There is a scene in the film Superman III in which Lorelei Ambrosia, the blonde bombshell, is secretly reading Kant’s Critique of Pure Reason. “But how can he say that pure categories have no objective meaning in transcendental logic? What about synthetic unity?” she squeaks, before hurriedly hiding the book and picking up some girlie trash as her gangster boss enters. Director Richard Lester’s choice of book was perfect: no other single work could both be so improbable, and be recognized as such by the audience. You might just about take Bertrand Russell on a beach holiday (I once did) but Kant, never. Incidentally although she has not quite mastered the jargon, Lorelei’s question is actually quite a good one, although I do not remember any philosopher in the credits.

Kant is not only notorious for opacity and difficulty, but also for having lived about the most unpromising life imaginable for a biographer. He spent it entirely within a few miles of the desolate coastal town of Königsberg, or Kaliningrad, in North East Prussia. He never travelled. In all his life he never saw a mountain, nor for that matter heard a decent orchestra. He never married. Once he met a ‘beautiful and well brought up widow from somewhere else’, but by the time Kant had calculated income and expenses, she had married someone else. Another girl, from Westphalia, also struck his fancy, but he was still thinking about making an offer when she crossed the border out of Prussia. He almost certainly never had any sexual relations, and one hope for his own peace of mind that this was so, since he held that outside marriage sex dishonors human nature, and indeed ‘exposes mankind to the danger of equality with the beasts’. Kant’s life, like that of a monk, was regular to the point of caricature: the familiar story that the townspeople could set their clocks by the time at which he took his afternoon walk had at least some truth in it. The university of Königsberg was his monastery. There were no heroics: when in 1794 he fell foul of the theological censors appointed by the Rosicrucian bigot Frederick William II, he gave in and promised not to do it again. He lectured, wrote, declined, and died a safe university man.

Not only are the externals unpromising, but they seem perfectly to express the inner man. Kant was small, and self-controlled, and unhealthy. He was preoccupied with the state of his bowels, and seems to have devoted a lot of quite public attention to what Hamann called his “evacuations a posteriori”. He found it difficult to laugh. Prussian virtues of discipline, efficiency, thrift, hard work and obedience, are all canonised in his life and writings. Although, surprisingly, it seems not to have been a Prussian, but an Englishman called Green, who led the young Kant into these rigorous pathways. It was Green, a merchant and close friend, who impressed Kant with the virtues of living according to uncompromising rules or maxims, and before Kant it was Green by whose doings the townspeople set their clocks.

Yet in this exhaustive and fascinating biography the notable German scholar Manfred Kuehn struggles to convince us that the bloodless, legalistic, Kant is mainly a myth. For Kuehn neither Kant nor his frontier town are half as bleak as the conventional picture portrays them. Königsberg was after all the first capital of Prussia, where Frederick the Great’s grandfather had proclaimed himself King in 1701 (Prussia’s third centenary is a matter of somewhat controversial celebration in Germany this year). It was a proud cosmopolitan city in which Russian and English businessmen rubbed shoulders with Prussian academics and nobles. Kuehn introduces us to a long list of more or less forgotten academics and divines, merchants and minor landowners, whose lives revolved around the university. His Kant was in the thick of a rich social and intellectual life. Anthony Quinton once wrote that the trouble with Kant is that “he is a wild and intellectually irresponsible arguer. Any innate leaning that way must have been enhanced by the intellectual isolation of Königsberg, which preserved him from serious criticism”. Kuehn has none of this, and indeed the long list of Kant’s academic wrangles certainly rebuts the charge that he was insulated from serious criticism.

Not only was Königsberg a kind of Athens of the Baltic, but neither is this Kant the cold automaton of legend. In his youth he played billiards well enough to be something of a hustler, and when targets refused to play with him he turned to cards as a supplementary source of income. With increasing respectability this had to cease, but Kant was not immune to temptation, even once he had adopted one of his own ironclad rules or maxims of conduct. So, emulating Green, he gave himself the rule of just one pipe of tobacco a day, but friends noticed that as the years went by the pipe got bigger. He seems to have been an enthusiastic guest and host, seldom dining alone, prone to talk about gossip and politics rather than matters intellectual, and not at all averse to a moderate quantity of wine.

