⎪⎪
⎪
⎨
⎪⎪
⎪⎪
⎩
C= {w0, w1, w2, ...} P = {h0, h1, h2, ...} O= {a0, a1, a2, ...}
The next step is to associate different types of sentences with different updates on the common ground. In order to keep matters relatively manageable, we are going to ignore the alternative parameter of the common ground from now on. We will assume that the common ground supplies a set of alternatives whenever these are needed, but we will not say anything else about how this mechanism works (beyond what was said in §4.2.1).
6.5 Evaluative & descriptive update (1st attempt)
Here is an initial view:declarativesentences can update both the context set and the hyperplan parameter of the common ground. But whiledescriptivesentences restrict the context set and leave the hyperplan parameter untouched, evaluative sentences restrict the hyperplan param-eter, while leaving the context set untouched. In Chapter 3-4, our proposal was to assign all declarative sentences a uniform semantic type that combined a descriptive and evaluative com-ponent, and then let descriptive sentences have an idle evaluative component while evaluatives have an idle worldly component. We will do the same here.
In order to interpret declarative sentences dynamically, we need to enrich our view about asser-tion, so that the assertion of a declarative sentence can operate an update on the context set as well as on the hyperplan parameter of the common ground. We can do this by assuming that assertion is set intersection with those two parameters (we do not assume any update operation on alternatives). Whereϕis any declarative sentence, our new rule of assertion is:
Definition 31 (Generalized Assertion) G[ϕ] =
The difference between the conversational impact of evaluative and descriptive sentences is due to their semantic values, which we already defined to be respectively insensitive to either worlds or hyperplans and alternatives. Let us go through each case.
Recall, first, our truth conditions for atomic, descriptive sentences (§4.2.2). Where M is a model consisting of a semantic structureS (as characterized in Definition 16) and a valuation functionV; and whereϕis any descriptive and atomic (i.e. non-Boolean) sentence of English,
(4.16) [[ϕ]]M
⟨wi,hi,ai⟩=1iff⟨wi, hi, ai⟩ ∈V(ϕ)(we henceforth skipM)
The semantic value that V assigns to this sentence is a set of world-hyperplan-alternative triplets.
(6.17) V(ϕ) = {⟨w, h, a⟩ ∶ϕ(w)(h)(a) =1}
Sinceϕ is descriptive,V(ϕ)contains all hyperplans and all alternative-generating functions, but not all worlds. In other words, (6.17) is hyperplan- and alternative-insensitive, but world-sensitive.
To see how an assertion of this type of sentence impacts the common ground, we need to apply this semantic object to a common ground G, following our rule of Generalized Assertion.
Assuming thatϕis compatible with a context setC (and assuming thatϕis not entailed byG and there is no presupposition failure),
Sinceϕis a descriptive sentence, it contains all hyperplans but not all worlds. Therefore, the update on the context set C will result in some epistemic possibilities being ruled out. By contrast, the update onP will leaveP untouched.
By contrast, asserting an evaluative sentence performs an update on the hyperplan parameter of the common ground, but leaves the context set untouched. Let us see how this work for the most basic type of evaluative sentence that we discussed, namely a sentence containing a thin evaluative adjective taking a full proposition as argument. These are the truth-conditions that we gave in §4.2.3for a sentence likeit is good thatϕ:
(4.17) [[it is good thatϕ]]⟨w
i,hi,ai⟩=1iff{w′∶ [[ϕ]]⟨w′,hi,ai⟩=1} ∈hi(ai[ϕ](wi))
That sentence is true just in case the worldly component ofϕis preferred by the hyperplan of the index, relative to the set of alternatives of the index (which includesϕ).
The semantic value assigned to the sentence in (4.17) is therefore a set of world-hyperplan-alternative triplets.
(6.19) [[it is good thatϕ]] = {⟨w, h, a⟩ ∶ {w′∶ [[ϕ]]⟨w′,h,a⟩=1} ∈h(a[ϕ](w))}
But because this sentence is evaluative, its semantic value contains all worlds, but not all hy-perplans and not all alternatives. Thus, the result of adding this sentence to a common ground (again, ignoring the alternative parameter) is an update to the hyperplan parameter of the com-mon ground.
In particular, adding (6.19) to a common groundGwill leave the context setC untouched, but will rule out hyperplans fromP that are not such that the worldly component ofϕis among the preferable alternatives.
