Joshua Fost

The SEP article on the Philosophy of Neuroscience, says that eliminative materialism (EM) says that folk psychology (FP) is “flawed beyond significant revision.” The example is when I ask you why Marica is not accompanying you this evening, you reply that she has a grant deadline looming. This entails the notion that Marica’s beliefs and desires about career explain her lack of attendance. The article implies that this notion of beliefs and desires driving action (one example of folk psychology) is flawed. While I am probably characterizable as an EM-ist, I might be more likely to say that in this case at least, FP is merely a pragmatic abstraction on top of the “more real” neuroscience. To say that Marica’s beliefs and desires caused a certain behavior is to say that her frontal cortex, when evaluating possible future payoffs, determined that staying home to work would yield more benefit than attending a recreational social event. The notion that a deterministic calculation done by the frontal cortex could ultimately make its way to the motor cortex and cause a behavior is consistent with EM.

Moreover, FP itself is the product of the very same brains whose outputs we seek to characterize as a product of underlying physical processes. For me, the more interesting question would be to ascertain the origins of FP itself, working from an EM stance. What aspects of our brains (and the evolutionary pressures on their outputs) would cause us to develop these kinds of abstractions? To say, as the article characterizes EM-ists as saying, that there is no such thing as a belief or a desire — as we use those terms in FP — is overstating my position, anyway. A desire is a weighted emotional disposition for a certain stimulus. Obviously such things exist. Are they causal? Yes — at a certain level of abstraction. They can be reduced, of course, to those brain processes that underlie emotion, and those processes can in turn be reduced to cellular physiology etc. But I would not go so far as to equate beliefs and desires with phlogiston.

All ontologies are abstractions, because ontologies are cognitive systems and cognitive systems are not in-the-world. Lower-level ontologies, with less abstraction, have less room for pure invention. In that sense, FP is less likely to be accurate than neuroscience. (This is not quite what I mean.)

The article goes on to characterize Paul Churchland as saying that the EM claim of vectorial-transformational neural processes contrasts sharply with the propositional processes of FP. I would probably deny that there is a sharp contrast here. Rather, again, I suspect that there is a pretty good (but not perfect) mapping between them. The early days of neural networks, as a matter of fact, clearly showed how one could implement logical flow structures in neurons: by appropriately configuring the connectivity and thresholds of the cells. Of course, real brains may not use those kinds of circuits very widely, at least at the microscopic level, but the mere fact that I am able to think about propositional structures means that my neurons are capable of representing those structures — even if through some collection of elaborate vectorial transformations — and proves that there cannot fail to be a mapping between the neural and propositional levels.