Transcript Entailment 蕴含

Entailment
蕴含
Shaozhong Liu, Ph.D. (Pragmatics) / Ph.D. (Higher Education)
School of Foreign Studies, Guilin University of Electronic
Technology
Homepage: www.gxnu.edu.cn/Personal/szliu
Blog: cyrusliu.blog.163.com
Email: [email protected]
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Objectives and SLOs
• Objectives
1) To familiarize students with the concept of
Entailment
2) To illustrate it with examples
3) To discuss its place in Pragmatics
• Student learning outcomes (SLOs)
1) To be able to define Entailment
2) To be able to distinguish it from other concepts in
meaning study
3) To be able to see its meaning in Pragmatics
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What on earth is entailment?
• Generally speaking, entailment is not a pragmatic
concept (i.e. having to do with speaker meaning), but
instead is considered a purely logical concept,
symbolized by ||-. Some examples of entailment for
the sentence in (1) are represented in (2).
• (1) Rover chased three squirrels. (=p)
• (2) a. Something chased three squirrels. (=q)
•
b. Rover did something to three squirrels. (=r)
•
c. Rover chased three of something. (=s)
•
d. Something happened. (=t)
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Inference
• Words and sentences do not tell us meanings
by themselves; it’s us who draw meanings
from words and sentences.
• An inference is a meaning we draw from an
utterance.
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Entailment as inference
• Declaratives or statements carry entailments;
others, such as imperatives and interrogatives, do
not.
• Declaratives and statements can be true and
false.
• Entailments are inferences that can be drawn
solely from our knowledge about the semantic
relationships in a language. (Peccei, 1999/2002,
p.14)
• If the original sentence is true, the entailment can
be true.
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• An entailment is a relationship between
sentences that forms the basis for some
inferences. (Peccei, 1999/2002, p.9)
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Entailments are everywhere!
• Last year was rather hard for them.
• But you must work three months on our
campus.
• …
• Where “year” (everyone knows) it’s 12
months and “month” (everyone knows) it’s 30
days.
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Entailments can be redundant informers!
• “slips (of tongue)” from radio and television
announcers:
a. It’s been an amazing year for Crystal Palace over
the past 12 months.
b. The robbery was committed by a pair of
identical twins, both are said to be about age 20.
c. Send in your competition answers with your
name, age, and how old you are.
d. So you’re a housewife and a mother. Do you
have any children?
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Features of entailments
• Analytic sentences:
a. My mother is a woman.
b. My mother is a doctor.
c. The tiger is unhappy.
d. The tiger is an animal.
(without knowing anything about my mother or the tiger
in question, you can quite easily answer ‘true’ to (a) and
(d) because of your knowledge of English. These
sentences are necessarily true because of the meaning
relationship between the words ‘mother’ and ‘woman’
and between ‘tiger’ and ‘animal’.) (Peccei,
1999/2002.p.10)
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• Contradictions:
e. My mother is a boy.
f. The tiger is a reptile.
(given that you interpret everything literally, you
can easily answer ‘false’ to (e) and (f); the
meanings of ‘mother’ and ‘boy’ and ‘tiger’ and
‘reptile’ make such sentences necessarily false
or contradictions. ) (Peccei, 1999/2002, p.10)
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• Synthetic sentences:
b. My mother is a doctor.
c. The tiger is unhappy.
(However, (b) and © present you with a
problem. They may or may not be true. You
cannot verify the truth or falsity of those
statements by looking in your dictionary. You
would need other, non-linguistic, information
about my mother and the particular tiger I am
referring to. These are sometimes referred to as
synthetic sentences.) (Peccei, 1999/2002. p.10)
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• Synthetically true:
If it turns out that my mother actually is a doctor or
that the tiger is unhappy, we would say that these
statements are synthetically true; that is their truth
is based on what is happening in the world, not on
what is happening in the language. ) (Peccei,
1999/2002, p.10)
• Synthetically false:
If my mother is an engineer rather than a doctor
and the tiger is quite happy, we would say that
these statements are synthetically false. (Peccei,
1999/2002, p.10)
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Advantages of entailments
• Entailing empower language and enables us
ample chance to be more flexible in speech, and
hence more expressive in communication.
