7.4 Cooperation and implicature

　 When people talk with each other, they try to converse smoothly and successfully. Cooperation is the basis of successful conversations. The following conversation in Hamlet is obviously a failure in communication:

　　Hamlet: Whose grave is this, sir?
　　Clown: (grave digger): Mine, sir...?br> 　　Hamlet: What man do you dig it for?
　　Clown: For no man, sir.
　　Hamlet: What woman then?
　　Clown: For none neither.

The conversation is abnormal in that the hearer's replies do not provide required information. The idea that people cooperate with each other in conversing is generalized by Grice (1975) as cooperative principle:

　 Make your conversational contribution such as is required, at the stage at which it occurs, by the accepted purpose or direction of the talk exchange in which you are engaged. Specifically, there are four maxims under this general principle.

　 The maxim of quantity:
　　(i) Make your contribution as informative as is required for the current purpose of exchange.
　　(ii) Do not make your contribution more informative than is required.

　 The maxim of quality:
　 Try to make your contribution one that is true.
　　(i) Do not say what you believe to be false.
　　(ii) Do not say that for which you lack adequate evidence.

　 The maxim of relevance:
　 Make your contributions relevant.

　 The maxim of manner:
　　(i) Avoid obscurity of expression.
　　(ii) Avoid ambiguity.
　　(iii) Be brief.
　　(iv) Be orderly.

It is assumed that the participants adhere to the cooperative principle and the maxims. Just like doing anything else together with others, people must cooperate in talking to each other.

　 Based on this assumption it is observed that there is more meaning than what is said if the maxims are violated by the speaker. This kind of implicit, non-conventional meaning is called conversational implicature. Consider the following examples:

　　(20) Man: Does your dog bite?
　　　　 Woman: No.
　　　　 (The man reaches down to pat the dog. The dog bites the man's hand.)
　　　　 Man: Quch! Hey! You said your dog doesn't bite.
　　　　 Woman: He doesn't. But that's not my dog.
　　　　 (Yule 2000: 36)

Asking the question, the man assumes that the dog belongs to the woman. The woman's answer provides less information than expected. The maxim of quantity is flouted. Is the woman willing to talk with the man? If your answer is No, you have rightly figured out the implicature.

　　(21) A: Do you reckon Sally will marry that sugar daddy?
　　　　 B: Do you want another cup of coffee?

B's response violates the maxim of relevance. The implicature is that the hearer doesn't want to gossip about Sally's love affair. These examples show that implicature is a kind of speaker meaning. It has to be worked out by the hearer through inference.