06 April, 2009

Presupposition and Entailment


Presupposition is what the speaker assumes to be the case prior to making an utterance. Entailment, which is not a pragmatic concept, is what logically follows from what is asserted in the utterance. Speakers have presuppositions while sentences, not speakers, have entailments. Take a look at the example below:

Jane’s brother bought two apartments.

This sentence presupposes that Jane exists and that she has a brother. The speaker may also hold the more specific presupposition that she has only a brother and her brother has a lot of money. All these presuppositions are held by the speaker and all of them can be wrong.

In pragmatics entailment is the relationship between two sentences where the truth of one (A) requires the truth of the other (B).
For example, the sentence (A) The president was assassinated. entails (B) The president is dead.


Presupposition

The concept of presupposition is often treated as the relationship between two propositions. In the case below, we have a sentence that contains a proposition (p) and another proposition (q), which is easily presupposed by any listener. However, the speaker can produce a sentence by denying the proposition (p), obtaining as a result the same presupposition (q).

Debora’s cat is cute. (p)

Debora has a cat. (q)

When I say that Debora’ s cat is cute, this sentence presupposes that Debora has a cat. In

Debora’ s cat is not cute. (NOT p)

the same thing holds true, that is, it presupposes that she has a cat. This property of presupposition is generally described as constancy under negation. Basically, it means that the presupposition of a statement will remain constant (i.e. still true) even when that statement is negated.

Types of Presupposition

In the analysis of how speakers’ assumptions are typically expressed, presupposition has been associated with the use of a large number of words, phrases and structures. These linguistic forms are considered here as indicators of potential presupposition, which can only become actual presupposition in contexts with speakers. The types of presupposition are:

1-Existential presupposition: it is the assumption of the existence of the entities named by the speaker.

For example, when a speaker says "Tom’s car is new", we can presuppose that Tom exists and that he has a car.

2-Factive presupposition: it is the assumption that something is true due to the presence of some verbs such as "know" and "realize" and of phrases involving glad, for example. Thus, when a speaker says that she didn’t realize someone was ill, we can presuppose that someone is ill. Also, when she says "I’m glad it’s over”, we can presuppose that it’s over.

3-Lexical presupposition: it is the assumption that, in using one word, the speaker can act as if another meaning (word) will be understood. For instance:

Andrew stopped running. (>>He used to run.)

You are late again. (>> You were late before.)

In this case, the use of the expressions "stop" and "again" are taken to presuppose another (unstated) concept.

4-Structural presupposition: it is the assumption associated with the use of certain words and phrases. For example, wh-question in English are conventionally interpreted with the presupposition that the information after the wh-form (e.g. when and where) is already known to be the case.


When did she travel to the USA? ( >> she traveled)
Where did you buy the book? (>> you bought the book)

The listener perceives that the information presented is necessarily true rather than just the presupposition of the person asking the question.

5- Non- factive presupposition: it is an assumption that something is not true. For example, verbs like "dream", "imagine" and "pretend" are used with the presupposition that what follows is not true.

I dreamed that I was rich. (>> I am not rich)
We imagined that we were in London. (>> We are not in London)


6-Counterfactual presupposition: it is the assumption that what is presupposed is not only untrue, but is the opposite of what is true, or contrary to facts. For instance, some conditional structures, generally called counterfactual conditionals, presuppose that the information, in the if- clauses, is not true at the time of utterance.

If you were my daughter, I would not allow you to do this. ( > you are not my daughter)

Projection Problem

Yule has also called attention to the projection problem, which occurs when a simple sentence becomes part of a more complex sentence. In this case, the meaning of some presupposition (as a part) doesn’t survive to become the meaning of a more complex sentence (as a whole).

a)Nobody realized that Kelly was unhappy

b)I imagined that Kelly was unhappy.

c)I imagined that Kelly was unhappy and nobody realized that she was unhappy.

Through these examples, we can observe that, when the speaker utters (a), we can presuppose that she was unhappy and that, when she utters (b), we can presuppose that she was not unhappy. However, when the speaker utters (c), we can't understand what the speaker means by that utterance without a context because the two parts have an opposite meaning.

