Philosophers are often misunderstood. In Kant’s case it is his own fault. A few write really well—Plato and Hume for instance—but Kant is not one of them. That is unfortunate. What he has to say is largely, in my view, right but certainly well worth thinking about, and as relevant now as when he wrote it. Amongst other things, his moral philosophy leaves no conceivable doubt that black lives matter. He claims that everyone knows this if they just stop and think coherently, instead of listening to unthinking bigots. All lives matter: the lives of all rational beings. That means the lives of all human beings, but also of any other beings that are capable of reason. If there are oddly-shaped green people on Mars who are rational, their lives matter too, and they matter as much as ours do. He firmly believes, he says, “that at least one of the planets is inhabited”.
Nowadays we look for intelligent life further away than Mars, but the same applies. We also know much more about animals than was known in Kant’s time. Chimpanzees and many higher primates show signs of intelligence; elephants, dolphins, whales, perhaps seagulls. Kant would certainly say we have a duty to treat intelligent animals with the same respect as we should show to other people. Black lives matter, and white lives matter, but the lives of dolphins matter just as much.
They should be treated with as much respect as we treat one another. That means that we should do whatever we can to promote their perfection and their happiness. Of course their capacities are different from ours, and what constitutes a happy life will be different too; but the same is true amongst human beings. By “perfection” Kant means not just moral perfection but making the most of their existence. “Happiness” means achievement and enjoyment of life, with the necessary proviso that it not be at the expense of other rational beings.
Kant’s first book on moral philosophy was the Groundwork of the Metaphysics of Morals (1785), and he was still thinking things through when he wrote it. It is by far his best known book on the subject—helped by the fact that it is the shortest—and it is still regularly used as a textbook. There he hardly mentions perfection and happiness, far less explaining them properly; what he says instead is that we should treat all rational beings as “ends in themselves”. But that turns out to mean the same thing.
The book is famous for the Categorical Imperative: “Act only in accordance with that maxim through which you can at the same time will that it should become a universal law.” By “maxim” Kant means, effectively, your intention: so, your intention must be one that you could happily envisage everyone else acting on. But just stated like this it is open to serious misunderstandings. To be fair to Kant, he goes on to reformulate it several times, trying to make clearer what he means. But what he says is hard to follow, and people often rely on that initial formulation. A famous case is Adolf Eichmann who, at his trial, claimed to have lived all his life in accordance with Kant’s Categorical Imperative. It does seem to say that you will be doing all right morally if what you intend to do could be done by everyone in the same situation. Eichmann could have thought, “I am an official of the master race, and I intend to gas members of inferior races. Kant asks, can I universalise my maxim? Yes! I should be very happy if everyone in my situation, every official of the master race, would gas members of inferior races too.”
That is very far from what Kant meant. Fortunately few have interpreted him as crudely as Eichmann. But many people do think Kant’s idea is that I should only act in ways that I should be content to see everyone else acting in too. That is a bad mistake. In his later Critique of Practical Reason (1788) Kant makes it quite clear that this idea can serve only as a rough and ready test, helpful in certain contexts, not in others. He wants the reader of the Groundwork to see that too, by considering the later formulations. These are much more helpful. It turns out that the idea of universality, which seemed at first to carry all the weight, carries very little. If an act is right for me, then it would be equally right for others—but is it right for me? That depends on what he calls the content of the Moral Law: “Act in such a way that you treat rational beings, whether yourself or any others, never simply as a means, but always at the same time as an end.” As we might say, you must never just use people like instruments for your own purposes. You can employ them to do a job, certainly, but they must consent to it, and you must always treat them as free agents like yourself, respecting their perfection and happiness as you do your own.
These later formulations have helped, but they have also misled people in a different way. To explain things Kant uses simple examples of bad maxims, such as “I shall break promises when it suits me” and “I shall not bother to develop my talents”. This has given the impression that Kant’s morality is one of rigid rules. It is true that he sometimes writes like that, condemning suicide and promise-breaking as absolutely wrong. But that is not consistent with his overall position, because he makes it very clear that it is the agent’s complete maxim that has to be evaluated: which means, her intention complete with all relevant details. He thinks suicide is generally wrong because it ends one’s ability to contribute morally. But he considers in detail whether Cato was wrong to kill himself, since he killed himself in an attempt to preserve the freedom of the state. And he poses for the reader a question: Can “a great king who died recently” be blamed for intending to take poison if captured in battle, so that the state would not have to be charged with his ransom? He does not tell us the answer, but the “great king” was Frederick the Great: and if Kant ever had a hero it was Frederick.