Inevitably, for someone of a dour, Pietist background, all this rioting gave rise to some serious soul-searching. In the early Lectures on Ethics gluttony comes in for especial criticism—bestial, again— and in the more humanistic late work, The Metaphysics of Morals Kant still tells us that stuffing oneself with food incapacitates a person “for actions that would require him to use his powers with skill and determination” and it is obvious that putting oneself in such a state violates one’s duty to oneself. Fortunately all is not quite lost:

Although a banquet is a formal invitation to excess in both food and drink, there is still something in it that aims at a moral end, beyond mere physical well-being: it brings a number of people together for a long time to converse with one another. And yet the very number of guests (if, as Chesterfield says, it exceeds the number of the muses) allows for only a little conversation…and so the arrangement is at variance with that end, while the banquet remains a temptation to something immoral…How far does one’s moral authorization to accept these invitations to intemperance extend?

With such a question buzzing in his mind one would hardly expect Kant to have been the life and soul of the party. Yet “jest, wit and caprice were in his command” raves—the verb is Kuehn’s—the younger Johann Gottfried Herder, hastening to add “but always at the right time, so that everyone laughed”, slightly spoiling the effect. Kant apparently thought very highly of Henry Fielding’s romp, Tom Jones. One can’t imagine that he thought as highly of Joseph Andrews, whose Parson Adams illustrates Fielding’s unswerving devotion to simple good nature, contrasted to the cold qualities of rectitude and the “abstract contemplation on the beauty of virtue”.

II

Kant would have remained a fairly minor figure in the history of philosophy had it not been for one decade of thought, and one of publication. In 1770, upon becoming Professor of Logic and Metaphysics, he delivered his Inaugural Dissertation ‘On the Form and Principles of the Sensible World’. Here, for the first time, some famous doctrines of the “critical philosophy” come into view. Kant insists on a number of sharp divisions. He separates concepts and intuition, or intellect and sensation. He separates “things in themselves” from “things as they are for us”, or in other words, distinguishes the noumenal from the phenomenal. He sees space and time as the forms of our sensibility, imposed on the noumenal world as a condition of our experience of it. But he also leaves room for a genuine “metaphysics” or science of the world as it is in itself, knowable through pure principles of the understanding.

There was a fatal flaw lurking in all this. The key to metaphysics would need to be causation: it is because it causes the world as we apprehend it that the noumenal is a possible object of knowledge. But thirty years previously, Hume had already blocked the road to any purely rational knowledge of what causes what. In Prussia, Hertz and Hamann soon brought Hume’s critique of speculative reasoning about causation to Kant’s attention: causation itself had to be seen as the work of the mind, or a form of sensibility. Kant was later to say that it was Hume who ‘first interrupted my dogmatic slumbers’. It took a decade for him to come to terms with the problem Hume had left him.

The result was eight hundred and fifty six pages: The Critique of Pure Reason, published in 1781, when Kant was fifty seven years old. The central doctrine of the Critique is the interdependence of intellectual cognition and experience: “Thoughts without content are empty, intuitions without concepts are blind”. It takes both conceptual ability and its application in experience to generate intelligible thought. It follows that the pure metaphysics he had previously imagined, reasoning beyond the limits of experience, could have been nothing but illusion.

On the other hand a priori or armchair reasoning is possible, but not about the world as it is in itself. It concerns only the world as it appears to us. When we attempt to reason beyond this, wanting to know about the nature of the soul, or the world as a whole, or the existence of God, reason falls into contradiction, and its exercise is doomed to failure. As its name implies, the Critique is fundamentally a sceptical work, and this is how it was seen by its contemporaries. Kant became famous as the Alleszermalmer or all-crushing skeptic and critic of rational theology and metaphysics. Indeed, contemporary opinion tended to assimilate Kant not only to Hume, but even more to the notorious idealist Berkeley, a charge with some justice to it, but one that particularly outraged Kant himself.