However, it does not mean that there are no situations in which the combination of two simple sentences in a complex one can be possible. For example:

a) It’s so sad. Blaine regrets getting Laura fired. (>> Blaine got Laura fired)
b) Blaine regrets getting Laura fired, but he didn’t get her fired.

One way to think about the whole sentence presented in b) is as an utterance by a person reporting what happened in the film that day. In the example above, when the speaker utters he didn’t get her fired actually entails Blaine didn’t get her fired as a logical consequence. Thus, when the person who watched the film tells you that Blaine regrets getting Laura fired, but he didn’t get her fired, you have a presupposition q and NOT q. In this case, we can infer that Blaine thought he was the cause of Laura’s discharge, but, in fact, he was not.

This shows that entailments (necessary consequences of what is said) are simply more powerful than presuppositions (earlier assumptions). In the example below, the power of entailment can also be used to cancel existential presuppositions .

The King of Brazil visited us. (The king of Brazil does not exist).

Ordered entailments

Generally speaking, entailment is not a pragmatic concept (i.e. having to do with the speaker meaning), but it is considered a purely logical concept.

Observe the examples below:

1)Bob ate three sandwiches.

a) Something ate three sandwiches.

b)Bob did something to three sandwiches.

c) Bob ate three of something.

d)Something happened.

When a speaker utters sentence (1), the speaker is necessarily committed to the truth of a very large number of background knowledge. On any occasion, in uttering (1), however, the speaker will indicate how these entailments are to be ordered. That is, the speaker will communicate, typically by stress, which entailment is assumed to be the foreground, or more important for interpreting intended meaning, than any others. For example, when the speaker utters the following sentences, she indicates that the foreground entailment, and hence her main assumption, is that Bob ate a certain number of sandwiches.

a) Bob ate THREE sandwiches.
b) BOB ate three sandwiches.

In b), the focus shifts to BOB, and the main assumption is that someone ate three sandwiches. The stress in English functions to mark the main assumption of the speaker in producing an utterance. As such, it allows the speaker to mark for the listener what the focus of the message is, and what is being assumed.

A very similar function is exhibited by a structure called cleft construction in English, as we can observe in the example below:

a) It was VICTOR that did the work.
b) It wasn’t ME who took your jacket.

In both the examples above, the speaker can communicate what she believes the listener may already be thinking (i.e. the foreground entailment). In b), that foreground entailment (someone took your jacket) is being made in order to deny personal responsibility. The utterance in b) can be used to attribute the foreground entailment to the listener(s) without actually stating it (as a possible accusation).

Presupposition

Presupposition concerns the way in which propositions already presumed in a discourse context are usually not stated or questioned, but encoded in a more ‘background’ way. For example, “Has he stopped bothering you?” presupposes the proposition that you and I know that he has been bothering you, and asks whether this has stopped.
The classical test for presupposition is survival under negation: “He hasn’t stopped bothering me” and “He has stopped bothering me” both presuppose that he was bothering me.
Languages have complex systems for foregrounding and backgrounding information in this way. Thus mental attitude verbs, like know or regret, or change of state verbs like start and stop presuppose their complements, definite descriptions (like the king of Buganda) presuppose the existence of the entities referred to, iteratives like again (as in John did it again) presuppose earlier occurrences, and so on.
The phenomena and corresponding explanations are complex, but the relevance to pragmatics is that presupposition clearly implies that natural languages are built to trade on, and signal, the dependency of utterances on propositions already taken for granted. The pragmatic aspects of the phenomena are often underplayed in semantic accounts of the phenomena. For example consider the sentence Sue cried before she finished her thesis – this would normally presume that she finished thesis, this being a presupposition from the before-clause. But the minimally different sentence Sue died before she finished thesis seems to make no such presumption, because of course we happen to know that the dead do not complete theses. This defeasibility, or cancellation of an inference in the context of contrary assumptions, is a hallmark of pragmatic inference.