He can express unduly rigoristic views at times. He seems to have had a particular horror of lying, but he does not condemn it under all circumstances. It is true that late in life he was criticised for holding that it would be wrong to lie even to save the life of a friend; he replied vigorously, insisting that lying was indeed wrong even in such circumstances. But he was an old man, and he hated being criticised. Whatever he himself thought about it at the time, it is clearly inconsistent with his own moral philosophy. For one of that philosophy’s great virtues is that it insists that the agent’s intention be evaluated in all its relevant detail, taking relevant circumstances into account. Simplistic rules such as “Never lie” find no place.
Morality, as Kant understands it, is practical reason. The Categorical Imperative, properly understood, is the imperative of moral duty, which he holds to be innate in every rational being. Theoretical reason and practical reason are parallel. One tells us how we ought to think, the other tells us how we ought (and ought not) to act. We do not learn either kind of reason from experience. Both are present in us from birth, though our understanding of both develops as we grow up. If someone’s action is motivated by their recognition that the Moral Law requires this act, Kant says they act out of respect for the law: the action has “moral worth”. Of course, people often do the right thing from some other motive, perhaps to gain the approval of friends. In such cases Kant says they act in accordance with the law—they do the right thing—but the action does not have “moral worth”. There is a similar contrast with theoretical reason: you may work out a mathematical proof on your own, or you may get the right answer by asking someone. Kant’s emphasis on the rational nature of morality has given rise to another misunderstanding. His morality is often thought to be altogether too austere, determined by reason alone and leaving no room for feeling. This again is due to the way he sets things out, particularly in the Groundwork.
He considers someone who helps people just because he enjoys it. That same person somehow loses the enjoyment entirely, but decides to help people out of duty instead: “then for the first time his action has its genuine moral worth”. That makes it look as if “moral worth” requires one’s action to be from duty alone. But he never actually says that one cannot be motivated in both ways, and in fact he is perfectly aware that one can: indeed it is very common. Kant’s real view is that one’s action has “moral worth” if, but only if, the controlling motivation is the moral one. If you do the right thing because you want to do it anyway, and incidentally note that morality requires it too, then you are still doing the right thing, but you are acting in accordance with the law rather than out of respect for the law, and your action lacks “moral worth”.
It would have been good if he had told us more about perfection and happiness, but philosophers often do leave us with too little detail. One thing is very clear: although he puts such weight on happiness, he is no utilitarian. Utilitarians believe in the greatest happiness of the greatest number, and so leave room to make one person less happy if it makes others much happier. Kant does not. Respecting individuals’ happiness means maximising each individual’s happiness, but in ways that do not detract from the happiness of others. An exception could, of course, be found in cases of justified punishment, where the punishment is aimed at helping the person concerned to increase in perfection. Surprisingly perhaps, Kant does not take this line on punishment, but rather adopts a vigorously retributive position. He is particularly firm about murderers: “anyone who commits murder, orders it, or is an accomplice in it, must suffer death”. This seems anomalous. His justification lies in the thought that this punishment has been willed by the criminal himself. Of course, the criminal would be surprised to be told that, but Kant is relying on the idea that by belonging to society one has notionally made a social contract, and committed to a “general will” which requires that criminals be punished. He was powerfully influenced by Rousseau—a little too much sometimes.
Kant believed it essential to moral action that the agent should have free will—and not just the kind of free will that is compatible with determinism. He describes that as “the freedom of the turnspit”, comparing it with the “freedom” of the complicated clockwork figures that were exhibited around Germany. This is a problem for him, since for many purposes he is committed to determinism himself. But he does not really need such a high standard of freedom: the ordinary freedom we enjoy every day is quite adequate. The validity of Kant’s moral philosophy, and the importance of the Categorical Imperative, are not affected by the issue about determinism. What matters is that we do make decisions, and have reasons for them, reasons which may or may not be grounded in the Moral Law.
We can also say this: that if Kant were alive today he would be a supporter of animal rights, as well as the rights of all humans of whatever colour, gender, age or ability.