As Kuehn describes, in the contemporary world Kant is more commonly seen as an opponent of skepticism, more interested in the scope of our knowledge rather than its limits. Such are the revolutions of philosophical interpretation. But although this positive side is certainly there, it is only part of the picture, since for Kant himself the point of the critical philosophy lay elsewhere entirely, namely in its religious and moral implications. So throughout the seventeen-eighties, Kant wrote the works on moral and religious themes that stand alongside the Critique as his great legacy to philosophy. The Groundwork of the Metaphysics of Morals appeared in 1784; by 1790 there were two more Critiques, as well as one book expounding his system in a more accessible form (The Prolegomena to Any Future Metaphysics) and the strange Metaphysical Foundations of Natural Science.

III

Even if Kant’s life was speckled with outbreaks of conviviality, it is difficult to say the same for his uncompromising, law-intoxicated moral philosophy. Kant’s moral psychology is one in which duty is forever at war with blind and slavish inclination, which itself is always a species of self-love. Emotions and desires are the enemy. You score moral points only when duty wins over them, and just because it is duty. In fact, at least in most of his moral writings, the less you care about other things, and other people, the better. Bliss, for Kant, is equated with complete independence from any inclinations and needs, including feelings of compassion and sympathy with others. But since as human beings we are unlucky enough not to have this freedom, we must be on the alert to slap our feelings down. We only gain moral credit when we do so. Hence Schiller’s famous jibe: “I must try to hate my friends so that my doing them good, which now I gladly do, will acquire moral worth”. More accurately you should try to be apathetic about your friends, and everything else. Only then does real freedom, or real “autonomy” hold sway. Kant would not have been a happy reader of books extolling emotional intelligence.

Nor is a life according to duty a bed of roses. As all students learn, for Kant the duty of truthfulness extends to telling the mad axe-man where your children are sleeping (if he asks, and makes you answer). There is no room to wriggle. You cannot argue, for instance, that the axe-man has no right to the truth. That just means that you do him no injustice by lying. But you still inflict a wrong upon humanity, and violate a sacred command of reason. In fact, it is quite easy to wrong humanity according to Kant—not only the bestialities of gluttony and misdirected sex, but more principled stands, such as rebellion against a government, wrong humanity just as well, however unjust, arbitrary, usurping or plain evil the government may be. It can be so grim doing your duty that we are forced to postulate a life after death where happiness and righteousness get back into alignment. So although the critical philosophy totally destroys any project of rational theology, our needs are supposed to step in and fill the gap. We may not be permitted to lie, but we are permitted this piece of wishful thinking.

Surprisingly, in spite of such unpromising doctrines, Kant is undoubtedly the most influential moral and political philosopher of modern times. At present he probably has more, and more crusading, defenders among professional moral and political philosophers than ever before. Partly, he is a foil to ‘utilitarianism’, which is equated in many minds with a fearsome social engineering that puts the individual firmly at the service of the collective. Better still, he directs attention away from any very demanding educational needs. So, according to the Greek tradition virtue is rare and requires the most careful cultivation and practise. Furthermore, for the Greeks, democracy requires virtuous citizens. For Kant on the other hand, people have the possibility of autonomy, or freedom, and above all they deserve respect, just like that. They do not have to work to earn respect. And however dim or dumb they may be, democratic republicanism is the right form of government.

Kuehn shows in detail how these views developed. Just as with the critical philosophy, there was a revolution in Kant’s thinking. As well as having a taste for Henry Fielding, Kant grew up accepting the ethical views of Frances Hutcheson, the great eighteenth-century Scottish moral philosopher. Hutcheson, who coined the phrase ‘the greatest happiness of the greatest number’ founded morality on a ‘moral sense’ or sentiment of impartial benevolence towards humanity. Kant was apparently disabused of this approach by reading Rousseau. He tells us about it:

I am an inquirer by inclination. I feel a consuming thirst for knowledge, the unrest which goes with the desire to progress in it, and satisfaction at every advance in it. There was a time when I believed this constituted the honor of humanity, and I despised the people, who know nothing. Rousseau set me right about this. This binding prejudice disappeared. I learned to honor humanity, and I would find myself more useless than the common laborer if I did not believe that this attitude of mine can give worth to all others in establishing the rights of humanity.