• E.g.:
1) a. Annie caught a trout.
b. Annie caught a fish.
2) a. Annie is thin.
b. Annie is not fat.
3) a. Annie baked a cake.
b. Annie baked something.
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• Each pair is synthetically true. ‘once we
establish the truth of sentence (a), sentence
(b) becomes automatically true because of the
meaning relationships between trout/fish,
thin/fat, and cake/something. In each case, we
can say that sentence (b) is an entailment of
sentence (a).) (Peccei, 1999/2002, p.11)
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Paraphrase as a form of entailment
• All sentences have a number of entailments.
That is, other (entailed) sentences which are
automatically true if the original sentence is
true. The thing about entailment is that this
kind of inference is ‘for free’. It requires only a
knowledge of the semantic system of the
language being used.
• In semantics, a paraphrase is a special kind of
entailment.
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• More examples of paraphrase as entailment:
1)a. Goldilocks (金发女孩，出自Goldilocks and
three bears) saw a bear.
b. Goldilocks saw an animal.
2)a. This porridge is too cold.
b. This porridge is not too hot.
3)a. Baby Bear cried.
b. Baby Bear wept.
4)a. Mama Bear is in front of Papa Bear.
b. Papa Bear is behind Mama Bear.
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Allusions as entailment
• Until recently, financial markets appeared to be betting that
the Goldilocks economy—neither too hot, nor too cold—
was safe from the bears. 前为止，金融市场显现的趋势是
, 市场不会太热或太冷，而会相对安全。
• What we’re hoping for is a Goldilocks solution, where
the economy starts to boom again but the
price of oil doesn’t. 我们所希望的就是一个如金发姑娘般的
解决方法，一个经济开始迅速发展而油价不急剧上涨的解
决方法。
• Goldilocks economy 金发女郎经济，温和经济
• 以上来源于：《21世纪大英汉词典》
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Types of entailments
• One-way entailment (): sentences 1-2:
1) a. Goldilocks saw a bear.
b. Goldilocks saw an animal.
2) a. This porridge is too cold.
b. This porridge is not too hot.
(if Goldilocks saw a bear, she necessarily saw an animal.
But if she saw an animal, she could have seen a bear but
not necessarily. It could have been a big wolf, for
example.) (Peccei, 1999/2002, p.12)
• (when there is only one-way entailment, the sentences
are not true paraphrases of each other. )
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• Two-way / mutual entailment (): sentences 3-4:
3) a. Baby Bear cried.
b. Baby Bear wept.
4) a. Mama Bear is in front of Papa Bear.
b. Papa Bear is behind Mama Bear.
• (when the meaning relationship between sentences are
mutually inclusive, it is a situation of two-way or mutual
entailment.)
• (two-way or mutual entailments are sentences of
paraphrases of each other.)
• (Generally speaking, ‘entailment’, ‘analytic sentence’, and
‘contradictions’ are considered to be purely semantic
concepts, having to do with sentence meaning rather than
speaker meaning.) (Peccei, 1999/2002, p.12)
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Pragmatic entailments
• The information in the following dialogs seems
redundant or contradictory form a semantic point
of view, however, sensemaking in pragmatics:
• A. Tom: What’s your stepmother like?
Bob: Well, she’s a woman and she married
my father.
• B Dave: There’s your Uncle George.
Lucy: That man’s a snake.
• C Jane: You ate all the cookies!
Steve: I ate some of the cookies.
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Foregrounding: intent + strategy
• A sentence may have many (one-way) entailments.
E.g.: “the painters broke the window” may entail:
• “someone broke the window.”
• “the painters did something to the window.”
• The painters broke something.”
• …
(when uttering “the painters broke the window” in a
context, a speaker will have one of these entailments in
mind as the main focus, the most important one for
interpreting the message.) (Peccei, 1999/2002, p.13)
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• One way for the speaker to communicate the
most important message to the hearer is to stress
one of the words in an utterance, or
foregrounding a particular entailment. Like in the
following:
• Utterance a: Annie RUINED the sweater.
