Predication and identity in copular sentences

Abstract

There are different types of copular sentence. does not mean the same thing as . The former is typically called a predication and the latter an identity. But where does this difference come from (and the difference between these sentences and , , and for that matter)? This thesis is an attempt to bring the combined forces of modern linguistics and philosophy together to understand how we make meaningfully distinct sentences. It is useful to focus on copular sentences for this task because they are the minimally-sized sentences in many of the world's languages. A debate in linguistics has persisted for some years about the status of sentences like , in particular, in terms of whether they should be aligned with predications or identities. The linguistic evidence points in different directions. I think there are conceptual clarifications that could elucidate the terms of this debate.

I start by investigating the obvious logical starting point: logic. Can copular sentences really be exhaustively specified as logical predications or identities in the first place? What about syntax? Does it have a problem-free definition of predication that might serve as a way of distinguishing meanings? I answer in the negative in both cases. From there the copula itself is studied, and I argue that it isn't any kind of real lexical verb that can be semantically ambiguous (like the verb can in vs.). I then give some examples of the sort of thing linguists have shown copulas actually can do. I argue that distinguishing copular sentence meanings is not something that can be truly in logical or syntactic terms; the best we can hope for is to the different uses of the biological capacity for language, to talk of `functions' of copular sentences and their components. I argue for an approach to a full description of copular sentences that is based mainly on use and information structure properties of the flankers of the copula. Different permutations of these give rise to different sentence types, and thus to a more pluralistic copular taxonomy. Syntax has a foundational role, but it does not serve to discriminate copular sentence meanings. Copular sentences are argued to be syntactic predications.

Overall, then, I argue that the taxonomy of copular sentences cannot be explained in terms of logical predication or logical identity. Rather, we can describe (not explain) the distinct meaning types of copular sentences in terms of the number of different licit permutations of flanker properties, where these are mainly use and information structure properties.