In Grounding for the Metaphysics of Morals, Immanuel Kant argues that morality can be derived from reason. According to Kant, reason gives us the Categorical Imperative, which is most commonly expressed through the universal law formula:
“Hence there is only one categorical imperative and it is this: Act only according to that maxim whereby you can at the same time will that it should become a universal law.”
– Grounding for the Metaphysics of Morals, 421
In short, this means that before you act, you must ask yourself: “Could I rationally want everyone else to act the way I’m about to act?”
If the answer is no, then that action is immoral, wrong, and you shouldn’t do it. Or, in more Kantian terms, you have a duty not to do that act.
Kant describes two types of duty based on how a maxim fails this test:
Perfect duties
A perfect duty is one that you must follow at all times, without exception (e.g. ‘do not steal’ or ‘do not lie’). Kant says “I understand here by a perfect duty one which permits no exception in the interest of inclination”.
Perfect duties arise when a maxim fails the first test: contradiction in conception.
This means that a world where everyone follows that rule or maxim is logically impossible – the rule itself becomes self-defeating and contradicts itself.
To illustrate the example of a maxim that contradicts itself when made into a universal law, Kant gives the example of making false promises:
“Another man in need finds himself forced to borrow money. He knows well that he won’t be able to repay it, but he sees also that he will not get any loan unless he firmly promises to repay it within a fixed time. He wants to make such a promise, but he still has conscience enough to ask himself whether it is not permissible and is contrary to duty to get out of difficulty in this way. Suppose, however, that he decides to do so. The maxim of his action would then be expressed as follows: when I believe myself to be in need of money, I will borrow money and promise to pay it back, although I know that I can never do so. Now this principle of self-love or personal advantage may perhaps be quite compatible with one’s entire future welfare, but the question is now whether it is right. I then transform the requirement of self-love into a universal law and put the question thus: how would things stand if my maxim were to become a universal law? He then sees at once that such a maxim could never hold as a universal law of nature and be consistent with itself, but must necessarily be self-contradictory. For the universality of a law which says that anyone believing himself to be in difficulty could promise whatever he pleases with the intention of not keeping it would make promising itself and the end to be attained thereby quite impossible, inasmuch as no one would believe what was promised him but would merely laugh at all such utterances as being vain pretenses.”
– Grounding for the Metaphysics of Morals, 422
Kant’s reasoning why making false promises leads to a contradiction in conception is that:
- The goal: The point of making a promise is to get someone to believe you.
- The maxim: If everyone followed the maxim ‘make false promises’ as a universal law, then everyone would know that promises are actually lies.
- The contradiction: And if everyone knows that promises are lies, then no one would ever believe a promise. This makes it impossible to successfully make a promise in the first place.
Another example of a perfect duty might be not to steal, for similar reasons:
- The goal: The point of stealing is to take something from another person and make it your own.
- The maxim: If everyone followed the maxim ‘to steal’ as a universal law, then it would be acceptable for anyone to take anyone else’s property at any time.
- The contradiction: And if anyone can take anything at any time, the very concept of ‘private property’ disappears. If no one owns anything, because anyone can take anyone else’s stuff at any time then you cannot ‘steal,’ because stealing requires taking something that belongs to someone else.
The upshot of both examples is that we have a perfect duty not to make false promises and a perfect duty not to steal.
A world in which everyone follows that maxim ‘to steal’, for example, is self-contradictory and incoherent, and so, according to the categorical imperative, we have a perfect duty not to steal. This perfect duty means it is never acceptable to steal, in any circumstances, regardless of the consequences.
Kant also says we have similar such perfect duties never to tell lies, never to murder, and never to commit suicide.
Imperfect duties
An imperfect duty is one that we must follow, but which allows for some flexibility in how and when we fulfil it (e.g. ‘to help others’ and ‘develop your talents’). Unlike perfect duties, which are negative prohibitions, imperfect duties are positive goals or “ends” that we should adopt.
Imperfect duties arise when a maxim fails the second test: contradiction in will.
