Thinking About Knowledge

By Andrew Wilson

Immanuel Kant is the very model of a modern major philosopher. He stares out of his portraits, contemplative and intense. His giant forehead, “built for thought,” gestures toward the range and depth of subjects in which he is an expert: mechanics, cosmology, ethics, theology, metaphysics, geography, aesthetics, even weather.[1]He writes books that everybody admires and nobody understands. When we hear that he is obsessed with duty and highly disciplined, with a servant who wakes him at five each morning with the phrase “It is time,” we are not surprised. We find his numerous eccentricities—eating one meal a day, never leaving East Prussia, disliking all music that is not military, changing into a nightgown after his morning lectures, refusing to have conversations outside to avoid breathing through his mouth—strangely reassuring. He publishes continuously for twenty years, then goes completely silent for a decade, then explodes into life again and revolutionizes Western thought. This is what all philosophers should be like, we think: brilliant, quirky, mysterious, incomprehensible, and German.

The year 1776 came at the midpoint of this “silent decade” of Kant’s career, in which he published nothing except advertisements for his classes. It is also when he first wrote an outline for what would become the foundational text of modern philosophy. In a lengthy note, he lays out an overview of a future work in four sections: “Dialectic of Sensibility,” “Dialectic of the Understanding,” “Transcendental Doctrine of Appearance,” and “Transcendental Doctrine of Experience.”[2] Though it would evolve a great deal in the following five years, this is clearly recognizable as a summary of the Critique of Pure Reason (1781), a complex, original, and breathtaking book that would turn philosophy on its head. Madame de Stäel, writing thirty years after it was published, declared that “virtually everything which has been done since, in literature as well as philosophy, comes from the impulse given by this work.”[3] Kant himself described it as a Copernican revolution in philosophy, inverting the relationship between the observer and the observed in such a way that we could never go back. As arrogant as that sounds, he was right.

The Critique of Pure Reason is extremely difficult to understand, let alone summarize.[4] But in simple terms, it is Kant’s attempt to resolve one of the Enlightenment’s major problems, which is the question of what we can know and how we can know it. We all know how the world appears to be, based on our observation of it. But how can we know the world as it really is? And if that turns out to be impossible, then what hope is there for the objective truths we value: in science, theology, metaphysics, or anywhere?

Prior to Kant, two main answers were available, running in parallel tracks. One track, running from Descartes and Spinoza to Leibniz and Wolff, was what we now call rationalism. Our minds have intuitive knowledge of necessary truths, and we can achieve an objective, “God’s-eye view” of the world through the use of our reason. The other track, which went from Bacon and Locke to Berkeley and Hume, was what we now call empiricism. This was the opposite position. Everything we know comes from experience, and the ideas that are generated by our sensory impressions, so objective knowledge is ultimately impossible: we cannot separate the known (the world) from the knower (the self).

Kant rejected both tracks. He thought Hume was wrong because there are certain truths that are neither true by definition nor established by experience (like “every event has a cause”). And he thought Leibniz was wrong because reason alone, without experience, would lead only to illusion, fallacy, and self-contradiction (as he argues with his famous “antinomies”).

Knowledge is possible, Kant insisted, only when you combine reason and experience. If you have sensory impressions without rational concepts, you have no ability to think. But if you have rational concepts without sensory impressions, you have nothing to think about. “Without sensibility no object would be given to us,” he wrote, “and without understanding none would be thought. Thoughts without content are empty, intuitions without concepts are blind.”[5] (Picture the mind as an ice cube mold: cubes only form where there is both a structured set of categories, like reason (the mold), and an external object for them to act upon, like experience (the water). These “categories”, for Kant, are basic concepts without which we cannot make sense of the world.) When understanding and sensibility come together, however, it is possible to have objective knowledge of an independent world that “transcends” the perspective of the knower—even if this world is still “ideal” (the world as it is perceived) rather than real (the world as it is). He called this transcendental idealism.

The Critique of Pure Reason was the start of a new phase for Kant, and for Western thought in general. Kant wrote two further “critiques,” on moral philosophy and aesthetics, as well as several other works on politics, morality, and religion. His moral philosophy is probably better known today, and it is certainly easier to understand. But it was his Copernican revolution in metaphysics, and his idealism in particular, that transformed European philosophy, prompting a wide variety of responses in the work of Fichte, Schelling, Hegel, Schopenhauer, Marx, and many since. No philosopher since Plato and Aristotle had forced such a fundamental rethink of what human beings can know, and how we can know it.

The Enlightenment Legacy

The shadow of the Enlighteners is longer than we realize.

Jane Austen does not feel like an “Enlightenment” figure, any more than we do. She was only two weeks old at the start of 1776, and she wrote her novels a generation later. Her characters seem light-years away from the Poker Club, the Turk’s Head Tavern, and the d’Holbachs’ salon on Rue Royale. To the extent that she engages with that world at all, it is through ironic critique of its manners and pretensions rather than fawning adulation of its ideas. There seems to be a chasm between Austen and the work of Linnaeus, Whitehurst, Anquetil-Duperron, Gibbon, Bassi, and Kant that was taking place during the first twelve months of her life.

