The Cooperative Principle
Watch the following movie scene from Pink Panther Strikes Again and pay particular attention to the conversation that takes place after Peter Sellers, as Inspector Clouseau, leaves the front desk of the hotel (00:50 - 1:17).
Obviously, one of the the problems in this scenario has to do with communication. Before you read on, Take a few minutes and try to specify what "went wrong".
Source of the picture: medicanti.de
One can assume that Inspector Clouseau holds the (unfortunate) assumption that more was communicated than was said. Yet, it was not the presupposition that was problematic (since the assumption in "your dog" is true for both the inspector and the man). Rather it is Inspector Clouseau's assumption that his question "Does your dog bite?" and the old man's answer "No!" both apply to the dog lying in the front door. The old man provided less information than expected.
The concept that there is an expected amount of information to be provided in a conversation is part of the idea that people, who are conversing with each other are cooperating. Going back to the movie scene, this might indicate that the old man deliberately provided less information in order to show that he does not want to be involved in a cooperative interaction with Inspector Clouseau.
The philosopher Paul Grice proposed a cooperative principle of conversation which can be elaborated in four sub-principles, called conversational maxims or Gricean Maxims.
The 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." (Grice, 1975)
Maxim of Quantity: Information
- Make your contribution as informative as is required for the current purposes of the exchange.
- Do not make your contribution more informative than is required.
Maxim of Quality: Truth
- Do not say what you believe to be false.
- Do not say anything for which you lack adequate evidence.
Maxim of Relation: Relevance
- Be relevant.
Maxim of Manner: Clarity
- Avoid obscurity of expression. ("Eschew obfuscation")
- Avoid ambiguity.
- Be brief.
- Be orderly.
Note that there may be an overlap, as regards the length of what one says, between the maxims of quantity and manner. This overlap can be explained (partially if not entirely) by thinking of the maxim of quantity (artificial though this approach may be) in terms of units of information. In other words, if the listener needs, let us say, five units of information from the speaker, but gets less or more than the expected number, then the speaker is breaking the maxim of quantity. However, if the speaker gives the five required units of information, but is either too curt or long-winded in conveying them to the listener, then the maxim of manner is broken. The dividing line, however, may be rather thin or unclear, and there are times when we may say that both the maxims of quantity and manner are broken by the same factors.