English is the main working language of contemporary philosophy: most journals, encyclopedias and conferences use it, and classic texts by Plato, Descartes, Kant or Sartre are widely read and discussed in English translation. This glossary collects the terms philosophy students and readers meet first, from argument, premise and validity to ethics, epistemology, metaphysics, political philosophy and philosophy of mind, with Turkish equivalents and examples from seminars, essays and textbooks. It also flags the traps for Turkish speakers, such as valid and sound in logic, the everyday meaning of argument, and Latin phrases like a priori and ad hominem.
100 terms
10 topics
48 core terms
200 example sentences
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Core Concepts
philosophy
noun
Meaning
The study of the most basic questions about knowledge, reality, values, mind and reasoning, carried out mainly through careful argument rather than experiment.
Where you use it
Used for the academic subject (study philosophy, a philosophy degree) and for one thinker's system (Kant's philosophy). In everyday English it also means a personal principle (my philosophy of teaching), which is a much looser sense.
Examples
She switched from law to philosophy because she preferred asking why rules exist at all.
This module introduces the main branches of philosophy: ethics, epistemology, metaphysics and logic.
Usage note
The stress falls on the second syllable: phi-LO-so-phy. A person who does philosophy is a philosopher; the adjective is philosophical.
Common phrases
study philosophy · moral philosophy · political philosophy · ancient philosophy · philosophy of mind
An imagined scenario used to test a theory or to bring out our intuitions, without carrying out any real experiment.
Where you use it
Philosophers often name thought experiments after their central image: the trolley problem, the Chinese room, Mary's room, the experience machine. You run, construct or appeal to a thought experiment, and critics may ask whether the scenario is even coherent.
Examples
Nozick's experience machine is a thought experiment aimed at hedonism.
The trolley problem began as a thought experiment in a 1967 paper by Philippa Foot.
Common phrases
run a thought experiment · famous thought experiment · appeal to a thought experiment · construct a thought experiment
The human ability to think logically, draw conclusions and judge what is true or right; also a consideration that counts in favor of a belief or an action.
Where you use it
Two senses matter: reason as a faculty (uncountable: the Age of Reason, Kant's Critique of Pure Reason) and reasons as considerations (countable: a reason to believe, moral reasons). As a verb, reason means to think step by step.
Examples
Rationalists hold that reason, not the senses, is the main source of knowledge.
Do I have a reason to help strangers even when I don't want to?
Common phrases
pure reason · practical reason · a good reason · reasons for action · the Age of Reason
A judgment that seems true to us immediately, without our being able to give a full argument for it; in philosophy it is often used as evidence.
Where you use it
Philosophers test theories against intuitions about cases, and a theory can be counterintuitive. Experimental philosophers study whether intuitions vary across cultures. Kant's term Anschauung is also translated as intuition, but in a different sense.
Examples
Most people share the intuition that the man in the Gettier case doesn't really know.
Utilitarianism has some deeply counterintuitive consequences.
Common phrases
moral intuition · strong intuition · counterintuitive · appeal to intuitions · intuition pump
To put forward something as true or as existing, usually as the basis for an argument or to explain something, without first proving it.
Where you use it
Very common in philosophical writing: theories posit entities (Descartes posits a non-physical mind). It is also a noun for something assumed in a theory (theoretical posits). More formal than suggest or assume.
Examples
Plato posits a realm of unchanging Forms to explain how knowledge is possible.
We shouldn't posit new entities unless they do real explanatory work.
Usage note
The stress is on the first syllable: PO-zit. Do not confuse it with deposit or positive.
Common phrases
posit an entity · posit the existence of · theoretical posit · posit a mechanism
An argument that starts from apparently true premises and uses apparently valid reasoning, yet reaches a conclusion that seems false or contradictory.
Where you use it
Famous examples are Zeno's paradoxes of motion, the liar paradox ('This sentence is false') and the sorites paradox of the heap. Solving a paradox means showing which premise or step fails. The adjective is paradoxical.
Examples
Zeno's paradox claims that Achilles can never overtake the tortoise.
The liar paradox has puzzled logicians since ancient times.
Common phrases
Zeno's paradoxes · the liar paradox · the sorites paradox · resolve a paradox
A set of statements in which some of them, the premises, are offered as reasons for accepting another one, the conclusion.
Where you use it
The basic unit of philosophical work. You present, reconstruct, defend, attack or reject an argument, and you call it valid, sound, strong or weak. Philosophy essays are judged mostly on the quality of their arguments.
Examples
Let's reconstruct the argument in standard form before we decide whether it works.
Hume's argument against believing in miracles is still widely discussed.
Usage note
In everyday English an argument is also a quarrel (we had an argument last night). In philosophy it never means a fight, only a chain of reasons.
Common phrases
present an argument · reconstruct an argument · valid argument · counter an argument · the argument from design
A statement that is given as a reason in an argument and from which the conclusion is supposed to follow.
Where you use it
Philosophers number premises (P1, P2) when they set out an argument and then ask which one to deny. Typical verbs: accept, grant, deny, reject or defend a premise. A premise that is not stated openly is a hidden or suppressed premise.
Examples
I accept the first premise, but the second one seems false to me.
The argument relies on a hidden premise about what counts as harm.
Usage note
British texts sometimes spell it premiss. The plural premises also means a building and its land in everyday English (no smoking on the premises).
Common phrases
first premise · deny a premise · hidden premise · major premise · grant the premise
The statement that an argument tries to establish, supported by the premises that lead up to it.
Where you use it
You draw, reach or establish a conclusion, and a conclusion follows (or does not follow) from the premises. In written arguments it is usually introduced by therefore, thus, so or hence.
Examples
The conclusion simply does not follow from these premises.
Before you criticize the argument, state its conclusion in one sentence.
Common phrases
draw a conclusion · reach a conclusion · the conclusion follows · jump to conclusions
The study of correct reasoning, especially of which conclusions follow from which premises and why.
Where you use it
Used for the academic subject (formal logic, a logic course) and for the reasoning inside a text (the logic of her argument). Formal logic works with symbols; informal logic studies everyday arguments and fallacies.
Examples
First-year students take an introductory logic course in their first semester.
Aristotle's logic shaped Western thought for roughly two thousand years.
Describes an argument whose form guarantees that if all the premises are true, the conclusion must be true as well.
Where you use it
In logic, validity is about form, not about truth: a valid argument can have false premises and a false conclusion. The noun is validity. In everyday English valid just means acceptable (a valid point, a valid ticket), which is much looser.
Examples
'All fish can fly; salmon are fish; so salmon can fly' is valid but obviously unsound.
To test validity, ask whether the premises could be true while the conclusion is false.
Usage note
A common exam mistake is calling a single statement valid. Statements are true or false; arguments are valid or invalid.
Common phrases
valid argument · logically valid · valid form · test for validity
Describes a deductive argument that is valid and has only true premises, so that its conclusion is guaranteed to be true.
Where you use it
Used in logic classes and critical discussion: valid form plus true premises makes a sound argument. The noun is soundness. Outside logic, sound simply means reliable or sensible (sound advice).
Examples
The argument is valid, but it isn't sound, because the second premise is false.
Critics rarely question the logic; they question whether the argument is sound.
Common phrases
sound argument · logically sound · soundness and validity
A statement that someone puts forward as true and is ready to defend, often the main point that an essay or argument tries to support.
