哲学英語：必須語彙とフレーズ

"ontological commitment"

The entities that a theory or statement implicitly requires to exist in order for that theory or statement to be true

"When we say "there are prime numbers greater than one hundred", we incur an ontological commitment to the existence of abstract mathematical objects."

"modal realism"

The view, associated with David Lewis, that all possible worlds are equally real and concrete, differing only in that they are spatiotemporally isolated from one another

"According to modal realism, the possible world in which you chose a different career is just as genuinely real as the actual world you inhabit."

"substance dualism"

The position that mind and body are two fundamentally distinct kinds of substance — one mental and non-extended, the other physical and extended — that somehow interact

"Descartes defended substance dualism, arguing that the thinking self is entirely different in nature from the material body it inhabits."

"property instantiation"

The relation by which a particular object possesses or exemplifies a property at a time; the "having" relation between a concrete thing and an abstract universal

"The rose's redness is explained by property instantiation: the rose participates in, or instantiates, the universal redness."

"persistence through time"

The philosophical problem of how a single object can remain the same entity across time while undergoing change in its intrinsic properties

"The Ship of Theseus is the classic puzzle about persistence through time: if every plank is replaced, is the resulting vessel numerically identical to the original?"

"supervenience"

A dependency relation in which facts of one kind cannot differ without a corresponding difference in facts of another kind; mental properties are often said to supervene on physical properties

"Physicalists typically hold that mental states supervene on brain states: there can be no psychological change without some underlying neurological change."

"mereology"

The formal study of part–whole relations: what it means for something to be a part of something else, and what conditions govern composition into wholes

"Debates in mereology about unrestricted composition ask whether any arbitrary collection of objects — a coffee cup and the moon — automatically constitutes a composite whole."

"causal closure"

The thesis that every physical event that has a cause has a sufficient physical cause, leaving no room for non-physical causes to intervene in the physical world

"Causal closure of the physical domain poses a serious challenge to substance dualism: if the body is fully explained by physical causes, there is no role for an immaterial mind to play."

"epistemic justification"

The property that a belief must have, in addition to being true, for it to count as knowledge; the feature that distinguishes a rational belief from mere lucky guessing

"Gettier cases show that epistemic justification and truth together are not sufficient for knowledge, since a belief can be justified and true yet still not constitute genuine knowledge."

"foundationalism"

The view that the structure of knowledge rests on a foundation of basic, non-inferentially justified beliefs that support all other beliefs through chains of inference

"Descartes sought indubitable foundational beliefs — such as the cogito — upon which to rebuild the entire edifice of human knowledge."

"reliabilism"

The externalist theory that a belief is justified if and only if it is produced by a reliable cognitive process — one that tends to produce true beliefs in the relevant circumstances

"On reliabilism, visual perception normally justifies perceptual beliefs because human visual systems are, in standard conditions, reliable truth-trackers."

"epistemic closure"

The principle that if a subject knows a proposition and knows that it entails a second proposition, the subject also knows the second proposition

"Sceptical arguments often exploit epistemic closure: if you know you have hands, and hands entail you are not a handless brain-in-a-vat, you should know you are not such a brain."

"contextualism"

The view that the truth conditions of knowledge attributions vary with the epistemic standards operative in the context in which the attribution is made

"Contextualism explains why we readily say "I know my car is in the driveway" in ordinary conversation, but hesitate when a sceptic raises the possibility that it was stolen minutes ago."

"testimonial knowledge"

Knowledge acquired through the sincere assertions of other people, which forms the basis of most of what any individual knows about the world

"We rely on testimonial knowledge for virtually all historical facts, scientific findings, and geographic information that we could not verify through personal observation."

"underdetermination"

The thesis that the available evidence is always compatible with multiple competing theories, so evidence alone cannot uniquely fix which theory is correct

"The underdetermination of theory by evidence motivates scientific antirealism: if rival hypotheses fit the data equally well, we have no rational basis for preferring one as literally true."

"pragmatic encroachment"

The view that practical stakes — how much it matters whether a belief is true — affect whether a subject counts as knowing a proposition, not merely whether it is rational to act on it

"Pragmatic encroachment implies that an investor who stands to lose a million dollars needs stronger evidence before she knows the market will rise than a casual observer checking the news."

"categorical imperative"

Kant's supreme principle of morality, which commands unconditionally: act only according to that maxim by which you can at the same time will that it should become a universal law

"Kant argued that lying is always wrong because the categorical imperative shows that a universal law permitting lying would be self-defeating — it would undermine the very practice of truth-telling."

