The Evening Star of
the Enlightenment

By Gabriel Blanchard

We find ourselves to be in a modern world; whose fault is it?

The traditional and perhaps best answer here is “Hegel,” though Voltaire, Christopher Columbus, William of Ockham, and Emperor Diocletian must each bear his own share of the blame. But when it comes to understanding what we mean by modernity, in contrast with antiquity,* probably no single figure in philosophical history can compete with Immanuel Kant for importance and influence—with the lone exception of René Descartes.

Kant was a native of the Baltic German realm of Prussia. Prussia was entering its ascendancy under the rule of Frederick the Great, who had invited the prestigious culture of France into common usage at the court; French might even be used in conversation in preference to German. Additionally, Prussia was a highly military society, and viewed disobedience to authorities with grave displeasure.

Early in his career, all this would likely have seemed incidental to Kant’s work: in the 1750s, he was most celebrated as a geographer and astrophysicist. (He worked out the fact that gravity caused the moon to become tidally locked, i.e. to always have the same face pointed at the earth.) It was after this that he became interested in questions of knowledge, ethics, and metaphysics, and began giving answers to them—ultimately, a whole philosophical system in answer to them.

His bibliography is a long one (not an uncommon trait in the men and women of our Author Bank), and the very titles—Prolegomena to Any Future Metaphysic, The False Subtlety of the Four Syllogistic Figures—may pardonably seem intimidating! And the material is difficult, even famously so; historian Will Durant wrote that “Our philosopher is like and unlike Jehovah; he speaks through the clouds, but without the illumination of the lightning flash.” But it is worth our time to dig into these books and ideas that have so influenced our world. We may look briefly at three as exemplars of Kantianism: the Groundwork of the Metaphysic of Morals,** his Critique of Pure Reason, and his Critique of Practical Reason. (Note that in both of these titles, critique is a slightly flawed translation of the German—”analysis” is more the idea.)

Groundwork of the Metaphysic of Morals is one of Kant’s earliest works. It expresses a number of characteristically Kantian ideas, such as deontology, an ethical system rooted in duty (from the Greek δέον deon “obligation, tie”), as opposed to one rooted in virtues as qualities of character, along the lines set forth by Aristotle. Probably the single most important concept from this work is what Kant called the categorical imperative, i.e. the supreme moral duty that binds us without any reference at all to specific circumstances. To obey the categorical imperative for its own sake was the only really righteous way to behave; obeying it out of self-interest was still “doing the right thing,” but not “for the right reason.” He formulated the categorical imperative as “Act only by that rule of which you can also will that it should be a universal law”; which, while a good deal more stiff and cool, is not so different from Do unto others as you would have them do unto you.

By a lie a man throws away and, as it were, annihilates his dignity as a man. A man who himself does not believe what he tells another … makes himself a mere deceptive appearance of man, not man himself.

The Groundwork, however, was Kant’s second major work in the field of philosophy. The first was his Critique of Pure Reason, which is specifically concerned with a priori knowledge. Things known a priori are known independently of experience,† in contrast with things known only through experience, which are called a posteriori. (E.g., we know a priori that two and two make four: we don’t need to go and research individual cases of two and two being added together—we intuitively see that they must make four, by the nature of numbers.) We have no space to devote to further details, but this led Kant to the question of how any complete metaphysics, covering everything that exists, was really possible. Imagine an entity—God, for instance—that does exist, but does not fall under any of the experiences or categories we have for understanding things that exist: it is therefore indetectable to us. We would be unable to disprove or prove its existence, or say anything else to the purpose about it, but it would be no less real for that reason. Metaphysics, Kant argued, therefore had to settle for being an inherently incomplete study of reality. We can know the way things seem, which he called the phenomenal world (from φαινόμενα [fainomena], Greek for “appearances”); but we cannot know things in themselves, the underlying realities that the phenomena represent. Things in themselves, or underlying realities, constitute the noumenal realm (from νοούμενα [nooumena], “known”); the only noumenal thing we really know, by direct perception, is ourselves.

With the Critique of Practical Reason, we return to the moral subject of the Groundwork. Here Kant lays down his ethical theory more fully, and places it in the wider context of his ontology and epistemology. Traditional ethical theories, even those as widely separated as, say, Stoicism and Epicureanism,‡ had agreed that the goal of all human actions is happiness, and that ethics is therefore the science of how to be happy. Kant’s issue with this was simply that different things make different people happy; happiness can hardly be the governing principle of ethics if it is not the same thing for everyone, just as a yardstick is no good if it changes in length every time it’s passed from one person to another. He therefore defined ethics not as the science of how to be happy, but as that of how to deserve to be happy. The issue of actually obtaining happiness—which, after all, was never a guarantee for virtuous people, or indeed any people—had to be left to the unknown and unknowable reality of the noumenal world, which (for reasons we again have no space to explain!) could be, and must be, presumed to include something approximating both a God who rewards and punishes, and an immortality for the human soul.

Kant’s legacy would be as difficult to sum up as his works! But in calling him “the evening star of the Enlightenment,” we indicate a profound break with previous thought. The wall Kant erected between the human mind and the rest of the noumenal world, while inspiring some deep analyses of consciousness (e.g., the school of phenomenology), was at the same time the root of a vast increase in skepticism among the educated. In another direction, his moral system, by cutting virtue and happiness asunder, also cut the ancients and medievals asunder from ourselves; among other things, most of us have absorbed at least enough Kantianism to feel that someone who does the right thing because they take joy in doing so is, somehow, almost cheating, and that our own efforts toward virtue (as proven by how thoroughly unpleasant we find them) are really the more meritorious ones. Philosophers, historians, theologians, and political scientists have stood ever since in his shadow.

*Roughly speaking, antiquity means “everything in human history until around five or six centuries after Christ,” while modernity generally indicates “our own” period. Most historiographers place the Middle Ages with modernity.
**Frustratingly enough, this is an entirely different book from that titled simply Metaphysics of Morals!
†It’s easy to be confused into thinking that this means we know a priori things before we know anything by experience (partly because the phrase does look like it has our English word “prior” in it). However, what it’s describing is how we know these sorts of things—the order in which we come to know them (like Communism) is a red herring in this context.
‡The Stoics taught that virtue is the only ingredient in happiness, and that a well-ordered mind can be happy in the midst of destitution, heartbreak, or even torture. The Epicureans, at the other extreme, taught that happiness consists in obtaining the greatest amount of pleasure possible, which has gained them a reputation for hedonism; however, their founder Epicurus defined pleasure mainly as mental tranquility and freedom from pain, not as the satisfaction of sensuous appetites. Hence, the historical Epicureans valued moderation, rest, and contemplation; they were a little like Buddhists.


Gabriel Blanchard, at least in terms of the phenomenal world, is CLT’s editor at large, and lives in Baltimore.

If you enjoyed this piece, you might enjoy some of our other author profiles as well: check out our pieces on the ancient playwright Terence, the medieval romancer Marie de France, the baroque poet John Donne, the Victorian essayist Henry David Thoreau, or the modern journalist Ida B. Wells.

Published on 10th May, 2023. Page image of the coat of arms of the Kingdom of Prussia; this version designed by Wikipedia user Glasshouse in 2016 (source).

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