 Second, in claiming the attention of a listener at all, a speaker implicitly assures him that the stimulus she’s offering him is relevant and indeed optimally relevant—the most relevant stimulus within reach. (In view of the Cognitive Principle, he wouldn’t process her utterance unless he took it to be the most relevant stimulus within reach, so to induce him to process it, she must get him to take it to be the most relevant stimulus within reach.) Such is the Communicative Principle of Relevance.