Where you use it
Found everywhere in philosophical writing: make, defend, support, challenge or reject a claim. It is also a verb (Hume claims that...). When reporting other views, philosophers prefer neutral verbs such as claim, argue and hold to says.
Examples
My central claim is that the objection misreads Kant's idea of duty.
That is a strong claim, and you need more than one example to support it.
Common phrases
make a claim · defend a claim · central claim · strong claim · knowledge claim
A reason given against a claim, theory or argument, suggesting that it may be false, unclear or badly supported.
Where you use it
Philosophy essays are often built around objections and replies: you raise, consider, anticipate, answer or rebut an objection. 'One might object that...' is the standard way of introducing one.
Examples
A famous objection to utilitarianism is that it seems to allow punishing the innocent.
In section three I consider two objections and show why neither succeeds.
Common phrases
raise an objection · reply to an objection · anticipate objections · serious objection · objections and replies
A particular case showing that a general claim or definition is false, or an example with true premises and a false conclusion showing that an argument form is invalid.
Where you use it
A key tool of analytic philosophy: someone proposes a definition (knowledge is justified true belief) and others search for counterexamples. You give, offer or find a counterexample, and a theory survives it or falls to it.
Examples
Gettier offered two short counterexamples to the view that justified true belief is knowledge.
One clear counterexample is enough to refute a universal claim.
Common phrases
offer a counterexample · decisive counterexample · immune to counterexamples · counterexample to a definition
Reasoning in which the conclusion is meant to follow necessarily from the premises, so that true premises guarantee a true conclusion.
Where you use it
Contrasted with induction. The adjective deductive is very common (deductive argument, deductive reasoning). The old textbook idea that deduction always goes from the general to the particular is not accurate; what matters is necessity.
Examples
Mathematical proofs are the clearest examples of deduction.
Some philosophers argue that deduction alone cannot tell us anything new about the world.
Usage note
In everyday English, and in Sherlock Holmes stories, deduction often means any clever inference, even when it is really induction or an educated guess.
Reasoning from observed cases to a general conclusion or a prediction, where the premises make the conclusion likely but not certain.
Where you use it
Inductive arguments are called strong or weak rather than valid or invalid. The problem of induction, made famous by Hume, asks what justifies our assumption that the future will be like the past.
Examples
Every swan I've seen is white, so all swans are white: a classic case of induction going wrong.
Hume's problem of induction is still one of the hardest questions in epistemology.
Common phrases
the problem of induction · inductive reasoning · inductive argument · enumerative induction
The step of reasoning from one or more statements to another, or the conclusion that is reached by taking that step.
Where you use it
The verb is infer: we infer a conclusion from premises. Common phrases are draw an inference, a valid inference, rules of inference, and inference to the best explanation (choosing the hypothesis that best explains the evidence).
Examples
The inference from 'most people believe it' to 'it is true' is not valid.
Scientists and detectives often rely on inference to the best explanation.
Usage note
Infer and imply are different: a speaker implies something, and a listener infers it. Using infer to mean imply is treated as a mistake in academic writing.
Common phrases
draw an inference · valid inference · rule of inference · inference to the best explanation
A condition that must be met for something to be true or to happen, although meeting it alone may not be enough.
Where you use it
A is a necessary condition for B if B cannot occur without A (if B, then A). Philosophers often analyze concepts in terms of necessary and sufficient conditions, and mixing the two up is a common source of invalid arguments.
Examples
Oxygen is a necessary condition for fire, but it isn't enough on its own.
Is truth a necessary condition for knowledge? Most epistemologists say yes.
Common phrases
necessary and sufficient conditions · a necessary condition for · individually necessary · jointly sufficient
A condition that, once it is met, guarantees that something is true or will happen, even if there are other ways it could also come about.
Where you use it
A is a sufficient condition for B if whenever A holds, B holds too (if A, then B). When philosophers define a concept they look for necessary and sufficient conditions; 'if and only if' (iff) expresses both together.
Examples
Being a square is a sufficient condition for being a rectangle.
Gettier showed that justified true belief is not a sufficient condition for knowledge.
Common phrases
necessary and sufficient conditions · a sufficient condition for · if and only if · jointly sufficient
In logic, a statement that is true in every possible case because of its form alone, such as 'Either it is raining or it is not raining'.
Where you use it
Checked with truth tables in propositional logic. In everyday English and rhetoric, a tautology is a needless repetition (a free gift) or an empty statement, and calling a claim tautological often means it says nothing informative.
Examples
'P or not P' is a tautology: no assignment of truth values can make it false.
Critics say 'survival of the fittest' becomes a tautology if the fittest simply means those who survive.
Common phrases
logical tautology · a mere tautology · tautological statement · truth table
An argument with two premises and a conclusion, each linking two categories, such as 'All humans are mortal; Socrates is human; so Socrates is mortal'.
Where you use it
Developed by Aristotle and central to logic until the nineteenth century. Its parts are the major premise, the minor premise and the conclusion, linked by a middle term. Students learn to test syllogisms for validity with Venn diagrams.
Examples
Write the argument as a syllogism and identify the middle term.
This syllogism is invalid because the middle term is not distributed in either premise.
Common phrases
categorical syllogism · valid syllogism · major premise · minor premise · middle term
A valid rule of inference: from 'If P, then Q' and 'P', you may conclude 'Q'.
Where you use it
Latin for 'the mode that affirms'. Its partner is modus tollens: from 'If P, then Q' and 'not Q', conclude 'not P'. Confusing these with affirming the consequent, which is invalid, is a classic student error.
Examples
If it rained, the street is wet; it rained; so the street is wet. That's modus ponens.
As the saying goes, one philosopher's modus ponens is another's modus tollens.
Usage note
Affirming the consequent ('If P, then Q; Q; so P') looks similar but is invalid: a wet street does not prove that it rained.
Common phrases
modus tollens · rule of inference · affirming the consequent · apply modus ponens
A statement, or a pair of statements, that cannot possibly be true, such as claiming both that something is the case and that it is not.
Where you use it
The law of non-contradiction says nothing can be both P and not-P at the same time and in the same respect. Showing that a view leads to a contradiction is a standard way to refute it (reductio ad absurdum). The adjective is contradictory.
Examples
If your theory implies both that he is free and that he isn't, you have a contradiction.
Hegel believed that contradiction drives the development of ideas.
Common phrases
law of non-contradiction · lead to a contradiction · derive a contradiction · a contradiction in terms
To make something logically necessary: if A entails B, then B must be true whenever A is true.
Where you use it
A precise logical verb, stronger than suggest or imply in everyday speech. The noun is entailment. Philosophers often say a view entails an unacceptable conclusion and then argue that we should reject the view.
Examples
'Everyone in the room is a student' entails 'Ali, who is in the room, is a student'.
If your theory entails that animals feel no pain, something has gone wrong.
Usage note
In everyday and business English, entail loosely means 'involve' (the job entails travel). In logic it always means strict necessity.
A common error in reasoning that makes an argument look convincing even though its premises do not properly support its conclusion.
Where you use it
Used in critical-thinking courses, debates and essay feedback. You commit a fallacy or spot one; a faulty argument is fallacious. Formal fallacies are errors of structure; informal fallacies come from content, ambiguity or irrelevance. Many have Latin names.
