Implicature and Explicature
Linguists and philosophers try to draw a line between semantics and pragmatics. Semantics is concerned with the literal meaning of words and sentences, while pragmatics analyzes the contributions of context to the final interpretation of sentences. The examples of conversational implicature introduced by Paul Grice provide good examples of the ways in which extra-linguistic factors impinge on our understanding of sentences.
Grice begins with the idea that all linguistic exchange follows what he termed the cooperative principle.
The Cooperative Principle
Make your conversational contribution such as is required, at the stage at which it occurs, by the accepted purpose or direction of the talk exchange in which you are engaged.
or
Be helpful.
He argued that all participants in a conversation seek to be cooperative by contributing helpful information. Grice identified a number of conversational rules or maxims that embody the cooperative principle.
Maxim of Quality (also called the Maxim of Truthfulness)
Try to make your contribution one that is true.
1. Do not say what you believe to be false.
2. Do not say that for which you lack evidence.
Maxim of Quantity (also called the Maxim of Informativeness)
1. Make your contribution as informative as is required (for the current purposes of the exchange).
2. Do not make your contribution more informative than is required.
Maxim of Relation (also called the Maxim of Relevance)
Be relevant.
Maxim of Manner (also called the Maxim of Clarity)
Be Perspicuous.
1. Avoid obscurity of expression.
2. Avoid ambiguity.
3. Be brief. (Avoid unnecessary prolixity.)
4. Be orderly.
Grice also observed that it is possible to violate or flout conversational rules, and that speakers
do this frequently to communicate ideas indirectly. Grice dubbed such indirect messages a
conversational implicature and studied the way speakers implicate messages by flouting
maxims of conversation.
Assume you find the following entry in a ship’s log:
The first mate wasn’t drunk last night.
At first glance, this entry seems to violate the maxim of quantity. It tells us something that we
would ordinarily take for granted. Because it violate the maxim of quantity, though, we can
assume the captain is implicating the first mate was drunk the previous nights.
Implicature vs. Entailment
Conversational implicatures resemble semantic entailment in that you can construct a relation
between two propositions that is either an entailment or an implicature. The main difference
between implicature and entailment is that you can cancel an implicature, but not an entailment.
For example, suppose our ship’s log read:
The first mate wasn’t drunk last night, or any of the previous nights.
The added clause cancels the implicature that he was drunk the previous nights.
Compare this result to what happens when you try to cancel an entailment:
? Ian drives a Corvette, but he doesn’t drive a car.
We can state the rule for implicature more formally as:
X implicates Y if
i. X does not entail Y
ii. the hearer has reason to believe Y is true based on the use of X and the Maxims of Conversation.
It seems rather paradoxical to propose rules for conversation that everyone violates. Grice claims
that his principles actually extend beyond conversation to other forms of human interaction.
Sticking to conversational exchanges, can you think of any examples that clearly violate Grice’s
Cooperative Principle?
Advertisers rely on implicature to make extravagant claims. How are Grice’s maxims exploited in the following claims?
Campbell’s Soup has one third less salt.
The Ford LTD is 700% quieter.
Maytags are built to last longer and need fewer repairs.
Mercedes-Benz are engineered like no other car in the world.
Chevy trucks are like a rock.
Scalar Implicature
Laurence Horn noted that words which denote quantities or degrees of attributes produce a scale of informative strength that is the source of what he termed scalar implicature. The prototype for such a scale is:
6. (weak) < some, most, all > (strong)
The use of some makes a weaker assertation than most which is in turn weaker than all. Speakers obey the cooperative principle by using the strongest term that is consistent with what they know or believe to be the case. The use of a scalar expression implicates the negation of any term that is higher on the scale. Kearns discusses how scalar implicature works in stating how students did on a test.
7a. Most of them passed.
implicature: Not all of them passed.
b. Some of them passed.
implicature: Not all of them passed.
implicature: Most of them did not pass.
c. Two or three did very well.
implicature: Not more than two or three did very well.
Kearns provides the following example with an adjective
9 It’s quite warm out (Implicature: It isn’t hot)
This example suggests such implicature would be available for non-complementary adjectives, but not for complementary adjectives.
