Knowledge of meaning and knowledge of facts
4.3 Interpersonal context: implicature
entities or propositions – apples and oranges, seeing and believing, Toni and Amitavo (see Chapter 6 for explanation). It may not at fi rst sight be obvious why one should take the logical function of and to be primary in natural language. The essential reason is that, for many philosophers, the principles of logic are universal and underlie the operation of all human conceptual activity, including language: to study logic is thus to study the fundamental bases of rational human thought. As a result, words like and, or and not, which have analogues in the ‘language’ of logic, are naturally thought of as basically expressing the same ideas as their strict logical counterparts. In light of this basic function of and, consider (4):
(4) He got into bed and took off his shoes.
Grice notes the obvious fact that it would not be appropriate to utter (4) about someone who fi rst took off his shoes and then got into bed. One might claim, therefore, that there is an element of temporal succession to the meaning of and which is not refl ected in its logical, truth-functional meaning. Grice does not want to say, however, that the meaning of and in (4) is any different from its basic meaning as a logical connective. This is for two reasons. Firstly, he is committed to a truth-functional approach to meaning in which the sense of logical operators like and simply is their role as a logical connector. This means that he needs a way of dealing with instances like (4) which seem to show that ordinary language does not obey truth-functional principles. Second, he believes that most people would say that although (4) is a misleading description of the situation in question, it is nevertheless true: strictly speaking, there is nothing false in (4) as a description of the situation in which someone took off his shoes and then got into bed, although it is an unusual and confusing way to describe this situation.
Another example of a discrepancy between truth-conditional (logical) and conventional meaning would be the meaning of some in the following sentence:
(5) Tuptim has finished some of her homework.
Under normal circumstances, the speaker of (5) would be taken to mean that Tuptim hasn’t fi nished all her homework. From a strictly logical point of view, however, (5) is just as true if Tuptim has fi nished all her homework as it is if she has just fi nished some of it: if she has fi nished all her homework (say her history, geometry and German homework), it fol- lows logically that she has also fi nished some of it (say her history and geometry homework). This would, however, be a misleading way of describing the situation, since in real conversation some typically gives rise to the interpretation ‘not all’: if I say that I have read some of the book, I imply that I have not read all of it. (This is called a scalar implicature; see Horn 1984.)
A fi nal example of the same sort is the conjunction but. Strictly, but has exactly the same truth-conditions as and: there is no logical distinction between them (see 6.2). As a result, the following pairs of sentences have identical truth-conditional meanings:
(6) a. He’s rich and he’s unhappy.
b. Hilda took a cab and Dirk took the bus.
(7) a. He’s rich but he’s unhappy.
b. Hilda took a cab but Dirk took the bus.
From the truth-conditional point of view, there is no difference between the sentences in (6) and (7): they are true in exactly the same conditions.
There is, however, a clear non-truth-conditional difference between (6) and (7): (7) has an implication of contrast entirely missing in (6).
4.3.2 Conventional and conversational implicature
How should we think about these discrepancies between logical and con- ventional meaning? Grice introduced the term implicature in order to talk about these different facets of what we might call (informally) the meaning of an expression. The introduction of this term is a way of gen- eralizing over the different types of communicative intention which hearers attribute to speakers: the implicatures of an utterance are what it is neces- sary to believe the speaker is thinking, and intending the hearer to think, in order to account for what they are saying. Some of these implicatures, like the implicature of contrast carried by but, are conventional implicatures:
they are part of the typical force of the word, whether or not they conform to its strict, truth-conditional (logically defi ned) meaning. Conventional implicatures are what we might otherwise refer to as the standard or typical meanings of linguistic expressions. Other implicatures are conversational.
Conversational implicatures are those that arise in particular contexts of use, without forming part of the word’s characteristic or conventional force:
the choice of the term ‘conversational’ is explained by the fact that Grice’s examples are mostly taken from imagined conversations.
Here are some examples of exchanges involving conversational implica- tures; in all of them, the sentence meaning of B’s reply has no direct con- nection to A’s question: it is the implicated utterance meaning which contains the answer:
(8) A: Have you read Sebald?
B: I haven’t read the back of the cereal packet.
(9) A: Do you know how to get to rue du Pasteur Wagner?
B: I’ve got a map in my bag.
(10) A: Do you like anchovies?
B: Does a hippo like mud?
In (8) B implicates that he hasn’t read anything by Sebald, since he hasn’t even read the back of the cereal packet. In (9) B implicates that he does not know how to get to the rue du Pasteur Wagner, but that he is prepared to consult his map for directions. In (10) B implicates that since the answer to his question is ‘yes’, then the answer to A’s question is also ‘yes’ and that, as a result, he does indeed like anchovies. In all these cases, what is implied goes beyond the conventional meanings of the words used. The sentence I
haven’t read the back of the cereal packet is not usually able to convey the infor- mation ‘I haven’t read Sebald’; in the context of this conversation, however, this is precisely the information which it does convey. In order to under- stand the use of language in real communicative exchanges, therefore, it is essential to develop some analysis of the ways in which implicatures like these arise.