At dinner someone asks, "Can you pass the salt?" Nobody answers "Yes" and goes on eating: it is a polite request. Words have meanings, but speakers also mean things by their words, and the two are not always the same. This level looks at both.

Two kinds of meaning

Semantics studies what words and sentences mean; pragmatics studies what speakers mean by them in context. "It's cold in here" has a fixed semantic meaning about the temperature. Said by a guest looking at an open window, it can also mean "please close the window."

Sense and reference

The German logician Gottlob Frege pointed out a puzzle in 1892. The bright object seen near the horizon at dawn was called the morning star, and the one seen at dusk the evening star. Both are the planet Venus. So "the morning star is the evening star" refers to the same thing twice, yet it was a real astronomical discovery, not an empty statement like "Venus is Venus." Frege concluded that two expressions can refer to the same thing while having different senses: different ways of presenting that thing. His distinction still shapes the study of meaning.

Categories and prototypes

What does "bird" mean? A dictionary might list features: feathers, wings, flight. But penguins do not fly, and they are birds. In the 1970s the psychologist Eleanor Rosch ran experiments showing that people judge category membership by resemblance to a typical example, or prototype. Americans rated a robin a better bird than a penguin. Earlier, the philosopher Ludwig Wittgenstein had argued that members of a category like "game" may share no single feature, only overlapping resemblances, like members of a family.

Saying more than you say

In lectures given in 1967 the British philosopher Paul Grice argued that conversation runs on a cooperative principle: listeners assume speakers are trying to be informative, truthful, relevant and clear. He broke this into maxims of quantity, quality, relation and manner. People do not always obey them, but listeners interpret everything as if speakers were trying to.

This explains implicature. If a teacher says "Some of the students passed," you conclude that not all did. The sentence does not say that: it would be true if all passed. You infer it because a cooperative speaker who knew all had passed would have said so. An implicature is a meaning suggested in context that the speaker can cancel without contradiction. "Some passed; in fact, all of them did" is odd but not self-contradictory. Compare an entailment: "All passed" entails "some passed," and "All passed, but none passed" is a flat contradiction.

Grice's own example was a reference letter praising only a student's handwriting and punctuality: it says nothing negative, yet reads as damning.

Doing things with words

The philosopher J. L. Austin noticed that some utterances do things rather than describe them, like promising, naming a ship or pronouncing a couple married. He called these speech acts. "I promise to come" is not true or false; it creates an obligation. But speech acts can fail: a guest at a wedding who says "I pronounce you married" marries no one, because the right person must say the words in the right setting. Austin called these requirements felicity conditions.

Many speech acts are indirect, like "Can you pass the salt?" The researchers Penelope Brown and Stephen Levinson argued in 1978 that people everywhere work to protect each other's "face," their public self-image, and that indirect requests protect the listener's face by leaving room to refuse. How much indirectness is polite varies greatly between cultures, which is one reason travelers can seem rude or evasive without meaning to.

Words that point

Some words cannot be understood without knowing the situation. Deictic words such as "here," "now" and "you" get their meaning from the situation of speaking. A note on a door that says "Back in an hour" is useless if you do not know when it was written.

Worked example: a text message

Two coworkers text. Sam writes: "Are you coming to Dana's party tonight?" Lee replies: "I have to be at work at six tomorrow."

Semantically, Lee has not answered the question. The reply is about tomorrow morning, not tonight. Yet Sam understands at once that Lee is probably not going, or at least not staying late. Sam gets there by assuming Lee is being relevant. Why mention an early shift unless it bears on the party? The "no" is an implicature.

Because it is an implicature, Lee can cancel it: "I have to be at work at six tomorrow, but I'm coming for an hour anyway." That is not a contradiction, which shows the "no" was never part of what the words strictly said.

Why answer this way at all? Politeness. A blunt "No" might sound like a judgment on Dana or on Sam. Giving a reason lets Lee decline while protecting everyone's face. And notice the deictic words: "tonight" and "tomorrow" only make sense because both people know when the messages were sent. If Sam reads the reply a week later, it means nothing.

A simple exchange thus uses implicature, politeness and deixis at once, so effortlessly that scholars took centuries to notice.