Interactive Paradox Encyclopedia

Liar paradox

"This sentence is false." True iff false.

Epimenides paradox

A Cretan says all Cretans are liars; the loose ancestor of the Liar.

Strengthened Liar

"This sentence is not true," which defeats truth-value-gap fixes.

Truth-teller paradox

"This sentence is true." Consistent either way, hence groundless.

No-no paradox

Two sentences each asserting the other is false; symmetry blocks any assignment.

Yablo's paradox

An infinite sequence of sentences, each saying all later ones are false; paradox without any circularity.

Curry's paradox

"If this sentence is true, then P" proves arbitrary P from little more than modus ponens.

Löb's paradox

The provability-logic sibling of Curry's.

Quine's paradox

"Yields falsehood when preceded by its quotation" yields falsehood when preceded by its quotation.

Grelling–Nelson paradox

Is "heterological" (not describing itself) heterological?

Berry paradox

"The least integer not nameable in under eleven words" was just named in ten.

Richard's paradox

Diagonalizing over definable reals using definitions in ordinary language.

Knower paradox

"This sentence is not known" — the Liar transposed into epistemic logic.

Barber paradox

The barber who shaves all and only those who don't shave themselves. (Russell's paradox, popularized.)

Pinocchio paradox

His nose grows when he lies; he says "My nose is growing now."

Card / postcard paradox

Each side of a card denies the other.

Paradox of the Court (Protagoras v. Euathlus)

A contingent-fee lawsuit whose verdict determines its own premise.

Crocodile dilemma

The crocodile will return the child iff the parent correctly predicts what it will do.

Buridan's bridge

Plato will let Socrates cross iff Socrates's next utterance is true; Socrates says "You will throw me in the water."

Paradox of analysis

A correct conceptual analysis is either trivial (synonymous) or false.

Moore's paradox

"It's raining, but I don't believe it's raining" — consistent yet absurd to assert.

Russell's paradox

The set of all sets not members of themselves; killed naive set theory.

Cantor's paradox

The set of all sets would have a power set larger than the largest cardinal.

Burali-Forti paradox

The set of all ordinals would be an ordinal greater than itself.

Skolem's paradox

First-order set theory has countable models that internally "prove" uncountability exists.

Hilbert's Grand Hotel

A full hotel with infinite rooms still accommodates infinitely many new guests.

Galileo's paradox

There are as many perfect squares as integers, though squares are sparse.

Banach–Tarski paradox

A solid ball can be cut into finitely many pieces and reassembled into two identical balls.

Gabriel's Horn (Torricelli's trumpet)

Finite volume, infinite surface area: fillable but not paintable.

Coastline paradox

Measured length grows without bound as the ruler shrinks.

Missing square puzzle

Rearranged triangle pieces appear to create area from nothing.

Interesting number paradox

The least uninteresting number is thereby interesting.

Gödel's incompleteness (as paradox-adjacent)

A true-but-unprovable sentence asserting its own unprovability.

Curry–Howard / Girard's paradox

Type-theoretic collapse when a type of all types is allowed.

Zeno: Achilles and the Tortoise

The faster runner must first reach where the slower began, ad infinitum.

Zeno: Dichotomy

To go anywhere you must first go halfway, so motion never starts.

Zeno: Arrow

At each instant the arrow is motionless, so motion is an illusion.

Zeno: Stadium (Moving Rows)

Relative velocities appear to make half a time equal a whole time.

Thomson's lamp

Toggled at 1, 1/2, 1/4… minutes; is it on or off at minute 2?

Ross–Littlewood paradox (balls and vase)

Add ten, remove one, infinitely often; the vase is empty at noon.

Benardete's paradox / grim reaper paradox

An infinite sequence of conditional killers kills without any one acting.

Zeno's plurality paradoxes

Divisible magnitudes must be both infinitely large and of zero size.

Sorites paradox (the heap)

One grain isn't a heap; adding one never makes a heap; therefore no heap exists.

Bald man (falakros)

The same argument run on hairs.

Ship of Theseus

Replace every plank; is it the same ship? And what if the old planks are reassembled?

Paradox of the 1,001 cats (Geach's Tibbles)

Overlapping cat-candidates make cat-counting indeterminate.

Problem of the many

Cloud boundaries are indeterminate, so there are billions of clouds where we see one.

Chrysippus's paradox / Dion and Theon

Amputation seems to destroy the larger object rather than the smaller.

Monty Hall problem

Switching doors doubles your odds.

