Out of Context

It's been, for some time now, a pet thesis of ours that compositionality is the key constraint on theories of linguistic content. On the one hand, we're convinced by the usual arguments that the compositionality of natural languages' explains how L-speakers can understand any of the indefinitely many expressions that belong to L.2 And, on the other hand, we claim that compositionality excludes all "pragmatist"3 accounts of content; hence, practically all of the theories of meaning that have been floated by philosophers and cognitive scientists for the last fifty years or so. A number of objections to our claim have been suggested to us, but none that we find persuasive (see, for example, the discussions of the "uniformity principle" and of "reverse compositionality" in Fodor and Lepore 2002). These objections have a common thread: they all grant that mental and linguistic content are compositional but challenge the thesis that compositionality is incompatible with semantic pragmatism. In this paper, we want to consider an objection of a fundamentally different kind, namely, that it doesn't matter whether compositionality excludes semantic pragmatism because compositionality isn't true; the content of an expression supervenes not on its linguistic structure4 alone but on its linguistic structure together with the context of its tokening.5 Here's the general idea: by stipulation, a sentence of L is compositional if and only if a (canonical) representation of its linguistic structure encodes all the information that a speaker/hearer of L requires in order to understand it.6 This means that, if L is compositional, then having once assigned a linguistic representation to a sentence token, there is no more work for a hearer to do in order to understand it. And