The Formula of Humanity
We have now seen what the categorical imperative says. In order to show that we actually have unconditional requirements, and so that moral obligation is real, we have to show that this principle is one that necessarily governs our wills. This investigation is in part a motivational one, since no law can truly govern our wills unless we can be motivated by our awareness of its authority. Although Kant denies that we can ever know for certain that someone has been morally motivated, the moral law cannot have authority over our wills unless it is possible for us to be motivated by it. But Kant warns us that we cannot appeal to any empirical and contingent sources of motivation when making this argument. As we saw earlier, the sense in which we are trying to show that the moral law governs our wills is not that it actually moves us, either always or sometimes, but that it moves us in so far as we are rational. So the argument must show that the moral law has an authority capable of moving any rational being, and this means it must appeal only to the principles of pure rational psychology.
As rational beings, as Kant said before, we act in accordance with our representations or conceptions of laws. But what inspires us to formulate a maxim or a law (“what serves the will as the objective ground of its self-determination”) is an end (4:427). Whenever we actually decide to take action, it is always with some end in view: either we regard the action as good in itself, or we are doing it as a means to some further end. If there are unconditional requirements, incumbent on all rational beings, then there must be ends that are necessarily shared by all rational beings – objective ends. Are there any such ends?
The ends that we set before ourselves in our ordinary actions, Kant urges, do not have absolute but only relative value: “merely their relation to a particular kind of desiderative faculty of the subject gives them their worth” (4:427). The point here is that most objects of human endeavor get the value that we assign them from the way in which they serve our needs, desires, and interests. Just as we value technology because it serves our needs, so we value pure science because we human beings, as Aristotle says, desire to know; we value the visual arts and music because of the way they arouse the human capacity for the disinterested enjoyment of sensory experience; we value literature and philosophy because they serve our thirst for self-understanding, and so forth. Although these other things are not mere means like technology, yet still the value that we assign them is not absolute or intrinsic, but relative to our nature. Yet, since we are rational beings, and we do pursue these things, we must think that they really are important, that there is reason to pursue them, that they are good. If their value does not rest in themselves, but rather in the fact that they are important to us, then in pursuing them, we are in effect taking ourselves to be important. In that sense, Kant says, it is a “subjective principle of human actions” that we treat ourselves as ends (4:429).
This suggests that the objective end which we need in order to explain why the moral law has authority for us is “the human being, and in general every rational being.” Accordingly, the categorical imperative can now be reformulated as a law instructing us to respect the value of this objective end:
So act that you use humanity, in your own person as well as in the person of any other, always at the same time as an end, never merely as a means. (4:429)
Using the same examples he used before, Kant proceeds to demonstrate how this principle can serve as a moral guide. Being of absolute value, human beings should not sacrifice themselves or one another for merely relatively valuable ends. Since it is in so far as we are rational beings that we accord ourselves this absolute value, the formula enjoins us to respect ourselves and each other as rational beings. So Kant thinks we should develop our own rational capacities, and promote one another’s rationally chosen ends. Respecting someone as a rational being also means respecting her right to make her own decisions about her own life and actions. This leads to particularly strong injunctions against coercion and deception, since these involve attempts to take other people’s decisions out of their own hands, to manipulate their wills for one’s own ends. Someone who makes you a false promise in order to get some money, for instance, wants you to decide to give him the money. He predicts that you will not decide to give him the money unless he says he will pay it back, and therefore he says that he will pay it back, even though he cannot do so. His decision about what to say to you is entirely determined by what he thinks will work to get the result he wants. In that sense he treats your reason, your capacity for making decisions, as if it were merely an instrument for his own use. This is a violation of the respect he owes to you and your humanity.
This example brings out something important about Kant’s conception of morality. What is wrong with the false promiser is not merely that he does not tell the truth. What is wrong with him is the reason that he does not tell the truth – because he thinks it will not get the result he wants – and the attitude towards you which that reason embodies. Even if he told you the truth, if it were only because he thought it would get the result he wanted, he would still be regarding you as a mere means. Instead, we must tell others the truth so that they may exercise their own reason freely. And that means, that in telling them the truth, we are inviting them to reason together with us, to share in our deliberations. When we need the cooperation of others, we must be prepared to give them a voice in the decision about what it is to be done. These ideas lead Kant to a vision of an ideal human community, in which people reason together about what to do. Because this is the community of people who regard themselves and one another as ends in themselves, Kant calls it the kingdom of ends.