Examples
Your reply commits a fallacy: you attack her motives instead of her reasons.
The textbook lists more than thirty informal fallacies with examples.
Usage note
In everyday English a fallacy can also be a widely held false idea (it is a fallacy that...). In logic it means a faulty pattern of reasoning, not just a false belief.
A fallacy in which someone attacks the person making an argument, such as their character or motives, instead of the argument itself.
Where you use it
Latin for 'to the person'. Used as an adjective (an ad hominem attack) and as a noun (that's an ad hominem). Pointing out a real conflict of interest is not always fallacious; it becomes a fallacy when it replaces engaging with the reasons.
Examples
Calling him a hypocrite is an ad hominem; it doesn't show that his argument is wrong.
The reviewer avoided ad hominem remarks and focused on the paper's second premise.
Common phrases
ad hominem attack · ad hominem argument · resort to ad hominem · tu quoque
A fallacy in which someone presents an opponent's view as weaker or more extreme than it really is and then attacks that easier version.
Where you use it
You attack, set up or knock down a straw man. The opposite good practice is the principle of charity: interpret an opponent's view in its strongest form, which some people call steelmanning.
Examples
Saying that utilitarians don't care about anyone's feelings is a straw man.
Before you criticize Hobbes, make sure you aren't attacking a straw man.
Usage note
Also written strawman, and often hyphenated before a noun (a straw-man argument).
Common phrases
attack a straw man · set up a straw man · straw man argument · principle of charity
A fallacy in which an argument assumes, openly or quietly, the very conclusion it is supposed to prove.
Where you use it
The verb form is beg the question (the argument begs the question against the skeptic). Its Latin name is petitio principii, and it is closely related to circular reasoning.
Examples
Defending the reliability of memory by appealing to what you remember is begging the question.
Critics accuse the argument of begging the question, since its first premise already assumes that God exists.
Usage note
In everyday English and the media, 'this begs the question' often means 'this raises the question'. In philosophy, use only the logical meaning.
Common phrases
beg the question · begging the question against · circular reasoning · petitio principii
An argument claiming that one small step will inevitably lead to a chain of events ending in disaster; it is a fallacy when the chain is not supported.
Where you use it
Common in applied ethics debates about euthanasia, genetic engineering or free speech. Not every slippery slope argument is fallacious: it can be fair if each step is shown to be likely. You make, use or reject a slippery slope argument.
Examples
Allowing one exception won't necessarily lead to chaos; that's a slippery slope.
The essay examines the slippery slope argument against voluntary euthanasia.
Common phrases
slippery slope argument · slippery slope fallacy · a slippery slope to · on a slippery slope
A fallacy that presents only two options as if they were the only possibilities, when in fact other options exist.
Where you use it
Also called a false dichotomy or the either-or fallacy. Typical in speeches and advertising (you're either with us or against us). To answer it, point to a third option or a middle ground.
Examples
'Either we ban all cars or the city will choke' is a false dilemma.
Your essay sets up a false dilemma between pure reason and pure experience.
Usage note
Not every dilemma is false: in ethics, a genuine moral dilemma is a situation in which every option breaks some duty.
Common phrases
false dichotomy · either-or fallacy · set up a false dilemma · a third option
A fallacy that treats a claim as true simply because an authority figure says so, especially when that person is not an expert on the topic.
Where you use it
Its Latin name is argumentum ad verecundiam. Relying on genuine expert consensus is usually reasonable; it becomes fallacious when the authority is irrelevant or disputed, or is used to end the discussion.
Examples
Quoting a famous actor on vaccine safety is an appeal to authority.
'Aristotle said so' settles nothing; it's just an appeal to authority.
Common phrases
argument from authority · expert consensus · ad verecundiam · rely on authority
An irrelevant point brought into a discussion, deliberately or not, that draws attention away from the real issue.
Where you use it
An informal fallacy of relevance, common in debates and question-and-answer sessions. The name comes from a strong-smelling smoked fish said to throw dogs off a scent. In detective fiction it also means a misleading clue.
Examples
Whether the author was a nice person is a red herring; focus on the argument.
Bringing up the history of the theory was a red herring in a debate about whether it is true.
Usage note
Red herring is an idiom; do not translate it word for word as 'kırmızı ringa' in a Turkish text.
Common phrases
a red herring · throw in a red herring · red herring fallacy · irrelevant to the issue
A fallacy that assumes that because one event happened after another, the first event must have caused the second.
Where you use it
Short for post hoc ergo propter hoc, Latin for 'after this, therefore because of this'. Common in arguments about health, the economy and superstitions. A closely related error is confusing correlation with causation.
Examples
I wore my lucky socks and we won, so the socks helped: a textbook post hoc fallacy.
Saying the new rule cut crime just because the drop came afterwards is a post hoc fallacy.
Common phrases
post hoc ergo propter hoc · commit the post hoc fallacy · false cause · correlation and causation
A fallacy of drawing a general conclusion from too few cases or from cases that are not representative.
Where you use it
A failure of inductive reasoning that often lies behind stereotypes and anecdotes. A typical comment on an essay: 'Two examples are not enough; this is a hasty generalization.' British spelling: generalisation.
Examples
My two neighbors from that city are rude, so everyone there is rude: that's a hasty generalization.
With a sample of only twelve students, the study is open to the charge of hasty generalization.
Common phrases
make a hasty generalization · small sample · unrepresentative sample · sweeping generalization
The branch of philosophy that studies knowledge: what it is, how we get it, how beliefs are justified and how far our knowledge can reach.
Where you use it
Common in course titles and in the opening lines of papers. In current work the adjective epistemic (epistemic justification, epistemic duty) is used more often than epistemological.
Examples
Descartes' Meditations are a classic starting point for a course in epistemology.
Social epistemology asks how we gain knowledge from other people's testimony.
Usage note
The stress is on the fourth syllable: e-pis-te-MO-lo-gy. The root is Greek episteme, meaning knowledge.
Knowing that something is the case; traditionally defined as a belief that is true and properly justified, although this definition is disputed.
Where you use it
Uncountable: say knowledge, never a knowledge or knowledges. Epistemologists distinguish knowing that (propositional knowledge), knowing how (practical knowledge) and knowledge by acquaintance.
Examples
Gettier's cases suggest that justified true belief is not enough for knowledge.
Can we have knowledge of right and wrong without any experience?
Usage note
Turkish bilgi covers both knowledge and information. In philosophy, information is data or content, while knowledge is an achievement of someone who knows.
Common phrases
propositional knowledge · a priori knowledge · the limits of knowledge · knowledge claim · theory of knowledge
A mental state of taking something to be true, whether or not it really is true and whether or not you have good reasons for it.
Where you use it
In philosophy belief is a neutral term, not a religious one: thinking that it will rain tomorrow is a belief. Philosophers talk about forming, holding, revising and justifying beliefs, and about degrees of belief.
Examples
A belief can be well justified and still turn out to be false.
Should we revise our beliefs every time we meet someone who disagrees with us?
Common phrases
true belief · justified belief · hold a belief · revise a belief · degree of belief
The reasons or evidence that make it rational to hold a belief, or the property a belief has when it is properly supported.
Where you use it
Central in epistemology (epistemic justification) and in ethics (moral justification). Major debates include foundationalism versus coherentism and internalism versus externalism. The verb is justify and the adjective justified.