Bertrand's paradox (chord)

"Random chord" has three defensible, incompatible answers.

Bertrand's box paradox

The two-drawer coin problem; the answer is 2/3, not 1/2.

Boy or Girl paradox

Ambiguous conditioning yields 1/2 or 1/3.

Two envelopes paradox

Expected-value reasoning says always switch, forever.

St. Petersburg paradox

A game of infinite expected value that nobody would pay much to play.

Sleeping Beauty problem

Halfers versus thirders on self-locating belief.

Doomsday argument

Your birth rank as evidence for humanity's imminent end.

Simpson's paradox

A trend present in every subgroup reverses when groups are pooled.

Lord's paradox

Two defensible analyses of change scores give opposite conclusions.

Berkson's paradox

Selection creates spurious negative correlation.

Birthday paradox

23 people suffice for a coin-flip chance of a shared birthday.

Friendship paradox

Your friends have more friends than you do, on average.

Inspection paradox

Sampled waiting times and class sizes are systematically inflated.

Borel–Kolmogorov paradox

Conditioning on a measure-zero event depends on the parametrization.

Raven paradox (Hempel)

A green apple confirms that all ravens are black.

Grue paradox (Goodman's new riddle)

Evidence confirms "all emeralds are grue" as well as "green."

Lottery paradox

Rational to believe each ticket loses, irrational to believe all do.

Preface paradox

An author rationally believes each claim in the book and that the book contains errors.

Fitch's paradox of knowability

If all truths are knowable, all truths are already known.

Problem of induction (Hume)

No non-circular justification for expecting the future to resemble the past.

Base rate fallacy / false positive paradox

A highly accurate test for a rare condition still mostly yields false positives.

Will Rogers phenomenon

Reclassifying cases raises average survival in both groups.

Regression to the mean as paradox

Punishment appears to work and praise to backfire.

Newcomb's problem

Evidential and causal decision theory give opposite advice.

Prisoner's dilemma

Individually rational defection yields a collectively worse outcome.

Tragedy of the commons

The same logic at scale, applied to shared resources.

Abilene paradox

A group does what no member wanted.

Buridan's ass

Perfectly balanced options produce paralysis and starvation.

Allais paradox

Observed preferences violate the independence axiom.

Ellsberg paradox

Ambiguity aversion violates expected utility.

Unexpected hanging / surprise examination

The prisoner disproves the sentence, then is duly surprised.

Kavka's toxin puzzle

You are paid to intend to do what you'll have no reason to do.

Chainstore paradox

Backward induction forbids the deterrence everyone finds sensible.

Centipede game

Rationality predicts immediate defection; people cooperate for many rounds.

Traveler's dilemma

Iterated undercutting drives the Nash equilibrium to the minimum.

Parrondo's paradox

Two losing games alternated produce a winning game.

Braess's paradox

Adding a road increases everyone's travel time.

Downs–Thomson paradox

Expanding road capacity worsens commute times where transit competes.

Pascal's wager

Infinite payoff swamps any finite probability.

Pascal's mugging

The same reasoning weaponized by tiny probabilities of vast utility.

Voting paradox (paradox of voting)

Rational individuals shouldn't vote, yet voting sustains democracy.

Condorcet paradox

Majority preferences can cycle: A beats B beats C beats A.

Arrow's impossibility theorem

No voting rule satisfies a short list of obvious fairness conditions.

Discursive dilemma (doctrinal paradox)

Majority voting on premises contradicts majority voting on conclusions.

Alabama paradox

Increasing House seats can reduce a state's allocation.

Population and new-states paradoxes

Apportionment anomalies of the same family.

No-show paradox

Voting for your favorite candidate can cause them to lose.

Twin paradox

The traveling twin returns younger; asymmetry resolves it.

Ladder-and-barn (pole-in-barn) paradox

Length contraction makes simultaneity frame-dependent.

Bell's spaceship paradox

A thread between identically accelerating ships snaps.

Ehrenfest paradox

A rigid rotating disk cannot have a Euclidean geometry.

Supplee's paradox

A relativistic bullet in fluid appears to both sink and float.

Schrödinger's cat

Superposition dragged up to macroscopic scale.

EPR paradox

Quantum mechanics is either incomplete or nonlocal.

Wigner's friend

Two observers disagree about whether a measurement has occurred.

Quantum Zeno effect

A continuously observed system never evolves.

Hardy's paradox

Interaction-free measurement implies contradictory particle histories.

Klein paradox

Relativistic particles tunnel through arbitrarily high barriers.

