Eliminativism regarding propositional attitudes is the outrageous thesis that there have never been any: No one has ever believed anything or desired anything or hoped or feared anything, etc., period.  Churchland, Churchland and Stich do not insist that this outlandish doctrine is true, but they contend that it may be true and indeed is a good bet.

    Yow.  How might anyone defend such a thing, even as a good bet?  The defense starts with a pair of claims about mental concepts.  First, that mental concepts are explanatory concepts; their job is to figure as they do in explanations and predictions of people’s behavior.  (Notice that this assumption is shared by Fodor, the arch-Representationalist, and by Dennett, the instrumentalist, each of whom is implacably opposed to Eliminativism.)
    Second, that mental concepts play this explanatory role by being part of a folk theory.  The leading example of a folk theory is “folk physics,” the commonsense view of physical objects and how they behave that each of us acquires by age 3 and that most people deploy for the rest of their lives.  Similarly, mental concepts are ensconced in folk psychology, a system of generalizations that we acquire very early and use in dealing with the social world.
    This pair of claims, the first of which is really contained in the second, is called the “‘Theory’ Theory” of mental concepts.  Churchland goes on to argue that folk psychology is a bad theory that is probably false.
    We get an “eternal triangle” of positions:  Churchland and Fodor agree against Dennett that if there are propositional attitudes, then those states are internal causes with semantic contents, much as Fodor says they are.  Churchland and Dennett agree against Fodor that there are no such internal causes.  Fodor and Dennett agree against Churchland that there are propositional attitudes.

The defense of Eliminativism

    Argument 0:  Folk physics is radically false and well known to be false.  By analogy, so, probably, is folk psychology.  Replies:  (1) That’s a very weak form of argument, in the first place—induction from one case alone.  (2) We know science has shown that folk physics is false; there’s not the slightest controversy about that.  But no science has shown that folk psychology is false, nor is it easy to see how any science could do so.  (Luca and Dennett:  Folk psychology is not an empirical theory at all.)

    Yet the Eliminativists believe that current neuroscience at least suggests that folk psychology is false.

    Argument 1:  Our best neuroscience reveals nothing in the brain that looks like a propositional attitude.  Except at the sensory periphery, brains are very homogeneous nets of neurons.  Nothing in a brain seems to correspond to the difference between a belief and a desire, or between those and other propositional attitudes.  Nor does anything in the brain look like a Fodorian quasi-sentential representation.  The brain works, uniformly, by excitation and inhibition of neural pathways, viz., by electrochemistry, which is to say by physics, not by semantic properties.  Reply:  This is only current appearances, not proof that there aren’t Fodorian representations interacting somewhere inside the marshmallow.

Argument 2 (Stich):

    1.  Methodological solipsism: Wide propositional-attitude contents must not be invoked by scientific psychology.  And they are also scientifically ill-behaved.

    2.  Anything that is robustly real is accessible to science.  [Stich is assuming that some version of materialism is true; this argument is an ad hominem against non-Eliminative materialists.]

  / 3.  Wide attitude contents are not robustly real (though the internal computational states themselves are).   [1,2; of course, it is all right to talk of attitudes, as a heuristic form of interpretation, but that is just a manner of speaking.]

    4.  If there are wide propositional attitudes, their contents are robustly real.
 

  / 5.  There are no wide propositional attitudes.  [3,4]

    6.  There are few if any narrow propositional attitudes.

  / 7.  There are few if any propositional attitudes.  [5,6]

    Argument 3 (Churchland):  Considered as a theory and in comparison to other theories that explain things about the mind, folk psychology is a terrible theory.  (1) It is stagnant.  It has not changed or improved since the ancient Greeks.  (2) It applies only within the very narrow range of mentation and behavior that is normal, everyday mentation and behavior.  As soon as mentation or behavior gets even a bit weird—and the tolerances here are very narrow—folk psychology breaks down, or at least is at a loss.  (3) Even within that normal range, folk psychology utterly fails to address some of the most interesting mental phenomena: dreams, for example, or the vagaries of memory.
    Now, in general, when a poor theory is overtaken by a better theory of the same phenomena, the better theory supplants the poor theory, and the poor theory is rejected.  That means rejected as false, and the poor theory’s characteristic entities are dumped (phlogiston vs. the oxygen theory of combustion, evil spirits vs. viruses and bacteria as causes of infection).
    And it looks as though a combination of cognitive psychology and neuroscience will soon be a much better empirical theory of the mind than is folk psychology (that wouldn’t be hard, Churchland thinks).  So, true to form, cognitive psychology and neuroscience will and should supplant folk psychology (as scientific physics supplanted folk physics), and propositional attitudes will and should go the way of phlogiston and evil spirits.
    Notice that this argument does not depend on futuristic speculation.  Churchland believes we know right now that folk psychology is a terrible theory, and he thinks it’s also pretty clear that cognitive psychology and neuroscience will soon be a better one.

Outcome

    If Eliminativism is true, the consequences are fathomless.  As Jerry Fodor would say, it’s the end of the world.

    I viciously leave the defense of the mind to you.