4.3 Relating the Two Notions of Context
4.3.3 The Over-generation of Content
Stalnaker acknowledges that
The upshot [of Kaplan’s notion of context] is that speakers and addressees never know what [metaphysical] context they are in, and for this reason, this notion of context is ill-suited for doing the pragmatic job of identifying the assertoric content of a speech act (forthcoming, p. 7).
And since he is interested in providing a pragmatic account of how assertions impact the state of information in which they occur, he avails of his epistemic notion of context to do this job. Moreover, he seems to favour the epistemic first construal of the
relation between the two notions of context, according to which the common ground
determines a set of centered possible worlds compatible with the propositions mutually presupposed by conversational participants.
According to Stalnaker,
The centers [of the worlds] emerge naturally from the cognitive situations of the relevant individuals; assumptions about indexical pronouns played no role in the construction [of the common ground], but given the centers it will be a simple matter to apply the Kaplan semantics for personal pronouns to members of the context set. The “I”s and “you”s are interpreted in the obvious way by who is speaking in the relevant K[aplan]-context (2014, p. 123).
However, there appear to be two issues here. First, it is not clear that applying Kaplan’s framework will be a simple matter given that there is a set of possible assignments of values for the context of use, potentially resulting in an over-generation of contents.
And secondly, it is also unclear how speakers identify the relevant context of use in
order to interpret indexical expressions since, as we noted above, the context of use is
inherently beyond the cognitive reach of speakers and hearers.
On the epistemic first construal, rather than a single assignment of values, the common ground determines a set of assignments of values for the context of use all of
which are compatible with common ground. If this is the case, however, then Kaplan’s
framework will not specify a unique object as the content of an indexical, but rather a multitude, one for each compatible assignment of values. Indexicals, in this framework, “require that the value of a certain parameter be given before a determinate element of
content is generated” and hence before the propositional content of sentences containing such expressions can be settled (1989b, p. 591). Provided there is more than one
4.3 Relating the Two Notions of Context | 119
assignment of values compatible with the common ground, the distinct values will give
rise to distinct contents.
To unpack this a little, consider a speaker who knows thecommon ground of the
conversation, which in this case is a set of contexts of use C, i.e., the set of all those
quadruples of value assignments that are compatible with the common ground. Now,
an occurrence of an indexical – an expression-context of use pair – specifies the content
of the indexical. So relative to c1, the indexical has content1, relative to c2 it has
content2, etc. For all the speaker knows, c1=c2, but it need not, and if c1 ̸=c2, then
the indexical does not determine a unique content.14 Rather, relative to each context
of use that is a member of C, the expression determines a unique content, but the
speaker doesn’t know which member of that set she is in (if any!). Mutatis mutandis
for the addressee who knows the common ground of the conversation. Relative to
the set C, where c1 ̸=c2, no unique content is specified. Instead, a unique content
is specified for each distinct assignment of values (e.g., as many contents for ‘I’ are specified as there are members of C with distinct values for the agent parameter, and
likewise for the other parameters). In this sense, Stalnaker is right that “it will be a simple matter to apply the Kaplan semantics [. . . ] to members of the context set.” But given the potential over-generation of content, it becomes unclear how conversational participants converge on the same content with which to update the context set in the
course of communication.
Contrary to Stalnaker’s sanguine suggestion, then, it appears that the application of Kaplan’s semantics on the epistemic first construal is not exactly a simple matter,
though it is certainly straightforward once values have been assigned to the parameters of the context of use. What’s not straightforward is which assignment of values to plug
into the semantics when given a set of assignments the elements of which generate distinct contents. Likewise, while it is obvious how to leverage Kaplan’s semantic framework to interpret first- and second-personal pronouns if one knows the relevant
context of use, it remains unclear how speakers and hearers identify the relevantcontext of use in a given situation on the epistemic first construal according to which there is
more than one context of use compatible with the common ground of that situation.
While the worry with the metaphysics first construal is that the content – what is
14 As Stalnaker (2014) makes clear,
a C[ommon]G[ground]-context in which an utterance event is presupposed to be taking place is compatible with many K[aplan]-contexts, and the information that distinguishes between the different K-contexts compatible with common ground is not presumed to be available (p. 217).
said – delivered by Kaplan’s formal framework is explanatorily idle in accounting for real-life utterance interpretation and, more generally, communication, the worry with the epistemic first construal is that the application of Kaplan’s formal framework
over-generates content, undermining Stalnaker’s account of communication whereby the information state in which conversation occurs is updated incrementally when participants converge on (i.e., mutually accept) a determinate content (the proposition expressed by an assertion). The upshot is a need to re-examine the semantic and pragmatic notions of context and the relationship between them.