Cooperative principle

In social science generally and linguistics specifically, the cooperative principle describes how people achieve effective conversational communication in common social situations—that is, how listeners and speakers act cooperatively and mutually accept one another to be understood in a particular way. The philosopher of language Paul Grice introduced the concept in his pragmatic theory:
Make your 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.[1]: 45 
These are Grice's four maxims of conversation or Gricean maxims: quantity, quality, relation, and manner. They describe the rules followed by people in conversation.[2] Applying the Gricean maxims is a way to explain the link between utterances and what is understood from them.
Though phrased as a prescriptive command, the principle is intended as a description of how people normally behave in conversation. https://en.wikipedia.org/wiki/Cooperative_principle

• "Be informative. Be truthful. Be relevant. Be clear."
• Relevance theory of Dan Sperber and Deirdre Wilson builds on and also challenges Grice's theory of meaning and his account of pragmatic inference. The theory argues that Grice's four Maxims of Conversation can be reduced to (and are implied by) a single one: "Be relevant" (because every utterance conveys a presumption of its own optimal relevance)
  • Relevance theory is a framework for understanding the interpretation of utterances. It was first proposed by Dan Sperber and Deirdre Wilson, and is used within cognitive linguistics and pragmatics. The theory was originally inspired by the work of Paul Grice and developed out of his ideas, but has since become a pragmatic framework in its own right. The seminal book, Relevance, was first published in 1986 and revised in 1995. The theory takes its name from the principle that "every utterance conveys the information that it is relevant enough for it to be worth the addressee's effort to process it", that is, if I say something to you, you can safely assume that I believe that the conveyed information is worth your effort to listen to and comprehend it; and also that it is "the most relevant one compatible with the communicator's abilities and preferences", that is, I tried to make the utterance as easy to understand as possible, given its information content and my communicative skills. https://en.wikipedia.org/wiki/Relevance_theory (vs bullshit?)

Herbert Paul Grice (13 March 1913 – 28 August 1988),[1] usually publishing under the name H. P. Grice, H. Paul Grice, or Paul Grice, was a British philosopher of language who created the theory of implicature and the cooperative principle (with its namesake Gricean maxims), which became foundational concepts in the linguistic field of pragmatics. His work on meaning has also influenced the philosophical study of semantics. https://en.wikipedia.org/wiki/Paul_Grice