In 1967, American philosopher H.P. Grice put forward the Cooperative Principle in Logic and Conversation: “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” (Yule, 37). Supporting this principle is the four maxims: Quantity Maxim: Make your contribution as informative as is required, but not more, or less, than is required. Quality Maxim: Do not say that which you believe to be false or for which you lack evidence. Relation Maxim: Be relevant. Manner Maxim: Be clear, brief and orderly.
The importance of this principle lies in two aspects: Firstly, it is the first time to systematically induce people’s conversational activities into law. Secondly, when violation of the Cooperative Principle takes place, in one case, understanding of the discourse is hindered and the speaker should make remedies immediately to smooth the conversation; in another case, if the speaker does so intentionally, there will be more to it than what is said. Conversational implicatures, in this way, will be given rise to.
1．Violation of the Quantity Maxim
1.1 知之为知之，不知为不知。（《论语》）
In this sentence, repetition of the same word appears twice, which accords with the formula “P=P”. From a purely logical perspective, the sentence has no communicative value since it expresses something completely obvious, but it can be understood easily that this sentence primarily advises people to be honest in engaging in scholarship. Similar apparently pointless expressions are “Business is business” and “Girls are girls”. This kind of phenomenon is called tautology. When tautology is applied in a conversation, it is clear that the speaker intends to express more than is said. Usually, this kind of usage has strong sense of emotion.
1.2 Polonius: What do you read, my lord?
Hamlet: Words, words, words. (Shakespeare, Hamlet)
1.3 “我们是睡在鼓里，等人家来杀！等人家来杀！”(矛盾：《子夜》)
From Polonius’ perspective, Hamlet’s answer provides less information than expected. For “words” being the object of “read” seems to be too general and Polonius still did not know what Hamlet read. In fact, repetition of the word “words” shows Hamlet’s strong impatience that he was unwilling to talk to Polonius. In another point of view, from the fact that Polonius’s attitude is warm and cooperative while Hamlet’s attitude is impatient and indifferent, there must be some implications. Similarly in example 3, repetition of a sentence shows the speaker’s strong indignation.
2． Violation of the Quality Maxim
2.1 南唐时，赋税繁重，京城地区又遭旱灾，人民叫苦连天。一天，烈祖在北苑饮宴，对群臣说：“外地都下雨了，只是都城却不下雨，怎么回事呢？”申渐应到：“雨不感入城，是怕抽税而已。”烈祖大笑，马上下令除掉重税。（《古今谭概—微词》）
Violation of the Quality Maxim has two cases, one case is a kind of “moral offence”, which means that the speaker is unwilling to observe the Quality maxim and is lying. The other case is a kind of “false lie”, which means that the speaker is unwilling to cooperative and is trying to express implicit meaning. In this example, Shen Jian cleverly used personification that even the rain is scared of the tax because the man he talked to was the king of the dynasty. Just think of the impossibility of abolishing the heavy taxation if Shen Jian used blunt words to remonstrate!