The trouble with benevolence, Kant came to feel, is that it appeals to our feelings. But Kant wants a moral order in which we don’t just happen to concern ourselves for others. Rather, we are under a duty to them: their equal dignity demands our respect, and “what properly belongs to me must not be accorded me as something I beg for”. The trouble with private benevolence, as with public charity, is that it treats its objects as pitiable, as beggars, and this is a way of refusing to recognize their rights. It conceals our own injustice. The beggar is to be submissive and grateful; the benefactor is gracious and generous. But a person with rights need be neither submissive nor grateful, and the person who heeds those rights is doing no more than listen to a demand, and so listening is neither gracious nor generous, but required.

There is something sublime here, and something that will appeal to anyone looking to legitimate a liberal social and political order. The claim is that there is indeed such a thing as a rational way of living, and there is a duty to respect it and aim for it. This duty is not something we create, or happen to find burdening us, like a chore imposed on us either by our own will or that of someone else. Rather, it is rationally compulsory. Its authority is visible to any rational agent. And of course, just because of this, unlike our inclinations, it is categorical and inescapable. Maxims of behaviour that appeal to our well-being (“honesty is the best policy”) merely advise us, but the law of morality commands.

Kant thus promises to provide the template or the form for a universal Enlightenment, liberal, politics. If the system works, there are no problems of skepticism, nihilism, or relativism. If our principles measure up we need not fear that our favourite view is arbitrary or parochial, or that we are imposing our opinions without rational warrant on others over whom we have power. No wonder, then, that moral and political philosophers want the system to work. Philosophers are then not merely fairly bourgeois, selfish, timid, creatures of a particular time and place, vainly hoping to impose their liberal standards on others unlike themselves. They are in the vanguard, articulating the demands that, because of the very structure of reason itself, must be heard by everyone. Perhaps Kant, because of his pietistic, protestant background, got those demands slightly wrong. But that leaves the hope of being able to soft-pedal some of the absolutism, while retaining the essence of the approach. This involves crying up the passages in which Kant seems a little less severe than usual. It means a little bit of pick’n’mix, trying to tow Königsberg some way to Edinburgh, or Athens, as it were. This is a major industry in philosophy departments from Cambridge to Los Angeles. There are Aristotelian Kants, and Humean Kants, and even post-war Parisian, existentialist Kants. One surprising feature of Kuehn’s book in this context is that while Kant himself is painted as a bit of a lad, the late Metaphysics of Morals, which is the main resource of humanising movements, is put down as disappointing: “it reads just like the compilation of old lecture notes that it is”.

Contemporary manifestations of Kantianism tend to work through ideas of what reasonable people could demand of each other, or in other words in terms of “contractarian” and “procedural” approaches to the foundations of society and morality. The fountainhead was John Rawls’s landmark work, The Theory of Justice of 1970, and Harvard has been the main powerhouse of the “back to Kant” movement in liberal political philosophy. In fact, however, there is a serious question how far the Kantian trappings of Rawls’s works, and those of his followers, are dispensable. The Theory of Justice cracks up a social and fiscal order somewhat resembling the social democracies of Western Europe, with their substantial freedoms and their substantial welfare floors. The book gives the impression that this is a Kantian exercise of pure practical reason, describing the necessary goal of rational politics. But over the years this appearance has eroded. Perhaps a nice liberal welfare state is no more (nor less) than the kind of place some of us would choose to live. It appeals to us not because of our autonomy, or our especially clear gaze into the crystal ball of pure practical reason, but just because we are prudent, and mildly benevolent, and not obsessive about the powers of the State or the beauties of the market.

Even if we do not all want to go back to Kant, none of us can escape him. He invented the guiding metaphor of contemporary thought, and indeed of all thought since his time. This is his “Copernican Revolution”, that the world as we know it is at least partly a creation of the conceptual and linguistic resources we bring to it. He articulated the guiding principles of liberal political thought. He may never have seen a decent painting, but he wrote the most interesting work on aesthetics in Western philosophy since Aristotle. Russell thought that Leibniz was the greatest example of pure intellect the world had ever known. Russell (who could write) was naturally prejudiced against Kant (who could not), but who is surely the only other contender.

3,400 words.