I’ve been revisiting some questions that lie in the intersection between philosophy of mind and language–some stuff I haven’t looked at very closely in a while. What follows in this and a subsequent post or two are some thoughts, beginning with some background as I try to get up to speed, so to speak.
What have come to be known as “Frege Cases” are instances of a subject failing to know that two terms co-refer. For example, someone who fails to realize “X” names the same person as “Y” may both affirm and deny that they are interested in dating the person named (think Oedipus). The most obvious way to resolve the apparent paradoxes suggested by Frege Cases is to acknowledge that terms such as proper names carry semantic content beyond their referent, so that there’s a straight forward way in which someone might desire X but not Y even though X=Y.
If we deny that names or other “singular” terms have semantic content beyond their referent–if we endorse a direct reference theory–the puzzles posed by Frege cases remain, and there is by now a very extensive literature on how these puzzles might be resolved while assuming direct reference. One well worked over move on the linguistic level begins by disambiguating the kinds of psychological attributions I casually made in the previous paragraph. Specifically we need to distinguish the meaning of a sentence like “Bob believes Venus is a planet” from the mental state it attributes to Bob. The sentence describes a relationship between Bob and a proposition, which is one thing; just what it is psychologically for Bob to be so related to that proposition is another. Figuring out how sentences of this sort work is the job of semantical theory. What it is for Bob to have beliefs is a matter for psychology.
With this in place we can sort of avoid the mess of Frege Cases by biting the bullet on the language part of it. We can insist that sentences such as a) “Venus is a planet” and b) “The Morning Star is a planet” mean the same thing (express the same proposition) while explaining away the evidence from (inter alia) belief ascriptions that seem to suggest that Bob might believe a) but not b). To do this we insist that our reluctance, for example, to say the Bob believes b) because he expressly denies b) is a purely pragmatic reluctance stemming from our use of language to track psychological states rather than from the semantics of belief ascriptions themselves. That is, though strictly speaking “Bob believes V is a P” is true if “Bob believes MS is a P” is true, using the formulation “Bob believes the MS is a planet” is likely to cause confusion if Bob doesn’t realize “Venus” names the same object as “Morning Star.”
Now, this move, whatever its merits as a piece of semantic theory, depends on a certain division of labor. Specifically, something needs to explain Bob’s assent to a) but not b), and the move depends on that something not being the sort of thing that is part of the subject matter of semantics. And so we are introduced to the “guise”, or “Mode of Presentation” under which or by means of which the object referred to (here, the planet Venus itself) is grasped or understood by a subject. Linguistically that something is a the name, considered not as a semantically evaluable entity, but as an orthographic (or phonetic) entity. So construed “Venus” is a different guise than “Morning Star”. With this in place we can allow that guises can play a role in propositional attitudes ascriptions, albeit it not a semantic role. Because it is possible to believe a proposition in two (or more) ways when part of it can be grasped under two (or more) guises, it may be useful, in various contexts, to use linguistically distinct guises to track the psychological distinctions.
Now, this works fine if we are content to stick to philosophy of language. Because guises can be distinguished linguistically without having to assume that they differ in meaning, the direct reference theorists can, as it were, kick the problem of Frege Cases to psychologists, who are now stuck with the problem of saying something plausible about what it means to believe the same proposition in two different ways. And it is fine with direct reference theorists if psychologists want to semantically individuate guises, so long as that is not taken to require semanticists to individuate them semantically. That is, one possible way to divide the labor is to suppose that Bob above believes both a) and b) because he has two semantically distinguishable psychological states that both amount to believing the proposition that Venus is a planet.
It turns out, though, that we can get Frege Cases at the psychological level if we assume that a subject might psychologically represent the same object to herself in different ways without realizing it. This is of interest to a philosophical psychology because it can lead to apparent failures of minimal standards of practical reason without apparent irrationality–an apparently rational person might act in ways that seem to violate minimal standards of reason. This is where things get interesting to me. More on what we should make of this in a later post.