Composing commands: an inferentialist semantics for subsententials and imperatives

Abstract

Standard theories in philosophy of language tend to endorse three claims:

1. Representationalist notions such as truth and reference are semantic primitives; 2. Sentence level meaning is propositional; 3. The meaning of complex expressions is a function of the meaning of their constituents.

This thesis develops a semantics for languages with both imperative and declarative sentences, along with constituent names and predicates, and which rejects 1. and 2. above. The key features of this semantics are: inferentialism, compositionality, and content pluralism. It is inferentialist in the sense that, contra 1., meanings are treated as inferential roles, determined by norms of use in speech acts such as asserting and commanding. This is formalised as a proof-theoretic semantics in a cut-free sequent calculus system. It is compositional in the sense that the inference rules assigned to sentences are a function of those assigned to their constituents, names and predicates. In contrast to 2., it is a kind of content pluralism. This means that declarative and imperatives sentences express different sentence level semantic types, rather than just propositions. Despite this, sameness of word meaning is preserved across these different sentence types.