Examples
What is our justification for believing that the future will resemble the past?
Foundationalists think that justification must finally rest on basic beliefs.
Common phrases
epistemic justification · moral justification · lack justification · provide justification
The property a statement or belief has when it matches how things are; philosophers disagree about what this matching really consists in.
Where you use it
The main theories are the correspondence, coherence, pragmatic and deflationary theories of truth. Logicians speak of truth values (true and false) and truth tables. The plural truths means particular true statements (mathematical truths).
Examples
On the correspondence theory, truth is a relation between a statement and a fact.
Fill in the truth table to check whether the formula is a tautology.
Usage note
In Turkish logic texts truth is doğruluk (truth value: doğruluk değeri), while hakikat sounds more philosophical or literary. Choose by context.
Common phrases
theory of truth · truth value · truth table · necessary truth · the pursuit of truth
Describes knowledge or justification that does not depend on experience, such as knowing that all bachelors are unmarried or that 7 + 5 = 12.
Where you use it
Used as an adjective (a priori knowledge) or an adverb (known a priori). The opposite is a posteriori. Kant asked whether there are synthetic a priori truths, which say something about the world yet are known independently of experience.
Examples
We know a priori that a triangle has three sides; no survey is needed.
Kant argued that mathematics gives us synthetic a priori knowledge.
Usage note
Two pronunciations are common: /ˌeɪ praɪˈɔːraɪ/ and /ˌɑː priˈɔːri/. Outside philosophy, a priori is also used loosely to mean 'assumed in advance'.
Common phrases
a priori knowledge · known a priori · synthetic a priori · a priori argument
Describes knowledge or justification that depends on experience or observation, such as knowing that water boils at 100°C at sea level.
Where you use it
The opposite of a priori. Most scientific knowledge is a posteriori. Saul Kripke famously argued that some truths, such as 'water is H2O', are necessary and yet can be known only a posteriori.
Examples
Whether this metal conducts electricity can only be known a posteriori.
Empiricists claim that all real knowledge about the world is a posteriori.
Common phrases
a posteriori knowledge · known a posteriori · necessary a posteriori · a posteriori argument
The view that we do not or cannot have knowledge in some area, or the method of doubting claims until they are properly justified.
Where you use it
Philosophers speak of skepticism about the external world, about other minds or about morality. Ancient skeptics such as Pyrrho and Sextus Empiricus recommended suspending judgment; Descartes used doubt as a method for finding certain foundations.
Examples
Radical skepticism says we can't know anything at all about the external world.
Descartes' dream argument is a classic route to skepticism about the senses.
Usage note
British spelling is scepticism (sceptic, sceptical). In both spellings the first sound is sk.
Common phrases
radical skepticism · external world skepticism · moral skepticism · reply to skepticism
Based on observation, experience or experiment rather than on pure reasoning or theory.
Where you use it
Used for evidence, claims, questions and research (empirical evidence, an empirical question). Philosophers call a question empirical when observation can settle it, unlike a conceptual or normative one. Related to empiricism, but you can use empirical data without being an empiricist.
Examples
Whether people are happier in cities is an empirical question, not a philosophical one.
Experimental philosophers collect empirical data on people's moral intuitions.
Usage note
Turkish deneysel usually means experimental, based on controlled experiments. Empirical is broader and also covers observation, so empirik or görgül is often more accurate.
The branch of philosophy that studies the basic nature of reality: what exists, what things are, and ideas such as time, cause, identity and possibility.
Where you use it
Takes a singular verb (metaphysics is). In academic philosophy it is a rigorous technical field; in bookshops the word is sometimes used for spiritual or occult topics, which is not what philosophers mean.
Examples
Whether numbers really exist is a question for metaphysics, not for mathematics.
Aristotle's Metaphysics got its title from later editors, not from Aristotle himself.
Common phrases
analytic metaphysics · the metaphysics of time · metaphysical question · metaphysical realism
The fact or state of being real or being there at all, as opposed to not being; in existentialism, also the concrete life of a human being.
Where you use it
Used in metaphysics (the existence of numbers, the existence of the external world) and philosophy of religion (arguments for the existence of God). Typical verbs: prove, deny or doubt the existence of something.
Examples
In the Sixth Meditation, Descartes argues for the existence of material things.
For Sartre, existence comes before essence.
Usage note
Turkish varlık means both existence and a being or entity. For a particular thing that exists, English uses being or entity, not existence.
Common phrases
the existence of God · prove the existence of · human existence · existence precedes essence
The ability to choose between different possible actions in a way that makes us genuinely responsible for what we do.
Where you use it
The free will debate asks whether this ability is compatible with determinism. Compatibilists say yes; incompatibilists say no and split into libertarians (we are free, so determinism is false) and hard determinists (determinism is true, so we are not free).
Examples
If every event has a prior cause, is there any room left for free will?
Compatibilists define free will as acting on your own desires without coercion.
Usage note
Libertarian here names a view about free will and has nothing to do with libertarianism in politics.
Common phrases
the free will debate · have free will · deny free will · free will and determinism
The view that every event, including human choices, is fixed by earlier causes together with the laws of nature.
Where you use it
Central to the free will debate. Hard determinism denies free will; soft determinism (compatibilism) says freedom and determinism can both be true. Do not confuse it with fatalism, the idea that what will happen will happen whatever we do.
Examples
If determinism is true, could you have done otherwise last night?
Some argue that quantum physics weakens the case for strict determinism.
Common phrases
causal determinism · hard determinism · soft determinism · free will and determinism
The part of metaphysics that studies what exists and what basic kinds of things there are, such as objects, properties, events or numbers.
Where you use it
Also countable: a theory's ontology is the list of things it says exist (a sparse ontology). The adjective ontological appears in phrases like ontological commitment and the ontological argument for God's existence.
Examples
Quine argued that our ontology should include only what our best scientific theories require.
Does your ontology include holes and shadows, or only material objects?
Common phrases
social ontology · ontological commitment · the ontological argument · sparse ontology
The relation between a cause and its effect, in which one event or state brings about another.
Where you use it
Hume argued that we never observe a necessary connection between cause and effect, only constant conjunction. Modern theories analyze causation in terms of regularities, counterfactuals, probabilities or physical processes. Causality is a near synonym.
Examples
Correlation is not causation: ice cream sales and drownings both rise in summer.
Hume's account of causation shaped the whole later debate.
Common phrases
theory of causation · mental causation · causation and correlation · counterfactual theory of causation
The question of what makes a person at one time the same person as someone at another time, despite changes in body and mind.
Where you use it
A metaphysical topic, not the psychological or social idea of identity (who you feel you are). Locke tied personal identity to memory and consciousness; later views stress bodily, brain or psychological continuity. Derek Parfit argued that identity matters less than we think.
Examples
Teleportation cases are a standard way to test theories of personal identity.
On Locke's view, personal identity reaches back as far as your memory does.
Usage note
Turkish kimlik is the everyday word for identity, but in metaphysics identity means sameness, so özdeşlik is the better translation here.
Common phrases
personal identity over time · theory of personal identity · psychological continuity · memory criterion
In metaphysics, something that exists in its own right and has properties, rather than being a property of something else.
Where you use it
A key idea from Aristotle to the early modern period. Descartes recognized two kinds of created substance, mind and matter; Spinoza argued that there is only one substance, God or Nature. The everyday sense (a material, or a drug) is unrelated.