"consequentialism"

The family of moral theories holding that the rightness or wrongness of an action is determined solely by its consequences — specifically, by how much good or harm it produces

"A strict consequentialist would endorse sacrificing one innocent person if doing so would reliably save five others, since the outcome with fewer deaths has greater net value."

"moral realism"

The metaethical position that there are objective moral facts or truths that are mind-independent — true regardless of what any individual or culture believes about them

"Moral realism implies that when abolitionists claimed that slavery was wrong, they were stating a fact that was true even during periods when most people accepted the institution."

"virtue ethics"

The tradition in normative ethics, rooted in Aristotle, that focuses on the character traits and dispositions of the agent rather than on rules or consequences

"Virtue ethics asks not 'What is the right action?' but 'What would a person of good character do?' — locating morality in human excellence rather than in any external standard."

"moral particularism"

The view that the moral relevance and weight of a feature of a situation can vary from case to case: a feature that counts in favour of an action in one context may count against it in another

"A moral particularist argues that because context alters the significance of every moral consideration, no universal principles can reliably guide ethical reasoning across all situations."

"reflective equilibrium"

A method of moral reasoning, associated with John Rawls, that seeks coherence between our considered particular moral judgements and our general principles, revising each in light of the other

"Rawls used reflective equilibrium to derive the principles of justice, moving back and forth between intuitions about fairness in specific cases and the general principles that could explain them."

"moral demandingness"

The objection that a moral theory requires too much of agents — demanding that they sacrifice their own projects, relationships, and well-being to benefit strangers or maximise aggregate welfare

"Singer's utilitarian argument for famine relief faces the moral demandingness objection: if we must donate until we reach the point of marginal utility, almost no personal expenditure is permissible."

"non-cognitivism"

The metaethical view that moral judgements do not express beliefs or describe facts but rather express attitudes, prescriptions, or endorsements — and therefore cannot be strictly true or false

"According to non-cognitivism, saying "cruelty is wrong" is not a factual claim but an expression of disapproval akin to saying "Boo, cruelty!" — it has emotive force but no truth value."

"modus ponens"

The valid argument form: if the premise "If P then Q" is true, and the premise "P" is true, then the conclusion "Q" must be true

"The argument "If it is raining, the streets are wet; it is raining; therefore, the streets are wet" is a textbook example of modus ponens."

"valid argument"

An argument in which it is impossible for all the premises to be true and the conclusion to be false simultaneously — the truth of the premises logically guarantees the truth of the conclusion

"A valid argument with a false premise can still have a false conclusion: "All fish are mammals; a shark is a fish; therefore a shark is a mammal" is valid but unsound."

"reductio ad absurdum"

An indirect proof strategy that refutes a position by deriving a contradiction or absurdity from it, thereby showing the original assumption must be false

"To show that there is no largest prime number, Euclid used reductio ad absurdum: he assumed a largest prime existed and derived a contradiction, so the assumption must be false."

"begging the question"

The informal fallacy of assuming in one's premises the very conclusion one is trying to prove, making the argument circular and epistemically worthless

"The argument "The Bible is true because it is the word of God, and we know it is the word of God because the Bible says so" commits the fallacy of begging the question."

"soundness"

The property of an argument that is both valid — its conclusion follows from its premises — and has all true premises, guaranteeing a true conclusion

"Philosophers aim to produce sound arguments, not merely valid ones: a valid argument with false premises may lead to a false conclusion and cannot establish the truth of anything."

"inference to the best explanation"

The ampliative reasoning pattern — also called abduction — in which one concludes that the hypothesis that best explains the observed evidence is likely to be true

"When a doctor concludes that a patient has pneumonia because it best explains the X-ray opacity, fever, and cough, she is using inference to the best explanation."

"logical entailment"

The relation that holds between a set of sentences and a sentence when it is impossible for all the members of the set to be true and the sentence to be false

"The sentence "John is a bachelor" logically entails "John is unmarried", because any possible situation in which the first is true is also one in which the second is true."

"ad hominem"

The informal fallacy of attacking the person making an argument — their character, motives, or personal circumstances — rather than addressing the content of the argument itself

"Dismissing a philosopher's argument about justice by pointing to their political affiliations commits an ad hominem: personal traits are irrelevant to the logical merits of the argument."

