I.
Introduction
Entailment
is a relation between sentence meanings, or propositions. (Sometimes, speaking
loosely, we talk as though it were a relation between sentences.)
Presupposition can also be seen as a relation between propositions, although
many linguists (including George Yule) prefer to see presupposition as strictly
pragmatic, and a relation between a speaker and a proposition. In any
case it is important to see that these are two independent kinds of relations.
A proposition which is presupposed in a particular utterance may or may not
also be entailed.
II.
Entailment (||-).
A.
A sentence (meaning) A entails B (A ||- B) if whenever A is true, then B must
also be true. Entailment is a very strong kind of implication. It is a semantic
relation — thus, it holds no matter what the facts of the world happen to be
(it holds in all possible worlds).
B.
Examples.
(1) a. Mary broke the window ||- The window broke
b. Sue and Fred went to the party ||- Sue went to the party
III.
Presupposition (>>).
A.
Presuppositions are implications that are often felt to be in the background —
to be assumed by the speaker to be already known to the addressee.
B.
A good diagnostic: presuppositions are shared by members of ‘the S family’ —
that is, they remain constant under
1.
Negation (denial)
2. Questioning
3. Embedding under modals (e.g. might, it is possible that)
4. Embedding as the antecedent of a conditional (i.e. in an if-clause).
2. Questioning
3. Embedding under modals (e.g. might, it is possible that)
4. Embedding as the antecedent of a conditional (i.e. in an if-clause).
Example:
A speaker of any of the sentences below would be presupposing that there is
a king of France.
(2) a. The king of France is bald.
b. The king of France is not bald.
c. Is the king of France bald?
d. The king of France might be bald/Possibly the king of France is bald.
e. If the king of France is bald, he should wear a hat in the winter.
C.
A presupposition of the S family may or may not be entailed by S itself (as it
is in the example above — see (2a)), but in any case it will not be entailed by
the negated, questioned, modalized, or conditionalized sentences.
D.
Some examples — the presupposition triggers are underlined in each
example. For the first three categories, the presupposition is also an
entailment of the S sentence (though not the negated version of S). For the
last two, the presupposition is not entailed by S — these are sometimes called conventional
implicatures.
1.
Definite referring expressions (singular terms).
(3)
Mary saw/didn't see the horse with two heads >> There exists a
horse with two heads
(4)
Kepler died/didn't die in misery >> There is some individual named
Kepler
2.
Change of state verbs (start, stop, continue, etc.).
(5)
Joan began/didn't begin planting tomatoes >> Joan had
not been planting tomatoes before
3.
Clefts, other focusing constructions.
(6)
What Bill lost was/wasn't his wallet >> Bill lost something
(7)
It was/wasn't his wallet that Bill lost >> Bill lost
something
(8)
Bill lost/didn't lose HIS WALLET >> Bill lost something
4.
Honorific terms.
(9)
Tu es/n’es pas très grande (Fr., ‘You (fam.) are/are not very
tall’) >> The addressee is a close friend, a social
inferior, or an animal
inferior, or an animal
5.
Various modifiers.
(10)
He is an Englishman; he is therefore brave >> Being brave is a
consequence of being English
(11)
Even Bill could solve that problem >> Bill is the last person
you’d expect to be able to solve the problem
No comments:
Post a Comment