Black hole information paradox

Hawking evaporation appears to destroy quantum information.

Firewall paradox (AMPS)

Monogamy of entanglement puts a wall of energy at the horizon.

Olbers' paradox

Why is the night sky dark in an infinite, eternal universe?

Fermi paradox

If life is common, where is everybody?

Loschmidt's paradox

Time-symmetric microphysics yields time-asymmetric thermodynamics.

Poincaré recurrence paradox

Systems must eventually return arbitrarily near their initial state.

Gibbs paradox

Entropy of mixing depends on whether particles are counted as distinguishable.

Maxwell's demon

Sorting molecules seems to defeat the second law; information erasure saves it.

Boltzmann brain

Random fluctuation observers should vastly outnumber evolved ones.

Faint young Sun paradox

Early Earth had liquid water under a dimmer Sun.

Algol paradox

The less massive star in a binary is the more evolved one.

D'Alembert's paradox

Ideal fluid theory predicts zero drag on a moving body.

Aristotle's wheel paradox

Concentric circles of different radii trace equal path lengths.

Hydrostatic paradox

Fluid pressure depends on depth, not on the amount of fluid.

Tea leaf paradox

Stirred leaves migrate to the center, not the rim.

Feynman sprinkler

Which way does a submerged sprinkler turn when it sucks water in?

Mpemba effect

Hot water can freeze faster than cold.

Painlevé paradox

Rigid-body friction models admit no consistent solution.

Denny's paradox

Small water-walking insects shouldn't be able to propel themselves.

Archimedes' / Sailing faster than the wind

Downwind craft exceeding wind speed.

Cool tropics paradox

Paleoclimate models conflict with proxy temperature data.

Heat death vs. recurrence

Two incompatible cosmic endings from the same physics.

Grandfather paradox

Kill your grandfather and you were never born to do it.

Bootstrap (ontological) paradox

An object or idea with no origin, looping through time.

Predestination paradox

Your attempt to prevent an event causes it.

Polchinski's paradox

A billiard ball knocks its earlier self off course.

Information paradox of retrocausality

Effects preceding causes in advanced-wave solutions.

Omnipotence paradox

Can God create a stone too heavy for God to lift?

Epicurean paradox / problem of evil

Omnipotence, omnibenevolence, and evil cannot all hold.

Paradox of free will and foreknowledge

Infallible foreknowledge appears to negate freedom.

Meno's paradox (paradox of inquiry)

You cannot search for what you don't know, nor for what you do.

Paradox of the stone-cutting Demiurge / creation ex nihilo

Something from nothing.

Nihilist / existence paradox

Why is there something rather than nothing?

Paradox of fiction

We feel real emotions for people we know don't exist.

Paradox of tragedy

We seek out art that makes us miserable.

Paradox of horror

Same, for fear.

Paradox of hedonism

Directly pursuing pleasure reliably fails to produce it.

Paradox of suspense

Rewatching preserves suspense despite known outcomes.

Bootstrapping / epistemic circularity

Using a faculty to validate itself.

Zombie / knowledge argument tensions

Physicalism seems to leave out what it is like.

Sleeping-pill paradox of personal identity (teletransportation)

Is the copy you?

Trolley problem

Killing one to save five, and its many variants (footbridge, loop, bystander).

Repugnant conclusion (Parfit)

Total utilitarianism prefers vast populations with lives barely worth living.

Mere addition paradox

The stepwise argument that generates the above.

Non-identity problem

Acts that harm no particular person still seem wrong.

Sadistic conclusion

Adding suffering lives can beat adding mediocre ones.

Paradox of deontology

Constraints forbid you from minimizing violations of themselves.

Paradox of tolerance (Popper)

Unlimited tolerance destroys tolerance.

Paradox of forgiveness

Forgiveness is either unwarranted or unnecessary.

Paradox of blackmail

Two legal acts (asking for money, revealing a secret) combine into a crime.

Moral luck (Williams/Nagel)

We blame people for outcomes outside their control.

Paradox of democracy

The majority may vote to end majority rule.

Paradox of freedom

Unlimited liberty permits the strong to destroy the liberty of the weak.

Paradox of nihilism

The claim that nothing matters is itself asserted as mattering.

Euthyphro dilemma

Is the pious loved by the gods because it is pious, or pious because loved?

Paradox of value (diamond–water)

Useless diamonds outprice essential water.

Paradox of thrift

Universal saving reduces aggregate saving.

Jevons paradox

Efficiency gains increase total resource consumption.

Giffen goods

Demand rises as price rises.

