 So my words may imply something I don’t: if something my words imply is manifestly so firmly accepted already as to need no certification from me, or so firmly rejected or patently unknowable by me as to be unable to benefit from any certification I might attempt, it forms no part of what I commit myself to in speaking my words. On the other hand, I may imply something my words don’t: I can and do vouch for the truth of a thing that isn’t implied by the words I speak when my audience can square my utterance of those words with the supposition that I am cooperative, rational, and unconfused about the state of conversational play only by assuming that I am in a position to vouch for that thing’s truth (in that I believe it and have good grounds for believing it) and am prepared to actually do so. Such, nearly enough, was how Grice defined the special kind of speaker meaning he dubbed conversational implicature.