Kearns also notes the ways in which scalar implicature depends upon the context as well. The first member in the following pairs of sentences have a scalar implicature ‘not all’ which is absent in the second member
16a Some cast members want to see you after the show.
b The photographer wants some cast members for the photo.
17a Some of you are working well.
b If some of you work solidly the mess could be cleared by tomorrow.
11.3 Horn’s Q Principle and R Principle
Horn provided an analysis of communication rooted in the balance between economy and effectiveness. His analysis is built on two clauses of Grice’s Informativeness Maxim:
1. Make your contribution as informative as is required.
2. Do not make your contribution more informative than is required.
Horn assumes that Grice’s Maxim of Quality (Truthfulness) always operates as a general requirement. Horn proposed two principles that replace Grice’s other maxims.
The Q principle
Make your contribution sufficient:
Say as much as you can (given both Quality and R)
The R principle
Make you contribution necessary:
Say no more than you must (given Q)
Horn’s principles produce two types of implicature.
Q-Implicatures
A Q-implicature is produce by flouting the Q principle—by not saying enough. The scalar implicatures that we discussed earlier would all arise from flouting the Q principle. Kearns provides these examples:
21a. It’s possible he’ll be elected.
Q-implicature: It’s not likely he’ll be elected.
b. Harold is as tall as Tom.
Q-implicature: Harold is not taller than Tom.
c. We recorded most of the tunes.
Q-implicature: We didn’t record all of the tunes.
The exclusive reading of the or connective can also be attributed to Q-implicature.
Do you want coke or pepsi?
The exclusive and inclusive interpretations of or form the scale in (24).
24. (weak) < exclusive or, inclusive or > strong
The exclusive interpretation of or entails the inclusive interpretation, but not vice versa, as seen by their logical expressions.
|
|
|
inclusive or |
exclusive or |
|
p |
q |
p v q |
(p v q) & ~(p & q) |
|
T |
T |
T |
F |
|
T |
F |
T |
T |
|
F |
T |
T |
T |
|
F |
F |
F |
F |
This gives inclusive or a larger set of conditions in which it is true.
R-Implicatures
R-implicature is produced by flouting the R principle—by saying too much. Kearns provides the following examples:
27a. This essay is not entirely satisfactory.
R-implicature: This essay is entirely unsatisfactory.
b. He isn’t very bright.
R-implicature: He’s thick.
c. He needs to go somewhere.
R-implicature: He needs to use the lavatory.
d. not at all bad (in fact, very good)
not bad (in fact, pretty good)
not too bad (OK)
not too good (in fact, pretty bad)
not good (in fact, bad)
Horn used R-implicature to provide a pragmatic account of Neg-Raising. The following sentences illustrate Neg-Raising.
28a. I don’t think John has left town.
b. I think John hasn’t left town.
29a. I don’t imagine the price will stay down.
b. I imagine the price will not stay down.
30a. I don’t expect to see you tomorrow.
b. I expect I won’t see you tomorrow.
The (a) sentences are all examples where Neg-Raising has applied. Since they have the same meaning as the (b) sentences, the negation in the (a) sentences doesn’t really negate the propositional attitude verb in the main clause. Neg-Raising isn’t possible with all verbs as shown in the following sentences.
31a. He doesn’t claim to have all the answers.
b. He claims not to have all the answers.
32a. It wasn’t possible to sit near him.
b. It was possible to not sit near him.
33a. Jones didn’t manage to stop the car.
b. Jones managed to not stop the car.
The Neg-Raised interpretation entails the non-Neg-Raised interpretation, and thus is stronger. Kearns provides the following analysis of these interpretations.
34 I don’t think John has left town.
Neg-Raised interpretation
a. ‘I have the thought “John has not left town” ’
non-Neg-Raised interpretation
b. ‘I lack the thought “John has left town” ’
The lack of thought does not entail having a thought, while thinking ‘John has not left town’ entails lacking the thought that ‘John has left town’. Horn claims the sentence (34) has the non-Neg-Raised interpretation as its literal meaning, consistent with the word order. The informationally stronger Neg-Raised interpretation is derived by R-implicature.
