 If we grant both (I) and (II), then we have at once a story about why listeners process utterances as relevance theory claims and a story about why speakers implicitly vouch for the results of such processing, insofar as these results are foreseeable. In claiming the attention of L for my utterance U, I’m implicitly vouching for the truth of whatever I can expect L to come up with if he processes U the way he’d process any promising stimulus and continues to do so until it yields a result that adequately repays his investment of effort to date. But this is all I implicitly vouch for in speaking as I do. After that, the listener is on his own.