A precept derived from the writings of the English philosopher H(erbert) P(aul) Grice (1913–88) according to which speakers normally try to cooperate when communicating, and in particular they usually attempt to be truthful, informative, relevant, and clear—following Grice's conversational maxims of quality, quantity, relevance, and manner, respectively. Speakers may flout any of these maxims, for example by lying or being sarcastic, but conversation normally proceeds on the assumption that the maxims are being followed. Thus if Person A says I'm thirsty, and Person B replies I can recommend the Queen's Head, then, in the UK at least, if the cooperative principle is being followed, A will normally assume that B is referring to a pub rather than, for example, to the upper part of the sovereign's body or to a coin or a banknote carrying her effigy. Some linguists believe that the maxim of relevance is the fundamental explanatory principle of human communication. See also distributed cognition, pragmatics, theory of mind.