On the accessiblity of possible worlds: The role of tense and *aspect
This dissertation deals with the interpretation of tense and aspect morphology in would-conditionals. These are conditionals headed by the modal would. Would-conditionals have been widely discussed in the philosophical literature, usually in the context of counterfactual reasoning. In this dissertation I propose a linguistic analysis that seeks to derive properties of would-conditionals from the compositional interpretation of tense and aspect morphology.
In Chapter 1 I present an introduction to the main problems, and discuss some aspects of the theoretical framework that I will be adopting.
In Chapter 2 I present an analysis of the interpretation of past tense morphology in would-conditionals. In dealing with would-conditionals, we are usually interested in worlds that are very similar the actual world up to the time corresponding to the event described by the antecedent clause. I propose to account for this by analyzing would-conditionals as de re claims about the past. I characterize the semantics of the modal would in terms of quantification over worlds that contain counterparts of the actual-world past.
In Chapter 3 I present an analysis of ‘backtracking’ conditionals. These are would-conditionals that manage to quantify over worlds that differ from the actual world at some time before the antecedent clause event. I claim that this is because in backtracking counterfactuals there is an extra layer of auxiliaries that makes relevant laws that are not usually taken into account when identifying counterparts of the actual-world past in other worlds.
In Chapter 4 I present an analysis of the difference between would-conditionals with simple past tense morphology in the antecedent clause and would-conditionals with past perfect morphology in the antecedent clause. Some simple would-conditionals appear not to allow for a counterfactual interpretation, and this militates against a unified analysis of would. However, I show that a unified analysis can be maintained, and the differences explained in terms of the interpretation of tense and aspect morphology. The crucial piece of my analysis will be a characterization of perfective aspect as a deictic aspectual head.