Veblen goods

Demand rises with price because of status.

Leontief paradox

Capital-rich America exported labor-intensive goods.

Lucas paradox

Capital doesn't flow from rich to poor countries as theory predicts.

Feldstein–Horioka puzzle

Domestic saving and investment correlate too tightly for open capital markets.

Equity premium puzzle

Stocks outperform bonds by more than risk aversion can explain.

Easterlin paradox

Rising national income doesn't raise reported happiness.

Productivity paradox (Solow)

"Computers everywhere but in the productivity statistics."

Bertrand paradox (economics)

Two firms suffice to drive price to marginal cost.

Edgeworth paradox

Capacity constraints destroy pure-strategy price equilibrium.

Metzler paradox

A tariff lowers the domestic price of the imported good.

Gibson's paradox

Interest rates track price levels rather than inflation rates.

Arrow's information paradox

You can't value information without being given it for free.

Icarus paradox

The strengths that made a firm succeed cause its failure.

Grossman–Stiglitz paradox

Perfectly efficient markets destroy the incentive to make them efficient.

Deposit / paradox of banking

Individually safe withdrawals cause bank runs.

Levinthal's paradox

Proteins fold far faster than random search allows.

C-value paradox

Genome size doesn't track organismal complexity.

G-value paradox

Neither does gene count.

Peto's paradox

Whales don't get more cancer than mice despite vastly more cells.

Paradox of the plankton

Too many species coexist on too few limiting resources.

Lek paradox

Female choice should exhaust the genetic variation it selects on.

Gray's paradox

Dolphins swim faster than their muscle power seems to permit.

Obesity paradox

Higher BMI associates with better survival in some patient groups.

French paradox

Low heart disease despite a high-saturated-fat diet.

Hispanic (immigrant) paradox

Better health outcomes despite worse socioeconomic indicators.

Antibiotic paradox

Using antibiotics undermines their effectiveness.

Paradox of enrichment

Adding food to an ecosystem destabilizes predator–prey cycles.

Sex paradox (cost of males)

Sexual reproduction halves fitness yet dominates.

Pesticide paradox

Pesticide use can increase pest populations.

Paradox of choice

More options reduce satisfaction.

Moravec's paradox

Hard reasoning is easy for machines; easy perception is hard.

Polanyi's paradox

We know more than we can tell, so we cannot fully automate it.

Paradox of automation

The more reliable the automation, the more critical and degraded the human operator.

Stockdale paradox

Confront brutal facts while retaining unwavering faith.

Service recovery paradox

Customers rate you higher after you fail and fix it.

Paradox of thrift in behavior (bystander effect)

More witnesses, less help.

Peter principle as paradox

Competence promotes you until you are incompetent.

Streisand effect

Suppression amplifies.

Paradox of the active user

Users refuse to read manuals that would save them time.

Jevons/rebound in time (Parkinson's law)

Work expands to fill available time.

Privacy paradox

People say they value privacy and act otherwise.

Productivity of interruption / Zeigarnik tension

Unfinished tasks occupy more attention than finished ones.

Potato paradox

Drying 100 kg of 99%-water potatoes to 98% leaves 50 kg.

Elevator paradox

Elevators near the top always seem to be going down.

Paradox of the second-hand smoke of queues

Your line is always the slow one (an inspection-paradox cousin).

Coin rotation paradox

A coin rolled around an identical coin turns twice, not once.

Chessboard/Curry's missing-area triangle

Dissection illusions.

Bootstrapping oneself over a fence (Baron Munchausen trilemma)

Justification must be circular, infinite, or arbitrary.

Paradox of the Incarnation

Fully God and fully man, without division or confusion.

Paradox of the Trinity

Three persons, one substance; neither three gods nor one mask.

Kierkegaard's Absolute Paradox

The eternal enters time; reason encounters what it cannot think.

Teleological suspension of the ethical

Abraham is praised for a willingness that ethics calls murder.

Paradox of divine hiddenness (Schellenberg)

A God who wants relationship yet permits non-belief.

Paradox of petitionary prayer

Asking an omniscient, immutable, perfectly good being to change its mind.

Paradox of grace and works

Salvation is unearnable, yet effort is commanded.

Paradox of predestination and evangelism

Why preach if the elect are already chosen?

Felix culpa

The Fall is called fortunate because it occasioned redemption.

Paradox of hell

Infinite punishment for finite offense, imposed by infinite love.

Paradox of the atonement

Justice satisfied by punishing the innocent to acquit the guilty.

