Frege-Geach Problem And A Two-Dimensional Reply To It

The main challenge to expressivism, according to which the function of moral discourse is not to state facts or express truth-apt beliefs, is what is called the Frege-Geach problem. This trouble originally came from Peter Geach and John Searle’s critique of R. M. Hare’s semantic theory about moral expressions. In this paper, I break this problem up into two arguments:one argument requires that expressivists should explain moral sentences’sense, regardless of various contexts, in a unified way; and another raises that expressivists cannot successfully illustrate the logical validity of moral inferences. There are mainly two approaches taken by expressivists to handle this problem:extreme expressivists such as Simon Blackburn maintain that moral sentences are not truth-apt and try to characterize the validity of moral arguments in virtue of consistent non-cognitive states or attitudes; and minimal expressivists just admit that moral discourses have some kind of minimal truth-values, so it seems no doubt that moral arguments can be logically valid. However, each of these two approaches fails in resolving Geach’s critique:merely claiming minimal truth-aptness for a moral sentence does not tell us what that sentence means and fractured attitudes cannot sufficiently parallel to classical inconsistency. By contrast, Allan Gibbard’s semantic theory is much more promising, though his view about the traits of moral terms is defective. As far as I’m concerned, moral terms such as "good" are both rigid designators and attributive adjectives, which can be nicely grasped by Two-Dimensional Semantics(2D). According to2D, we may say there are two propositions associated with a moral sentence:one describes the types of actions or events in a moral rule system, while the other expresses our acceptance of this system. The former is descriptive and truth-apt, while the latter is normative and not capable of being true or false. In my opinion, this two-dimensional framework may give us some advantages over those earlier expressivists in responsing to Geach’s objection.