Meaning, Intention, Uncertainty

In #2.6 of Speech Acts, Searle challenges the concept of Meaning as Intention: "Meaning is more than intention, it is also at least sometimes a matter of convention", for, otherwise, "any sentence can be uttered with any meaning whatsoever".  However, as is evident in even the simplest case of 'convention'--two people with a long history of verbal exchanges--misunderstanding is always possible, which demonstrates that what is additional to Intention in any Communication is a combination of uncertainty and trust, not some mysterious property of the language itself.  In other words, that extra dimension is Moral, not Semantic, as Searle himself exploits in his study of False Promising in chapter 8.