Examples
For Spinoza, there can be only one substance, which he calls God or Nature.
Descartes held that the mind is a thinking substance distinct from the body.
Common phrases
thinking substance · material substance · substance dualism · substance and attribute
The set of properties that make a thing what it is, without which it would not be that kind of thing at all.
Where you use it
Contrasted with accidents, properties a thing can lose while remaining itself. Essentialism is the view that things or kinds have essences. Sartre's slogan that, for humans, existence precedes essence denies a fixed human nature.
Examples
Is rationality part of the essence of a human being?
Sartre denies that we are born with an essence that decides who we are.
Usage note
In everyday English 'in essence' means 'basically', and essence can also be a concentrated flavor extract (vanilla essence), the sense of Turkish esans.
Common phrases
essence and existence · real essence · essence and accident · the essence of
The branch of philosophy that studies right and wrong, good and bad, and how we ought to live and treat one another.
Where you use it
As the name of a branch it takes a singular verb (ethics is). It is usually divided into normative ethics, applied ethics and metaethics. The same word also means the rules of a profession (medical ethics), and in that sense it can take a plural verb.
Examples
Ethics asks not only what we do, but what we ought to do.
This week's applied ethics seminar is on research with animals.
The principles about right and wrong behavior that people or societies accept, or the quality of an action being morally right or wrong.
Where you use it
Many writers use morality for the actual practice of judging right and wrong and ethics for the philosophical study of it, but the two are often interchangeable. The adjective is moral and the adverb morally.
Examples
Does morality depend on religion, or can it stand on its own?
Nietzsche criticized what he called slave morality.
Usage note
Turkish moral means morale (spirit, confidence), not morality. 'Morali bozuk' is 'he feels down', not 'he is immoral'.
Common phrases
common-sense morality · the morality of war · slave morality · morally wrong
An ethical theory holding that the right action is the one that produces the greatest overall happiness or well-being for everyone affected.
Where you use it
Associated with Jeremy Bentham and John Stuart Mill. Key distinctions are act versus rule utilitarianism and hedonistic versus preference utilitarianism. It is the best-known form of consequentialism. A follower is a utilitarian.
A family of ethical theories holding that some actions are right or wrong in themselves, because of duties or rules, whatever their consequences.
Where you use it
Most often linked to Kant. The adjective deontological is common (deontological ethics, deontological constraints). Deontologists hold, for example, that you may not lie or kill an innocent person even to bring about better results.
Examples
Deontology explains why breaking a promise seems wrong even when breaking it would help.
Kant's ethics is the standard example of a deontological theory.
An approach to ethics that focuses on good character and virtues such as courage, honesty and practical wisdom, rather than on rules or consequences.
Where you use it
Rooted in Aristotle and revived in the twentieth century. Instead of asking 'What should I do?', virtue ethicists ask 'What kind of person should I be?' Key terms: virtue, vice, character, eudaimonia and practical wisdom (phronesis).
Examples
Virtue ethics asks what an honest and kind person would do in your situation.
Anscombe's 1958 paper helped bring virtue ethics back into mainstream debate.
Common phrases
Aristotelian virtue ethics · virtue and vice · moral character · practical wisdom
The view that whether an action is right or wrong depends only on its consequences, so the best action is the one with the best outcome.
Where you use it
A broad family that includes utilitarianism but also theories that value things other than happiness. The term was coined by Elizabeth Anscombe in 1958. It is usually contrasted with deontology and virtue ethics.
Examples
For consequentialism, lying is wrong only when it leads to worse results.
She defends a version of consequentialism that also counts fairness as a good outcome.
The view that truth, knowledge or moral rightness is not absolute but depends on a culture, a person or a framework.
Where you use it
Most often discussed as moral or cultural relativism. Philosophers separate descriptive relativism (cultures do in fact disagree) from metaethical relativism (there is no single correct morality). A common objection is that global relativism refutes itself.
Examples
Moral relativism has trouble explaining how a society's values could ever improve.
If relativism is only true for you, why should I accept it?
Common phrases
moral relativism · cultural relativism · epistemic relativism · self-refuting relativism
Concerned with how things ought to be, or with what is good, right or reasonable, rather than with describing how things actually are.
Where you use it
Contrasted with descriptive or empirical. Normative ethics asks which actions are right, and normative claims contain words like ought, should, good and wrong. Hume's is-ought problem asks how normative conclusions can follow from purely descriptive premises.
Examples
'Most people eat meat' is descriptive; 'people ought to eat less meat' is normative.
Your conclusion is normative, but all your premises are factual. Where does the 'ought' come from?
Common phrases
normative ethics · normative claim · normative theory · normative and descriptive
The branch of ethics that asks what moral claims mean, whether they can be true or false and how we could know them, rather than which actions are right.
Where you use it
Major positions include moral realism, anti-realism, expressivism and error theory. G. E. Moore's Principia Ethica (1903) is often seen as its modern starting point. Also spelled meta-ethics, especially in British texts.
Examples
In metaethics we ask whether 'cruelty is wrong' states a fact or expresses a feeling.
Mackie's error theory is one of the most debated positions in metaethics.
The metaethical view that there are objective moral facts, which hold independently of what any person or culture believes about them.
Where you use it
Opposed by anti-realist views such as relativism, expressivism and error theory. Realists must explain what kind of facts moral facts are and how we come to know them. Someone who holds the view is a moral realist.
Examples
According to moral realism, slavery was wrong even when most people accepted it.
Critics of moral realism ask how we could ever perceive a moral fact.
Common phrases
robust moral realism · defend moral realism · moral facts · realism and anti-realism
The idea that political authority or moral rules are justified because rational people would agree, or have agreed, to accept them for mutual benefit.
Where you use it
Associated with Hobbes, Locke and Rousseau, and revived in the twentieth century by John Rawls. The contract is usually hypothetical, not a real historical event. Rousseau's The Social Contract (1762) is one of the classic texts.
Examples
In Hobbes's version of the social contract, people give up their natural liberty to escape constant war.
Social contract theories face the objection that nobody ever actually signed the contract.
Common phrases
social contract theory · the social contract tradition · hypothetical contract · consent of the governed
The condition of being free to act and choose without unjustified interference, especially from the state or from other people.
Where you use it
In political philosophy liberty and freedom are mostly interchangeable, though liberty sounds more formal. Isaiah Berlin's distinction between negative liberty (freedom from interference) and positive liberty (self-mastery) is standard. Mill's On Liberty (1859) is a key text.
Examples
Mill argued that the only good reason to limit someone's liberty is to prevent harm to others.
Berlin warned that appeals to positive liberty can be used to justify coercion.
Common phrases
negative liberty · positive liberty · individual liberty · civil liberties · restrict liberty
The imagined condition of human beings living without any government or political authority, used to explain why we need a state.
Where you use it
The starting point of social contract theory. Hobbes pictured it as a war of all against all; Locke saw it as governed by natural law but insecure; Rousseau described people in it as relatively peaceful and independent.
Examples
Hobbes thought that life in the state of nature would be violent and short.
Was the state of nature ever a real stage of history, or only a thought experiment?
Common phrases
in the state of nature · Hobbesian state of nature · leave the state of nature · law of nature
The quality of political power being rightful, so that those who hold it have a genuine right to rule and people have reasons to obey.
