Philosophy of Language: What Words Mean and What They Do

Someone asks, "Can you pass the salt?" and you do not answer "Yes." Someone says, "Some of the students passed," and you hear that not all did, although nobody said so. A friend says, "Great weather," in a storm, and you hear the opposite. In each case the words on the page are not what is communicated, and in each case you got it right without thinking.

Philosophy of language asks how that is possible. How can a sound or a mark be about something? Why can a true statement be informative or empty depending on which name you use? What are we doing when we promise, or name a ship, or say "I do"? The questions are old, but the modern subject begins in the 1890s with Gottlob Frege, and the tools it built (sense, reference, presupposition, rigid designation, implicature) are now used in linguistics, law, computer science and the study of language models.

Sense and reference: Frege and the two stars

The obvious theory says a name means the thing it names. "Venus" means Venus. Then "Hesperus" (the evening star) and "Phosphorus" (the morning star) mean the same thing, because both are Venus, and the sentence "Hesperus is Phosphorus" should say no more than "Venus is Venus." But the first was a discovery, and the second is a triviality. In "Über Sinn und Bedeutung" (1892) Frege put it plainly: statements of the form a = a and a = b differ in what they tell you.

His answer is that an expression has two things attached. Its reference is the object it picks out. Its sense is the way it picks it out, the route by which a thinker gets to the object. "The bright point at dawn" and "the bright point at dusk" are two routes to one planet. Frege then did the same for whole sentences: the sense of a sentence is the thought it expresses, and its reference is its truth-value. That explains why swapping co-referring names keeps a sentence true (the reference is unchanged), yet can change what a thinker believes (the sense is changed).

Without JavaScript: "The Morning Star is the Evening Star" is true and informative (one reference, two senses); "The Morning Star is the Morning Star" is true and trivial; "The Morning Star is the Moon" is informative and false.

Sense does extra work. Ancient sailors did not know that the two stars were one, so "the sailors believed the Morning Star rose at dawn" is true while "the sailors believed Venus rose at dawn and again at dusk" may not be. Frege said that inside a belief report an expression refers to its usual sense, not to its usual object. Critics found this heavy, and the next two sections are attempts to do without it.

Descriptions: Russell and the king of France

Bertrand Russell's "On Denoting" (1905) attacked a different puzzle. Take "The present King of France is bald." France has no king. If the phrase must refer to something for the sentence to mean anything, the sentence is meaningless. But it is not: it is plainly false, or so Russell thought. His fix was to say that "the F is G" is not a subject and predicate at all. It is a hidden claim in three parts:

This also exposes an ambiguity. "The King of France is not bald" can deny the whole claim (true: there is no such king) or say of the king that he lacks hair-loss (false: there is no king). Logicians call this a difference of scope. Peter Strawson replied in "On Referring" (1950) that the sentence has a presupposition, that there is a king, and when that fails the sentence is neither true nor false. Keith Donnellan (1966) added that "the man drinking a martini" can pick out a particular man even if he is drinking water, which Russell's account does not allow. Play with the scenarios below.

Without JavaScript: with no king, Russell makes "the King is bald" false and "it is not the case that the King is bald" true; Strawson makes both lack a truth-value.

Names: Kripke and the rigid designator

Russell extended his analysis to ordinary names: "Aristotle" is short for a description such as "the teacher of Alexander". Frege agreed on something like it. In three lectures at Princeton in January 1970, later the book Naming and Necessity (1980), Saul Kripke argued that this is wrong. His arguments, in order:

1. Modal. Aristotle might never have taught Alexander (his father was a court physician; he might have become one). If "Aristotle" meant "the teacher of Alexander", "Aristotle taught Alexander" would be necessary. It is not. A name is a rigid designator: it picks the same person in every possible world, while a description picks whoever fits in each.
2. Epistemic. Most of us know little that is uniquely true of the people we name, and we still refer to them.
3. Semantic. Suppose "Gödel" is associated only with "proved incompleteness", and the proof was actually done by a man called Schmidt. A description theory says that you are talking about Schmidt. Almost no one thinks so (Kripke's case is hypothetical; Gödel's proof was his own).

Without JavaScript: "Aristotle" picks Aristotle in every world; "the tutor of Alexander" picks Aristotle in w0, Isocrates in w1 and nobody in w2. So "Aristotle tutored Alexander" is true in w0 only, while "the tutor of Alexander tutored Alexander" is true in all three.

