Two-Layer Metaphysics: Reconciling Dispositionalism about Belief with Underlying Representational Architecture

What makes it *correct to say* that someone believes =/= in virtue of *what particular structures* they believe

During the question period following UCR visiting scholar Brice Bantegnie's colloquium talk on dispositional approaches to the mind, one of my colleagues remarked -- teasingly, but also with some seriousness -- "one thing I don't like about you dispositionalists is that you deny cognitive science".  Quilty-Dunn and Mandelbaum express a similar thought in their 2018 critique of dispositionalism: Cognitive science works in the medium of representations.  Therefore (?), belief must be a representational state.  Therefore (?), defining belief wholly in terms of dispositional structures conflicts with the best cognitive science.

None of this is correct.  We can understand why not through what I'll call two-layer metaphysics.  Jeremy Pober's 2022 dissertation under my direction was in part about two-layer metaphysics.  Bantegnie also supports a type of two-layer metaphysics, though he and Pober otherwise have very different metaphysical pictures.  (Pober is biological reductionist and Bantegnie a Ryle-inspired dispositionalist.)  Mandelbaum and I in conversation have also converged on this, recognizing that we can partly reconcile our views in this way.

Two-layer metaphysics emphasizes the distinction between (to somewhat misappropriate David Marr) the algorithmic and the implementational level, or alternatively between conceptual and nomological necessities, or between role and realizer, or between what makes it correct to say that someone believes some particular proposition and in virtue of what particular structures they actually do believe that proposition.  (These aren't equivalent formulations, but species of a genre.)

To get a clearer sense of this, it's helpful to consider space aliens.

Rudolfo, let's say, is an alien visitor from Alpha Centauri.  He arrives in a space ship, quickly learns English, Chinese, and Esperanto, tells amusing stories about his home world illustrated with slide shows and artifacts, enjoys eating oak trees whole and taking naps at the bottom of lakes, becomes a 49ers football fan, and finds employment as a tax attorney.  To all outward appearances, he integrates seamlessly into U.S. society; and although he's a bit strange in some ways, Rudolfo is perfectly comprehensible to us.  Let's also stipulate (though it's a separate issue) that he has all the kinds of conscious experiences you would expect: Feelings of joy and sadness, sensory images, conscious thoughts, and so on.

[Dall-E image of an alien filling out tax forms]

Does Rudolfo believe that taxes are due on April 15?  On a dispositionalist account of the sort I favor, as long as he stably possesses all the right sorts of dispositions, he does.  He is disposed to correctly file tax forms by that deadline.  He utters sentences like "Taxes are due on April 15", and he feels sincere when he says this.  He feels anxiety if a client risks missing that deadline.  If he learns that someone submitted their taxes on April 1, he concludes that they did not miss the deadline, etc.  He has the full suite of appropriate behavioral, experiential, and cognitive dispositions.  (By "cognitive dispositions" I mean dispositions to enter into other related mental states, like the disposition to draw relevant conclusions.)

Knowing all this, we know Rudolfo believes.  Do we also need to dissect him, or put him in some kind of scanner, or submit him to subtle behavioral tests concerning details of reaction time and such, to figure out whether he has the right kind of underlying architecture?  Here, someone committed to identifying belief in a strict way with the possession of a certain underlying architecture faces a dilemma.  Either they say no, no dissection, scan, or subtle cognitive testing is needed, or they say yes, a dissection, scan, or series of subtle cognitive tests is needed.

If no, then the architectural commitment is vacuous: It turns out that having the right set of dispositions is sufficient for having the right architecture.  So one might as well be a dispositionalist after all.

If yes, then we don't really know whether Rudolfo believes despite the behavioral and experiential patterns that would seem to be sufficient for believing.  This conclusion (1.) violates common sense and ordinary usage, and (2.) misses what we do and should care about in belief ascription.  If a hardcore cognitive realist were to say "nope, wrong architecture! that species has no beliefs!", we'd just have to invent a new word for what Rudolfo and his kind share in common with humans when we act and react in such patterns -- maybe belief*.  Rudolfo believes* that taxes are due on April 15.  That's why he's working so hard and reminding his clients.  But then "belief*" is the more useful term, as well as the more commonsensical, and it's probably what we meant, or should have meant, by "belief" all along.

Now it might be that in humans, or in Alpha Centaurians, or in some other Earthly or alien species, belief works by means of manipulating internal representations written in the language of thought.  That could be!  (I have my doubts, unless the view is given a very weak formulation.)  But even if we allow that possibility, the reason that having that architecture counts as believing is because that architecture, in that species, happens to be the architecture that underwrites the dispositional pattern.

There are, then, so to speak, two layers here.  There's the dispositional characterization, which, if an entity matches it well enough, makes it true to describe them as someone who believes.  And then there's the underlying subpersonal architecture, which is how the belief is implemented in them at the detailed cognitive level.

Thus, my dissatisfied colleague, and Quilty-Dunn and Mandelbaum, are wrong: There is no conflict between a dispositional approach to belief and representationalist realism in cognitive science.  The metaphysical dispositionalist and the psychological representationalist are engaged in different tasks, and both can be correct -- or rather, both can be correct unless the representationalist also attempts the dispositionalist's broader metaphysical task (in which case they face the Rudolfo dilemma).

Does this make dispositionalism unscientific?  Not at all!  Two comparisons.  Personality traits: These can be defined dispositionally.  To be an extravert is nothing more or less than to have a certain dispositional profile — that is, to tend to act and react in characteristically extraverted ways.  There can still be a science of dispositional profiles (most of personality psychology, I'd say); and there can also be a science of implementation (e.g., what subpersonal brain or lower-level cognitive structures explain the extravert's energy and sociality?).  Evolution: At a broad theoretical level, evolution just requires heritable traits with different rates of reproductive success.  At a lower level, we can look at genes as the architectural implementation.  One can work on the science of evolution at either layer or with an eye on both layers at once.