Paradox of kenosis

God's power displayed by emptying itself of power.

Paradox of divine freedom

A perfect being cannot choose worse, so how is it free?

Paradox of creation

An eternal, timeless God performs an act with a date.

Paradox of miracles

The lawgiver breaks the laws to prove authorship of them.

Paradox of divine impassibility

A God who cannot suffer is said to love.

Apophatic paradox

Negative theology says God is unsayable, in words.

Paradox of idolatry

Prohibiting images requires an image of what must not be imaged.

Paradox of Job

The righteous suffer, and the answer given is that there is no answer for us.

Paradox of the Sabbath

Rest becomes an obligation, and mercy must break the law of mercy.

Paradox of religious exclusivism

A universal love mediated by a particular and excluding creed.

Paradox of martyrdom

Life is affirmed by surrendering it.

Nirvana paradox

Liberation requires extinguishing desire, including the desire for liberation.

Bodhisattva paradox

A vow to save all beings, taken by one who denies that beings exist.

Paradox of anatta

The self must labor to discover there is no self doing the laboring.

Zen koan

The sound of one hand; understanding arrives by exhausting understanding.

Taoist naming paradox

"The Tao that can be named is not the eternal Tao," in a named book.

Wu wei

Achievement through non-action; effortlessness pursued effortfully.

Paradox of mysticism

The ineffable experience described at length and in libraries.

Paradox of the sacred

Setting something apart to honor it removes it from the life it sanctifies.

Sartre's condemnation to freedom

We are not free to be unfree.

Bad faith

Lying to oneself requires knowing the truth one hides.

Paradox of authenticity

Deliberately being authentic is a performance.

Paradox of self-deception

The deceiver and deceived are one mind.

Akrasia (weakness of will)

Doing what one judges, at that moment, one ought not do.

Paradox of self-control

Who controls the controller, and why does he lose?

Paradox of spontaneity

"Be spontaneous!" cannot be obeyed.

Paradox of insomnia

Trying to fall asleep guarantees wakefulness.

Paradox of relaxation

Effortful unwinding.

Ironic process (the white bear)

Suppressing a thought summons it.

Paradox of the examined life

Examination interrupts the living it evaluates.

Schopenhauer's pendulum

Unfulfilled desire is pain; fulfilled desire is boredom.

Paradox of the achieved goal

Arrival empties the aim of its meaning.

Epicurus on death

Where death is, I am not; so it can never harm me.

Lucretius' symmetry

We dread future non-existence but not the eternity before birth.

Paradox of grief

Mourning a person who, by hypothesis, is no longer there to be wronged.

Paradox of immortality

Endless life would drain life of urgency (Williams's Makropulos case).

Paradox of nostalgia

Longing for a past that was not happy while it was present.

Beisser's paradoxical theory of change

One changes only by ceasing to try to change.

Paradox of vulnerability

Exposure of weakness is the source of strength.

Paradox of control

Loosening one's grip increases one's actual command.

Paradox of intimacy

Closeness requires preserved separateness.

Paradox of self-esteem

Pursuing it directly corrodes it.

Paradox of humility

Recognizing one's humility forfeits it.

Paradox of perfectionism

Impossibly high standards produce nothing at all.

Paradox of the ascetic

Renunciation becomes the most refined form of appetite.

Paradox of addiction

Choosing, repeatedly, what one sincerely does not want.

Paradox of procrastination

A rational agent acting against a judgment it has not revised.

Paradox of the resolution

The self that promises is not the self that must perform.

Paradox of promising

Binding a future person who did not consent.

Paradox of gratitude

A free gift creates a debt, which unfrees the gift.

Derrida's paradox of the gift

A gift recognized as a gift is already an exchange.

Derrida's paradox of hospitality

To welcome unconditionally, one must remain master of the house.

Paradox of forgiveness

Only the unforgivable needs forgiving; the excusable needs none.

Paradox of trust

Trust cannot be justified in advance without ceasing to be trust.

Paradox of loyalty

Genuine loyalty must be capable of disobedience.

Paradox of love's reasons

Loving someone for their qualities makes them replaceable.

Paradox of jealousy

Guarding a love destroys what it guards.

Paradox of solitude

Being alone is bearable only for those who are securely attached.

Paradox of the therapist's neutrality

Refusing to advise is itself an intervention.

Paradox of supererogation

If an act is truly best, why is it not required?

Paradox of moral sainthood (Wolf)

The morally perfect person would be intolerable company.

Paradox of self-sacrifice

Valuing another's life above one's own devalues the giver.

