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Conversational Implicatures
LX 502 - Semantics I
Oct 2, 2008
1. Introduction
With entailments and presuppositions under our belts, I turn briefly to one other kind of inference called a
conversational implicature (or simply an
implicature). This inference is also an implicational relation but it is
distinct from entailments and presuppositions and important in our understanding of meaning.
Conversational implicatures are pragmatic inferences: unlike entailments and presuppositions, they
are not tied to the particular words and phrases in an utterance but arise instead from contextual factors and
the understanding that conventions are observed in conversation. The theory of conversational implicatures is
attributed to Paul Herbert Grice, who observed that in conversations
what is meant often goes beyond
what is
said and that this additional meaning is inferred and predictable. As an illustration of what Grice was talking
about, consider the sentence in (1).
(1)
John ate some of the cookies
The sentence in (1) expresses the proposition that John ate a portion of the cookies and is true just in
case it corresponds to the outside world. Intuitively, all of the cookies still constitutes a portion of the cookies.
So the sentence in (1) is true even if in the outside world John ate all of the cookies. However, something
interesting happens when this sentence is uttered in a conversation like (2).
(2)
A: “John ate some of the cookies”
B: “I figured he would. How many are left?”
It is clear from (2) that A conveys the literal meaning of the sentence in (1), i.e., its semantic content.
It is equally clear that A implies—or at least B infers—the proposition expressed by (3).
(3)
John didn’t eat all of the cookies
You might suspect that what the word
some really means is something like
a portion but not all, so
that the sentence in (1) literally means that John ate a portion but not all of the cookies and (1) entails (3). Let
me show you that this is not the case by comparing the sentences in (4).
(4)
a.
John ate some of the cookies;
# in fact, he ate none of the cookies
b. John ate some of the cookies;
in fact, he ate all of the cookies
In (4a), I cannot follow the sentence
John ate some of the cookies with the sentence
in fact, he ate
none of the cookies because the second sentence contradicts the first sentence. In other words, there is no way
in which the world could correspond to both sentences simultaneously. However, no such contradiction arises