What fixes reference instead? Kripke's picture is causal-historical: a baptism ties a name to a person, and each speaker who hears it and means to use it as others do passes the link along. Predict first, then look.

Without JavaScript: the description theory says Schmidt; Kripke says Gödel, because your use of the name is linked back to Gödel by a chain of speakers.

The critics have good cases. Gareth Evans (1973) noted that "Madagascar" began as a name of part of the African mainland and came, through a chain of speakers' mistakes, to name the island, so the chain alone can't be all of it. And Kripke left an old puzzle open: if a name just stands for its bearer, why is "Hesperus is Phosphorus" informative? Defenders of the Millian view reply with pragmatics; Fregeans keep sense. The PhilPapers Survey of 2020 asked professionals exactly this ("Proper names: Millian or Fregean?"); see its results page for the split, which I do not reprint here.

Meaning as use: Wittgenstein's two philosophies

Ludwig Wittgenstein held both a view of language and its sharpest critique. The Tractatus Logico-Philosophicus (German 1921, English 1922) said that a sentence is a picture of a possible fact, names stand for simple objects, and what can't be pictured can't be said.

"The limits of my language mean the limits of my world."Wittgenstein, Tractatus 5.6, C. K. Ogden's 1922 translation

Later he rejected the picture. Philosophical Investigations (published 1953, after his death in 1951) starts with a scene: a builder calls "Slab!" and an assistant brings a slab. Here a word is not a label for a thing; it is a move in a language-game, tied to what people do. For a large class of cases, he wrote, the meaning of a word is its use in the language (section 43). He also argued that "game" has no single feature common to all games, only overlapping family resemblances (section 66), and that a language only one person could ever understand is incoherent (the private language argument, from about section 243). Each claim has opponents, and the last has produced shelves of books. What most readers keep is a change of question: not "what does this word stand for?" but "what are people doing with it?"

Doing things with words: Austin and Searle

J. L. Austin's William James Lectures at Harvard in 1955, published in 1962 as How to Do Things with Words, began with an observation. Some sentences are not true or false; saying them does something. "I name this ship," "I promise," "I bet you," "I do." Austin called these performatives, and noticed that they can go wrong in different ways from statements. They can be unhappy rather than false. Each needs a recognised procedure, the right people in the right circumstances, correct execution, and (for some) sincerity. The tool below lets you break them.

Without JavaScript: if the speaker has no authority the act misfires and no marriage results; if everything is in order but the speaker is insincere the marriage still happens (an abuse); on stage nothing is done.

Austin's second step was to say that every utterance is several acts at once: the locutionary act (uttering words with a sense), the illocutionary act (what you do in saying it: warn, ask, order) and the perlocutionary act (what you bring about by it: scare, persuade). "There's a bull in that field" can be a warning, whether or not it frightens anyone. John Searle's Speech Acts (1969) developed rules for them, and his later scheme sorts illocutions into five kinds: assertives, directives, commissives, expressives and declarations. "Can you pass the salt?" is the case that shows why this matters: it is literally a question about ability, and in practice a request.

What you mean beyond what you say: Grice

Paul Grice, in the William James Lectures of 1967 (the essay "Logic and Conversation" appeared in 1975), explained the salt case with one idea. Conversation is cooperative, and we assume a speaker is following four maxims: say as much as is needed (Quantity), say what you believe true (Quality), be relevant (Relation), be clear and orderly (Manner). When a speaker visibly breaks one, we infer that something else is meant: an implicature. A reference letter that praises a student's handwriting and nothing else says very little; the hearer concludes there is nothing good to say. Sort the cases yourself.

Without JavaScript: the vague letter flouts Quantity; "Great weather!" in a storm flouts Quality; a reply that seems off-topic flouts Relation; an absurdly roundabout phrase flouts Manner.

Implicatures differ from what a sentence strictly entails by a test. They can be cancelled: "Some of the students passed; in fact all did" is not a contradiction, so "not all" was never part of the meaning of "some", only something we read in. Rivals disagree on how many maxims there are. Dan Sperber and Deirdre Wilson's relevance theory (1986) reduces them to a single principle of relevance, and the neo-Griceans (Larry Horn, Stephen Levinson) keep a short list.