11.4 Relevance Theory
Deirdre Wilson and Dan Sperber developed Relevance Theory to account for implicatures in terms of cognitive information processing. Such processing includes the hearer’s current knowledge, beliefs, assumptions, and cultural and social conventions in the form of propositions. These propositions spell out the hearer’s mental content.
The hearer may revise his or her mental content on the basis of new information. When Jenny tells Tom The movie ends at 3:50, he can revise the propositions in his mental content by adding the information that the movie will end in time for him to make it to his 4 o’clock lecture.
Processing this information requires a moderate degree of effort for Tom, but has a potentially high cognitive benefit (his seeing the movie that afternoon). Sperber and Wilson define relevance in terms of the balance between processing cost and cognitive benefit. A highly relevant utterance has a high cognitive effect in relation to its processing costs.
Speakers can use their knowledge of the hearer to figure out what information is the most relevant for the hearer and, thus, what implicatures the hearer can infer. Hearers are more likely to work out highly relevant implicatures (high benefit and moderate processing costs).
11.5.1 Disambiguation, Reference Assignment and Indexicality
Theories of implicature often take for granted that the literal meaning of sentences, or explicature, can be separated from the sentences’ implicatures. However, reference to the context of a sentence is almost always needed to construct its literal meaning. Contextual information is used for: i) the disambiguation of ambiguous expressions, ii) the assignment of reference to variables, and iii) the interpretation of indexical expressions.
Contextual information can be used to disambiguate both lexical and structural ambiguities, as in the following sentences.
41a. They’ve got that creamy duck on special at Weaver’s.
b. Everyone should bring a pencil.
The assignment of reference to variables is needed to interpret pronouns and time reference. This is illustrated in the following sentences.
42a. He’ll never make it.
b. I left your mail on your desk.
c. The plumber came and he’ll send a quote.
d. Everyone came to dinner last night and Jones got tipsy.
Indexical or deictic expressions derive their interpretation from the context. Indexical expressions express the central anchoring points of an utterance such as the identity and position of the participants, the time and place of the utterance.
Obviously, the evaluation of deictic expressions must be part of any sentence’s explicature. Assuming that explicature is responsible for determining the truth conditions for a sentence raises the question of whether we can maintain a clear boundary between explicature and implicature. Another possibility is that literal meaning constrains the ways in which listeners make use of implicature in determining truth conditions.
Pronouns
At one time linguists distinguished between “deictic” and “anaphoric” uses of person pronouns. Deictic pronouns receive their interpretations through the non-linguistic context as in the sentence
I wonder who she is.
An anaphoric pronoun receives its reference from its linguistic context as in the following sentence.
Jeb thinks he knows everything.
A long syntactic tradition attempts to connect pronoun interpretation to a set of binding conditions, but there are many examples of pronoun usage beyond the deictic pronouns that do not fit simple binding rules:
Most accidents that Mary reported were caused by her cat.
I don’t know Smith. Is he a linguist?
One question is whether a single theory for the interpretation of pronouns can account for all of these examples. People rely on many sources of information to make the correct pronoun interpretation. Jurafsky & Martin (2000) describe several of these sources.
Selectional restrictions
Many verbs limit the types of objects they can take. Pronouns that occur with such verbs probably refer to entities that meet the verb’s selectional restrictions. Consider the following sentences
I found a bowl on the table.
I filled it with candy.
Here the verb fill selects objects that can be used as containers. We are more likely to use a bowl than a table as a container, so the bowl is the most likely referent for the pronoun it.
The only difficulty in using selectional restrictions to resolve pronoun reference comes through metaphorical contexts. Consider the following example
Tom has a new sound card for his computer.
It fills his need for material possessions.
Practically anything can be used to fill abstract needs and desires. The computer has to detect when the discussion turns to such abstract levels.
World knowledge
Many times hearers rely on their knowledge of the real world to resolve pronoun interpretation. Consider this example
Tom bought a new sound card for the computer.
It still needs several more upgrades.