But the gap is much smaller than it appears. She is unmistakably a child of the Enlightenment. The connection between botany and romance that so intrigued Linnaeus, and concerned Withering, emerges clearly in Emma, Mansfield Park and especially Northanger Abbey: “a taste for flowers is always desirable in your sex. . . . I am pleased that you have learnt to love a hyacinth. The mere habit of learning to love is the thing.”[6] InPersuasion, Austen describes the rocks and cliffs at Lyme Regis on the Jurassic Coast, which were already known as a geologically important area, rich with fossils and visible rock strata (the first ichthyosaur skull had been found there just six years earlier). At the age of fifteen, she wrote The History of England, mimicking historians like Goldsmith, Hume, Macaulay, and Gibbon and satirizing the pretense of historical objectivity. The women in her books reflect both halves of the paradox we saw earlier: for every Elinor, Emma, or Elizabeth Bennet, celebrated for having “more quickness of observation and less pliancy of temper than her sister,” there is a corresponding Lucy Steele, Jane Fairfax or Mary Bennet, mocked for having “neither genius nor taste.” And in Elinor and Marianne Dashwood, we have a memorable pair of heroines to represent the parallel tracks that Kant was trying to bring together in the Critique of Pure Reason. Philosophers called them rationalism and empiricism, or understanding and sensation, or reason and experience. Austen called them Sense and Sensibility.

Over two centuries later, the Western world stands in a similar position. We feel a long way removed from the philosophes, both in form and substance. Like Austen, we find their self-importance and stylized manners a little ridiculous. But we are profoundly influenced by them nonetheless. Like it or not, the Enlighteners have educated us all.

It seems obvious to us, for example, that we should classify species along biological lines and analyze the earth scientifically, even if some of our interpretative assumptions are challenged in the process. We instinctively use critical methods to reconstruct the past. We are committed to the education of all people of both sexes. We think of knowledge as a dialogue between the knower and the known, and take it for granted that information should be classified and shared in dictionaries or encyclopedias. When it is, we expect them to look pretty much like Johnson’s Dictionary (1755), Diderot’s Encyclopédie (1751–1772), or the Encyclopaedia Britannica (1768–1771), and not remotely like the Siku Quanshu (1772–1783), which was being compiled in Qing China at the same time. We expect truth claims to be established by persuasion, not imposed by fiat. If we are honest with ourselves, we will admit that our society has absorbed many of the Enlighteners’ more odious traits as well: their self-exalting narrative of world history, their dismissive view of “backward” and “outdated” cultures, their intellectual condescension, and racial superiority.

Ideally, we would keep their strengths and weaknesses separate, appropriating the former and rejecting the latter. Every philosophe would become either a pioneering genius who embodies our contemporary standards perfectly or a villainous caricature who must be thrown under the bus. But history is more complex than that. Heroes and villains are often the same people; good ideas and bad ideas come tangled together, growing like wheat and tares in the same soil. So it is hardly surprising that the Enlighteners have bequeathed to us a mixed legacy. The Western world has been illuminated by their powerful blend of sense and sensibility, and their laudable commitment to persuasion—but we have also been darkened by their pride, and prejudice.

Content taken from Remaking the World by Andrew Wilson, ©2023. Used by permission of Crossway, a publishing ministry of Good News Publishers.


[1] Johann Gottfried Herder, Briefe zur Beförderung der Humanität (Riga: Hartknoch, 1793), no. 79.

[2] Immanuel Kant, Notes and Fragments, trans. Curtis Bowman, Paul Guyer, and

Frederick Rauscher, ed. Paul Guyer (Cambridge: Cambridge University Press, 2005), 181–84; cf. 73, on the question of dates.

[3] Madame de Stäel, De L’Allemagne (1813; repr., Paris: Charpentier, 1844), 452.

[4] The best summary I know of is Roger Scruton, Kant: A Very Short Introduction (Oxford: Oxford University Press, 2001).

[5] Immanuel Kant, Critique of Pure Reason, trans. Mary Gregor (Cambridge: Cambridge University Press, 1998), 193–94 (A51, B75).

[6] Jane Austen, Northanger Abbey (London: Penguin, 2011), chap. 22; cf. Deirdre Shauna Lynch, ‘“Young Ladies Are Delicate Plants”: Jane Austen and Greenhouse Romanticism,” English Literary History 77, no. 3 (2010): 689–729.

Published October 16, 2023

Andrew Wilson

Andrew is Teaching Pastor at King's Church London, and has degrees in history and theology from Cambridge (MA) and King's College London (PhD). He is a columnist for Christianity Today, and has written several books, most recently Remaking the World. Andrew is married to Rachel and they have three children: Zeke, Anna and Samuel.