Paradox of pity

Compassion presupposes the inferiority of its object.

Paradox of charity

Aid can entrench the dependence it means to relieve.

Paradox of anonymous giving

The purest gift forfeits the accountability that improves giving.

Paradox of punishment

Inflicting harm to demonstrate that harm is wrong.

Paradox of deterrence

It can be right to threaten what it would be wrong to do.

Nuclear deterrence (MAD)

Safety secured by a credible commitment to suicide.

Paradox of the arms race

Each side's defense is the other's threat.

Paradox of pacifism

Refusing violence permits the violent.

Paradox of just war

Rules of restraint may prolong the killing they civilize.

Paradox of dirty hands

The good politician must sometimes do wrong to govern well.

Paradox of humanitarian intervention

Sovereignty is violated to defend the rights sovereignty protects.

Paradox of sanctions

Civilians are starved to inconvenience a ruler who eats.

Paradox of moral progress

We congratulate ourselves using standards our descendants will condemn.

Paradox of moral relativism

Asserted absolutely, it refutes itself.

Paradox of collective responsibility

Everyone is guilty, so no one is.

Paradox of the diffusion of responsibility

More witnesses, less help.

Paradox of omission

Letting die is treated as lesser than killing, with identical outcomes.

Paradox of moral licensing

Doing good today licenses doing worse tomorrow.

Paradox of virtue signaling

Sincere virtue becomes suspect once display is profitable.

Paradox of the golden rule

Treating others as you wish imposes your preferences on them.

Paradox of paternalism

Overriding a person's choices in the name of their autonomy.

Paradox of consent

Consent is shaped by the very system it is asked to legitimate.

Paradox of care

Caring labor is indispensable and therefore unpriced.

Paradox of the future generations

We owe duties to people whose existence our choices decide.

Paradox of the effective altruist

Maximizing good may require abandoning those near you.

Paradox of guilt

The most scrupulous feel guiltiest; the culpable feel least.

Paradox of the confession

Admitting fault can function as a way of retaining it.

Paradox of sovereignty

A power that makes the law cannot itself be bound by it.

Schmitt's paradox of the exception

The sovereign is defined by the power to suspend the order that defines him.

Paradox of constituent power

The people authorize the constitution that first constitutes "the people."

Rousseau's legislator paradox

Good laws require a good people, who require good laws.

Paradox of self-amendment (Suber)

Can an amendment rule be used to repeal itself?

Paradox of the social contract

Binding obligation from an agreement nobody signed.

Paradox of revolution

An illegal act founds the legality that judges it.

Paradox of the successful revolution

It devours its own children.

Paradox of civil disobedience

Breaking the law to affirm the rule of law.

Paradox of democratic suicide

The majority may vote to abolish majority rule.

Tocqueville paradox

Grievance intensifies as conditions improve.

Paradox of reform

Concessions accelerate rather than defuse revolt.

Hegel's master–slave dialectic

The master's recognition is worthless because it comes from a slave.

Plato's paradox of the tyrant

The most powerful man is the least free.

Paradox of political power

Holding it requires courting those you rule.

Iron law of oligarchy

Organizations formed for democracy generate ruling elites.

Paradox of representation

Representing a people that only exists once represented.

Paradox of the veto

Unanimity requirements block the action they exist to legitimate.

Paradox of bureaucracy

Rules written to eliminate arbitrariness create new arbitrariness.

Goodhart's law

A measure ceases to be a good measure once it becomes a target.

Campbell's law

The same, in social policy, with corruption included.

Paradox of transparency

More disclosure often lowers trust.

Paradox of accountability

Being watched shifts effort from the work to the record of it.

Paradox of expertise

Experts underperform simple rules while enjoying more confidence.

Paradox of secrecy

Secret law cannot guide the conduct it governs.

Paradox of surveillance

Freedom is defended by the apparatus of its erosion.

Paradox of censorship

Suppression advertises.

Streisand effect

The named case of the above.

Paradox of propaganda

It works only while its audience denies it is working.

Paradox of the free press

Freedom includes the freedom to destroy the conditions of freedom.

Paradox of multiculturalism

Respect for all cultures includes cultures that respect no others.

Paradox of assimilation

Belonging is offered on the condition of ceasing to be who arrived.

Paradox of nationalism

A universal form of feeling with an exclusively particular content.

Paradox of open borders

Solidarity strong enough to redistribute may require a boundary.

Paradox of equality

Identical treatment of unequal people entrenches inequality.

