What is the duty that is to motivate our actions and to give them moral value? Kant distinguishes two kinds of law produced by reason. Given some end we wish to achieve, reason can provide a hypothetical imperative, or rule of action for achieving that end. A hypothetical imperative says that if you wish to buy a new car, then you must determine what sort of cars are available for purchase. Conceiving of a means to achieve some desired end is by far the most common employment of reason. But Kant has shown that the acceptable conception of the moral law cannot be merely hypothetical. Our actions cannot be moral on the ground of some conditional purpose or goal. Morality requires an unconditional statement of one’s duty.
And in fact, reason produces an absolute statement of moral action. The moral imperative is unconditional; that is, its imperative force is not tempered by the conditional “if I want to achieve some end, then do X.” It simply states, do X. Kant believes that reason dictates a categorical imperative for moral action. He gives at least three formulations of the Categorical Imperative.
- “Act only according to that maxim by which you can at the same time will that it should become a universal law.” (Ibid., 422)
- “Act as though the maxim of your action were by your will to become a universal law of nature.” (Ibid)
- Act so that you treat humanity, whether in your own person or in that of another, always as an end and never as a means only.” (Ibid., 429)
What are Kant’s arguments for the Categorical Imperative? First, consider an example. Consider the person who needs to borrow money and is considering making a false promise to pay it back. The maxim that could be invoked is, “when I need of money, borrow it, promising to repay it, even though I do not intend to.” But when we apply the universality test to this maxim it becomes clear that if everyone were to act in this fashion, the institution of promising itself would be undermined. The borrower makes a promise, willing that there be no such thing as promises. Thus such an action fails the universality test.
The argument for the first formulation of the categorical imperative can be thought of this way. We have seen that in order to be good, we must remove inclination and the consideration of any particular goal from our motivation to act. The act cannot be good if it arises from subjective impulse. Nor can it be good because it seeks after some particular goal which might not attain the good we seek or could come about through happenstance. We must abstract away from all hoped for effects. If we remove all subjectivity and particularity from motivation we are only left with will to universality. The question “what rule determines what I ought to do in this situation?” becomes “what rule ought to universally guide action?” What we must do in any situation of moral choice is act according to a maxim that we would will everyone to act according to.
The second version of the Categorical Imperative invokes Kant’s conception of nature and draws on the first Critique. In the earlier discussion of nature, we saw that the mind necessarily structures nature. And reason, in its seeking of ever higher grounds of explanation, strives to achieve unified knowledge of nature. A guide for us in moral matters is to think of what would not be possible to will universally. Maxims that fail the test of the categorical imperative generate a contradiction. Laws of nature cannot be contradictory. So if a maxim cannot be willed to be a law of nature, it is not moral.
The third version of the categorical imperative ties Kant’s whole moral theory together. Insofar as they possess a rational will, people are set off in the natural order of things. They are not merely subject to the forces that act upon them; they are not merely means to ends. They are ends in themselves. All means to an end have a merely conditional worth because they are valuable only for achieving something else. The possessor of a rational will, however, is the only thing with unconditional worth. The possession of rationality puts all beings on the same footing, “every other rational being thinks of his existence by means of the same rational ground which holds also for myself; thus it is at the same time an objective principle from which, as a supreme practical ground, it must be possible to derive all laws of the will.” (Ibid., 429)