50 Fun Facts About Immanuel Kant

Neighbours in Königsberg were said to set their watches by which punctual habit of Immanuel Kant?

His daily walk was so regular that neighbours reportedly timed their watches by it. Kant kept a rigid, clocklike schedule and never married, though he twice considered it and on both occasions waited too long.

Immanuel Kant spent nearly his whole life in Königsberg, a Baltic port now known by which name?

Kaliningrad is the name the Soviet Union gave the city in 1946, after taking it from a defeated Germany. Its university has since been renamed in Kant's honour.

Whose doubts about cause and effect did Kant credit with waking him from his 'dogmatic slumber'?

David Hume argued that we never perceive a necessary connection between a cause and its effect. Kant's long answer to that doubt became the Critique of Pure Reason.

Kant likened his idea that objects conform to the mind to the revolution of which astronomer?

Copernicus set the observer in motion instead of the sky, and Kant claimed a similar shift in perspective for metaphysics. What we can know, he argued, depends partly on the knower.

Kant argued that which act is wrong even when a murderer asks where your friend is hiding?

Lying, Kant held, is wrong even to a would-be killer, because the worth of a moral act does not depend on consequences. He made the claim in a 1797 reply to the French writer Benjamin Constant.

Kant wrote that two things fill the mind with awe: the moral law within him and what above him?

The starry heavens and the moral law are paired at the close of his Critique of Practical Reason, in what is perhaps his most quoted sentence. He said both filled him with ever-growing reverence.

In an early book on the cosmos, Kant suggested that faint, distant nebulae might be what?

Other galaxies were what Kant proposed in 1755, having correctly deduced that the Milky Way is a large disk. The idea carried astronomy far beyond the Solar System.

Kant wrote three papers explaining which 1755 disaster by natural rather than supernatural causes?

The Lisbon earthquake drew three papers from Kant in 1756. His theory of shifting caverns full of hot gases was wrong, but it was one of the first systematic attempts to explain such shocks by nature alone.

Baptized Emanuel, Kant changed the spelling of his first name after learning which language?

Hebrew study persuaded him to respell his name as Immanuel. He was the fourth of nine children in a devout Lutheran home, and only six of them reached adulthood.

Kant's categorical imperative says to treat humanity never merely as a means but always as what?

An end in itself is how every rational being must be treated, Kant argued in his Groundwork of 1785. Using a person purely as a tool for your own goals fails that test.

Kant contrasted the categorical imperative with which kind, binding only if you want some goal?

Hypothetical imperatives say what to do if you happen to want something, such as exercise if you want to stay fit. The categorical kind, Kant argued, binds every rational agent whatever they desire.

Kant's best-known moral test asks whether the maxim behind an act could become what for everyone?

A universal law is the test: act only on a maxim you could want everyone to follow. A maxim of breaking promises fails, because nobody would trust a promise in a world where all did so.

At the opening of the Groundwork, Kant names what as the only thing valuable without qualification?

A good will, Kant wrote, is good in itself and not because of what it achieves. Other fine qualities, such as courage or cleverness, lose their value when they serve a bad purpose.

Kant says a fair shopkeeper's honesty has moral worth only when it springs from which motive?

Duty is the only motive Kant credits with moral worth. A shopkeeper who gives fair prices just to protect his reputation does the right thing, Kant argued, but earns no moral credit for it.

Kant's ethics is the classic case of which family of moral theories, opposed to consequentialism?

Deontology takes its name from the Greek deon, meaning obligation. It holds that some acts are right or wrong in themselves, whatever results they happen to produce.

Kant denied that his categorical imperative matched which ancient precept about treating others?

The Golden Rule fails, Kant argued, because a convicted criminal could appeal to it to make the judge set him free. His own test asks what could hold for everyone, not what one person would like.

Which term did Kant use for a rational being's capacity to make its own moral law?

Autonomy joins the Greek words for self and law. For Kant, a person who obeys the moral law is free rather than constrained, because that law comes from the person's own reason.