A PRESUPPOSITION TRIGGER

Definition

A presupposition trigger is a construction or item that signals the existence of a presupposition in an utterance.

Examples (English)

Both positive and negative forms are presented, showing that the presuppositions are constant under negation:

· Definite descriptions
In John saw/didn't see the man with two heads, the definite description the man with two heads triggers the presupposition "There exists a man with two heads." (The unbelievability of the presupposition is what makes the positive utterance unbelievable and the negative one odd.)
· Factive verbs
In John realized/didn't realize that he was in debt, both realize and didn't realize that trigger the presupposition "John was in debt."
Other factives are:

  • (it) be odd that
  • be sorry/proud/indifferent/glad/sad that
  • know that, and
  • regret that.

· Implicative verbs
In John managed/didn't manage to open the door, both managed/didn't manage to trigger the presupposition "tried to," as in "John tried to open the door."
Other implicative verbs are :

  • avoided (X-ing), which presupposes "was expected to"
  • forgot to, which presupposes "ought to have"
  • happened to, which presupposes "didn’t plan/intend to," and
  • intended to.

. Change of state verbs
In Kissinger continued/didn’t continue to rule the world, both continued/didn’t continue to trigger the presupposition "had been," as in "Kissinger had been ruling the world."
Other change of state verbs are:

  • arrive
  • begin
  • come
  • enter
  • go
  • leave
  • stop, and
  • take (X from Y), which presupposes "X was at/in/with Y."

· Expressions of repetition
In Carter returned/didn’t return to power, both returned/didn’t return trigger the presupposition "Carter held power before."
Other such expressions are :

  • again
  • another time
  • anymore
  • come back
  • repeat, and
  • restore.

· Expressions of temporal relations
In while Chomsky was revolutionizing linguistics, the rest of social science was/wasn’t asleep, the clause introduced by while triggers the presupposition "Chomsky was revolutionizing linguistics."
Other such conjunctions triggering presuppositions are:

  • after
  • as
  • before
  • during
  • since, and
  • whenever.

· Cleft sentences
In it was/wasn’t Henry that killed Rosie, the cleft structure triggers the presupposition "someone killed Rosie."
The pseudocleft structure in what John lost was his wallet triggers the presupposition "John lost something."
· Stressed constituents
In John did/didn’t compete in the OLYMPICS, the stressed constituent triggers the presupposition "John did compete somewhere."
· Returned actions
In Adolph called Marianne a Valkyrie, and she complimented him back/in return, too, both back/in return, too trigger the presupposition "to call Marianne a Valkyrie is to compliment her."
· Comparisons
In Carol is/isn’t a better linguist than Barbara, the comparison triggers the presupposition "Barbara is a linguist."
· Counterfactual conditions
In if the notice had only said ‘mine-field’ in English as well as Welsh, we would/would never have lost poor Llewellyn, the form of the condition triggers the presupposition "The notice didn’t say mine-field in English."
· Questions
Questions presenting alternatives tend to trigger a presupposition of the truth of one of the alternatives. The utterance is Newcastle in England or in Australia? triggers the presupposition "Newcastle is either in England or in Australia."
Questions containing interrogative pro-forms tend to trigger a corresponding presupposition containing an indefinite pro-form. The utterance who is the professor of linguistics at MIT? triggers the presupposition "someone is the professor of linguistics at MIT."

Source:
Compiled by Karttunen No date and presented by Levinson 1983: 181–184

Reference and Inference

Referring is one of the basic things we do with words, and it would be a good idea to understand what that involves and requires.

Speaker reference

Speaker reference is a four-place relation, between a speaker, an expression, an audience, and a referent: you use an expression to refer someone to something.

· To be in a position to refer to something (or to understand a reference to it) requires being able to have singular thoughts about it, and that requires perceiving it, being informed of it, or (having perceived or been informed of it) remembering it.

· To succeed in referring to something in using a certain expression requires getting them to think of it (and generally to grasp a singular proposition about it) via identifying it as what you intend them to think of by virtue of your using that expression.

