Abstract

David Lewis [1973] offers a possible worlds approach to a theory of counterfactuals. He attempts to specify necessary and sufficient conditions according to which a given counterfactual is true or false. This MA Thesis surveys Lewis's theory of counterfactuals in detail. Although for the most part I defend Lewis's account from several objections, in the final chapter I reason that his theory is susceptible to skepticism, which threatens any philosophical theory that relies on Lewis's theory to distinguish between non-paradigmatically true and false counterfactuals. As for the more sympathetic portion of my project, while I show how Lewis's canonical account cannot handle some paradigmatically false counterfactuals--viz., those containing true components--I try to repair his analysis in the spirit of Alan Penczek [1997]. I then discuss Lewis's extension or enhancement to his original theory, which he gives in order to foil an objection advanced by Kit Fine [1975] and Jonathan Bennett [1984]. Finally, I outline and raise several worries inherent in Bennett's rival theory. As for the less then sympathetic section of this paper, I exploit arguments put forward by G. Lee Bowie [1979] as well as by Daniel Krasner and Mark Heller [1994], which are designed to undermine any systematic procedure to circumscribe Lewis's crucial three-place comparative similarity relation between possible worlds.