In these cases, a world where everyone follows the maxim is logically possible and does not result in a contradiction in conception. However, it is a world that a rational person could not consistently will to exist because it contradicts their own ends/goals/will.
To illustrate this, Kant gives the example of a person who refuses to help others in need:
“A fourth man finds things going well for himself but sees others (whom he could help) struggling with great hardships; and he thinks: what does it matter to me? Let everybody be as happy as Heaven wills or as he can make himself; I shall take nothing from him nor even envy him: but I have no desire to contribute anything to his well-being or to his assistance when in need. If such a way of thinking were to become a universal law of nature, the human race admittedly could very well subsist and doubtless could subsist even better than when everyone prates about sympathy and benevolence and even on occasion exerts himself to practice them but, on the other hand, also cheats when he can, betrays the rights of man, or otherwise violates them. But even though it is possible that a universal law of nature could subsist in accordance with that maxim, still it is impossible to will that such a principle should hold everywhere as a law of nature. For a will which resolved in this way would contradict itself, inasmuch as cases might often arise in which one would have need of the love and sympathy of others and in which he would deprive himself, by such a law of nature springing from his own will, of all hope of the aid he wants for himself.”
– Grounding for the Metaphysics of Morals, 423
Kant’s reasoning why refusing to help others leads to a contradiction in will is that:
- The goal: The point of the maxim is to avoid the burden of helping others and to remain self-reliant.
- The maxim: If everyone followed the maxim ‘never help others,’ the world would be a place where no one ever assists anyone else.
- The contradiction: While this world is logically possible to imagine (it is not a contradiction in conception), a rational being cannot consistently will it. This is because, as finite humans, we are not self-sufficient; we will inevitably encounter situations where we need the help and ‘sympathy’ of others. By universalising the rule ‘no one helps anyone,’ you are essentially willing a law that would rob you of the very assistance you would want for yourself in the future.
Although a world in which nobody helps anyone else is not self-contradictory (like a world where everyone steals or makes false promises), Kant says we can’t rationally will that ‘never help others’ be a universal law because it is self-defeating in a different way: It contradicts our own goals, or ‘ends’ as Kant would say.
Another example of an imperfect duty Kant gives is to develop one’s own skills and talents:
- The goal: The point of the maxim is to indulge in pleasure and ‘idleness’ rather than putting in the hard work required to cultivate one’s natural gifts.
- The maxim: If everyone followed the maxim ‘neglect all natural talents and devote life to mere enjoyment,’ the world would be a place where human potential is ignored and no one possesses any specialised skills or abilities.
- The contradiction: Like the example of helping others, this world is logically possible to imagine (it is not a contradiction in conception). However, a rational being cannot will it because you necessarily will that your faculties be developed in order to achieve things you want. You cannot rationally will a world where the very tools (means) you need to achieve your own future goals (ends) have been allowed to rust.
The upshot is that we have an imperfect duty to help others and an imperfect duty to ourselves to cultivate our skills and talents.
Because the contradiction lies in the will rather than in conception, imperfect duties do not apply all the time and so give the individual some choice over when to follow them. Imperfect duties are instead a general duty to make the welfare of others one of your goals.
Summary
- The categorical imperative says morality is about acting on maxims (i.e. rules) that can be made into universal laws.
- There are two reasons your maxim/rule can’t be made into a universal law:
- It leads to a contradiction in conception.
- E.g. If everyone follows the rule ‘to steal’, then nobody owns anything, and it’s not possible to steal.
- This creates a perfect duty never to steal.
- E.g. If everyone follows the rule ‘to steal’, then nobody owns anything, and it’s not possible to steal.
- It leads to a contradiction in will.
- E.g. If everyone follows the rule ‘not to help others’, then you would be willing nobody helps you when you need help, which contradicts your own goals/ends.
- This creates an imperfect duty to help others in need sometimes.
- E.g. If everyone follows the rule ‘not to help others’, then you would be willing nobody helps you when you need help, which contradicts your own goals/ends.
- It leads to a contradiction in conception.