Paradox of meritocracy

Success justified by merit produces a hereditary elite.

Paradox of affirmative action

Race is used to arrive at a society where race is not used.

Paradox of rights

Rights are claimed against the state that must guarantee them.

Paradox of collective action (Olson)

Shared interest does not produce shared effort.

Free-rider paradox

Rational abstention undermines what everyone rationally wants.

NIMBY paradox

Universal support for housing, universal opposition to housing here.

Paradox of the crisis

Emergency both suspends legitimacy and manufactures it.

Paradox of security theater

Visible measures reassure precisely by not working.

Paradox of the whistleblower

Betrayal is the highest form of loyalty to the institution.

Paradox of the court jester

Only the powerless fool may speak the truth to power.

Paradox of precedent

The first case decided under a common-law rule has no precedent.

Paradox of the rule of law

Law rules only through the discretion of persons.

Paradox of obligation to unjust law

Legality claims obedience it may not deserve.

Paradox of legal fiction

Truth is served by an official falsehood.

Paradox of the reasonable person

A standard defined by a person who has never existed.

Paradox of the presumption of innocence

Maintained sincerely up to the moment of conviction.

Paradox of jury nullification

Jurors may lawfully refuse to apply the law.

Paradox of the plea bargain

The trial right is preserved by punishing those who exercise it.

Paradox of coerced confession

Torture produces speech, and thereby destroys evidence.

Paradox of self-incrimination

Silence protected, and universally read as guilt.

Paradox of the death penalty

Life's sanctity asserted by ending one.

Paradox of copyright

Monopoly granted in order to enlarge the commons.

Paradox of the patent thicket

Incentives to invent that make invention infeasible.

Paradox of the corporation as person

A person that cannot be imprisoned or die.

Paradox of privacy in public

Individually visible acts become a violation in aggregate.

Paradox of the contract of adhesion

Consent to terms no one has read or can alter.

Paradox of the statute of limitations

Justice expires so that justice remains possible.

Paradox of amnesty

Peace bought by declining to do justice.

Paradox of transitional justice

Truth commissions trade punishment for testimony.

Hume's paradox of taste

Judgments are subjective, yet some critics are simply better.

Paradox of tragedy

We pay to feel grief. (Volume I lists this; here as the root of the family.)

Paradox of the sublime

Terror contemplated at a safe distance yields pleasure.

Diderot's paradox of the actor

The performer must feel nothing to make an audience feel everything.

Paradox of catharsis

Purging emotion by inducing it.

Paradox of the ugly

Beautiful depictions of repellent things.

Paradox of the forgery

A physically identical canvas is worth nothing.

Benjamin's paradox of the aura

Reproduction democratizes art by destroying what made it worth reproducing.

Paradox of originality

Novelty is legible only against a tradition it departs from.

Paradox of the avant-garde

Institutionalized rebellion; the museum of the anti-museum.

Paradox of the readymade

Art created by nothing but the declaration that it is art.

Paradox of iconoclasm

Smashing images produces the era's most memorable images.

Paradox of the canon

Preservation requires exclusion.

Paradox of the intentional fallacy

The artist is the last authority on the work.

Paradox of documentary

Reality is staged in order to be truthfully shown.

Paradox of realism

Convincing fiction is achieved by artifice, not accuracy.

Paradox of the unreliable narrator

We learn the truth from a source stipulated to be false.

Paradox of spoilers

Knowing the ending often deepens the experience.

Paradox of suspense on rereading

Tension survives certainty about the outcome.

Paradox of the unfinished work

Incompletion becomes the source of its power.

Paradox of kitsch

Sincere feeling, deployed so efficiently it becomes false.

Paradox of comedy

Pain, correctly timed, is pleasure.

Paradox of the museum

Objects are honored by removal from the life that gave them meaning.

Paradox of restoration

Preserving an artifact requires replacing it.

Wittgenstein's private language argument

A language only I could understand could not be a language.

Kripkenstein's rule-following paradox

Nothing in my past fixes what "following the rule" now requires.

Quine's indeterminacy of translation

All behavioral evidence is compatible with incompatible translations.

Paradox of ostensive definition

Pointing presupposes knowing what is being pointed at.

Paradox of metaphor

A literal falsehood that communicates a truth nothing literal can.

Paradox of irony

Meaning is conveyed by asserting its opposite and being understood.

Paradox of silence

Saying nothing is often the most emphatic statement.

Euphemism treadmill

Each polite term acquires the stigma of what it replaced.

Paradox of jargon

Terms adopted for precision produce systematic obscurity.