Here, we are most likely to interpret the pronoun as referring to the computer rather than to the sound card, since computers are the sort of thing that is constantly in need of an upgrade. Computer upgrades are probably not part of the lexical meaning of the word computer, but rather come about through an interaction with computers in the real world.
Recency
Everything else being equal, we are more likely to tie pronoun reference to an object mentioned in the most recent sentence. See the following example
Sally got a blue case for her computer.
Mabel’s computer has a red case.
I like it better.
In this example, there is a strong preference to interpret the pronoun it as referring to the case on Mabel’s computer rather than the case on Sally’s.
Grammatical Relation
Listeners display the following preference hierarchy for pronoun interpretation
Subject > Object > Oblique
Consider the following example
Tom went to the computer store with Ralph.
He found a sound card for his computer.
There is a slight preference for Tom over Ralph as the referent for the pronoun he in the second sentence. This preference hierarchy can be overridden fairly easily though. Consider the following example
Tom took Ralph to the computer store.
He found a sound card for his computer.
In this example the action of taking someone somewhere implies that the person who was taken was the one in need of new equipment for the computer. There would not be a good reason to mention Ralph if Tom was the only person interested in sound cards.
Repeated Mention
Pronouns are more likely to refer to entities that are mentioned repeatedly in previous sentences. Consider the following example
Mabel took Sally to the computer store to look at sound cards.
She didn’t like the noise her current card was producing.
The sales clerk showed her a card she could afford.
In this example, listeners prefer to give the pronouns the same referent (Sally) throughout the entire sequence. English lacks a formal distinction between pronouns that signals when the pronoun referent has changed, so the default interpretation is to maintain the same referent over a sequence of sentences.
Verb Semantics
Some verbs emphasize specific arguments over others and this can affect pronoun reference. Consider the following sentences
Mabel promised to ask Sally. She didn’t understand directions.
Mabel hesitated to ask Sally. She didn’t understand directions.
There is a strong preference for Mabel to serve as the referent of the pronoun in the first sentence while Sally is strongly preferred in the second sentence. The verb hesitate focuses attention on the object of the embedded clause while the verb promise emphasizes the action of its subject. Local effects such as verb semantics can override preferences due to recency or repeated mention.
Discourse Relevance
Heim & Kratzer (1998:240) suggest that listeners assign pronoun readings to the most salient individual(s) in the discourse. The factors that we have just reviewed in addition to the context of utterance would affect the saliency of potential pronominal referents. H & K go on to suggest that pronouns in sentences with quantified NPs are non-referring pronouns in contrast to the examples we have discussed so far. An example of such a non-referring pronoun would be
Every farmer beats his donkey.
They argue that in such cases, the pronoun does not single out a single individual and therefore cannot refer to the most salient individual in the discourse. H&K claim that such examples should be analyzed as bound variables since the interpretation of the pronoun is fixed by the quantified expression.
The problem of sloppy identity is illustrated in the following sentence
(On Mary’s birthday), Sally went to her office. Jane didn’t.
These sentences have several interpretations:
referential: (On Mary1’s birthday), Sally went to her1 office. Jane didn’t (go to her1 office).
sloppy identity: (On Mary1’s birthday), Sally2 went to her2 office. Jane3 didn’t (go to her3 office).
H&K attribute the first reading to a referential pronoun and sloppy identity to a bound variable reading. In order to make the referential reading work, H&K add the condition that pronouns in the same set of sentences cannot have both referential and bound readings. This stipulation rules out the interpretation where Sally goes to Mary’s office and Jane goes to her own (Jane’s) office.
11.5.2 Pragmatic Contributions to Explicature
Robyn Carston (1988) draws attention to a range of ways in which listeners draw upon the context for sentence interpretation. Kearns points to the ambiguity in the sentence
49. The park is some distance from my house.
A logician might consider this sentence to be literally true even when the house is located across the street from the park. Many people would interpret the sentence to mean that the house is a long distance away from the park, at least two or more city blocks. Can we attribute such a discrepancy to implicature? Kearns believes the long distance interpretation should be part of the sentence’s explicature. She thinks this reading does not depend on the interpretation of indexical expressions, although she does not provide an analysis for some.
Kearns offers the following sentences as further evidence that the content of explicature must include contextual information.