• Utterance b: Annie ruined the SWEATER.
• Utterance c: ANNIE ruined the sweater.
• Entailment 1: ‘someone ruined the sweater.’
• Entailment 2: ‘Annie did something to the
sweater.”
• Entailment 3: ‘Annie ruined something.’
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• Utterance a has foregrounded Entailment 2.
Message: ‘you and I are taking for granted that
Annie did something to the sweater. I’m telling
you what Annie did.’
• Utterance b has foregrounded Entailment 3.
Message: ‘you and I are taking fro granted that
Annie ruined something. I’m telling what Annie
ruined.’
• Utterance c has foregrounded Entailment 1.
Message: ‘you an di are taking for granted that
someone ruined the sweater. I’m telling you that
Annie did it.’
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So, what’s entailment?
• All sentences have a number of entailments – other
sentences which are automatically true if the original
sentence is true.
• Entailments are inferences that can be drawn solely from
our knowledge about the semantic relationships in a
language.
• This knowledge allows us to communicate much more than
we actually ‘say’.
• Each of these different messages illustrate how more can
be communicated than simply “what is said’. The
importance given to one entailment over another by a
speaker has important consequences for the pragmatic
analysis of that utterance. (Peccei, 1999/2002, p.14)
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Entailment as pragmatic strategy and analytical tool
• Ex.2.11 The following are from Howlers by Russell Ash (1985)
and The 776 Stupidest Things Ever Said by Ross and Kathryn
Petras (1994). Where has the communication gone wrong?
Or has it?
a. All creatures are imperfect bests. Man alone is the perfect
beast.
b. The brain of a woman is almost as heavy as a human brain.
c. A coroner’s duty is to decide whether a person died a fatal
death.
d. We do not have censorship. What we have is a limitation on
what newspapers can report.
e. Snakes are two sexes, poisonous and non-poisonous.
f. I have reiterated over and over again what I have said
before.
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• Ex.2.12 Look at these pairs of utterances. The
sentences being uttered in each pair are arguably
semantic paraphrases of each other (in a
relationship of mutual entailment). Do you think
they communicate the same information?
1) a. that food was delicious.
b. that grub was yummy.
2) a. she designs clothes for adult male humans.
b. she designs clothes for men.
3) a. that guy’s a bachelor.
b. that guy never got married.
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Summary
• Entailment (pragmatics)
• In pragmatics (linguistics), 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. Notice
also that if (B) is false, then (A) must necessarily be
false. To show entailment, we must show that (A)
true forces (B) to be true and (B) false forces (A) to
be false.
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• Entailment differs from implicature (in their
definitions for pragmatics), where the truth of
one (A) suggests the truth of the other (B), but
does not require it.[dubious – discuss] For example,
the sentence (A) Mary had a baby and (B) got
married implicates that (A) she had a baby
before (B) the wedding, but this is cancellable
by adding -- not necessarily in that
order. Entailments are not cancellable.
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• Entailment also differs from presupposition in that in
presupposition, the truth of what one is
presupposing is taken for granted. A simple test to
differentiate presupposition from entailment is
negation. For example, both The king of France is
ill and The king of France is not ill presuppose that
there is a king of France. However The president was
not assassinated no longer entails The president is
dead(nor its opposite, as the president could have
died in another way). In this case, presupposition
remains under negation, but entailment does not.
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•
•
•
•
•
Types of Entailment
There are three types of entailment:
formal or logical entailment,
analytic entailment,
synthetic entailment.
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References
• Hurford, J. and Heasley, B. (1988). Semantics:
A Coursebook. (Units 9-11). Cambridge:
Cambridge University Press.
• Simpson, P. (1993). Language, Ideology and
Point of View. (Chapter 5). London: Routledge.
• Yule, G. (1996). Pragmatics. (Chapter 4).
Oxford: Oxford University Press.
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