In the Groundwork, Kant says everything has either a price or, if beyond price, which quality?

Dignity belongs to whatever has no equivalent and cannot be exchanged. For Kant, persons have it because they can act morally, which is why they may never be traded like merchandise.

Alongside God and freedom, which third idea did Kant treat as a postulate of practical reason?

Immortality of the soul joins God and free choice as beliefs Kant said morality requires, though none of the three can be proved by theory. He set out the argument in his second Critique.

A formula ascribed to Immanuel Kant holds that anyone who ought to perform an act necessarily what?

Whoever ought to act is able to do it, a principle summed up in the slogan 'ought implies can'. It means nobody can be blamed for failing to do what was impossible for them.

Kant's Critique of Pure Reason treats which pair as mere forms of intuition structuring experience?

Space and time, for Kant, are not features of things in themselves but a framework the human mind brings to every perception. It follows, he argued, that we know objects only as they appear to us.

Kant contrasted phenomena, things as they appear, with which objects of pure thought we cannot know?

Noumena are things considered apart from how the senses present them. Kant said we may refer to them only in a negative sense, as a boundary marking where human knowledge stops.

Kant classed '7 + 5 = 12' as which kind of knowledge, informative yet independent of experience?

Synthetic a priori truths were Kant's great puzzle: the idea of 12, he said, is not contained in 7, 5 and addition, yet the sum is certain. How such knowledge is possible is the central question of his first Critique.

Which name did Kant give his doctrine that we know only appearances, never things in themselves?

Transcendental idealism was Kant's own label, and he was keen to set it apart from the subjective idealism of George Berkeley. Kant insisted his view did not deny a reality beyond our own minds.

In the Critique of Pure Reason, Kant wrote that he had to deny knowledge to make room for what?

Faith gained room, Kant argued, because limiting knowledge to what we can experience means nobody can disprove God or free choice either. Belief in them could then rest on moral grounds.

Kant wrote that thoughts without content are empty, while intuitions without concepts are what?

Blind is his word for raw sensation that no concept has organised. The line sums up his view that knowledge needs both the senses and the understanding working together.

Which bird does Immanuel Kant picture wrongly supposing it could fly even better in a vacuum?

A dove, feeling the air resist its wings, might fancy that an airless void would suit it better. Kant used the image to warn that reason gets nowhere once it leaves experience behind.

What did Kant call his four pairs of opposed claims that reason seems to prove equally well?

Antinomies set reason against itself: in the first, the universe seems provably both finite and infinite. Kant argued that such deadlocks arise when reason strays beyond possible experience.

Kant's objection that existence is not a real predicate was aimed at which classic proof of God?

The ontological argument, used by Anselm and Descartes, claims that God's very essence entails existence. Kant replied that it proves only an empty tautology: if God exists, then God exists.

Kant posed three great questions: what can I know, what should I do, and which third?

Kant's third question, 'What may I hope?', rounds off the list he set out in the Critique of Pure Reason. That book tackles the first question, and his later works on ethics and belief take up the other two.

Kant was born a subject of which kingdom, whose ruler Frederick the Great he praised in print?

Prussia was ruled by Frederick the Great for much of Kant's adult life. In his essay on enlightenment, Kant praised the king for letting subjects argue as much as they liked, provided they obeyed.

Which English scientist's physics did the teacher Martin Knutzen introduce to the young Kant?

Isaac Newton's physics became Kant's model of secure knowledge. Kant's early book on the cosmos even announced in its subtitle that it explained the universe on Newtonian principles.

Kant argued in an early essay that the Moon's gravity was gradually doing what to the Earth?

Slowing its spin was Kant's answer to a prize question set by the Berlin Academy about the Earth's rotation. A year later he widened his ideas into a theory of how the whole Solar System formed.

Kant, who spent almost his whole life in one city, was among the first to teach what as its own subject?

