Content and Theme in Attitude Ascriptions

This chapter addresses a less-commonly discussed substitution failure in attitude ascriptions: a “that”-clause and its corresponding proposition description cannot in general be interchanged in the scope of psych-verbs, despite the standard view that the two forms refer to the same proposition. For example, “Holmes suspects that Moriarty has returned” and “Holmes suspects the proposition that Moriarty has returned” mean something quite different. The chapter accounts for these data in the framework of neo-Davidsonian semantics, arguing that substitution does not simply change the syntactic category of the attitude verb from clausal to transitive or vice versa, but also triggers the side-effect of changing thematic relations: when the transitive verb is used, it is the theme of the attitude-state or event that is identified, but when the clausal verb is used, it is the content of the state that is identified.

On Fregean Sense and Mental Content1

Fregeans follow Frege (1892) in accepting informativeness and substitution failure as reliable criteria for the existence of senses as objects of thought. In this paper I show that if we accept this, we must also accept the existence of an infinite hierarchy of senses as objects of thought. This is a bad result since it turns Fregeanism into a doctrine according to which object-related thoughts either have an infinite number of objects as contents or none at all. This shows, against the Fregean, that senses cannot themselves be constituents of thought.

Difficulties in interpretation associated with substitution failure

In one of their arguments against the radical neuron doctrine, Gold & Stoljar (G&S) use the idea that, in certain situations, equivalent terms may not be substitutable into statements that regard properties of the objects to which the terms refer. This device allows G&S to refute the necessity of the conclusion that “the science of the mind equals the science of the brain” even though they take as a premise that the mind equals the brain. I argue, however, that this practice leaves the meaning of the “science of the mind” and the “science of the brain” indeterminate.