For instance, when a speaker uses an evaluative sentence such as (6.21) It’s good that we didn’t call off our walk.
our proposal is that this sentence should be understood as an update of the hyperplan parameter of the common ground, relative to whatever choice of alternatives is determined by the common ground at that point of the conversation. It is a proposal to rule out hyperplans that do not count the propositionthat we didn’t call off our walkamong the preferable alternatives.
The question for us is whether we can take on board this proposal and apply it to our cases, that is, to evaluative sentences such as the one uttered by Amir in the different scenarios of (6.7):
(6.7) The Mercedes is better than the Audi.
Bracketing for now the semantic features of this particular type of sentence (we come back to them in the following section), all we would need to do is associate (6.7) (whose semantic value would also be a set of world-hyperplan-alternative triplets) with an update function. And since (6.7) is evaluative, its semantic value would be hyperplan- and alternative-sensitive, but world-insensitive. Therefore, its update function would target the hyperplan parameter of the common ground, while leaving the context set untouched.
(6.22) G[(6.7)] =
This proposal would be immediately well-suited to account for evaluative uses of evaluative sentences (cf. (Vis-à-vis)): since the function of evaluative sentences (in their evaluative use) is to update the hyperplan parameter (rather than add information to the context set), it is to be ex-pected that utterances of those sentences lackEPISTEMIC STATUSandDECEIT POTENTIAL, as we saw in §6.2.1-6.2.2. Moreover, disagreeing utterances might be taken as proposals to adopt conflicting plans (that is, different sets of hyperplans), which coheres with the idea that no plan of action isa priorisuperior to any other, thereby accounting for the intuition ofSUBJECTIVE
-NESS (§6.2.3). Finally, taking evaluative sentences to update the hyperplan parameter of the common ground has the advantage of offering an intuitive grasp of theACTION-GUIDANCEof evaluative uses of those sentences (§6.2.4). What we would be doing, essentially, is hardwiring the ability to update the practical commitments of interlocutors into the semantic value of those sentences.24
24See the discussion on action-guidance on §2.3.1-2.3.2.
The obvious shortcoming of this view is that it does not account for descriptive (nor mixed) uses of evaluative sentences, since it predicts that evaluative sentences invariably update the hyper-plan parameter. We have seen, however, that there are reasons to think that this is not always the case: in contexts like (Experts), where a standard for good cars is assumed to be shared by speakers, evaluative sentences are used to communicate factual information. Consider again (Experts), repeated here:
(6.7c) (Experts): Amir and Mora are car experts, they have a very similar standard for cars and they know that they do; Amir is telling Mora on the phone about the cars he is seeing at the auto show.
Amir: The Mercedes is better than the Audi.
We argued in §6.2 that Amir’s utterance in (Experts) has the status of a judgment of fact, offering information about the properties of the two cars. But given that (6.7) contains an evaluative adjective, according to this initial proposal its utterance would effect an update on the hyperplan parameter of the common ground. Recall that this update consists on, roughly, a proposal to adopt a common plan of action. This type of update is hardly reconcilable with the utterance in (Experts)’s attestedEPISTEMIC STATUSandDECEIT POTENTIAL—as we saw, (Experts) appears to provide information about the world that can be supported or falsified by evidence. For that same reason, such an update would also be at odds with the impression that a disagreement in the context of (Experts) would not beSUBJECTIVE. Finally, if the hyperplan parameter tracks shared practical commitments and, if what we said in §6.2.4is right, it follows that the practical commitments of the interlocutors should be updated as a result of accepting this utterance. But that is not the case in (Experts), as we saw; no new practical commitments are adopted there as a result of accepting this utterance. That is, in that context, (6.7) is not
ACTION-GUIDING. We conclude that, as it stands, this simple story is insufficient to account for the contrast between (Vis-à-vis) and (Experts).
To sum up: although we have yet to give the full picture, a straightforward dynamic version of our proposal for evaluative sentences in Chapter4correctly captures the discursive features that characterize evaluative sentences in their evaluative uses. The problem is that such sentences can also have descriptive and mixed uses, and these are unaccounted for. As far as we have said, the prediction of our view is that all evaluative sentences are used evaluatively (in accordance with the piece of received wisdom #1). What we need however, is a view that can accommodate the possibility of using evaluative sentences evaluatively, descriptively and in a mixture of both;
moreover, we need a proposal according to which whether an evaluative sentence is used in any of these ways depends on the state of the conversation.