Kent Bach has this idea he calls “conversational impliciture.” It comes out of his reading of Grice. He says that Grice posits a constraint on what is said that each part of what is said should correspond (be expressed by?) a syntactic element of the sentence. What does that get us? If you have a sentence that looks “semantically incomplete” then without the constraint you would be tempted to say that the missing semantic elements are there, just unexpressed or unarticulated. Bach says these things aren’t part of what is said since they don’t have a corresponding syntactic realization. They are implicit in the conversation though. Rather than enriching what is said, he suggests a new layer, conversational impliciture, which is the material that is implicit in a given utterance. This meshes with some of his recent stuff because he does not think that utterances of full sentences always express complete thoughts or propositions. He is all for accepting semantic incompleteness.

Here are three quick, related questions I have about his view. First, how much different is it than, say, the unarticulated constituent view of Perry? Both have implicit, assumed information making its way into propositions. (I’m pretty sure conversational impliciture is propositional.) The main difference seems to be that Perry puts it in what is said (or the locutionary content, which, I believe, is his preferred term these days) while Bach leaves what is said semantically incomplete and puts it somewhere else. Does this difference end up coming to much though?

Second, how does impliciture interact with implicature? Is it used in the derivation of implicatures? Grice says that what is said is used to determine what the implicatures are, in combination with the maxims. I suppose it becomes a part of the background knowledge, but it makes what is said seem otiose. If we have an implicature whose derivation requires using the impliciture, which is an enriched version of what is said, then what is said is doing exactly 0 work in the derivation. It only serves to get us to impliciture, then drops out. It does not seem difficult to construct cases in which this would happen, say an implicature depending on someone not having eaten today when the person says “I have not eaten.” This example needs a lot of fleshing out before it becomes convincing, but hopefully one can see where it is heading. This leads to the third question.

What exactly is the difference between implicitures and implicatures? They seem to require very similar mechanisms in their determination. Why not say that impliciture is an intermediate step in the derivation (if I may use these terms like the derivations were well-defined) of implicature from what is said? There doesn’t seem to be any good demarcation line between the two concepts. Of course, an unclear boundary doesn’t mean that the concepts are worthless (Quine didn’t win that fight in all cases) but it would be good to clarify.