Where you use it
Political philosophers ask what makes authority legitimate: consent, fair procedures, good outcomes or tradition. Max Weber distinguished traditional, charismatic and legal-rational legitimacy. Typical verbs: gain, lose, confer or undermine legitimacy.
Examples
Locke grounds the legitimacy of government in the consent of the governed.
Does a state lose its legitimacy if it fails to protect basic rights?
Common phrases
political legitimacy · democratic legitimacy · undermine legitimacy · source of legitimacy
Rights that people are thought to have simply by being human, before and independently of any law or government.
Where you use it
Closely linked to Locke, who listed life, liberty and property, and to the natural law tradition. The idea shaped later declarations of rights. Bentham famously mocked natural rights as 'nonsense upon stilts'.
Examples
For Locke, governments exist to protect natural rights, not to create them.
If natural rights don't come from the state, where do they come from?
Common phrases
natural rights theory · natural law · inalienable rights · life, liberty and property
A tradition in political philosophy that puts individual liberty, equal rights and limits on state power at the center of political life.
Where you use it
Key figures include Locke, Mill and, in the twentieth century, Rawls. Philosophers distinguish classical liberalism, which stresses free markets and limited government, from egalitarian liberalism, which supports more redistribution. In US everyday politics, liberal means center-left, a much narrower sense.
Examples
Political liberalism asks how people with different worldviews can share fair institutions.
Communitarians criticize liberalism for treating individuals as if they had no social ties.
Common phrases
classical liberalism · political liberalism · egalitarian liberalism · liberal democracy
The state of having experiences, of there being something it is like to see, feel or think; also the state of being awake and aware.
Where you use it
Central in philosophy of mind and cognitive science. Philosophers separate phenomenal consciousness (what an experience feels like) from access consciousness (information available for reasoning and report). The adjective is conscious.
Examples
No one has yet explained how brain activity gives rise to consciousness.
Could a machine ever have consciousness, or only imitate it?
Usage note
Do not confuse consciousness (awareness) with conscience, the inner sense of right and wrong.
Common phrases
phenomenal consciousness · the nature of consciousness · stream of consciousness · explain consciousness
The question of how the mind, with its thoughts and feelings, is related to the body and especially to the brain.
Where you use it
Usually traced back to Descartes, who treated mind and body as two different substances and then struggled to explain how they interact. The main answers include dualism, physicalism, idealism and functionalism.
Examples
In her letters, Princess Elisabeth of Bohemia pressed Descartes hard on the mind-body problem.
Neuroscience has advanced a great deal, but the mind-body problem remains open.
Common phrases
the mind-body problem · solve the mind-body problem · Cartesian mind-body problem
The view that the mind and the body are fundamentally different kinds of thing, so that mental states are not simply physical states.
Where you use it
Substance dualism (Descartes) says the mind is a separate non-physical thing; property dualism says one physical thing has both physical and non-physical properties. The main challenge is explaining how the mental and the physical interact.
Examples
Cartesian dualism treats the mind as a thinking thing that takes up no space.
Property dualism has gained new supporters through the debate on qualia.
The view that everything that exists is physical or depends entirely on the physical, so that the mind is ultimately part of the physical world.
Where you use it
Today the most widely held position in philosophy of mind. Often used interchangeably with materialism, although physicalism stresses whatever physics describes rather than just matter. Versions include identity theory and non-reductive physicalism.
Examples
If physicalism is true, then pain is nothing over and above a brain state.
Frank Jackson designed the Mary's room argument as an objection to physicalism.
Common phrases
reductive physicalism · non-reductive physicalism · physicalism about the mind · reject physicalism
The subjective qualities of conscious experience, such as how the redness of red looks or how a headache feels to the person who has it.
Where you use it
A plural noun; the singular quale is rare. Qualia are central to arguments against physicalism, such as Mary's room and the inverted spectrum. Some philosophers, such as Daniel Dennett, deny that qualia exist in the sense their defenders claim.
Examples
Could a robot that reacts to colors have qualia, or only the behavior?
Mary's room is meant to show that qualia are something physics leaves out.
Usage note
Usually pronounced /ˈkwɑːliə/, sometimes /ˈkweɪliə/. It takes a plural verb: qualia are, not qualia is.
Common phrases
visual qualia · inverted qualia · the problem of qualia · deny qualia
The property of mental states of being about or directed at something, as a belief is about a fact or a desire is for an object.
Where you use it
Brought into modern philosophy by Franz Brentano, who saw it as the mark of the mental. Central to phenomenology and to debates on whether computers can really think. It has nothing to do with intention in the everyday sense of a plan.
Examples
Brentano held that intentionality is what separates the mental from the physical.
Searle's Chinese room asks whether a program could have genuine intentionality.
Usage note
A common mistake is reading intentionality as 'doing something on purpose'. For the same reason, Turkish niyetlilik is a misleading translation.
Common phrases
the mark of the mental · original intentionality · derived intentionality · intentional state
The view that a mental state is defined by what it does, its causal role between inputs, other mental states and behavior, rather than by what it is made of.
Where you use it
Developed from the 1960s by Hilary Putnam and others. It allows multiple realizability: the same mental state could exist in a human brain, an octopus or a computer. Sociology and architecture have unrelated theories with the same name.
Examples
On functionalism, pain is whatever state is caused by damage and causes avoidance.
The Chinese room was designed as a challenge to functionalism and to strong AI.
Common phrases
machine functionalism · multiple realizability · functional role · functionalism about the mind
The problem of explaining why and how physical processes in the brain give rise to subjective experience at all, instead of running without any inner feeling.
Where you use it
The phrase was introduced by David Chalmers in the mid-1990s. He contrasted it with the easy problems of explaining functions such as attention, memory and the ability to report. People often just say the hard problem.
Examples
Even a complete map of the brain might leave the hard problem of consciousness untouched.
Some physicalists argue that the hard problem of consciousness is an illusion created by our concepts.
Common phrases
the hard problem · easy problems of consciousness · solve the hard problem · explanatory gap
The view that all or most of our knowledge comes from experience through the senses, rather than from reason alone.
Where you use it
Usually taught alongside rationalism. The classic empiricists of the seventeenth and eighteenth centuries are Locke, Berkeley and Hume. A follower is an empiricist; the adjective empirical has a broader, everyday scientific meaning.
Examples
Locke's empiricism starts from the claim that the mind begins as a blank slate.
Hume pushed empiricism to skeptical conclusions about causation and the self.
Common phrases
British empiricism · logical empiricism · radical empiricism · empiricism and rationalism
The view that reason, rather than sense experience, is the main source of knowledge, and that some knowledge is innate or a priori.
Where you use it
In histories of philosophy it names the seventeenth-century continental rationalists Descartes, Spinoza and Leibniz. In everyday English rationalism can also mean a general preference for reason over religion or emotion.
Examples
Descartes' rationalism rests on clear and distinct ideas known by reason alone.
The exam question asks you to compare rationalism and empiricism on innate ideas.
Usage note
Rationalism, a theory of knowledge, is different from rationalization, which means inventing good-sounding reasons for something after the fact.
Common phrases
continental rationalism · rationalism and empiricism · moral rationalism · critical rationalism
A philosophical movement centered on individual existence, freedom and choice, holding that people create meaning through how they live rather than finding it ready-made.
