Grice’s model seems to assume that the speaker meaning (total meaning that the speaker intends to communicate) is the sum of the sentence meaning (“what is said”, i.e., the meaning linguistically encoded by the words themselves) plus implicatures. Moreover, implicatures were assumed not to affect the truth value of the proposition expressed by the sentence; truth values were assumed to depend only on sentence meaning.11
In many cases, however, the meaning linguistically encoded by the words themselves does not amount to a complete proposition, and so cannot be evaluated as being either true or false. Grice recognized that the proposition expressed by a sentence like (13a) is not complete, and its truth value cannot be determined, until the referents of pronouns and deictic elements are specified. Most authors also assume that any potential ambiguities in the linguistic form (like the syntactic and lexical ambiguities in 13b) must be resolved before the propositional content and truth conditions of the sentence can be determined.
(13) a. She visited me here yesterday.
b. Old men and women gathered at the bank.
Determining reference and disambiguation both depend on context, and so involve a limited kind of pragmatic reasoning. However, it turns out that there are many cases in which more significant pragmatic inferences are required in order to determine the propositional content of the sentence. Kent Bach (1994) identifies two sorts of cases where this is needed: “Filling in is needed if the sentence is semantically under-determinate, and fleshing out will be needed if the speaker cannot plausibly be supposed to mean just what the sentence means.”
The first type, which Bach refers to as semantic under-determination, involves sentences which fail to express a complete proposition (something capable of being true or false), even after the referents of pronouns and deictic elements have been determined and ambiguities resolved; some examples are presented in (14).12
(14) a. Steel isn’t strong enough.
b. Strom is too old.
c. The princess is late.
d. Tipper is ready.
In these cases a process of completion (or “filling in” the missing information) is required to produce a complete proposition. This involves adding information to the propositional meaning which is unexpressed but implicit in the original sentence, as indicated in (15). The hearer must be able to provide this information from context and/or knowledge of the world. The truth values of these sentences can only be determined after the implicit constituent is added to the overtly expressed meaning.
(15) a. Steel isn’t strong enough [to stop this kind of anti-tank missile].
b. Strom is too old [to be an effective senator].
c. The princess is late [for the party].
d. Tipper is ready [to dance].
The under-determination of the sentences in (14) is not due to syntactic deletion or ellipsis; they are semantically incomplete, but not syntactically incomplete. The examples in (16–17) show that the potential for occurring in such constructions may be lexically specific, and that close synonyms may differ in this respect.
(16) a. The king has arrived [at the palace].
b. * The king has reached.
(17) a. Al has finished [speaking].
b. * Al has completed.
The second type of sentence that Bach discusses involves those in which “there is already a complete proposition, something capable of being true or false (assuming linguistically unspecified references have been assigned and any ambiguities have been resolved), albeit not the one that is being communicated by the speaker.” For example, imagine that a mother says (18a) to her young son who is crying loudly because he cut his finger.
(18) a. You’re not going to die.
b. You’re not going to die [from this cut].
Clearly she does not intend to promise immortality, although that is what the literal meaning of her words seems to say. In order to determine the intended propositional content of the sentence, the meaning has to be expanded (or “fleshed out”) as shown in (18b). Once again, the hearer must be able to provide this additional information from context and/or knowledge of the world. A more complex kind of pragmatic reasoning is required here than would be involved in assigning referents to deictic elements or resolving lexical ambiguities. Further examples are provided in (19), illustrating how identical sentence structures can be expanded differently on the basis of knowledge about the world.
(19) a. I have eaten breakfast [today].
b. I have eaten caviar [before].
c. I have nothing to wear [nothing appropriate for a specific event].
d. I have nothing to repair [nothing at all].
Bach uses the term impliciture to refer to the kinds of inference illustrated in this section. The choice of this label is not ideal, because the words impliciture and implicature look so much alike. A very similar concept is discussed within Relevance Theory under the label explicature,13 expressing the idea that the overtly expressed content of the sentence needs to be explicated in order to arrive at the full sentence meaning intended by the speaker. In the discussion that follows we will adopt the term explicature.14
K. Bach (1994: 11) describes the difference between “impliciture” (=explicature) and implicature as follows:
Although both impliciture and implicature go beyond what is explicit in the utterance, they do so in different ways. An implicatum is completely separate from what is said and is inferred from it (more precisely, from the saying of it). What is said is one proposition and what is communicated in addition to that is a conceptually independent proposition, a proposition with perhaps no constituents in common with what is said…
In contrast, implicitures are built up from the explicit content of the utterance by conceptual strengthening … which yields what would have been made fully explicit if the appropriate lexical material had been included in the utterance. Implicitures are, as the name suggests, implicit in what is said, whereas implicatures are implied by (the saying of) what is said.
In other words, implicatures are distinct from sentence meaning. They are communicated in addition to the sentence meaning and have independent truth values. A true statement could trigger a false implicature, or vice versa. Explicatures are quite different. The truth value of the sentence cannot be determined until the explicatures are added to the literal meanings of the words.
Since explicatures involve pragmatic reasoning, we must recognize the fact that pragmatic inferences can affect truth-conditional content. Further evidence that supports this same conclusion is discussed in the following section.
11 Of course, the implicatures themselves also have propositional content, which may be true or false/misleading even if the literal sentence meaning is true.
12 Examples (14–19) are adapted from K. Bach (1994).
13 Sperber & Wilson (1986); Carston (1988).
14 We are ignoring for now the relatively minor differences between Bach’s notion of impliciture and the Relevance Theory notion of explicature; see K. Bach (2010) for discussion.
