Eliminative Materialism Vs Folk Psychological Concepts

Introduction and Context:
Up until now we've been looking at substance dualism and its problems.  For most people, the interaction problems and the account of brain damage are insurmountable, particularly since dualism seems to conflict with our best scientific theories of mind. So, if dualism is so wrong, how did we end up with it in the first place?

Simply put--contra Descartes--you can't do a priori science.  In other words, we can't rely on our intuitions to tell us about the physical world.  This is why many of the ancient Greek physics are so spectacularly wrong.  It might make intuitive sense that everything is made of fire, earth, wind, and water...or whatever combination, but you simply can't make conclusions about nature based on intuition alone.  You need empirical observation.  If you want to know about the world you have to examine it, make observations, and form theories that account for those empirical observations.

Many contemporary philosophers of mind attribute the failure of dualism to people trying to do science of mind using a priori reasoning.  The hodge-podge collection intuitive concepts of how the mind works are called folk psychology and include concepts like beliefs, attitudes, and desires.  

Because folk psychology seems to fail in explaining the mind, Paul Churchland argues that we should instead adopt eliminative materialism:  This is the idea that we should eliminate folk psychological terms like belief, attitude, and desire from our theory of mind and talk only about physical brain states.  Underpinning the eliminative approach is a skepticism about introspection and as a means of developing scientific theories of the mind as well as an opposition to trying to fit centuries old concepts to modern observations.

Main Arguments for Eliminative Materialism
Eliminative materialist give three main reasons for rejecting folk psychological terms from (contemporary) theories of mind:
(1)  the theory has not meaningly progressed for a long time;
(2)  the concepts don't integrate well with promising up and coming approaches to mind (cognitive science and neuroscience);
(3) the concepts don't refer to anything real.

Regarding point (1), we have seen tremendous progress in explaining how the mind works by using the modern paradigms of neuroscience and cognitive science.  Folk psychological explanations haven't contributed much in comparison to these other frameworks.   Given the relative discrepancy in the rate explanatory progress between modern frameworks and folk psychological framework, it's time to abandon the latter.

Point (2) is that it doesn't make sense to try to force millennia old pre-scientific concepts onto modern theories of mind (e.g., cog sci and neuroscience).  What we need to do is let the new fields adopt whatever concepts best reflect the empirical findings they produce.  Just as it doesn't make sense to apply the pre-scientific concepts of the elements of earth, wind, fire, and water to our modern physics, it doesn't make sense to do this with modern theories of mind.  If fact, it is very likely that trying to force these pre-scientific folk psychological concepts onto modern theories of mind will hamper their progress and force poor interpretations of empirical findings.

Lets quickly expand on point (3):  But before doing that, we need to know something about what philosophers (and linguists) call "theories of reference." 

Theories of Reference
Some philosophers of science say that scientific concepts, in order to be "real", must refer to something that is underpinned by/reducible to physical structure.  For example, anytime I use the concept "water" it refers to H20.  Because "water" picks out (i.e., refers to) something real in the world, it is a legitimate scientific concept.  If I point to something that doesn't have the structure H20 and call it "water", I'm misapplying the concept.

Now lets look at the concept of "belief."  Does it pick out any real physical structure in the world? When I say "I believe that ice cream tastes good" and "I belief Joe Biden is the VP of America", what are the underlying physical structures that these two things have in common?

Think of all the different possible beliefs you can have.  In terms of their underlying physical structure (i.e., brain states/neurological states), what do all of them share?  Especially when you consider that everyone's brain is a little bit different. 

Unlike the case of water and H20, it doesn't seem like this collection of things which are all called beliefs share anything in common in terms of underlying physical structure.  While there may be overlap between the brain structures underpinning some beliefs, there will be other beliefs that don't have any meaningful overlapping physical structures.

The idea here is that scientific theories should postulate entities that can be observed, quantified, and studied and for this to happen the concept has to refer to something that has uniform underlying structure across all cases.  But what is the underlying physical structure of a belief?  How do you measure it? It doesn't seem to have any properties that we can measure scientifically. They don't seem to "exist" in any way which allows them to be studied.

Folk psychological concepts don't actually refer to any"thing" in the "real" world.  There is no thing in the world that satisfies the description of "belief".  Scientific terms should refer to things that exist and can be studied, and since we can't do this with folk psychological terms, we should eliminate them from theories of mind.

Summary
Interestingly, dualism and eliminative materialism do agree on one point:  you can't reduce mental states to physical states; however, the reasons for this shared conclusion are very different! As we saw with dualism, mental states can't be reduced to physical states because each are properties of a different respective substance:  mental states are properties of minds and brain states are properties of brains.

Eliminative materials say you can't reduce mental states to brain states because mental states don't really exist! There are only physical brain states because they say we should eliminate folk psychological terms.  We can think of it this way:  some very folk theories of mind say that people act loco because they are possessed by a demon.  The eliminativist says not only can we not readjust our notion of loco to fit what was previously meant by demonic possession, we should only talk about the brain states that occur concurrent with certain behaviours.