Where you use it
Kierkegaard is seen as a forerunner; in the twentieth century the movement is linked with Sartre, Simone de Beauvoir and, more loosely, Camus and Heidegger. Key ideas: existence precedes essence, anxiety, authenticity, bad faith and the absurd.
Examples
Sartre's lecture 'Existentialism Is a Humanism' is a short and readable introduction.
Camus rejected the label, but his work is usually taught alongside existentialism.
Usage note
Existential in everyday English (an existential crisis, an existential threat) is much broader than the philosophical movement.
A philosophical method and movement that studies the structures of experience as they appear to consciousness, from the first-person point of view.
Where you use it
Founded by Edmund Husserl and developed by Heidegger, Merleau-Ponty and others. In analytic philosophy of mind, 'the phenomenology of an experience' simply means what the experience is like, which is a narrower sense.
Examples
Merleau-Ponty's phenomenology puts the lived body at the center of perception.
Husserl described phenomenology as a return 'to the things themselves'.
The metaphysical view that reality is fundamentally mental or depends on minds, so that no world exists entirely independent of thought or experience.
Where you use it
Berkeley's subjective idealism says that to be is to be perceived; Kant's transcendental idealism and the German idealism of Fichte, Schelling and Hegel are other major forms. In everyday English idealism means pursuing high ideals, which is a different sense.
Examples
Berkeley's idealism denies that matter exists independently of perception.
German idealism dominated philosophy in the decades after Kant.
Usage note
In philosophy the opposite of idealism is usually realism or materialism, not cynicism or pragmatism as in everyday speech.
An American philosophical movement holding that the meaning and truth of ideas depend on their practical consequences and on how well they work in experience.
Where you use it
Founded by Charles Sanders Peirce and William James and developed by John Dewey; Richard Rorty is a later representative. In everyday English pragmatism means a practical, realistic attitude, which is related but much looser.
Examples
William James's pragmatism treats true beliefs as those that prove useful in the long run.
Dewey applied pragmatism to education and democracy.
Common phrases
American pragmatism · classical pragmatism · pragmatic theory of truth · neo-pragmatism
An ancient Greek and Roman school teaching that virtue is the only true good and that we should calmly accept what we cannot control.
Where you use it
Founded by Zeno of Citium around 300 BCE; its best-known later writers are Seneca, Epictetus and Marcus Aurelius. The school is written with a capital S; lowercase stoicism and stoic in everyday English mean enduring hardship without complaint.
Examples
Stoicism teaches that our judgments, not events themselves, are what disturb us.
Interest in Stoicism has grown again through popular books on resilience.
Common phrases
ancient Stoicism · Roman Stoicism · Stoic ethics · modern Stoicism
The view that life has no meaning, value or purpose, or more narrowly that there are no moral truths or no knowledge at all.
Where you use it
Philosophers separate existential nihilism (life is meaningless), moral nihilism (nothing is right or wrong) and epistemological nihilism. Nietzsche is often linked to nihilism, but he described it as a crisis to be overcome, not as his own position.
Examples
Nietzsche saw the decline of religious belief as opening the door to nihilism.
Moral nihilism says that no action is really right or wrong.
Common phrases
moral nihilism · existential nihilism · overcome nihilism · slide into nihilism
A style of philosophy, dominant in English-speaking universities, that stresses clear argument, logical analysis and close attention to language and science.
Where you use it
Traced to Frege, Russell, Moore and the early Wittgenstein around 1900. Usually contrasted with continental philosophy, though many now think the division is outdated. Analytic papers tend to be short, argument-driven and full of examples and counterexamples.
Examples
Analytic philosophy began partly as a revolt against British idealism.
She works in analytic philosophy of language, mainly on reference.
Usage note
Do not confuse analytic philosophy with analytic truths (statements true by meaning alone) or the analytic-synthetic distinction; they share a word but are different things.
Common phrases
analytic tradition · analytic philosopher · early analytic philosophy · analytic and continental
A loose label for mainly French and German traditions since Kant and Hegel, including phenomenology, existentialism, hermeneutics, critical theory and post-structuralism.
Where you use it
The label was largely created by English-speaking philosophers to describe what they were not doing, so many of the thinkers it covers would not use it. It tends to stress history, culture, interpretation and lived experience. Often-read names: Heidegger, Sartre, Foucault, Derrida.
Examples
Our department offers modules in both analytic and continental philosophy.
Foucault is a central figure in continental philosophy, though his work also shaped history and sociology.
Kant's supreme principle of morality: a command that binds every rational being unconditionally, whatever their desires or goals.
Where you use it
Contrasted with hypothetical imperatives (if you want X, do Y). Its best-known versions are the formula of universal law (act only on maxims you could will as universal laws) and the formula of humanity (never treat people merely as means). Set out in Kant's Groundwork of the Metaphysics of Morals (1785).
Examples
According to the categorical imperative, making a false promise to get a loan is wrong because the maxim cannot be universalized.
Students often confuse the categorical imperative with the Golden Rule.
Usage note
Imperative here means a command, not 'very important'. It also differs from the Golden Rule (treat others as you want to be treated), which Kant himself criticized.
Common phrases
formula of universal law · formula of humanity · hypothetical imperative · apply the categorical imperative
Descartes' argument 'I think, therefore I am', meant to show that you cannot doubt your own existence while you are thinking.
Where you use it
Short for the Latin cogito, ergo sum; the French version (je pense, donc je suis) appears in the Discourse on Method (1637). Philosophers debate whether the cogito is really an inference, and whether it proves a self or only that thinking is going on.
Examples
According to Descartes, the cogito survives even the most radical doubt.
Critics such as Lichtenberg suggested that the cogito shows only that thinking is happening, not that there is an 'I'.
Usage note
The exact Latin phrase cogito, ergo sum appears in the Principles of Philosophy (1644). In the Meditations, Descartes says instead that 'I am, I exist' is true whenever he thinks it.
Common phrases
the Cartesian cogito · cogito, ergo sum · Descartes' cogito · certainty of the cogito
Plato's theory that beyond the changing physical world there are perfect, eternal and unchanging Forms, such as Beauty or Justice itself, which things only imperfectly copy.
Where you use it
Also called the theory of Ideas; Forms is often capitalized to avoid confusion with ordinary forms. It is developed in dialogues such as the Phaedo and the Republic, and criticized by Aristotle and even, in the Parmenides, by Plato himself.
Examples
According to the theory of Forms, a beautiful painting only shares in Beauty itself.
The allegory of the cave is often read as an illustration of the theory of Forms.
Usage note
Plato's Ideas are not ideas in anyone's head; they exist independently of minds. This is why many English translators prefer the word Forms.
Common phrases
Plato's theory of Forms · the Form of the Good · participate in a Form · the world of Forms
A way of examining ideas through a series of questions and answers that exposes contradictions in someone's beliefs and pushes them toward clearer thinking.
Where you use it
Named after Socrates as he appears in Plato's early dialogues, where he asks questions such as 'What is courage?' and tests each answer. The Greek term is elenchus. Law schools and philosophy seminars still use versions of it.
Examples
In the Euthyphro, Socrates uses the Socratic method to test definitions of piety.
Our tutor runs the seminar using the Socratic method, so be ready to answer questions.