· We generally choose the least informative sort of expression whose use will enable the hearer to identify the individual we wish to refer to, but this is not a matter of convention.

Reference – an act by which a speaker (or writer) uses language to enable a listener (or reader) to identify something (Yule, 2006: 115).

  • Words that we use to identify things are not in direct relation to these things:

Example:

  • Have you seen my Yule?

“Referring is not something an expression does; it is something that someone can use an expression to do.” (Strawson: 1950).

Strawson exploited the fact that almost any referring expression, whether an indexical, demonstrative, proper name, or definite description, can be used to refer to different things in different contexts. This fact, he argued, is enough to show that what refers are speakers, not expressions.

Inference any additional information use by the listener to connect what is said to what must be meant (Yule, 2006: 116).

Anaphora

  • Anaphora – is a subsequent reference to an already introduced entity. Speakers (writers) use anaphora in texts to maintain reference.

Example:

A: Have you seen my Yule?

B: Yeah, it is on the desk.

  • Yule” and “it”: “it” – anaphora, Yule – antecedent.

A referring expression, in linguistics, is any noun phrase, or substitute for a noun phrase, whose function in a text (spoken, signed or written on a particular occasion) is to "pick out" an individual person, place, object, or a set of persons, places, objects, etc. The technical terminology for "pick out" differs a great deal from one school of linguistics to another. The most widespread term is probably refer, and a thing "picked out" is a referent, as for example in the work of John Lyons. In linguistics, the study of reference belongs to pragmatics, , the study of language use, though it is also a matter of great interest to philosophers, especially those wishing to understand the nature of knowledge, perception, and cognition more generally. (From Wikipedia, the free encyclopedia)

The kinds of expressions which can refer (as so defined) are:

(1) a noun phrase of any structure, such as: the taxi in The taxi's waiting outside; the apple on the table in Bring me the apple on the table; and those five boys in Those five boys were off school last week. In those languages which, like English, encode definiteness, referring expressions are typically marked for definiteness. In the examples given, this is done by the definite article the or the demonstrative adjective, here those.

(2) a noun-phrase substitute i.e. a pronoun, such as it in It's waiting outside and Bring me it; and they in They were off school last week. The referent of such a pronoun may vary according to context - e.g. the referent of me depends on who the speaker is - and this property is technically an instance of deixis.

(3) a proper noun, like Sarah, London, The Eiffel Tower, or The Beatles. The intimate link between proper names and type (1) referring expressions is shown by the definite article that appears in many of them. In many languages this happens far more consistently than in English. Proper names are often taken to refer, in principle, to the same referent independently of the context in which the name is used and in all possible worlds, i.e. they are in Saul Kripke's terminology rigid designators.

Referring can take place in a number of ways. Typically, in the case of (1), the referring expression is likely to succeed in picking out the referent because the words in the expression and the way they are combined together give an true, accurate, description of the referent, in such a way that the hearer of the expression can recognize the speaker's intention. In the first example, if the hearer knows what an apple and a table are, and understands the relation expressed by on, and is aware that the is a signal that an individual thing/person is intended, s/he can build up the meaning of the expression from the words and grammar and use it to identify an intended object (often within sight, or at any rate easily recoverable, but not necessarily). Of course, the speaker may use a mistaken description and still manage to refer successfully. If I ask you to "Take this plate to the woman with the glass of soda", you may take it to the intended person even if, unbeknown to me, her soda is really water. On the other hand I may be accurate in calling it soda, but you may believe wrongly that it is water, and therefore not deliver the plate. So accurate reference is not a guarantee of successful reference, and successful reference does not wholly depend on accurate reference. But naturally there is a strong positive correlation between them.

Proper names, on the other hand, generally achieve reference irrespective of the meaning of the words which constitute them (if any are recognizable). If my local café is called The Anchor, this is simply a label which functions conversationally with no appeal to the meaning of the words. If I say, I'm going to the Anchor, I do not mean I'm going to the device for halting and securing a ship, and you will not necessarily call such a device to mind when I say this. The Anchor just serves to identify a particular building. This point is more obvious still with those names like Sarah and London which have no lexical meaning of their own.