53a. We don’t have enough rice.
b. The park is too far from the house.
The words enough and too must be evaluated in relation to some unexpressed purpose or proposed action. Such purposes can be overtly expressed as in the following sentences:
54a. We don’t have enough rice to make curry and rice for three people.
b. The park is too far away from the house to walk the distance in half an hour.
Carston also investigates the variable interpretation of the sentence connective and. Kearns provides the following examples:
55a. Alice opened the wine and poured a glass.
b. Alice opened the wine and after that poured a glass.
56a. Jackie has won the Golden Kiwi and she’s going to pay off the mortgage.
b. Jackie has won the Golden Kiwi and as a consequence she’s going to pay off the mortgage.
57a. Stephen was tuning his bike and he was listening to the cricket.
b. Stephen was tuning his bike and simultaneously he was listening to the cricket.
Listeners are aware of the different connections between these sentences even without the and:
59a. Alice opened the wine. She poured out a glass.
b. Stephen was tuning his bike. He was listening to the cricket.
Carston argues that this pragmatic information should be part of the explicature. She uses evidence from responses to questions and assertions. The following response is made to the explicature, not the implicature:
60. (Jones is generally scruffy, but tidies himself up from time to time when he was a girlfriend. His friends are familiar with this pattern.)
A: Jones has transformed himself again. (implicature: Jones has a new girl.)
B: No he hasn’t. (Denying that he has clean up his act, not that he has a new girl.)
Unlike implicature, the pragmatic relation between clauses can be questioned or denied, e.g.,
A: Jackie has won the Golden Kiwi and she’s going to pay off the mortgage.
B: I thought she paid off the mortgage from her inheritance.
61. A: (to director) I light her cigarette and she smiles, right?
B: No, she smiles and then you light her cigarette.
Carston also discusses examples like (64):
64. It’s better to meet the love of your life and get married than to get married and meet the love of your life.
These examples point to the need to include a wide variety of pragmatic information in interpreting literal meaning.
Grice maintained that implicatures are logically independent of what the speaker actually says. The explicature of the sentence The movie ends at 3:50 is independent of the implicature You can see the film and still attend your 4 o’clock lecture. We can cancel this implicature by adding But I was forgetting the detour at Fifth. We cannot cancel explicature in the same fashion. As Kearns states:
the literal meaning of a sentence lays down a framework which determines the set of propositions, perhaps infinitely many, that a speaker can express by uttering the sentence. But the context allows the hearer to identify which of these propositions the speaker actually expressed. (281)
Metaphor
One of the most frequent violations of Grices conversational principles occurs when we use
metaphor. Metaphors like ‘You’re the cream in my coffee’ obviously violate the Maxim of
Quality since they state propositions that are not literally true.
Lakoff and Johnson (Metaphors We Live By) observe that many metaphors observe common
themes, e.g.,
Good is up
Examples:
I’m feeling up. That boosted my spirits. My spirits rose.
You’re in high spirits. I’m feeling down. I’m depressed.
Much of our language about language is structured by metaphor:
IDEAS (or meanings) are objects.
linguistic expressions are containers.
communication involves sending ideas in containers.
Examples:
It’s hard to get that idea across to him.
I gave you that idea.
It’s difficult to put my ideas into words.
His words carry little meaning.
The sentence is without meaning.
What difficulties does metaphor create for a theory of meaning that uses truth conditions?
References
Carston, R. 1988. Implicature, explicature and truth-theoretic semantics. In R. M. Kempson (ed.), Mental Representations: The Interface Between Language and Reality, 155-181. Cambridge: Cambridge University Press.
Grice, H. P. 1975. Logic and conversation. In P. Cole & J. L. Morgan (eds.), Speech Acts, 41-58. New York: Academic Press.
Heim, I. & Kratzer, A. 1998. Semantics in Generative Grammar. Malden, MA: Blackwell.
Jurafsky, D. & Martin, J. H. 2000. Speech and Language Processing. Upper Saddle River, NJ: Prentice Hall.
Lakoff, G. & Johnson, M. 1980. Metaphors We Live By. Chicago: University of Chicago Press.