Why Compositionality Won't Go Away: Reflections on Horwich's 'Deflationary' Theory

Paul Horwich argues for a 'deflationary'account of compositionality, according to which, '. . . the compositionality of meaning imposes no constraint at all on how the meaning properties of words are constituted'. We have arrived at a tentative diagnosis, which is that Horwich fails to enforce several distinctions that turn out to be crucial. For example, sometimes he puts his main conclusion in the way we just quoted but sometimes, even on the following page, he puts it like this: 'understanding one of oneÕs own complex expressions (non-idiomatically) is, by definition, nothing over and above understanding its parts and knowing how they are combined'. We propose, in what follows, to consider how Horwich's deflationary account of compositionality fares if the distinction between theories of meaning and theories of understanding is properly attended to. Here's how we think it all turns out:
– Horwich is right to claim that compositionality is neutral with respect to the metaphysics of understanding expressions when 'understanding' refers to a (merely) dispositional state; but not when it refers to an occurrent state.
– Horwich is right strictu dictu to claim that compositionality is neutral with respect to the character of lexical meanings, but only strictu dictu.
– Compositionality taken, together with other constraints that semantic theories are required to satisfy, reduces the options in the theory of lexical meaning to a bare minimum.
The first part of the paper is about compositionality and understanding, the second part is about compositionality and lexical meaning.