"social contract"

A foundational concept in political philosophy according to which political authority and citizens' obligations derive from an actual or hypothetical agreement among individuals to form a society

"Hobbes, Locke, and Rousseau each offered contrasting accounts of the social contract: they agreed it justifies political authority but disagreed about its terms and what it permits."

"distributive justice"

The branch of political philosophy concerned with the fair allocation of goods, opportunities, burdens, and benefits across members of a society

"Rawls's difference principle is a principle of distributive justice: economic inequalities are permissible only if they maximally benefit the least-advantaged members of society."

"liberal neutrality"

The principle that the state should not promote any particular conception of the good life but should remain neutral among competing comprehensive doctrines held by citizens

"Liberal neutrality implies that a government may not favour religious observance over secular lifestyles, even if the majority endorses religion, because no one conception of the good should be privileged."

"deliberative democracy"

A model of democratic governance that emphasises reasoned public debate and mutual justification among citizens as the legitimate source of political decisions

"Deliberative democracy theorists argue that majority voting alone is insufficient: legitimate law-making requires genuine public reasoning in which all affected parties can participate."

"positive liberty"

The freedom to actually achieve self-realisation or self-governance — having the real capacities, resources, and power to pursue one's goals — as distinguished from mere absence of external interference

"A person who is formally free to attend university but cannot afford it lacks positive liberty in Isaiah Berlin's sense: the absence of legal barriers is not sufficient for genuine freedom."

"political legitimacy"

The property a political authority or legal system possesses when there is a morally sufficient basis for its subjects to recognise and comply with its directives

"Philosophers disagree about whether political legitimacy requires democratic consent, substantive justice, procedural fairness, or some combination of all three."

"civil disobedience"

A deliberate, public, nonviolent, and conscientious violation of law undertaken to protest an injustice and appeal to the moral sense of the majority

"Rawls argued that civil disobedience is justified in a nearly just society when legal channels have been exhausted and the injustice being protested is clear and substantial."

"veil of ignorance"

A thought experiment by John Rawls in which principles of justice are chosen by parties who do not know their place in society, class position, fortune, intelligence, or conception of the good

"Behind the veil of ignorance, rational agents would choose principles that protect even the worst-off, because they might turn out to be among the least advantaged themselves."

"qualia"

The subjective, felt qualities of conscious experience — the "what it is like" character of seeing red, tasting coffee, or feeling pain — that resist purely functional explanation

"Frank Jackson's knowledge argument uses qualia to challenge physicalism: Mary the colour scientist learns all physical facts about colour but still learns something new when she first sees red."

"intentionality"

The property of mental states whereby they are directed at or about something — objects, states of affairs, or properties — whether those things exist or not

"Beliefs and desires exhibit intentionality: the belief that Paris is beautiful is about Paris and the property of beauty, even in a mind that has never visited France."

"functionalism"

The theory that mental states are defined by their causal-functional roles — by their relationships to sensory inputs, behavioural outputs, and other mental states — rather than by their physical constitution

"Functionalism implies that silicon-based robots could have genuine mental states as long as their internal states play the right causal roles, regardless of whether they are made of neurons."

"propositional attitude"

A mental state defined by a subject's attitude — believing, desiring, hoping, fearing — toward a proposition, which serves as the content of that state

"The sentence "Sarah believes that it will rain tomorrow" reports a propositional attitude: Sarah stands in the believing relation to the proposition that it will rain tomorrow."

"speech act"

An utterance that performs an action — such as promising, asserting, commanding, or apologising — as identified in the work of Austin and Searle

"When a judge says "I hereby sentence you to three years", the utterance is not merely describing a sentencing but is itself the speech act that constitutes the sentencing."

"hard problem of consciousness"

Chalmers's distinction between the 'easy problems' of explaining cognitive functions and the genuinely difficult challenge of explaining why there is subjective experience at all

"Explaining how the brain integrates information is an "easy problem"; the hard problem of consciousness asks why any of this neural activity feels like anything from the inside."

"semantic externalism"

The view that the meaning or content of mental and linguistic representations is partly determined by factors external to the individual mind — including the physical environment and social practices

"Putnam's Twin Earth thought experiment supports semantic externalism: the word "water" means H₂O on Earth but refers to a different substance on a planet where the superficially identical liquid is XYZ."

"conceptual analysis"

The philosophical method of breaking down a concept into its necessary and sufficient conditions, typically by constructing and testing definitions against real and hypothetical counter-examples

"The traditional analysis of knowledge as justified true belief was subjected to conceptual analysis by Gettier, who produced counter-examples showing the three conditions are not jointly sufficient."