines the possibility of having a good life, since if everyone murdered, nobody could live a happy and secure life.
Thus murder has a contradictory goal – it both assumes and undermines the possibility of living a stable and secure life.

So murder is unconditionally wrong and we have a strict duty not to murder.

In all of these cases, the result is the same. Immoral action has ultimately irrational motives, motives that assume and undermine one and the same thing. Thus the only way to act immorally is presume a kind of double standard – “There is one set of standards that I expect everyone else to follow, but another set for me.”

The argument for Kantian ethics is the most abstract of all of the arguments we have considered. And perhaps it seems to be stretching the limits of what reason alone can do as a method for grasping just what is wrong with immoral or unethical actions. Nevertheless, it seems to be at least a plausible argument, or set of arguments, since it seems to capture some important features of morality. First, morality does in fact seem to require consistency. If there is such a thing as morality, it would have to be the same for everyone, otherwise it would be nothing but an arbitrary set of rules lacking any ultimate basis. Second, Kant’s argument makes it clear how morality can be universal, without being the kind of thing that one group can simply impose on other groups. To grasp the content of morality requires only thinking things through carefully enough to see that what I am doing either makes sense or fails to make sense when considered as something practiced universally. We certainly expect that every rational adult can grasp the fact that lying and stealing and murder just should not be done. Kant’s theory shows us why we might be justified in having such expectations and in holding people responsible for seeing that “you just shouldn’t do those kinds of things.” His theory certainly seems to impose some strict demands on us as moral agents, but then again, who said being good was easy?