Saturday, December 23, 2006

Is Eliminative Materialism a Misleading Term?

I usually don’t agree with Hiero5ant, but I think his comment based on what he heard Pat Churchland say is pretty significant. He said that Pat said that she would probably not call her position eliminativism if she were developing it today.

The point I am making here is that the Churchlands do propose to replace propositional attitude psychology with successor concepts, and that those concepts are intentional concepts. In fact, those successor concepts have play a role in propositional knowledge. Scientific knowledge is knowledge that f=ma, that humans evolved from primate ancestors, etc. Eliminativists think that they know that eliminativism is true. The challenge is to see how these successor concepts can really replace propositonal attitudes without being propositional attitudes.

The Churchlands wrote an essay entitled “Intertheoretic Reduction: A Neuroscientist’s Field Guide,” in On the Contrary: Critical Essays 1987-1997 (Cambridge, MIT Press, 1988) in which they distinguish three types of intertheoretic reductions: conservative, reforming, and eliminiative. The reduction of temperature in a gas to the mean kinetic energy of the gas’s molecules was a conservative reduction, in that it doesn’t require us to reconceive temperature in any radical way in order to view it as the MKE of the molecules. The secondary qualities of temperature, how it feels, are not denied, they are simply pronounced to be the way we react to temperature rather than something in temperature itself. If the concept of temperature was essential to the meaning of our lives, this type of reduction would not threaten us in any way.

The second type is a reforming reduction, which shows that an earlier theory had significantly misconceived the phenomena it covered. Newtonian mass is replaced in relativity theory with mass relative to a frame of reference, but we were not just dead wrong when we used the concept of mass.

The most radical is an eliminative reduction. In this, the old idea is so wide of the mark that it is simply deleted by the new theory. No single has does the work of phlogiston, but phlogiston is replaced by a theory that distinguishes between oxygen, carbon monoxide, and carbon dioxide.

Now, what I have trouble understanding is what sense it makes to say that any reduction of mental states is can possibly be eliminative, because whatever the replacement theory is going to do, it is going to have to do the work that propositional attitudes do in any account of propositional knowledge. Second, are there any hard and fast rules for determining whether a reduction is eliminative or reforming? Bill Ramsey, a former student of Stich who last I heard taught at Notre Dame, while willing to defend eliminativism against my self-refutationist attacks in an exchange in Inquiry in 1990-91, nevertheless doesn’t really embrace eliminativism himself because of this problem. Isn’t the term eliminativism here just misleading?

Hasker maintains that functionalism is quasi-eliminiativism, in the sense that it removes important parts of what we ordinarily understand our mental lives to consist in.

7 comments:

Blue Devil Knight said...

Good summary of the three possibilities.

The term is not misleading: it might be implausible that EM is true, or even have insurmountable problems, but it is certainly a position that the Churchland's and others endorse. So if they endorse EM, i.e., the view that internal propositional contents will go the way of phlogiston in psychology, how can you say it is misleading to advocate it? It would be misleading for them to say anything else!

As for your second question (are there rules for deciding if theory T1 was eliminated or reduced by subsequent theory T2?). Thinking about it naively, since there is a kind of graded transition between smooth reduction and violent elimination (as you discuss nicely in your post), I think that complicates things and you really need to look in detail at each case of theory change and figure out just how damaged the ontology of the old theory is in light of the new theory For instance, how should we approach 'space' from Newtonian physics now that we have relativity theories? Does Newtonian space even exist? I frankly don't know, and would probably have to spend a few years studying it to reach a conclusion.

So clearly these are sometimes extremely complicated issues (even with the phlogiston case: Kitcher argues nicely in his 'Advancement of Science' that the term 'phlogiston' did have a referent).

Note saying that there is an 'eliminative reduction' of a theory is a bit confused: if the theory is eliminated it is not reduced. If a theory is reduced to another theory then it is preserved and not eliminated). However, you can have some parts eliminated, others preserved (e.g., phlogiston, the substance, is gone, but people still think that hot things tend to cool down).

Churchland discusses this stuff in detail in his wonderful first book, 'Scientific Realism and the Plasticity of Mind.' It is short, quite readable, and swimmingly sets the stage for everything else he has done.

Have a nice Christmas.

jeff g said...

I agree with BDK,

"Now, what I have trouble understanding is what sense it makes to say that any reduction of mental states is can possibly be eliminative, because whatever the replacement theory is going to do, it is going to have to do the work that propositional attitudes do in any account of propositional knowledge."

Here is where I get really confused. Intentional properties, according to the Eliminative Materialist, are simply theoretical entities used in order to make accurate predictions and interact in our social environment. This is the "work" which PA's do. I don't see how the EM cannot simply say that PA's are not real just as Ernst Mach denied that atoms were real in the early 20th century. Thus, PA's or any other intentional property should not be reduced by science, but eliminated altogether just as an intelligent designer is (for the sake of argument) eliminated from biology by darwinian evolution given the materialist's world view.

Furthermore, I do not see why propositional attitudes cannot be used to describe a scientific theory which does not itself invoke propositional attitudes. After all, we don't accuse physicists or biologists of invoking PA's in their work.

I think that EM simply calls beliefs useful fictions; non-existent, but very useful (indeed, almost necessary) in our social environment.

Victor Reppert said...

Jeff G: That would make eliminative materialists instrumentalists about propositional attitudes. That is a position that has been frequently attributed to Dennett but the Churchlands, to the best of my knowledge, have not embraced it.

It also implies that we can make a distinction between empirically adequate theories and true ones. That's not a distinction that the Churchlands view very favorably.

Blue Devil Knight said...

Victor is right: they think that the successor theory will be not only true but much more useful than propositional attitude theories precisely because it is true. Paul discusses this somewhere in his book Neurocomputational Perspective.

jeff g said...

Right, but isn't the difference simply that Dennett sees them as being useful fictions for making predictions, whereas Churchland doesn't see such fictions as being useful? I was simply trying to say that even Churchland sees able to claim that PA's are moderately useful instruments, though not as useful (or as real!) as a fully matured neuroscience.

"It also implies that we can make a distinction between empirically adequate theories and true ones."

While I understand your point, I don't see what it is supposed to accomplish in the present context. Perhaps you could elaborate?

Victor Reppert said...

It's just that if you are using the Mach model (later developed by Van Fraassen), you have to say that FP is an empirically adequate theory that is useful for making predictions but is not true. You can say that, but all I was saying was that the Churchland's don't say it. If that were the case, then we would not have a fully eliminativist theory.

jeff g said...

While I certainly agree that Churchland highlights the failures of FP, I don't think his view of it is all that far from the instrumentalist's.

Both position hold that FP is not true.

The instrumentalist holds that it might, nevertheless, be empirically adequate to a large extent. Churchland clearly doesn't want to agree too much with this. Nevertheless, he does seem committed to the idea that FP works somewhat well in making predictions in our environment or else it never would have become so ingrained or so widespread in our language.