Shannon's paradox of information

A message informs only to the extent that it was not expected.

McLuhan's paradox

The content of a medium distracts from the medium, which is the real message.

Observer's paradox (Labov)

Natural speech cannot be recorded, because recording it makes it unnatural.

Hawthorne effect

Studying a behavior changes it.

Self-fulfilling prophecy

The prediction causes the event.

Self-defeating prophecy (Oedipus effect)

The prediction prevents the event, and so is false.

Bateson's double bind

Contradictory demands where noticing the contradiction is also forbidden.

Therapeutic paradox

Prescribing the symptom relieves it.

Open-label placebo paradox

Placebos work when patients are told they are placebos.

Nocebo paradox

Warning of side effects produces them.

Paradox of the information age

Unprecedented access to data, declining shared knowledge.

Paradox of the filter bubble

Personalization narrows the person it serves.

Paradox of the attention economy

Content is free because you are what is sold.

Paradox of virality

Spontaneity, professionally manufactured.

Paradox of online anonymity

The condition of free speech and of its worst abuses.

Paradox of connection

Continuously in touch and increasingly alone.

Paradox of invented tradition

Ancient customs are usually recent inventions.

Paradox of the Renaissance

Advance achieved by returning to a lost antiquity.

Dialectic of Enlightenment

Reason, pressed to its conclusion, produces new myth and new terror.

Benjamin's paradox of civilization

Every document of civilization is a document of barbarism.

Morgan's American paradox

Ideals of liberty developed most vigorously in a slave society.

Paradox of empire

The conquests that build an empire generate the burdens that destroy it.

Paradox of progress

The past is judged by standards it made possible.

Paradox of the frontier

The wilderness that formed a national character is destroyed by settling it.

Paradox of decadence

Prosperity dissolves the discipline that produced it.

Paradox of the archive

Recording everything is a mode of forgetting.

Paradox of memory

Every act of recall rewrites what is recalled.

Paradox of counterfactual history

Explaining what happened requires imagining what did not.

Parkinson's law

Work expands to fill the time available.

Paradox of labor-saving devices

A century of automation, no gain in leisure.

Paradox of busyness

Efficiency creates the demand that consumes the time saved.

Paradox of the meeting

Gatherings held to make decisions prevent decisions.

Paradox of delegation

Retaining control requires surrendering it.

Paradox of the founder

The qualities that start a company wreck it at scale.

Innovator's dilemma

Serving your best customers correctly leads to your destruction.

Paradox of best practices

Universal adoption eliminates the advantage.

Peltzman effect / risk compensation

Safety equipment causes riskier behavior.

Paradox of the safety net

Insurance against a risk increases the risk (moral hazard).

Paradox of redundancy

Backups breed the complacency that defeats them.

Normal accidents (Perrow)

Complexity added for safety guarantees unforeseeable failure.

Paradox of automation

The more reliable the system, the less capable its human supervisor.

Moravec's paradox

What a child does effortlessly defeats machines; what a grandmaster does yields easily.

Polanyi's paradox

We know more than we can say, so we cannot instruct a machine to do it.

Paradox of AI alignment

We must specify values we have never successfully articulated.

Paradox of the Turing test

Passing it may measure our credulity rather than the machine's mind.

Paradox of encryption backdoors

A key for the good guys is a key.

Paradox of the password

Security requirements produce sticky notes.

Paradox of open source

Private, uncompensated labor produces the world's public infrastructure.

Paradox of the productivity app

Managing the system consumes the time it recovers.

Paradox of remote work

Flexibility that abolishes the boundary it was meant to protect.

Paradox of the checklist

Rigid procedure is what enables expert judgment.

Paradox of teaching

The student must already grasp something to recognize the lesson.

Socratic paradox

The wisest man is the one who knows that he knows nothing.

Socratic paradox (moral)

No one does wrong willingly; all vice is ignorance.

Curse of knowledge

Expertise makes it impossible to model the novice.

Paradox of grading

Measuring learning reliably distorts what is learned.

Paradox of credentialism

Universal degrees devalue the degree and raise its necessity.

Paradox of the exam

It ends up testing the ability to take exams.

Paradox of the autodidact

No teacher, and therefore no way to detect one's own gaps.

Paradox of the curriculum

Intellectual freedom is produced by constraint.

Paradox of reading

The books that change you most are the ones you were not ready for.

Paradox of the beginner's mind

Mastery consists in recovering the ignorance one started with.

Paradox of interdisciplinarity

Crossing fields requires standing in one.