Abstract

The aim of this dissertation is to provide support for the following claim: if Hanks’ theory of propositions as act-types is correct, then there exists a plausible extension of this theory that solves the Frege-Geach problem for normative propositions. I assume that Hanks’ theory is correct, and in this framework develop an account of semantic expressivism that addresses three versions of the Frege-Geach problem: the embedding, inference and negation problems. First, I examine in detail one existing attempt to support the claim, due to Hom and Schwartz. I argue that their extension is not plausible for two reasons: it does not satisfy a key expressivist constraint, and it encounters a problem with interrogatives. Then I argue that even if their extension were plausible, it would not solve the embedding problem for conditionals, for two reasons: it does not place suitable constraints on applications of force-indicators, and it encounters a problem with mixed descriptive-normative conditionals. Second, I give a new extension of Hanks’ theory for atomic normative sentences, and argue that it is plausible. Then I extend it further by defining force-indicators that are generalizations of assertion and of normative endorsement (and of denial and anti-endorsement) and by defining logical relations that apply uniformly to as- sertive and normative propositions. I argue that this extension provides a neutral logical framework within which the embedding, inference and negation problems for normative propositions can be more effectively addressed.