In addition to the (in many languages) grammatically obvious singular and plural reference, linguists typically distinguish individual or specific reference, exemplified by each case presented so far, from generic reference, where a singular expression picks out a type of object (etc.) rather than an individual one, as in The bear is a dangerous animal. Plural expressions can, of course, be interpreted in the same way, as in Bears are dangerous animals.

Definite reference to single individuals is usually taken to be the prototypical type of reference.

Other types of reference recognized by linguists include indefinite as opposed to definite reference, and collective and distributive reference. Definite referring expressions refer to an identifiable individual or class (The Dalai Lama; The Coldstream Guards; the student with the highest marks), whilst indefinite referring expressions allow latitude in identifying the referent (a corrupt Member of Parliament; a cat with black ears - where a is to be interpreted as 'any' or 'some actual but unspecified'). Collective reference is the picking out of the members of a set as a set, whilst distributive reference is the picking out of the members of a set individually. The difference may not be marked linguistically, but arrived at by interpretation in context. Compare Manchester United won again today (where the reference of Manchester United is to members of the team as a unit), with Manchester United wear red shirts and black shorts (where the reference of Manchester United is to the team members as individuals). English allows such expressions to be ambiguous: compare Manchester United are rich beyond my wildest dreams.

Referring as a Collaborative Process

Clark and Wilkes-Gibbs (1986) investigated how participants in a conversation collaborate in making a referring action successful. They conducted experiments in which participants had to refer to objects--tangram patterns--that are difficult to describe.

They found that typically the participant trying to describe a tangram pattern would present an initial referring expression. The other participant would then pass judgment on it, either accepting it, rejecting it, or postponing his decision. If it was rejected or the decision postponed, then one participant or the other would refashion the referring expression. This would take the form of either repairing the expression by correcting speech errors, expanding it by adding further qualifications, or replacing the original expression with a new expression. The referring expression that results from this is then judged, and the process continues until the referring expression is acceptable enough to the participants for current purposes. This final expression is contributed to the participants' common ground.

Below are two exampless from Clark and Wilkes-Gibbs's experiments that illustrate the acceptance process.

A: 1 Um, third one is the guy reading with, holding his book to the left.

B- 2 Okay, kind of standing up?

A: 3 Yeah.

B" 4 Okay.

In this dialog, person A makes an initial presentation in line 1. Person B postpones his decision in line 2 by voicing a tentative "okay," and then proceeds to refashion the referring expression, the result being "the guy reading, holding his book to the left, kind of standing up." A accepts the new expression in line 3, and B signals his acceptance in line 4.

A: 1 Okay, and the next one is the person that looks like they're carrying something and it's sticking out to the left. It looks like a hat that's upside down.

B: 2 The guy that's pointing to the left again?

A" 3 Yeah, pointing to the left, that's it! (laughs)

B: 4 Okay.

In the second dialog, B implicitly rejects A's initial presentation by replacing it with a new referring expression in line 2, "the guy that's pointing to the left again." A then accepts the refashioned referring expression in line 3.

Sources

  • Cann, Ronnie (1993) Formal semantics. Cambridge University Press.
  • Clark, Herbert H., and Wilkes-Gibbs, Deanna (1986). "Referring as a collaborative process." Cognition, 22, 1-39. Reprinted in Arenas of Language Use, edited by Herbert H. Clark, 107-143.
  • University of Chicago Press and CSLI.
  • Kripke, Saul (1980) Naming and necessity, second edition. Basil Blackwell.
  • Lyons, John (1977) Semantics. Cambridge University Press.
  • Saeed, John (1997) Semantics. Blackwell.
  • Strawson, P. F. (1950), “On Referring,” Mind 59: 320-44.
  • Yule, G. (2006). The Study of Language. Cambridge: Cambridge University Press. (p. 112 – 117).