Common phrases
use the Socratic method · Socratic questioning · Socratic dialogue · Socratic irony
Aristotle's idea that a virtue lies between two vices, one of excess and one of deficiency, as courage lies between cowardice and rashness.
Where you use it
Also called the doctrine of the mean, from the Nicomachean Ethics. The mean is relative to us and is found through practical wisdom; it is not a mathematical average or a call for moderation in everything.
Examples
For Aristotle, generosity is the golden mean between wastefulness and stinginess.
The golden mean doesn't tell you always to feel a moderate amount of anger.
Usage note
Do not confuse it with the golden ratio in mathematics and art, or with the Golden Rule in ethics.
Common phrases
Aristotle's golden mean · doctrine of the mean · excess and deficiency · find the mean
John Rawls's thought experiment in which people choose principles of justice without knowing their own place in society, such as their class, talents or gender.
Where you use it
Part of the original position in A Theory of Justice (1971). Rawls argued that people behind the veil would choose equal basic liberties and the difference principle. People speak of choosing or reasoning behind the veil of ignorance.
Examples
Behind the veil of ignorance, you wouldn't know whether you'd be born rich or poor.
Critics ask whether the veil of ignorance strips away too much of who we are.
Common phrases
behind the veil of ignorance · the original position · the difference principle · choose principles of justice
Rousseau's idea of the shared will of the people as a whole, aimed at the common good, as opposed to the sum of private interests.
Where you use it
A central concept of The Social Contract (1762). Rousseau contrasted it with the will of all, which is just the sum of individual preferences. Critics worry that appeals to the general will can be used to override individuals.
Examples
For Rousseau, laws are legitimate only when they express the general will.
How can a majority vote reveal the general will rather than the will of all?
Common phrases
express the general will · the will of all · the common good · Rousseau's general will
The idea that the mind at birth is like a blank slate with no built-in ideas, so that all its contents come from experience.
Where you use it
Latin for 'scraped tablet'. Strongly associated with Locke's Essay Concerning Human Understanding (1689), although Locke himself mostly used the image of white paper. Still used in debates about nature and nurture.
Examples
Locke's attack on innate ideas is usually summed up with the phrase tabula rasa.
Modern psychology suggests that the mind is far from a tabula rasa at birth.
Common phrases
a blank slate · innate ideas · nature and nurture · Locke's tabula rasa
The principle that we should not assume more entities or causes than we need: among competing explanations, prefer the simplest one that works.
Where you use it
Named after the fourteenth-century philosopher William of Ockham, although its best-known wording came later. Also called the principle of parsimony. It is a rule of thumb for choosing between theories, not a proof that the simplest theory is true.
Examples
By Occam's razor, we shouldn't posit ghosts if a draft explains the creaking door.
Physicalists often appeal to Occam's razor in arguments against dualism.
Usage note
Both spellings, Occam and Ockham, are correct. Ockham is a village in Surrey, England.
Common phrases
apply Occam's razor · principle of parsimony · the simplest explanation · Ockham's razor
A method of reaching truth through the clash of opposing positions, from the questions and answers of Plato's dialogues to Hegel's account of ideas developing through contradiction.
Where you use it
In Hegel, thought overcomes contradictions while keeping what was true on each side; Marx turned this into dialectical materialism, a theory of history. The neat formula thesis, antithesis, synthesis is a popular simplification that Hegel himself rarely used.
Examples
Plato's dialectic proceeds by testing definitions through questions and answers.
Hegel's dialectic shows how a concept turns into its opposite and is then taken up into something richer.
Plato's story in the Republic of prisoners who see only shadows on a cave wall, used to show how education leads the mind from appearances to true reality.
Where you use it
Found in Book VII of the Republic. The shadows stand for appearances, the sun for the Form of the Good, and the freed prisoner who goes back down for the philosopher. A favorite topic in introductory lectures and essays.
Examples
In the allegory of the cave, the prisoners mistake shadows for real things.
Many films borrow from the allegory of the cave to question what is real.
Common phrases
Plato's allegory of the cave · the cave allegory · leave the cave · shadows on the wall
Nietzsche's idea that a basic drive of living things is to grow, overcome resistance and express their strength, not merely to survive or seek pleasure.
Where you use it
A translation of the German Wille zur Macht. It does not simply mean a desire to dominate others; it includes self-overcoming and creativity. The book called The Will to Power was compiled from Nietzsche's notes after his death and should be used with care.
Examples
Nietzsche treats the will to power as more basic than the drive for self-preservation.
Reading the will to power as a simple love of violence misses Nietzsche's point.
Common phrases
Nietzsche's will to power · self-overcoming · master and slave morality · revaluation of values
Ten questions from this glossary. Pick the right meaning for each term and see your score.
How to learn philosophy vocabulary
Learn terms in contrasting pairs, because philosophers define them against each other: valid and sound, a priori and a posteriori, deduction and induction, necessary and sufficient, descriptive and normative.
Read real philosophical texts every week, such as encyclopedia entries, journal articles and classic works in English translation, and collect the phrases that structure arguments: 'it follows that', 'one might object that', 'this begs the question'.
Practice reconstructing arguments in standard form: number the premises, write the conclusion, then say in English which premise you would reject and why.
Learn the Greek and Latin building blocks (-ism, -ology, onto-, episteme, a priori, ad hominem, modus ponens): they unlock dozens of terms and their pronunciation.
Keep a list of everyday words that have a strict technical meaning in philosophy, such as argument, valid, sound, claim, idealism and stoic, and check it before you hand in an essay.
Frequently asked questions
How can I learn philosophy vocabulary in English effectively?
Study by topic (logic, ethics, epistemology and so on) rather than alphabetically, and learn each term inside a short argument or example, not as an isolated word. Read real texts regularly, such as encyclopedia entries, introductory textbooks and classic works in English translation, and then write a few sentences of your own that use the new terms. Discussing a reading out loud with classmates in English fixes the vocabulary much faster than lists alone.
What is the difference between a valid and a sound argument?
An argument is valid when its form guarantees that true premises would lead to a true conclusion; it says nothing about whether the premises are actually true. An argument is sound when it is valid and all its premises really are true. So every sound argument is valid, but a valid argument with a false premise is unsound.
What does 'beg the question' mean in philosophy?
In philosophy and logic, an argument begs the question when it quietly assumes the very thing it is supposed to prove. In everyday English and journalism, people often use the phrase to mean 'raise the question'. In a philosophy essay, use it only in the logical sense, and say 'raises the question' when you simply mean that a question comes up.
Which philosophy terms should I learn first?
Start with the vocabulary of arguments, because every course uses it: argument, premise, conclusion, claim, objection, counterexample, valid and sound. Then learn the names of the main branches (ethics, epistemology, metaphysics, logic) and their key ideas, such as knowledge, belief, justification, free will and consciousness. The first tier of this list covers exactly these.
Why do some philosophy terms have several Turkish equivalents?
Turkish philosophical vocabulary comes from different periods: older Arabic-origin words (cevher, kıyas), newer coinages (töz, tasım, önsel) and borrowings from European languages (empirizm, fenomenoloji). Translators and departments choose differently, so you will see deneycilik and empirizm, or kuşkuculuk and septisizm, for the same idea. When you write in Turkish, choose one term, give the English or Latin original in brackets the first time, and use it consistently.