Geography was a course Kant taught for about forty years, though he hardly ever left his home city. His lecture notes on it were published as a book in 1802.

Which physicist was introduced to Kant's Critique of Pure Reason at thirteen by his tutor?

Albert Einstein made Kant his favourite philosopher, and his tutor Max Talmud recalled that works baffling to ordinary readers seemed clear to the boy. Einstein later criticized and rejected Kant's views on knowledge.

Which mathematician solved the Seven Bridges of Königsberg puzzle while Kant was a boy there?

Leonhard Euler proved in 1736 that no route could cross each of the city's seven bridges exactly once. His proof laid the foundations of graph theory.

Immanuel Kant borrowed which Latin phrase from the poet Horace as his motto for the Enlightenment?

Sapere aude means dare to know, which Kant glossed as having the courage to use your own understanding. He made it the rallying cry of his 1784 essay on what enlightenment is.

Kant is credited with synthesizing early modern rationalism and which rival school of thought?

Empiricism traces knowledge to the senses, while rationalism traces it to reason. Kant argued that each camp had half the story: the senses supply the content and the mind supplies its form.

At his 1961 trial, which Nazi official claimed to have lived by Kant's categorical imperative?

Adolf Eichmann made the claim in court in Jerusalem. Hannah Arendt, reporting on the trial, replied that he had taken the wrong lesson from Kant and misunderstood his moral principles.

Kant's aesthetics pairs the beautiful with which feeling, aroused by things too vast to take in?

The sublime, for Kant, ends in pleasure: the imagination is overwhelmed, yet we feel the superiority of our own reason over nature. He split it into mathematical and dynamical kinds.

Which form of government did Kant call necessarily a despotism, because all may decide against one?

Democracy in Kant's day meant direct government by the majority, which he thought a threat to individual liberty. He favoured a republican constitution instead, and made it the first condition of lasting peace.

Kant's essay Perpetual Peace says which institution should eventually be totally abolished?

Standing armies are condemned in the essay's preliminary articles, beside peace treaties that secretly keep grounds for a future war. Kant's lasting remedy was a federation of free states.

After a royal reprimand, Kant was ordered never to publish or speak publicly on which subject?

Religion was off limits after he sent a book on it through the University of Jena to avoid the theological censors. He later printed his reply to the king's reprimand in a 1798 preface.

Kant's father Johann Georg supported a family of nine children by working at which trade?

Harness-maker Johann Georg Kant came from Memel, a port now called Klaipėda in Lithuania. He died after a stroke in 1746, which interrupted his son's university studies.

Which philosopher beat Kant into second place in the Berlin Academy's prize essay contest?

Moses Mendelssohn won with an essay on applying mathematical proofs to metaphysics. His grandson Felix became one of the best-loved composers of the following century.

Kant's satire Dreams of a Spirit-Seer attacked the visions of which scientist turned mystic?

Swedenborg had at first impressed Kant, who asked an English friend to call at the seer's home and check the stories. Three years later Kant published his scathing little book.

Whose anonymous first book was taken for Kant's own, years before Kant publicly denounced him?

Fichte owed his sudden fame to the mix-up over his 1792 Attempt at a Critique of All Revelation. In 1799 Kant rejected his former admirer's system in an open letter.

The poet Heinrich Heine likened Kant, as a destroyer of old beliefs, to which French revolutionary?

Maximilien Robespierre and Kant, Heine wrote, were both provincial bourgeois whom fate handed a pair of scales: on them one weighed a king, the other a god.

Which English poet credited Kant in his Biographia Literaria and spread Kant's ideas in Britain?

Coleridge wrote that Kant had taught him to see the mind as an active agent in grasping reality, not a passive one. He helped make German thought known in both Britain and America.

Kant wrote that laughter arises from the sudden transformation of a strained expectation into what?

Nothing is what the tension dissolves into, on Kant's account, which is why a punchline ends in a burst of laughter. He told three jokes in the Critique of Judgment to make the point.