Beliefs Don't Need to Be Causes (if Dispositions Aren't)
I favor a "dispositional" approach to belief, according to which to believe something is nothing more or less than to have a certain suite dispositions. To believe there is beer in the fridge, for example, is nothing more than to be disposed to go to the fridge if you want a beer, to be ready to assert that there is beer in the fridge, to feel surprise should you open the fridge and find no beer, to be ready conclude that there is beer within 15 feet of the kitchen table should the question arise, and so on -- all imperfectly, approximately, and in normal conditions absent countervailing pressures. Crucially, on dispositional accounts it doesn't matter what interior architectures underwrite the dispositions. In principle, you could have a head full of undifferentiated pudding -- or even an immaterial soul! As long as it's still the case that (somehow, perhaps in violation of the laws of nature) you stably have the full suite of relevant dispositions, you believe.
One standard objection to dispositionalist accounts (e.g. by Jerry Fodor and Quilty-Dunn and Mandelbaum) is this. Beliefs are causes. Your belief that there is beer in the fridge causes you to go to the fridge when you want a beer. But dispositions don't cause anything; they're the wrong ontological type.
A large, fussy metaphysical literature addresses whether dispositions can be causes (brief summary here). I'd rather not take a stand. To get a sense of the issue, consider a simple dispositional property like fragility. To be fragile is to be disposed to break when struck (well, it's more complicated than that, but just pretend). Why did my glass coffee mug break yesterday morning when I drove off with it still on the roof of my car and it fell to the road? (Yes, that happened.) Because it was fragile, yes. But the cause of the breaking, one might think, was not its dispositional fragility. Rather, it was a specific event at a specific time -- the event of the mug's striking the pavement. Cause and effect are events, analytically distinct from each other. But the fragility and the breaking are not analytically distinct, since to be fragile just is to be disposed to break. To say something is fragile is to say that certain types of causes will have certain types of effects. It's a higher level of description, the thinking goes.
Returning to belief, then, the objector argues: If to believe there is beer in the fridge just is to be disposed to go to the fridge if one wants a beer, then the belief doesn't cause the going. Rather, it is the general standing tendency to go, under certain conditions.
Now maybe this argument is all wrong and dispositions can be causes (or maybe the event of having a particular dispositional property can be a partial cause), but since I don't want to commit on the issue, I need to make sense of an alternative view.
[Midjourney rendition of getting off the couch to go get a beer from the fridge, happy]
On the alternative view I favor, dispositional properties aren't causes, but they figure in causal explanations -- and that's all we really want or need them to do. It is not obvious (contra Fodor, Quilty-Dunn, and Mandelbaum) that we need beliefs to do more than that, either in our everyday thinking about belief or in cognitive science.
Consider the personality trait of extraversion. Plausibly, personality traits are dispositional: To be an extravert is nothing more or less than to be disposed to enjoy the company of crowds of people, to take the lead in social situations, to seek out new social connections, etc. (imperfectly, approximately, in normal conditions absent countervailing pressures). Even people who don't like dispositionalism about belief are often ready to accept that personality traits are dispositional.
If we then also accept that dispositions can't be causes, we have to say that being extraverted didn't cause Nancy to say yes to the party invitation. On this view, to be extraverted just is the standing general tendency to do things like say yes when invited to parties. But still, of course, we can appeal to Nancy's extraversion to explain why she said yes. If Jonathan asks Emily why Nancy agreed to go, Emily might say that Nancy is an extravert. That's a perfectly fine, if vague and incomplete, explanation -- a different explanation than, for example, that she was looking for a new romantic partner or wanted an excuse to get out of the house.
Clearly, people sometimes go to the fridge because they believe that's where the beer is. But this can be an explanation of the same general structure as the explanation that Nancy went to the party because she's an extravert. Anyone who denies that dispositions are causes needs a good account of how dispositional personality traits (and fragility) can help explain why things happen. Maybe it's a type of "unification explanation" (explaining by showing how a specific event fits into a larger pattern), or maybe it's explanation by appeal to a background condition that is necessary for the cause (the striking, the invitation, the beer desire) to have its effect (the breaking, the party attending, the trip to the fridge). However it goes, personality trait explanation works without being vacuous.
Whatever explanatory story works for dispositional personality traits should work for belief. If ordinary usage or cognitive science requires that beliefs be causes in a more robust metaphysical sense than that, further argument will be required than I have seen supplied by those who object to dispositional accounts of belief on causal grounds.
Obviously, it's sometimes true that to say "I went to the fridge because I believed that's where the beer was" and "because Linda strongly believed that P, when she learned that P implies Q, she concluded Q". Fortunately, the dispositionalist about belief needn't deny such obvious truths. But it is not obvious that beliefs cause behavior in whatever specific sense of "cause" a metaphysician might be employing if they deny that fragility causes glasses to break and extraversion causes people to attend parties.