India's argument about words: Nyāya, Mīmāṃsā and Buddhist apoha

None of this was invented only in Europe. Indian philosophers argued about meaning for well over a thousand years, often more precisely than the West did for most of that time. The main schools were the Nyāya logicians (the Nyāya Sūtra, compiled in the early centuries CE), the Mīmāṃsā interpreters of the Vedic texts (Jaimini's Sūtra, with Śabara, and later Kumārila Bhaṭṭa and Prabhākara, about the 7th century CE), the Buddhist logicians Dignāga and Dharmakīrti, and the grammarians led by Bhartṛhari. Four debates are worth knowing.

• What does a word denote? The Nyāya answer, in the Sūtra: a word denotes an individual together with its form and its universal (a cow, the shape of a cow, cowness). Others stressed the universal alone; Buddhists denied universals exist.
• Where does word-meaning come from? Mīmāṃsā held that the link between word and meaning is eternal and not made by anyone; this protected the Veda as authorless. Nyāya held that it is conventional, set by divine will (the later Navya-Nyāya school, from Gaṅgeśa in the 14th century, kept and refined that view).
• How do we learn it? By watching elders. If one elder says "Bring the cow" and another does it, a child links the words to the act, then isolates "cow" by changing one word. Many scholars note the likeness to Wittgenstein's builders; it is an echo, not an influence.
• Do words mean on their own, or only in sentences? Kumārila: words first denote their meanings, then the sentence's meaning is put together from them. Prabhākara: words convey meanings only as already related, which he took to be what children learn from commands. Bhartṛhari went further: the sentence is a whole (sphoṭa), understood in a flash. The Buddhist apoha theory says a word like "cow" works by excluding what is not a cow, so it needs no real universals.

Nyāya textbooks also list conditions for a string of words to give an understood sentence: ākāṅkṣā (expectancy: the words need each other to complete a sense), yogyatā (compatibility: the meanings can sensibly combine) and sannidhi (proximity: said together, not hours apart). This is a surprisingly modern checklist, and you can run it.

Without JavaScript: "Bring the cow" meets all three; a bare list of nouns lacks expectancy; "he sprinkles with fire" lacks compatibility; words said an hour apart lack proximity.

What a graduate just sees

• Two expressions can refer to the same thing and still not mean the same, and the proof is that one identity is news and the other is not.
• A sentence that sounds like it is about someone may secretly be a claim that "there is exactly one such person", and where "not" goes can change the truth.
• A name is not a hidden description; it is a tag that stays on the person across the ways things could have gone.
• Ask what people are doing with a word before asking what it stands for.
• Some sentences are acts: they can misfire without being false.
• What is meant often outruns what is said, and the extra can be cancelled, which shows it was never part of the sentence.
• The theory of meaning has been argued across traditions, and the Indian debates are not footnotes.

Where it shows up next

• Semantics & Pragmatics (36/24): the linguist's formal versions of sense, scope, presupposition and implicature.
• Philosophy of Mind (36/05): whether thoughts are meaningful in the way words are, and what a machine that handles words understands.
• Computational Linguistics (36/30) and How Large Language Models Actually Work (29/02): models learn meaning as use, in Wittgenstein's sense, and whether that is all of meaning is exactly the debate above.
• In the world: contracts and statutes (a promise is an act; "the" in a statute may bring a presupposition); advertising and politics (implicature lets a speaker mislead while saying only true things); and courtroom questions about what a defendant "meant".

If you want to go deeper

• 📘 Textbook. William Lycan, Philosophy of Language: A Contemporary Introduction (Routledge, 3rd edition, 2019), clear and organised by problem; Alex Miller, Philosophy of Language (Routledge, also in later editions), similar in range. Check the current edition.
• 📘 Primary and gentler. Bertrand Russell's The Problems of Philosophy (1912), chapter 5, free at Project Gutenberg, for the idea of knowledge by description; then Saul Kripke, Naming and Necessity (Harvard University Press, 1980), which is short and readable.
• 📘 India. Bimal Krishna Matilal, The Word and the World: India's Contribution to the Study of Language (Oxford University Press, 1990).
• 🌐 Free course. MIT OpenCourseWare 24.251 Introduction to Philosophy of Language (Fall 2011), with lecture notes. The Stanford Encyclopedia of Philosophy has free entries on descriptions, implicature and speech acts.